This document discusses oral squamous cell carcinoma (OSCC) and cancer stem cells. It states that OSCC arises from the squamous epithelium lining the oral cavity. Risk factors include tobacco, alcohol, and HPV infection. Microscopically, OSCC shows varying degrees of keratinization and cellular abnormalities. The presence of lymph node metastasis is a strong negative prognostic factor. The document then discusses the existence of cancer stem cells in tumors. These cells can regenerate the original tumor heterogeneity and are more resistant to chemotherapy and radiation, potentially leading to tumor recurrence. Epithelial-to-mesenchymal transition allows cancer cells to migrate and invade other tissues, which is important for metastasis.
This document discusses the evolving concept of cancer stem cells over time. It begins by describing how the concept of normal stem cells developed based on studies of blood cell formation and tissue regeneration in the 1970s. This provided a framework for later investigating cancer stem cells. The concept of cancer stem cells originated in the 1940s from studies of teratocarcinomas showing they contained both differentiated and undifferentiated malignant cells. Further work in the 1960s demonstrated the clonal origin of teratocarcinomas from single malignant stem cells. Since then, advances in defining normal stem cell properties and the multistep nature of cancer have led to new insights into cancer stem cells and their role in tumor propagation and heterogeneity.
Trabalho 2012 teo2010 regenerative therapyFelemon Porto
This document summarizes the emerging use of stem cells in regenerative medicine. It discusses the different types of stem cells, including somatic stem cells, pluripotent stem cells, and their potential clinical applications. Specifically, it notes that somatic stem cells found endogenously in tissues like brain, skin, and liver represent an ideal target for regenerative medicine as their mobilization would not require invasive procedures. However, identifying and characterizing these endogenous stem cells in humans remains challenging. The document also discusses how pluripotent stem cells, including ESCs and iPSCs, could enable personalized cell-based therapies but have drawbacks like tumorigenicity that require further progress.
Cancer Stem Cells and the Unicellular Life Cycle of Cancer_Crimson PublishersCrimsonpublishersCancer
All eukaryotes, from protists to mammalians, preserve a unicellular life cycle inherited from the common ancestor that can be reactivated under unfavorable living conditions. The cell-of-origin of cancer escapes its death by forming a protected polyploid cyst-like structure (CLS), that starts the unicellular life cycle of cancer. The reversal to unicellularity occurs through genomic and epigenetic alterations that activate the MUT switch of early Metazoans and not through mutations. The microcell progeny of CLSs spread into tissues and organs and form the CSC pool of aCLS cancers. Depending on the environment, the CSC pool differentiates a reproductive cell subline, which forms new aCLSs by cyclic encystment and asymmetric cell division, or a somatic subline, which proliferates strongly by symmetric cell division without cyst differentiation.
Reprogramming to pluripotency is possible from adult cells of different tissues and species through the ectopic expression of defined factors. The generated induced Pluripotent Stem Cells (iPSCs) are relevant for various purposes, including disease modeling, drug or toxicity screening and autologous cell therapy. Over the last few years, increased efforts are being made to improve the reprogramming techniques, the efficiency and quality of the generated iPSCs, as well as to identify the best cell source to be reprogrammed. Cells derived from fetal tissues, such as amniotic fluid, placenta and umbilical cord, offer distinct advantages in terms of reprogramming compared to adult somatic cells. Importantly, fetal cells are more primitive, easily achievable in sufficient numbers and are devoid of any ethical concern. They show great plasticity, high proliferation rate, low immunogenity and absence of teratoma formation. Therefore, they can be reprogrammed much faster and more efficiently than adult cells. Here, we provide a comprehensive overview of the advantages of reprogramming fetal sources in comparison to other commonly used cell types.
This document summarizes recent research on the malaria parasite's liver infection stage. Key findings include:
1) Parasite sporozoites can traverse and wound liver cells before invading a hepatocyte and forming a parasitophorous vacuole to develop into liver stages.
2) Traversal may activate secretions needed for invasion or signal nearby cells to allow infection, though mutant studies found traversal is not required for infection.
3) The host hepatocyte protein CD81 appears necessary for productive infection and formation of the parasitophorous vacuole.
4) As liver stages develop, the parasite remodels the host cell and inhibits apoptosis, growing large enough to emerge from the cell
Identification Of Pancreatic Cancer Stem Cellsbegelfer
The study identified cancer stem cells in pancreatic tumors that have the ability to self-renew and generate differentiated tumor cells. Highly tumorigenic cancer cells were found that expressed the cell surface markers CD44, CD24, and ESA. These cells showed properties of stem cells by forming tumors in mice after injection, undergoing self-renewal, and generating differentiated progeny. Targeting these cancer stem cells may be needed to effectively treat pancreatic cancer as traditional therapies often miss these cells.
Ayurvedic Cancer Treatment- Get the best Sino Vedic cancer clinic and Alternative Treatment for cancer in India, we offer the best Ayurvedic treatment for cancer.
1) Human umbilical cord blood CD34+ enriched cells can engraft and develop in the bone marrow of irradiated NOD/LtSz-scid/scid mice without human growth factor support.
2) The human cells home to the mouse bone marrow and develop into myeloid, lymphoid, erythroid, and CD34+ progenitor populations, indicating development proceeds from primary hematopoietic sites to the periphery.
3) Repopulation of secondary recipients with human cells from primary recipient bone marrow demonstrates the human precursor population maintains substantial proliferative capacity.
This document discusses the evolving concept of cancer stem cells over time. It begins by describing how the concept of normal stem cells developed based on studies of blood cell formation and tissue regeneration in the 1970s. This provided a framework for later investigating cancer stem cells. The concept of cancer stem cells originated in the 1940s from studies of teratocarcinomas showing they contained both differentiated and undifferentiated malignant cells. Further work in the 1960s demonstrated the clonal origin of teratocarcinomas from single malignant stem cells. Since then, advances in defining normal stem cell properties and the multistep nature of cancer have led to new insights into cancer stem cells and their role in tumor propagation and heterogeneity.
Trabalho 2012 teo2010 regenerative therapyFelemon Porto
This document summarizes the emerging use of stem cells in regenerative medicine. It discusses the different types of stem cells, including somatic stem cells, pluripotent stem cells, and their potential clinical applications. Specifically, it notes that somatic stem cells found endogenously in tissues like brain, skin, and liver represent an ideal target for regenerative medicine as their mobilization would not require invasive procedures. However, identifying and characterizing these endogenous stem cells in humans remains challenging. The document also discusses how pluripotent stem cells, including ESCs and iPSCs, could enable personalized cell-based therapies but have drawbacks like tumorigenicity that require further progress.
Cancer Stem Cells and the Unicellular Life Cycle of Cancer_Crimson PublishersCrimsonpublishersCancer
All eukaryotes, from protists to mammalians, preserve a unicellular life cycle inherited from the common ancestor that can be reactivated under unfavorable living conditions. The cell-of-origin of cancer escapes its death by forming a protected polyploid cyst-like structure (CLS), that starts the unicellular life cycle of cancer. The reversal to unicellularity occurs through genomic and epigenetic alterations that activate the MUT switch of early Metazoans and not through mutations. The microcell progeny of CLSs spread into tissues and organs and form the CSC pool of aCLS cancers. Depending on the environment, the CSC pool differentiates a reproductive cell subline, which forms new aCLSs by cyclic encystment and asymmetric cell division, or a somatic subline, which proliferates strongly by symmetric cell division without cyst differentiation.
Reprogramming to pluripotency is possible from adult cells of different tissues and species through the ectopic expression of defined factors. The generated induced Pluripotent Stem Cells (iPSCs) are relevant for various purposes, including disease modeling, drug or toxicity screening and autologous cell therapy. Over the last few years, increased efforts are being made to improve the reprogramming techniques, the efficiency and quality of the generated iPSCs, as well as to identify the best cell source to be reprogrammed. Cells derived from fetal tissues, such as amniotic fluid, placenta and umbilical cord, offer distinct advantages in terms of reprogramming compared to adult somatic cells. Importantly, fetal cells are more primitive, easily achievable in sufficient numbers and are devoid of any ethical concern. They show great plasticity, high proliferation rate, low immunogenity and absence of teratoma formation. Therefore, they can be reprogrammed much faster and more efficiently than adult cells. Here, we provide a comprehensive overview of the advantages of reprogramming fetal sources in comparison to other commonly used cell types.
This document summarizes recent research on the malaria parasite's liver infection stage. Key findings include:
1) Parasite sporozoites can traverse and wound liver cells before invading a hepatocyte and forming a parasitophorous vacuole to develop into liver stages.
2) Traversal may activate secretions needed for invasion or signal nearby cells to allow infection, though mutant studies found traversal is not required for infection.
3) The host hepatocyte protein CD81 appears necessary for productive infection and formation of the parasitophorous vacuole.
4) As liver stages develop, the parasite remodels the host cell and inhibits apoptosis, growing large enough to emerge from the cell
Identification Of Pancreatic Cancer Stem Cellsbegelfer
The study identified cancer stem cells in pancreatic tumors that have the ability to self-renew and generate differentiated tumor cells. Highly tumorigenic cancer cells were found that expressed the cell surface markers CD44, CD24, and ESA. These cells showed properties of stem cells by forming tumors in mice after injection, undergoing self-renewal, and generating differentiated progeny. Targeting these cancer stem cells may be needed to effectively treat pancreatic cancer as traditional therapies often miss these cells.
Ayurvedic Cancer Treatment- Get the best Sino Vedic cancer clinic and Alternative Treatment for cancer in India, we offer the best Ayurvedic treatment for cancer.
1) Human umbilical cord blood CD34+ enriched cells can engraft and develop in the bone marrow of irradiated NOD/LtSz-scid/scid mice without human growth factor support.
2) The human cells home to the mouse bone marrow and develop into myeloid, lymphoid, erythroid, and CD34+ progenitor populations, indicating development proceeds from primary hematopoietic sites to the periphery.
3) Repopulation of secondary recipients with human cells from primary recipient bone marrow demonstrates the human precursor population maintains substantial proliferative capacity.
This literature review finds that umbilical cord tissue, specifically Wharton's jelly, offers the greatest number of harvestable mesenchymal stem cells. The review analyzed 161 studies reporting mesenchymal stem cell yields from various tissue sources, including adipose tissue, bone marrow, umbilical cord tissue, and placental tissue. It found that yields from umbilical cord tissue ranged from 10,000 to 4,700,000 cells per milliliter, far exceeding yields from other sources. Adipose tissue provided the next highest yields, ranging from 4,737 to 1,550,000 cells per milliliter. Bone marrow yields ranged more widely from 1 to 317,400 cells per millil
Role of cancer stem cells in cancer therapyniper hyd
This document discusses cancer stem cells (CSCs) and potential therapies targeting them. It begins with introductions to stem cells and CSCs, then covers the history of discovering CSCs. New therapies discussed include targeting CSC-specific markers, signal pathways like Wnt and Notch, CSC metabolism, and epithelial-mesenchymal transition. Clinical trials targeting CSC pathways are also summarized. The document provides an overview of CSCs and recent research into developing treatments focused on these cells.
Como afrontar células madre de cáncer con alimentos Nutriline SRL
III Congreso mundial de medicina y nutrición moluecular e integrativa.
Alejandro Sacha Barrio Healey
"Como Afrontar Células Madre de Cáncer con Alimentos y Plantas"
Cancer arises from mutations in genes that control cell division. These mutations cause cells to divide uncontrollably and form tumors. There are over 100 types of cancer that can develop. Cancer is one of the leading causes of death worldwide, with 1 in 4 deaths due to cancer. Lung cancer is the most common cancer in men and breast cancer is most common in women. Cancers become malignant when they spread from the original tumor site through the bloodstream and lymphatic system to form secondary tumors in other parts of the body.
This study investigated how acellular gelatinous Wharton's jelly (AGWJ) enhances skin wound healing. Through proteomics analysis, they detected proteins characteristic of exosomes in AGWJ. Exosomes were isolated from AGWJ using ultracentrifugation. In vitro, these exosomes enhanced fibroblast viability and migration. In a mouse model of skin wounds, treatment with AGWJ exosomes enhanced wound healing. Mass spectrometry analysis revealed that AGWJ exosomes contain high amounts of alpha-2-macroglobulin, a protein that likely mimics the wound healing effects of AGWJ exosomes. Therefore, exosomes and their cargo, such as alpha-2-macroglobulin,
1) The document presents a new method for synchronizing proliferating mammalian cells in the G1 phase of the cell cycle using standard optical flow cytometry to separate cells by size.
2) Current methods for synchronizing cells rely on chemical agents that arrest the cell cycle, which can introduce unwanted variables and decouple cell growth from the cell cycle.
3) The new method exploits the correlation between cell size and age, sorting for the smallest cells using light scattering parameters as a proxy for size, which yields a highly purified population of over 90% G1 cells without chemical treatment.
This document summarizes the biology and potential clinical applications of mesenchymal stem cells (MSCs) derived from the Wharton's jelly of the umbilical cord. It discusses how MSCs were originally isolated from bone marrow but umbilical cord is now seen as a promising alternative source due to its abundance of MSCs and the non-invasive collection method. MSCs from Wharton's jelly (WJ-MSCs) share properties with bone marrow MSCs yet are considered more primitive. The review examines the multilineage potential and immunomodulatory abilities of WJ-MSCs and their emerging roles in treating cancer, graft-versus-host disease, and systemic lupus erythemat
This document discusses the potential use of mesenchymal stem cells (MSCs) derived from Wharton's jelly (WJ) of the human umbilical cord for regenerative medicine applications. MSCs from WJ present several advantages over other stem cell sources, including reduced immunogenicity, increased proliferative capacity, and ability to differentiate into various cell types. The document reviews potential applications of WJ-MSCs in cell therapy for cancer, liver disease, peripheral nerve damage, cardiovascular and connective tissue repair, and obesity/diabetes. However, challenges remain in optimizing isolation methods and tracking techniques for clinical applications of WJ-MSCs.
Mammalian MSC from Selected Species: Features and Applications
Christiane Uder, Sandra Br€uckner, Sandra Winkler, Hans-Michael Tautenhahn,†‡ Bruno Christ†*
Mesenchymal stromal/stem cells (MSC) are promising candidates for cellular therapy of different diseases in humans and in animals. Following the guidelines of the International Society for Cell Therapy, human MSC may be identified by expression of a specific panel of cell surface markers (CD1051, CD731, CD901, CD34-, CD14-, or CD11b-, CD79- or CD19-, HLA-DR-). In addition, multiple differentiation potential into at least the osteogenic, adipogenic, and chondrogenic lineage is a main criterion for MSC definition. Human MSC and MSC of a variety of mammals isolated from different tissues meet these criteria. In addition to the abovementioned, they express many more cell surface markers. Yet, these are not uniquely expressed by MSC. The gross phenotypic appearance like marker expression and differentiation potential is similar albeit not identical for MSC from different tissues and species. Similarly, MSC may feature different biological characteristics depending on the tissue source and the isolation and culture procedures. Their versatile biological qualities comprising immunomodulatory, anti-inflammatory, and proregenerative capacities rely largely on the migratory and secretory capabilities of MSC. They are attracted to sites of tissue lesion and secrete factors to promote self-repair of the injured tissue. This is a big perspective for clinical MSC applications in both veterinary and human medicine. Phase I/II clinical trials have been initiated to assess safety and feasibility of MSC therapies in acute and chronic disease settings. Yet, since the mode of MSC action in a specific disease environment is still unknown at large, it is mandatory to unravel the response of MSC from a given source onto a specific disease environment in suitable animal models prior to clinical applications.
This document summarizes the challenges and progress of human gene therapy. It discusses three categories of gene therapy delivery (ex vivo, in situ, in vivo) and focuses on challenges of using retroviral vectors, including inefficient delivery, inability to transduce non-dividing cells, lack of long-term gene expression, and difficulties with large-scale manufacturing. While over 300 clinical trials have been approved, gene therapy efficiency remains low and no protocols have conclusively treated human disease. The document evaluates efforts to address these challenges through envelope protein engineering, hybrid vectors, and improved regulatory sequences.
Compartment specific micro rna expression profiles (poster) posterJackie Lau
This document describes a study investigating compartment-specific microRNA expression profiles in normal human colons and tumor counterparts. Tissue samples from normal colons were microdissected to enrich for different crypt compartments, including whole mucosa, top crypt, and basal crypt. High-throughput quantitative PCR was used to analyze the expression of 677 microRNAs across these samples. Statistical analysis identified microRNAs differentially expressed between compartments that are involved in intestinal epithelial development. Five candidate microRNAs were selected for further validation using individual quantitative PCR on formalin-fixed samples from 42 normal-tumor pairs and 16 top-basal crypt pairs from normal tissue. The aim is to identify microRNA markers that define colonic stem cell niches and
The differences between a cow and a monkey are clear. It is easy to tell a moth from a mosquito. So why are there still scientific studies that mix them up? The answer is simple: hundreds of cell lines stored and used by modern laboratories have been wrongly identified. Some pig cells are labelled as coming from a chicken; cell lines advertised as human have been shown to contain material from hamsters, rats, mice and monkeys. Problems have already been found with more than 400 cell lines. (Cited from Nature 520 (2015)).
An increasing number of scientific publications (i.e. Nature journals) are now sistematically asking for cell line authentication at the moment of paper submission. To help researchers to meet this requirement, UAT is starting to offer a new service for human cell line authentication.
Articulos cientificos celulas madre dentales nuevoBioEDEN Mexico
The document discusses the potential therapeutic uses of stem cells derived from dental tissues. It provides an overview of several scientific articles on this topic, which found that dental stem cells can differentiate into various cell types, including nerve cells, adipocytes, osteoblasts, chondrocytes, myocytes and odontoblasts. The stem cells may be useful for dental tissue regeneration, bone and craniofacial structure regeneration, cardiac regeneration, neurological problems, corneal regeneration, skin regeneration, diabetes treatment, and hepatic regeneration among other applications. The document provides links to read full articles on stem cells from dental tissues and their potential to treat various medical conditions.
1) Researchers studied over 50,000 cancer karyotypes and found common chromosomal aberrations and patterns of chromosomes being lost or gained together across different cancer types.
2) Stress can increase chromosomal instability in cells, allowing them to generate genetic diversity and adapt to stressful environments. Studies in yeast found stress increased chromosome loss and gain.
3) Understanding stress-induced chromosomal changes could provide insights into cancer progression and how cells develop resistance to drugs and environmental stresses.
1) Researchers studied over 50,000 cancer karyotypes and found common chromosomal aberrations and patterns of chromosomes being lost or gained together across different cancer types.
2) Stress can increase chromosomal instability in cells, allowing them to generate genetic diversity and adapt to stressful environments. Yeast exposed to chemical stress developed chromosomal changes that increased survival rates.
3) Understanding stress-induced chromosomal changes may help combat cancer and bacterial drug resistance by revealing how cells adapt to threats. Tracking genomic alterations provides insights into cancer progression and adaptation.
The document discusses the potential use of in situ bone marrow stem cells for treating degenerative diseases. It proposes that stimulating the natural release and migration of bone marrow stem cells into tissues, rather than removing and reintroducing stem cells, could effectively treat conditions like Parkinson's, diabetes, and heart disease. Recent research has found that bone marrow stem cells can differentiate into various cell types and help repair damaged tissues, suggesting they may have similar pluripotent properties as embryonic stem cells but without the ethical issues.
Umbilical cord mesenchymal stem cells (UC-MSCs) show potential advantages over mesenchymal stem cells (MSCs) from other sources for regenerative medicine applications. UC-MSCs display higher proliferation rates and expression of embryonic genes compared to adult MSCs. Transcriptomic analyses indicate UC-MSCs express genes related to development of multiple tissues including bone, liver, cardiovascular and neural systems. While UC-MSCs can differentiate into cell types of multiple lineages, their therapeutic impact is thought to be mainly due to their paracrine effects and immunomodulatory properties. UC-MSCs could have advantages for treating autoimmune and neurodegenerative diseases.
Embryonic stem cells have potential to cure diseases like Parkinson's and Huntington's, but extracting them requires destroying embryos, which causes moral controversy. While stem cell research could help many people, opponents argue that destroying embryos is unethical and funding research is too costly. However, scientists have found ways to extract stem cells without destroying embryos entirely. Continuing stem cell research could unlock cures for currently incurable diseases and greatly improve many lives, justifying the costs and moral concerns.
Many evidences that CSCs also play a central role in the pathogenesis and progression of carcinomas of the head and neck (HNSCC), including OSCC,have been found.
Early tissue culture studies showed that only a subpopulation of OSCC cells can form expanding tumor colonies, suggesting that human OSCC may contain some form of stem cells and it was subsequently shown that only a small subpopulation of the cells in OSCC corresponds to tumor-initiating cells.
These finding are in accordance with CSCs concept (17,34) that the tumor mass is a mixture of (a) CSCs dividing themselves to feed the tumor's growth, b) transient amplifying cells that divide themselves a few times before maturing into (c) differentiated tumor cells that do not contribute to tumor growth (4).
The isolation of CSCs from oral cancers has mainly been performed with the CD44 marker that was initially used to isolate breast cancer CSCs.
Many evidences that CSCs also play a central role in the pathogenesis and progression of carcinomas of the head and neck (HNSCC), including OSCC,have been found.
Early tissue culture studies showed that only a subpopulation of OSCC cells can form expanding tumor colonies, suggesting that human OSCC may contain some form of stem cells and it was subsequently shown that only a small subpopulation of the cells in OSCC corresponds to tumor-initiating cells.
These finding are in accordance with CSCs concept (17,34) that the tumor mass is a mixture of (a) CSCs dividing themselves to feed the tumor's growth, b) transient amplifying cells that divide themselves a few times before maturing into (c) differentiated tumor cells that do not contribute to tumor growth (4).
The isolation of CSCs from oral cancers has mainly been performed with the CD44 marker that was initially used to isolate breast cancer CSCs.
This literature review finds that umbilical cord tissue, specifically Wharton's jelly, offers the greatest number of harvestable mesenchymal stem cells. The review analyzed 161 studies reporting mesenchymal stem cell yields from various tissue sources, including adipose tissue, bone marrow, umbilical cord tissue, and placental tissue. It found that yields from umbilical cord tissue ranged from 10,000 to 4,700,000 cells per milliliter, far exceeding yields from other sources. Adipose tissue provided the next highest yields, ranging from 4,737 to 1,550,000 cells per milliliter. Bone marrow yields ranged more widely from 1 to 317,400 cells per millil
Role of cancer stem cells in cancer therapyniper hyd
This document discusses cancer stem cells (CSCs) and potential therapies targeting them. It begins with introductions to stem cells and CSCs, then covers the history of discovering CSCs. New therapies discussed include targeting CSC-specific markers, signal pathways like Wnt and Notch, CSC metabolism, and epithelial-mesenchymal transition. Clinical trials targeting CSC pathways are also summarized. The document provides an overview of CSCs and recent research into developing treatments focused on these cells.
Como afrontar células madre de cáncer con alimentos Nutriline SRL
III Congreso mundial de medicina y nutrición moluecular e integrativa.
Alejandro Sacha Barrio Healey
"Como Afrontar Células Madre de Cáncer con Alimentos y Plantas"
Cancer arises from mutations in genes that control cell division. These mutations cause cells to divide uncontrollably and form tumors. There are over 100 types of cancer that can develop. Cancer is one of the leading causes of death worldwide, with 1 in 4 deaths due to cancer. Lung cancer is the most common cancer in men and breast cancer is most common in women. Cancers become malignant when they spread from the original tumor site through the bloodstream and lymphatic system to form secondary tumors in other parts of the body.
This study investigated how acellular gelatinous Wharton's jelly (AGWJ) enhances skin wound healing. Through proteomics analysis, they detected proteins characteristic of exosomes in AGWJ. Exosomes were isolated from AGWJ using ultracentrifugation. In vitro, these exosomes enhanced fibroblast viability and migration. In a mouse model of skin wounds, treatment with AGWJ exosomes enhanced wound healing. Mass spectrometry analysis revealed that AGWJ exosomes contain high amounts of alpha-2-macroglobulin, a protein that likely mimics the wound healing effects of AGWJ exosomes. Therefore, exosomes and their cargo, such as alpha-2-macroglobulin,
1) The document presents a new method for synchronizing proliferating mammalian cells in the G1 phase of the cell cycle using standard optical flow cytometry to separate cells by size.
2) Current methods for synchronizing cells rely on chemical agents that arrest the cell cycle, which can introduce unwanted variables and decouple cell growth from the cell cycle.
3) The new method exploits the correlation between cell size and age, sorting for the smallest cells using light scattering parameters as a proxy for size, which yields a highly purified population of over 90% G1 cells without chemical treatment.
This document summarizes the biology and potential clinical applications of mesenchymal stem cells (MSCs) derived from the Wharton's jelly of the umbilical cord. It discusses how MSCs were originally isolated from bone marrow but umbilical cord is now seen as a promising alternative source due to its abundance of MSCs and the non-invasive collection method. MSCs from Wharton's jelly (WJ-MSCs) share properties with bone marrow MSCs yet are considered more primitive. The review examines the multilineage potential and immunomodulatory abilities of WJ-MSCs and their emerging roles in treating cancer, graft-versus-host disease, and systemic lupus erythemat
This document discusses the potential use of mesenchymal stem cells (MSCs) derived from Wharton's jelly (WJ) of the human umbilical cord for regenerative medicine applications. MSCs from WJ present several advantages over other stem cell sources, including reduced immunogenicity, increased proliferative capacity, and ability to differentiate into various cell types. The document reviews potential applications of WJ-MSCs in cell therapy for cancer, liver disease, peripheral nerve damage, cardiovascular and connective tissue repair, and obesity/diabetes. However, challenges remain in optimizing isolation methods and tracking techniques for clinical applications of WJ-MSCs.
Mammalian MSC from Selected Species: Features and Applications
Christiane Uder, Sandra Br€uckner, Sandra Winkler, Hans-Michael Tautenhahn,†‡ Bruno Christ†*
Mesenchymal stromal/stem cells (MSC) are promising candidates for cellular therapy of different diseases in humans and in animals. Following the guidelines of the International Society for Cell Therapy, human MSC may be identified by expression of a specific panel of cell surface markers (CD1051, CD731, CD901, CD34-, CD14-, or CD11b-, CD79- or CD19-, HLA-DR-). In addition, multiple differentiation potential into at least the osteogenic, adipogenic, and chondrogenic lineage is a main criterion for MSC definition. Human MSC and MSC of a variety of mammals isolated from different tissues meet these criteria. In addition to the abovementioned, they express many more cell surface markers. Yet, these are not uniquely expressed by MSC. The gross phenotypic appearance like marker expression and differentiation potential is similar albeit not identical for MSC from different tissues and species. Similarly, MSC may feature different biological characteristics depending on the tissue source and the isolation and culture procedures. Their versatile biological qualities comprising immunomodulatory, anti-inflammatory, and proregenerative capacities rely largely on the migratory and secretory capabilities of MSC. They are attracted to sites of tissue lesion and secrete factors to promote self-repair of the injured tissue. This is a big perspective for clinical MSC applications in both veterinary and human medicine. Phase I/II clinical trials have been initiated to assess safety and feasibility of MSC therapies in acute and chronic disease settings. Yet, since the mode of MSC action in a specific disease environment is still unknown at large, it is mandatory to unravel the response of MSC from a given source onto a specific disease environment in suitable animal models prior to clinical applications.
This document summarizes the challenges and progress of human gene therapy. It discusses three categories of gene therapy delivery (ex vivo, in situ, in vivo) and focuses on challenges of using retroviral vectors, including inefficient delivery, inability to transduce non-dividing cells, lack of long-term gene expression, and difficulties with large-scale manufacturing. While over 300 clinical trials have been approved, gene therapy efficiency remains low and no protocols have conclusively treated human disease. The document evaluates efforts to address these challenges through envelope protein engineering, hybrid vectors, and improved regulatory sequences.
Compartment specific micro rna expression profiles (poster) posterJackie Lau
This document describes a study investigating compartment-specific microRNA expression profiles in normal human colons and tumor counterparts. Tissue samples from normal colons were microdissected to enrich for different crypt compartments, including whole mucosa, top crypt, and basal crypt. High-throughput quantitative PCR was used to analyze the expression of 677 microRNAs across these samples. Statistical analysis identified microRNAs differentially expressed between compartments that are involved in intestinal epithelial development. Five candidate microRNAs were selected for further validation using individual quantitative PCR on formalin-fixed samples from 42 normal-tumor pairs and 16 top-basal crypt pairs from normal tissue. The aim is to identify microRNA markers that define colonic stem cell niches and
The differences between a cow and a monkey are clear. It is easy to tell a moth from a mosquito. So why are there still scientific studies that mix them up? The answer is simple: hundreds of cell lines stored and used by modern laboratories have been wrongly identified. Some pig cells are labelled as coming from a chicken; cell lines advertised as human have been shown to contain material from hamsters, rats, mice and monkeys. Problems have already been found with more than 400 cell lines. (Cited from Nature 520 (2015)).
An increasing number of scientific publications (i.e. Nature journals) are now sistematically asking for cell line authentication at the moment of paper submission. To help researchers to meet this requirement, UAT is starting to offer a new service for human cell line authentication.
Articulos cientificos celulas madre dentales nuevoBioEDEN Mexico
The document discusses the potential therapeutic uses of stem cells derived from dental tissues. It provides an overview of several scientific articles on this topic, which found that dental stem cells can differentiate into various cell types, including nerve cells, adipocytes, osteoblasts, chondrocytes, myocytes and odontoblasts. The stem cells may be useful for dental tissue regeneration, bone and craniofacial structure regeneration, cardiac regeneration, neurological problems, corneal regeneration, skin regeneration, diabetes treatment, and hepatic regeneration among other applications. The document provides links to read full articles on stem cells from dental tissues and their potential to treat various medical conditions.
1) Researchers studied over 50,000 cancer karyotypes and found common chromosomal aberrations and patterns of chromosomes being lost or gained together across different cancer types.
2) Stress can increase chromosomal instability in cells, allowing them to generate genetic diversity and adapt to stressful environments. Studies in yeast found stress increased chromosome loss and gain.
3) Understanding stress-induced chromosomal changes could provide insights into cancer progression and how cells develop resistance to drugs and environmental stresses.
1) Researchers studied over 50,000 cancer karyotypes and found common chromosomal aberrations and patterns of chromosomes being lost or gained together across different cancer types.
2) Stress can increase chromosomal instability in cells, allowing them to generate genetic diversity and adapt to stressful environments. Yeast exposed to chemical stress developed chromosomal changes that increased survival rates.
3) Understanding stress-induced chromosomal changes may help combat cancer and bacterial drug resistance by revealing how cells adapt to threats. Tracking genomic alterations provides insights into cancer progression and adaptation.
The document discusses the potential use of in situ bone marrow stem cells for treating degenerative diseases. It proposes that stimulating the natural release and migration of bone marrow stem cells into tissues, rather than removing and reintroducing stem cells, could effectively treat conditions like Parkinson's, diabetes, and heart disease. Recent research has found that bone marrow stem cells can differentiate into various cell types and help repair damaged tissues, suggesting they may have similar pluripotent properties as embryonic stem cells but without the ethical issues.
Umbilical cord mesenchymal stem cells (UC-MSCs) show potential advantages over mesenchymal stem cells (MSCs) from other sources for regenerative medicine applications. UC-MSCs display higher proliferation rates and expression of embryonic genes compared to adult MSCs. Transcriptomic analyses indicate UC-MSCs express genes related to development of multiple tissues including bone, liver, cardiovascular and neural systems. While UC-MSCs can differentiate into cell types of multiple lineages, their therapeutic impact is thought to be mainly due to their paracrine effects and immunomodulatory properties. UC-MSCs could have advantages for treating autoimmune and neurodegenerative diseases.
Embryonic stem cells have potential to cure diseases like Parkinson's and Huntington's, but extracting them requires destroying embryos, which causes moral controversy. While stem cell research could help many people, opponents argue that destroying embryos is unethical and funding research is too costly. However, scientists have found ways to extract stem cells without destroying embryos entirely. Continuing stem cell research could unlock cures for currently incurable diseases and greatly improve many lives, justifying the costs and moral concerns.
Many evidences that CSCs also play a central role in the pathogenesis and progression of carcinomas of the head and neck (HNSCC), including OSCC,have been found.
Early tissue culture studies showed that only a subpopulation of OSCC cells can form expanding tumor colonies, suggesting that human OSCC may contain some form of stem cells and it was subsequently shown that only a small subpopulation of the cells in OSCC corresponds to tumor-initiating cells.
These finding are in accordance with CSCs concept (17,34) that the tumor mass is a mixture of (a) CSCs dividing themselves to feed the tumor's growth, b) transient amplifying cells that divide themselves a few times before maturing into (c) differentiated tumor cells that do not contribute to tumor growth (4).
The isolation of CSCs from oral cancers has mainly been performed with the CD44 marker that was initially used to isolate breast cancer CSCs.
Many evidences that CSCs also play a central role in the pathogenesis and progression of carcinomas of the head and neck (HNSCC), including OSCC,have been found.
Early tissue culture studies showed that only a subpopulation of OSCC cells can form expanding tumor colonies, suggesting that human OSCC may contain some form of stem cells and it was subsequently shown that only a small subpopulation of the cells in OSCC corresponds to tumor-initiating cells.
These finding are in accordance with CSCs concept (17,34) that the tumor mass is a mixture of (a) CSCs dividing themselves to feed the tumor's growth, b) transient amplifying cells that divide themselves a few times before maturing into (c) differentiated tumor cells that do not contribute to tumor growth (4).
The isolation of CSCs from oral cancers has mainly been performed with the CD44 marker that was initially used to isolate breast cancer CSCs.
This document discusses adipose-derived regenerative cells and their potential for use in regenerative medicine. It summarizes key findings from studies conducted by the authors: (1) mesenchymal stem cells can be isolated from various tissues including adipose tissue and differentiated into cells from all three germ layers, supporting the hypothesis that a universal stem cell exists; (2) the microenvironment determines the orientation and differentiation of mesenchymal stem cells; (3) these stem cells can be obtained from small amounts of adipose tissue using appropriate isolation techniques and applied to patients without processing or manipulation. The document argues that use of a patient's own adipose-derived regenerative cells has potential as a new generation of regenerative
“Stem Cell, Possibilities And Utility In Health sector” Ajit Tiwari
The role of stem cells in basic biological processes in vivo, namely in development, tissue repair and cancer.
Remarkable progress has been achieved in studying stem cells. The most exciting use of cultured stem cells is the promise for curing many devastating diseases like Parkinson's and diabetes. However, more basic research remains before stem-cell based therapy is widely used.
ES cells have the most capacity to differentiate into a variety of cells and their proliferation capacity is also unsurpassed by any other cell type. There are three major problems with ES cells; ethical issues, immunological rejection problems and the potential of developing teratomas.
In the future, ideally, somatic stem cells from the patient will be extracted and manipulated and then reintroduced into the same patient to cure debilitating diseases.
Cancer stem cells (CSCs) are rare cancer cells that have properties similar to normal stem cells, allowing them to both self-renew and differentiate into the other cell types that make up a tumor. CSCs are thought to drive tumor growth and relapse after treatment. The first evidence of CSCs came from studies in 1997 that isolated a subpopulation of leukemia cells capable of initiating new tumors. Since then, CSCs have been identified in several other cancer types based on their ability to form tumors from very few cells in animal models. CSCs may explain why conventional cancer treatments fail to cure cancers by mainly targeting differentiated cells rather than the tumor-initiating CSCs.
Stem cells have the ability to reproduce and differentiate into specialized cells. The document discusses various types of stem cells including embryonic, adult, dental, and induced pluripotent stem cells. It provides details on stem cell sources from oral and maxillofacial regions like dental pulp stem cells, stem cells from exfoliated deciduous teeth, and periodontal ligament stem cells. The document concludes that stem cell-based therapies show potential for repairing and regenerating tissues and that continued research may enable whole tooth regeneration.
This document discusses stem cells, providing a historical background of stem cell discoveries from 1908 to present. It defines stem cells and categorizes them into embryonic, adult, and induced pluripotent stem cells. Various sources of adult stem cells are described, including bone marrow-derived mesenchymal stem cells and different dental tissue-derived stem cells like dental pulp stem cells, periodontal ligament stem cells, stem cells from apical papilla, and dental follicle stem cells. Studies on the potential of these stem cells for periodontal regeneration are summarized.
(1) Stem cells can be embryonic, adult, or induced pluripotent. Embryonic stem cells are pluripotent while adult stem cells are multipotent.
(2) Cancer stem cells are a small fraction of tumor cells that can self-renew and differentiate to form the heterogeneous tumor mass. They rely on signaling pathways like JAK/STAT, Hedgehog, Wnt, and Notch to maintain their stem-like properties.
(3) Targeting these pathways and surface markers on cancer stem cells is a promising strategy for cancer treatment, though more research is still needed to develop effective therapies.
This document discusses the potential of adult stem cells to treat degenerative diseases by regenerating cells. It outlines two types of stem cells - embryonic stem cells which are controversial due to ethical issues, and adult stem cells which are readily available and have been safely used for therapies. The document describes how adult stem cells can be collected from healthy individuals using growth factors and apheresis, then cryogenically stored for future autologous use to treat diseases like cancer and heart disease. It provides examples of current adult stem cell therapies including bone marrow transplants to treat blood cancers.
This document discusses the potential of adult stem cells to treat degenerative diseases by regenerating cells. It outlines two types of stem cells - embryonic stem cells which are controversial due to ethical issues, and adult stem cells which are readily available and have been safely used for therapies. The document describes how adult stem cells can be collected from healthy individuals using growth factors and apheresis, then cryogenically stored for future autologous use to treat diseases like cancer and heart disease. It provides examples of current adult stem cell therapies including bone marrow transplants to treat blood cancers.
Stem cells exist in both embryos and adult tissues. They are unspecialized cells that can differentiate into other cell types and have self-renewal abilities. There are several types of stem cells defined by their differentiation potential, ranging from totipotent stem cells that can form the entire organism, to pluripotent stem cells that can form any fetal cell type but not extraembryonic tissues, to multipotent, oligopotent, and unipotent stem cells with progressively narrower differentiation abilities. Stem cell lines can be derived from embryonic stem cells, adult tissues, or through reprogramming adult cells into induced pluripotent stem cells. These cell lines have various applications in research and regenerative medicine to treat diseases.
1. The proposal aims to characterize the heterogeneity of the bone marrow endothelium and its impact on hematopoietic stem and progenitor cells (HSPCs) biology using novel genetic tools.
2. New mouse lines will be used to visualize and profile the localization and cell cycle stage of proliferating endothelial and hematopoietic cells in vivo to create a spatiotemporal map of endothelial proliferation and its effects.
3. The research will investigate how modulation of endothelial proliferation impacts adjacent HSPCs and how HSPCs impact endothelial biology, with the goal of providing insights into endothelial-hematopoietic interactions that could inform new therapeutic strategies for blood diseases.
The document discusses stem cells and their potential use in cancer therapy. It describes the different types of stem cells, including embryonic stem cells and adult stem cells derived from tissues like bone marrow. While embryonic stem cells are more potent, adult stem cells are more commonly used due to ethical issues with embryonic stem cells. The document also discusses sources of adult stem cells, challenges with targeting cancer stem cells for treatment, and implications for improving cancer therapies.
The document discusses different types of stem cells, their properties and potential uses. It explains that stem cells are unspecialized cells capable of dividing and renewing themselves that can differentiate into specialized cells. The document also outlines a study where high-dose immunosuppression followed by stem cell transplantation helped patients with newly diagnosed type 1 diabetes achieve prolonged insulin independence in most cases.
The document discusses different types of stem cells, their properties and potential uses. It explains that stem cells are unspecialized cells capable of dividing and renewing themselves that can differentiate into specialized cells. The document also outlines a study where high-dose immunosuppression followed by autologous hematopoietic stem cell transplantation helped patients with newly diagnosed type 1 diabetes to reduce or stop insulin use.
These hallmarks constitute an organizing principle for rationalizing the complexities of neoplastic disease. They include sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis.
The Potential Application Of Stem Cells For RejuvenationStefanus Nofa
Stem cells may have potential applications for rejuvenation and life extension. As we age, stem cell functionality declines, impacting tissue regeneration and repair. Replacing aged stem cells with youthful stem cells from sources like bone marrow or umbilical cord blood could theoretically rejuvenate aged body organs and tissues over time. Further research is still needed but stem cell therapy may one day help reverse signs of aging at the cellular level.
. HIV-1-infected monocyte–macrophages traverse the BBB and enter the CNS throughout the course of HIV-1 disease. Once in the brain, both free virus and virus-infected cells are able to infect neighboring resident microglia and astrocytes and possibly other cell types.
HIV-1-infected cells in both the periphery and the CNS give rise to elevated levels of viral proteins, including gp120, Tat, and Nef, and of host inflammatory mediators such as cytokines and chemokines.
It has been shown that the viral proteins may act alone or in concert with host cytokines and chemokines, affecting the integrity of the BBB. The pathological end point of these interactions may facilitate a positive feedback loop resulting in increased penetration of HIV into the CNS
. HIV-1-infected monocyte–macrophages traverse the BBB and enter the CNS throughout the course of HIV-1 disease. Once in the brain, both free virus and virus-infected cells are able to infect neighboring resident microglia and astrocytes and possibly other cell types.
HIV-1-infected cells in both the periphery and the CNS give rise to elevated levels of viral proteins, including gp120, Tat, and Nef, and of host inflammatory mediators such as cytokines and chemokines.
It has been shown that the viral proteins may act alone or in concert with host cytokines and chemokines, affecting the integrity of the BBB. The pathological end point of these interactions may facilitate a positive feedback loop resulting in increased penetration of HIV into the CNS
Inflammatory gingival hyperplasia is an inflammatory restraint to local irritant correlating with the gingiva; the irritant could be microbial like plaque and calculus.
Clinically present as deep red or bluish, considerably friable and fine with smooth glossy surface and commonly bleed easily [1].
These conditions are presented with the epithelial to mesenchymal transition (EMT), where the basal lamina show disruptions and epithelial cells migrate into connective tissue and change their phenotypes to fibroblast-like cells [12].
Clinical Description
Cleidocranial dysplasia (CCD) spectrum disorder is a skeletal dysplasia representing a clinical continuum ranging from classic CCD (triad of delayed closure of the cranial sutures, hypoplastic or aplastic clavicles, and dental abnormalities), to mild CCD, to isolated dental anomalies without other skeletal features [Golan et al 2000]. Most individuals are diagnosed because they have classic features. CCD spectrum disorder affects most prominently those bones derived from intramembranous ossification, such as the cranium and the clavicles, although bones formed through endochondral ossification can also be affected. Cooper et al [2001] recorded the natural history of 90 probands and 56 first- and second-degree relatives; findings highlight the clinical variability of this condition within affected members of the same family who harbor the same pathogenic variant. Roberts et al [2013] reviewed their experience with more than 100 affected individuals in South Africa.
Classic CCD. The most prominent clinical findings in individuals with classic CCD are listed in Suggestive Findings and include: abnormally large, wide-open fontanelles at birth that may remain open throughout life; clavicular hypoplasia resulting in narrow, sloping shoulders that can be opposed at the midline; and abnormal dentition
Further medical problems identified in individuals with CCD spectrum disorder include short stature, skeletal/orthopedic findings, dental complications, ENT complications, endocrine findings, and mild developmental delay.
Molecular Pathogenesis
RUNX2 encodes runt-related transcription factor 2 (RUNX2), a transcription factor involved in osteoblast differentiation and skeletal morphogenesis. RUNX2 is essential for osteoblast differentiation during intramembranous ossification as well as chondrocyte maturation during endochondral ossification [Zheng et al 2005]. RUNX2 contains an N-terminal stretch of consecutive polyglutamine and polyalanine repeats known as the Q/A domain, a runt domain, and a C-terminal proline/serine/threonine-rich (PST) activation domain. The runt domain is a 128-amino-acid polypeptide motif originally described in the Drosophila runt gene that has the unique ability to independently mediate DNA binding and protein heterodimerization [Zhou et al 1999].
The majority of RUNX2 pathogenic variants in individuals with classic CCD affect the runt domain and most are predicted to abolish DNA binding [Lee et al 1997, Mundlos et al 1997, Otto et al 2002]. Pathogenic missense variants cluster at arginine 225 (p.Arg225) of RUNX2, a critical residue for RUNX2 function. In vitro studies have shown that pathogenic missense variants at p.Arg225 interfere with nuclear accumulation of RUNX2.
Hypomorphic RUNX2 alleles with partial loss of protein function, c.90dupC and c.598A>G, are associated with mild CCD, isolated dental anomalies, and significant intrafamilial variability.
Mechanism of disease causation. Loss of function
RUNX2-sp
Cleidocranial dysplasia (CCD) spectrum disorder is a skeletal dysplasia representing a clinical continuum ranging from classic CCD (triad of delayed closure of the cranial sutures, hypoplastic or aplastic clavicles, and dental abnormalities), to mild CCD, to isolated dental anomalies without other skeletal features [Golan et al 2000]. Most individuals are diagnosed because they have classic features. CCD spectrum disorder affects most prominently those bones derived from intramembranous ossification, such as the cranium and the clavicles, although bones formed through endochondral ossification can also be affected. Cooper et al [2001] recorded the natural history of 90 probands and 56 first- and second-degree relatives; findings highlight the clinical variability of this condition within affected members of the same family who harbor the same pathogenic variant. Roberts et al [2013] reviewed their experience with more than 100 affected individuals in South Africa.
Wound healing is a highly dynamic process and involves complex interactions of extracellular matrix molecules, soluble mediators, various resident cells, and infiltrating leukocyte subtypes.
The immediate goal in repair is to achieve tissue integrity and homeostasis
PV is caused by autoantibodies that target cadherins, specifically desmogleins, though there may be some role for desmocollin; thus, this is a type 2 hypersensitivity reaction.[24][25] Acantholysis, or the loss of keratinocyte–keratinocyte adhesion, is interrupted by circulating IgG autoantibodies to intercellular adhesion molecules.[26][27] Acantholysis is seen as a result of the autoantibodies destroying the intracellular connections, leading to bullae that can easily rupture (known clinically as the Nikolsky sign).
A “super-compensation hypothesis” recently submitted by Sinha et al. proposes that additional factors may also play a role in PV.[28] Multiple mechanisms for antibody-induced acantholysis have been suggested, including the induction of signal transduction and the inhibition of adhesive molecule function through steric hindrance, which can trigger cell separation.[29] The pathogenesis of PV has been described in more detail by Hammers et al.[30]
In patients with PV, autoantibodies against desmoglein 1 (Dsg 1) and desmoglein 3 (Dsg 3) is the purported cause.[31] Desmogleins are transmembrane glycoproteins that are an integral part of desmosomes which, in part, are required for cell–cell adhesion via interaction with intermediate filaments. The most common targets of desmoglein for IgG antibodies are the extracellular cadherin domains, which can result in the loss of desmosome-adhesive properties. These signaling pathways trigger endocytosis, depletion, and direct inhibition of Dsg 3 interactions.[32] It is generally believed that the amino portion of the cadherin proteins is most implicated in the pathogenesis of acantholysis leading to PV.[33]
Many animal models have shown that enzymatic inactivation of Dsg 1 and gene deletion of Dsg 3 results in pathology similar to PV.[34][35] This phenomenon was observed to be dose-dependent and suggests that reducing the circulating levels of IgG against Dsg 1 and Dsg 3 can improve patient outcomes.[36] In patients with primarily cutaneous disease, Dsg 1 likely plays a role more superficially, whereas Dsg 3 is more likely to be found in deeper cutaneous structures and mucous membranes.[37][38] The implication is that Dsg 3 can compensate for the absence of Dsg 1 in mucosal structures (thus demonstrating PV in cutaneous lesions only). In contrast, Dsg 1 without Dsg 3 is insufficient to manage mucous membranes or cutaneous lesions alone, implying that Dsg 1 is in lower proportion in mucous membranes.
The binding of antibodies to desmogleins has been confirmed by epitope mapping and is presumed to disrupt desmoglein binding by affecting steric hindrance.[39] Another theory for the pathophysiology of PV is the desmoglein nonassembly depletion hypothesis. This theory suggests that autoantibodies not only bind desmoglein but that they also bind each other, leading to crosslinking and the inability of desmosomes to maintain cell–cell adhesion.[40][41]
PV is caused by autoantibodies that target cadherins, specifically desmogleins, though there may be some role for desmocollin; thus, this is a type 2 hypersensitivity reaction.[24][25] Acantholysis, or the loss of keratinocyte–keratinocyte adhesion, is interrupted by circulating IgG autoantibodies to intercellular adhesion molecules.[26][27] Acantholysis is seen as a result of the autoantibodies destroying the intracellular connections, leading to bullae that can easily rupture (known clinically as the Nikolsky sign).
A “super-compensation hypothesis” recently submitted by Sinha et al. proposes that additional factors may also play a role in PV.[28] Multiple mechanisms for antibody-induced acantholysis have been suggested, including the induction of signal transduction and the inhibition of adhesive molecule function through steric hindrance, which can trigger cell separation.[29] The pathogenesis of PV has been described in more detail by Hammers et al.[30]
In patients with PV, autoantibodies against desmoglein 1 (Dsg 1) and desmoglein 3 (Dsg 3) is the purported cause.[31] Desmogleins are transmembrane glycoproteins that are an integral part of desmosomes which, in part, are required for cell–cell adhesion via interaction with intermediate filaments. The most common targets of desmoglein for IgG antibodies are the extracellular cadherin domains, which can result in the loss of desmosome-adhesive properties. These signaling pathways trigger endocytosis, depletion, and direct inhibition of Dsg 3 interactions.[32] It is generally believed that the amino portion of the cadherin proteins is most implicated in the pathogenesis of acantholysis leading to PV.[33]
Many animal models have shown that enzymatic inactivation of Dsg 1 and gene deletion of Dsg 3 results in pathology similar to PV.[34][35] This phenomenon was observed to be dose-dependent and suggests that reducing the circulating levels of IgG against Dsg 1 and Dsg 3 can improve patient outcomes.[36] In patients with primarily cutaneous disease, Dsg 1 likely plays a role more superficially, whereas Dsg 3 is more likely to be found in deeper cutaneous structures and mucous membranes.[37][38] The implication is that Dsg 3 can compensate for the absence of Dsg 1 in mucosal structures (thus demonstrating PV in cutaneous lesions only). In contrast, Dsg 1 without Dsg 3 is insufficient to manage mucous membranes or cutaneous lesions alone, implying that Dsg 1 is in lower proportion in mucous membranes.
The binding of antibodies to desmogleins has been confirmed by epitope mapping and is presumed to disrupt desmoglein binding by affecting steric hindrance.[39] Another theory for the pathophysiology of PV is the desmoglein nonassembly depletion hypothesis. This theory suggests that autoantibodies not only bind desmoglein but that they also bind each other, leading to crosslinking and the inability of desmosomes to maintain cell–cell adhesion.[40][41]
The primary function of platelets is their role in hemostasis. Briefly, under normal physiological conditions, platelets will adhere to and begin to spread over the surface of subendothelial cells exposed by damage to the vascular endothelium.(1) Adhesion is dependent on the platelet membrane glycoprotein lb complex. The von Willebrand factor (vWF) is required for both adhesion and spreading.
The primary function of platelets is their role in hemostasis. Briefly, under normal physiological conditions, platelets will adhere to and begin to spread over the surface of subendothelial cells exposed by damage to the vascular endothelium.(1) Adhesion is dependent on the platelet membrane glycoprotein lb complex. The von Willebrand factor (vWF) is required for both adhesion and spreading.
Phagocytosis begins with adhesion of the phagocyte surface receptors to the pathogen, which then is internalized into vesicles called phagosomes.
Inside the phagocyte, the phagosome fuses to lysosomes, whose contents are released with consequent digestion and pathogen elimination.
Changes in the oxidase’s gene system components present in phagolysosome membrane lead to disability in respiratory burst and generation of reactive oxygen species (ROS).
Phagocytosis begins with adhesion of the phagocyte surface receptors to the pathogen, which then is internalized into vesicles called phagosomes.
Inside the phagocyte, the phagosome fuses to lysosomes, whose contents are released with consequent digestion and pathogen elimination.
Changes in the oxidase’s gene system components present in phagolysosome membrane lead to disability in respiratory burst and generation of reactive oxygen species (ROS).
Platelets have many functions, including phagocytosis of viruses, latex, immune complexes and iron; maintenance of vascular integrity
by filling gaps that form in the endothelium and by directly supporting endothelial cells; synthesis and release of vWF in humans and some animal species, and fibronectin;
participating in surface adhesion andactivation processess (Caen and Rosa, 1995; Clemetson, 1995; Nurden, 1995);
production and release of potent smooth muscle and endothelial cell proliferating factor( s); and retraction of clots, a process that stabilizes the initial hemostatic plug and activates clot lysis.
Platelets have many functions, including phagocytosis of viruses, latex, immune complexes and iron; maintenance of vascular integrity
by filling gaps that form in the endothelium and by directly supporting endothelial cells; synthesis and release of vWF in humans and some animal species, and fibronectin;
participating in surface adhesion andactivation processess (Caen and Rosa, 1995; Clemetson, 1995; Nurden, 1995);
production and release of potent smooth muscle and endothelial cell proliferating factor( s); and retraction of clots, a process that stabilizes the initial hemostatic plug and activates clot lysis.
Tooth development proceeds with reciprocal inductive interactions between stomadeum ectoderm and underlying ectomesenchymal cells in a strictly controlled temporal and spatial order.
Well studied at the molecular biologic level, over 300 genes and 100 growth and differentiation factors are implicated in the control of cellular differentiation and crosstalk in dental development that result in structures containing combination of mineralized tissues (enamel, dentine, cementum), soft connective tissues (dental pulp, periodontal ligament), blood vessels, nerves and lymphatics.
Tooth development proceeds with reciprocal inductive interactions between stomadeum ectoderm and underlying ectomesenchymal cells in a strictly controlled temporal and spatial order.
Well studied at the molecular biologic level, over 300 genes and 100 growth and differentiation factors are implicated in the control of cellular differentiation and crosstalk in dental development that result in structures containing combination of mineralized tissues (enamel, dentine, cementum), soft connective tissues (dental pulp, periodontal ligament), blood vessels, nerves and lymphatics
Diagnostic polymerase chain reaction (PCR) is an extremely powerful, rapid method for diagnosis of microbial infections and genetic diseases, as well as for detecting microorganisms in environmental and food samples.
However, the usefulness of diagnostic PCR is limited, in part, by the presence of inhibitory substances in complex biological samples, which reduce or even block the amplification capacity of PCR in comparison with pure solutions of nucleic acids .
In general, diagnostic PCR may be divided into four steps: (1) sampling, (2) sample preparation, (3) nucleic acid amplification, and (4) detection of PCR products
Diagnostic polymerase chain reaction (PCR) is an extremely powerful, rapid method for diagnosis of microbial infections and genetic diseases, as well as for detecting microorganisms in environmental and food samples.
However, the usefulness of diagnostic PCR is limited, in part, by the presence of inhibitory substances in complex biological samples, which reduce or even block the amplification capacity of PCR in comparison with pure solutions of nucleic acids .
In general, diagnostic PCR may be divided into four steps: (1) sampling, (2) sample preparation, (3) nucleic acid amplification, and (4) detection of PCR products
The etiology of a disease refers to the causative trigger(s), whereas pathogenesis refers to the mechanism(s) by which the disease progresses.
In other words, while the microbial biofilm developing on the tooth surface constitutes a necessary etiological factor, its mere presence is insufficient for the initiation of the disease.
Further risk factors, such as host genetics, lifestyle, stress, and systemic conditions, that dictate the immunopathogenesis are crucial for the transition from a healthy to a diseased state.
The etiology of a disease refers to the causative trigger(s), whereas pathogenesis refers to the mechanism(s) by which the disease progresses.
In other words, while the microbial biofilm developing on the tooth surface constitutes a necessary etiological factor, its mere presence is insufficient for the initiation of the disease.
Further risk factors, such as host genetics, lifestyle, stress, and systemic conditions, that dictate the immunopathogenesis are crucial for the transition from a healthy to a diseased state.
More from Romissaa ali Esmail/ faculty of dentistry/Al-Azhar university (20)
Muktapishti is a traditional Ayurvedic preparation made from Shoditha Mukta (Purified Pearl), is believed to help regulate thyroid function and reduce symptoms of hyperthyroidism due to its cooling and balancing properties. Clinical evidence on its efficacy remains limited, necessitating further research to validate its therapeutic benefits.
Here is the updated list of Top Best Ayurvedic medicine for Gas and Indigestion and those are Gas-O-Go Syp for Dyspepsia | Lavizyme Syrup for Acidity | Yumzyme Hepatoprotective Capsules etc
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
share - Lions, tigers, AI and health misinformation, oh my!.pptxTina Purnat
• Pitfalls and pivots needed to use AI effectively in public health
• Evidence-based strategies to address health misinformation effectively
• Building trust with communities online and offline
• Equipping health professionals to address questions, concerns and health misinformation
• Assessing risk and mitigating harm from adverse health narratives in communities, health workforce and health system
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
TEST BANK For Community Health Nursing A Canadian Perspective, 5th Edition by...Donc Test
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NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
3. Oral squamous cell carcinoma (OSCC) is the most commonly
occurring oral malignancy and one of the most widely occurring
cancers throughout the world (9,25,33).
OSCC is a malignancy that arises in the squamous epithelium
lining the oral cavity and includes tumors found on the tongue, lip,
gingival, Palate, floor of mouth and buccal mucosa(13,25).
J Appl Oral Sci. 2017;25(6):708-15
4. The risk factors for development of OSCC include
tobacco exposure, alcohol consumption, and infection with
oncogenic viruses such as HPV (9,35).
The tumor can invade deeply into adjacent tissues of the
tongue and the floor of mouth , as well as, Intrabony of the
alveolar crest (41).
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5. Microscopically, OSCC usually shows variable degrees
of keratinization, cellular and nuclear pleomorphism, and
mitotic activity.
They are graded as well-, moderately- or poorly-differentiated
(grades 1 to 3) according to WHO criteria (23,43).
J Appl Oral Sci. 2017;25(6):708-15
6. The tumor's features, including size and site, histological
malignant grade, perineural spread at the invasive
front,lymphovascular invasion and tumor thickness, can Act as
major risk factors affecting prognosis for OSCC patients (32);
However, the main negative prognostic factor is the
presence of lymph node metastasis, which occurs in 25 to
65% of cases (15,29). J Appl Oral Sci. 2017;25(6):708-15
8. The general term “stem cells” includes several different
types of cells and the first distinction to be made is between (a)
normal stem cells (SC), which are responsible for the
development and maintenance of all of the tissues of the body,
and (b) their diseased counterpart, called cancer stem cells
(CSC), that have lost the close growth control that is a
property of normal stem cells. J Appl Oral Sci. 2017;25(6):708-15
9. The most primitive type of stem is fertilized egg and its first
few divisions early in development produce cells that retain the
ability to generate all the different cell types of the adult body.
They are therefore described as “totipotent” and, unusually for
stem cells, they are transient.
As the embryonic development proceeds, these totipotent
stem cells become directed towards differentiation into the
many distinct tissue types of the adult individual (e.g. stem cells for
blood, bones, mucosa, etc.). J Appl Oral Sci. 2017;25(6):708-15
10. As they do so they lose some of their developmental
potential and become either “pluripotent”, that is, restricted to
forming only a few types of tissues, or "unipotent", restricted to
generating only a single tissue.
Thus, several subtypes of stem cells exist in adult individuals,
each with different potentialities depending on their developmental
history.
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11. The epithelial stem cells of oral mucosal epithelia are
typically unipotent and form only the type of epithelium
typical of the region where they are found .
The general property that characterizes adult (somatic)
stem cells is that they can be divided indefinitely,
normally producing one cell that remains a stem cell
and one cell that differentiates itself into a functional tissue
cell.
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12.
13.
14. This normal “asymmetrical” division pattern is important
as it results in the maintenance of the same number of stem
cells while also providing another cell for tissue function.
However, when it is necessary to replace stem cells, such as
those lost after wounding, stem cells can be divided
“symmetrically” to form two stem cells and thus increase their
number.
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16. Although normal adult stem cells can divide themselves
to regenerate tissues throughout life, they can be difficult to
grow for along period in the laboratory.
However, totipotent cells taken early in embryonic
development have been shown to continue divide
themselves indefinitely in tissue culture without losing their
totipotent abilities.
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17. Further studies on the genes expressed by embryonic
stem cells have identified genes that are responsible for
maintaining “stemness” and this led to another major step.
It was found that when such genes are artificially
expressed in adult stem cells they regain the totipotent
properties of embryonic stem cells. J Appl Oral Sci. 2017;25(6):708-15
18. For his work with these “induced pluripotent stem cells (iPSCs),
Shinya Yamanaka was awarded the Nobel prize in 2012.These
findings are important mainly to the field of Regenerative
Medicine and Tissue Bioengineering.
However, this work also shows that although adult stem cells are
normally restricted permanently to a particular tissue type, they
can be manipulated experimentally to form different cell types .
Such cell plasticity is also of interest to cancer development,
progression and metastasis.
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19. Thus, stem cell research now has two different directions:
(a) how to encourage the growth and differentiation of stem cells
for tissue regeneration, and (b) how to prevent the growth of
cancer stem cells to prevent the expansion, metastasis and
recurrence of the tumors in which they are found.
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21. Normal oral mucosa is covered by stratified squamous
epithelium and although keratinocytes form the primary cell type of
the tissue, these epithelia also contain a minority of cells such as
melanocytes, Langerhans cells, Merkel cells, and transit
inflammatory cells.
Some regions of the mouth have a keratinized or cornified
surface layer that is able to resist the forces of mastication, but
other regions, where the epithelium acts as a lining that is
required to stretch, have a non-keratinized epithelium.
J Appl Oral Sci. 2017;25(6):708-15
22. Oral epithelia are formed of a number of cell strata known as the basal,
spinous, granular and corneal layers in keratinized regions, and as basal,
spinous, intermediate and superficial layers in non keratinized regions.
In all regions, cell proliferation occurs in the basal cell layer to
provide new cells that undergo differentiation as they move upwards
through the strata and the whole epithelial component of the mucosa is
renewed in 5-40 days depending on
the region. J Appl Oral Sci. 2017;25(6):708-15
23. The rapid tissue renewal that confers a remarkable regenerative
potential to the oral mucosa is ultimately related to the presence
and dynamics of the epithelial stem cells (eSC) present in the
basal cell layer.
The carefully ordered structure and balanced cell renewal found in
normal oral mucosa is progressively lost with the development of
cancer.
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24. It was originally thought that all epithelial basal cells are
similar and all divide themselves to produce cells that are
committed to differentiation as a result of being randomly
squeezed out of the basal layer by population pressure.
However, measurements of regional differences in
proliferation rates, and of the cell lineages produced by
labeled cells, indicate that only a small fraction of the
proliferating cells have the stem property of indefinite
division.
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25. The present concept is that such stem cells form only a
small fraction of the total dividing cells and that they divide
quite slowly to produce cells committed to differentiation.
These differentiating “transit-amplifying” (TA) cells have
a high proliferative rate but a low self-renewal capacity, so
they eventually differentiate into specialized cells that stop
dividing and fully differentiate themselves (11,12).
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26. Such cell proliferation is fundamental for epithelial renewal but it
requires tightly controlled mechanisms that balance epithelial cell
production and loss.
The loss of such balance can be resulted from the increased
or decreased expression of genes (proto-oncogenes and their
opposite, tumor suppressor genes) related to the control of the
cell cycle and death.
J Appl Oral Sci. 2017;25(6):708-15
27. Accumulation of somatic mutations may alter the expression
pattern of genes involved in the control of cell growth and
differentiation leading to the loss of proliferative control that
characterizes cancer.
Such mutations arise as a result of long-term exposure to
carcinogens such as tobacco and alcohol .
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28.
29.
30.
31. It might be thought that with the loss of proliferative
control and spatial organization, the normal stem cell
patterns would disappear.
From what has been described above, it can be seen that if
all dividing cells of a tumor have equal proliferative abilities
they can all be considered stem cells and a sub-population of
stem cells would not exist.
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32. The experimentally difficulty in testing this has been to find
good markers for stem cells and to test whether initiation and
maintenance of tumors is restricted to the sub-population of the cells
identified .
The existence of such tumor-initiating stem cells was provided
in 1997, when Bonnet & Dick found that only the small
subpopulation of leukemic cells, marked by staining, positively for
CD34 and negatively for CD38, was able to regenerate the original
leukemia when transplanted into immunodeficient mice (5).
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33. Subsequently, CSCs were identified in solid tumors by Al-Hajj and
co-workers who reported in 2003 that only a subpopulation of
breast cancer cells staining, positively for CD44 and negatively
for CD24, could reinitiate tumors with the cellular heterogeneity
typical of the original tumor (1).
Since then, increasing evidence for the presence of such cells has
been found for many tumors including those of the central nervous
system, breast, prostate and pancreas (22,31,39).
J Appl Oral Sci. 2017;25(6):708-15
34. Many evidences that CSCs also play a central role in the
pathogenesis and progression of carcinomas of the head and neck
(HNSCC), including OSCC,have been found.
Early tissue culture studies showed that only a
subpopulation of OSCC cells can form expanding tumor
colonies, suggesting that human OSCC may contain some form
of stem cells (24) and it was subsequently shown that only a small
subpopulation of the cells in OSCC corresponds to tumor-initiating
cells (26,46).
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35. These finding are in accordance with CSCs concept (17,34)
that the tumor mass is a mixture of (a) CSCs dividing
themselves to feed the tumor's growth, b) transient amplifying
cells that divide themselves a few times before maturing into (c)
differentiated tumor cells that do not contribute to tumor growth (4).
The isolation of CSCs from oral cancers has mainly been
performed with the CD44 marker that was initially used to isolate
breast cancer CSCs.
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36. CD44 is an adhesion molecule that binds itself to hyaluronan
and its expression is necessary for the maintenance of the
CSC’s properties.
CSCs lose their “stemness” when CD44 is experimentally reduced
(44).
However, a problem with CD44, and also with all other CSC
markers that have been identified so far, is that is that they are
not entirely specific. No single marker is capable of specific
recognizing CSCs and additional markers have therefore been
J Appl Oral Sci. 2017;25(6):708-15
37. ALDH1 is an intracellular enzyme involved in
detoxification and drug resistance via the oxidation of
aldehydes, and ALDH-positive cells in HNSCC are reported to
have typical CSC behavior and increased tumorigenic ability (21).
The combination of CD44 with other markers, such as
ALDH1, may improve the specificity of CSCs’ recognition and
isolation.
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41. As they are the cells stimulating tumor growth, elimination of
CSCs is necessary for the elimination of tumors.
However, many studies have now shown that CSCs are
more resistant than other tumor cells to chemotherapy and
radiotherapy(7).
In vitro assays show that when CD44-high CSCs are
irradiated or exposed to chemotherapy, they may be over 10
times more resistant to apoptosis than CD44-low cells(18).
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42. The sensitivity of surrounding normal tissues to high doses of
chemo- and radio-therapies restricts the dose levels that can be
administered and, despite the various methods of targeting, the
dose provided may be sufficient to kill many tumor cells but
not all of the CSCs.
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2017;25(6):708-15
43. Clinically, therefore, the tumor may appear to shrink, and even
perhaps disappear, only for a few remaining CSCs to begin to
divide and subsequently regenerate it.
Local tumor recurrence is a major problem for OSCC
therapy and elimination of CSCs is a target of therapy but
one that is made more complex by the heterogeneity of CSCs.
J Appl Oral Sci.
2017;25(6):708-15
45. The epithelial to mesenchymal transition (EMT) was
first recognized as feature of embryogenesis but it is also
activated during wound healing and organ fibrosis (40).
Recent evidence indicates that genetic programs
relevant for EMT are also activated in epithelial cancers
and that the changes induced in cancer cells by EMT appears
to play a central role in cancer progression and metastasis
(8,19).
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2017;25(6):708-15
46. Epithelial cells are normally attached firmly to basement
membrane and adjacent cells, but EMT allows them to acquire a
mesenchymal cell phenotype that is migratory and invasive,
and also has elevated resistance to apoptosis (19,20(.
These changes are characterized by the down-regulation of E-
cadherin, translocation of beta-catenin the from cell membrane
to the nucleus, and up-regulation of mesenchymal molecular
markers such as vimentin, fibronectin and N-cadherin (28,36,42).
J Appl Oral Sci.
2017;25(6):708-15
47. There is also up-regulation of transcription factors such as
SNAIL, TWIST, and LEF-1that promote EMT (14,45).
Metastasis is a major therapeutic problem for OSCC and the
presence of lymph node metastasis is a strong predictor of
therapeutic failure. J Appl Oral Sci.
2017;25(6):708-15
48. For metastasis of OSCC to occur, cells of the primary tumor
need to undergo EMT, invade the surrounding tissue, gain
access to lymphatic or blood vessels, and then survive transport
to exit from vessels and invade a new tissue site (38).
Through the reverse process of mesenchymalto- epithelial
transition (MET), the cells then transition back to the proliferative
epithelial phenotype to form secondary tumors (6).
J Appl Oral Sci.
2017;25(6):708-15
49. Applying this to the cancer stem cell concept suggests that
CSCs can exist as two interchangeable populations and Biddle,
et al.3 (2011) confirmed that CSCs from a dynamic cell
population that uses EMT and MET to switch backwards and
forwards between a proliferative epithelial phenotype (EPI-CSC;
CD44highESAlow/+ALDH+) and a migratory mesenchymal
phenotype (EMT-CSC; CD44 high ESAlow/-ALDH-).
50. Of particular interest, EMT not only enables cell
migration but also alters drug sensitivities so that EPI-
CSCs and EMT CSCs respond quite differently to chemo-
and radio-therapies (2,3,16).
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2017;25(6):708-15
52. Surgical resection is still a major therapy for OSCC and is
effective, especially in treating smaller lesions (30). Current
anti-cancer therapies for more advanced lesions are typically
based on radio- and chemo-therapeutic agents that target
proliferative cancer cells (27).
However, compared to the bulk of tumor cells, the
resistance of EPI-CSC populations to such therapies is greatly
enhanced due to their slow cell cycle and their mechanisms for
rapid DNA repair and drug exclusion (37).
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2017;25(6):708-15
53. Consequently, although most non-CSC tumor cells may be
eradicated with standard therapies, the therapy resistant CSCs
may selectively survive the doses of radio- and chemotherapies that
are achievable without major damages to the surrounding normal
structures.
With such partially effective therapies, CSCs can be expected to
survive through a process similar to natural selection, and their self-
renewal capacity can then enable them to regenerate themselves
and stimulate the growth of a new tumor.
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2017;25(6):708-15
54. To avoid such recurrence, therapy therefore needs to employ
agents, or combinations of agents, which provide widely
effective actions, along with better assays which may allow
the effective screening of new and existing drugs for their
differential effects on all sub-types of CSCs and non-CSCs.
J Appl Oral Sci.
2017;25(6):708-15
55. The molecular advances in tumor biology studies are guiding an
individualized treatment approach.
For example, a clinically validated chemo-predictive assay
(ChemoID®) is now being tested for HNSCC, in which both
CSCs and bulk tumor cells are challenged by various FDA-
approved drugs and their combinations to determine the most
effective chemotherapy scheme.
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2017;25(6):708-15
56. This assay, although still not FDA-approved,was recently
published as a new complementary procedure to HNSCC drug
treatment, aiming at both
the elimination of unnecessary toxicity in patients as well as
avoiding ineffective chemotherapy regimens(10).
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2017;25(6):708-15
57. A better understanding of CSC properties is crucial for the
development of effective alternative strategies, for example,
targeting stem cell maintenance, signaling pathways or
blocking EMT/MET to prevent the switching of CSCs between
drug resistant phenotypes.
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2017;25(6):708-15