2. overview
➔ Introduction on cancer
➔ Characteristics of cancer cells
➔ Important mechanisms in cancer.
➔ Reason for cancer
➔ Types of mutagens
➔ Importance to cancer
➔ Developmental process of cancer.
➔ Immune system function in cancer.
➔ Tumor suppressor and oncogenes
➔ Diagnosis and treatment methods for cancer
3. Introduction:Cancer
● Cancer is process of uncontrolled multiplication or proliferation of mutated
cells , in which the cell division is abnormal in case of cancer cells compared
to normal healthy cells, Also invades nearby tissue and metastasize to
distant sites.
● The process of formation of cancer where normal healthy cells are
converted into cancer cells is called carcinogenesis,tumorigenesis or
oncogenesis.the changes in the cellular levels and genetic level reprograms
the cells to become cancerous mass.
● All cancers are multifactorial in origin. They include genetic, hormonal, metabolic,
physical, chemical and environmental factors.
4. ● If we are going to study cancer the term tumor is unavoidable ,there are
2 types of tumor one is benign tumor and malignant tumor .
● Tumor is an abnormal growth of body tissue , for this tumor also
uncontrolled cell division is one of the reason .tumor is one of the
indication for cancer formation.
● Benign tumor: Abnormal lump formation These are not cancerous. They either
cannot spread or grow, if the lump is removed by surgical method ,then they do not
re occur.
● Malignant cancer : abnormal lump formation which are cancerous. The cells
can grow and spread to other parts of the body.
● benign tumor cells are not cancer cells ,but malignant tumor cells are
considered to be cancer cells.
5. Characteristics of cancer cells
● Cancer cell growth and cell division will be at rapid rate.
● Cancer restrict apoptosis(Apoptosis is a form of programmed cell death that
occurs in multicellular organisms) and cell signalling mainly insensitivity to
antigrowth signals.
● Cell division will be out of control .cell proliferation and cell death death will
not be equal.
● Cancer cells reprogram the energy metabolism . for example :cancer cells
consume more glucose than normal cell and convert end product pyruvate
into lactate.the rate of glycolysis(in presence of oxygen) will be faster
produce low atp at faster rate than normal cells .(Otto Warburg effect ).
● Cancer cells are immature and immortal.
● Absence of contact inhibition
6. Important mechanisms in cancer
Angiogenesis and metastasis are the important programs that helps the cancer
cells survive and invade other organs .
Angiogenesis : the process of forming new blood vessels from old vessels, but
in case of cancer Angiogenesis helps the cancer cells in supplying the nutrients
needed and it also helps in invasion of cancer to other parts .
Metastasis : The spread of cancer cells from the place where they first formed
to another part of the body. In metastasis, cancer cells break away from the
original (primary) tumor, travel through the blood or lymph system, and form a
new tumor in other organs or tissues of the body.
7. In this video clip, process of angiogenesis and metastasis is
explained
8. Why the cancer arises ?....
● The cause of cancer is mutation,The unwanted change in dna sequence is
called mutation.
● The substance causing mutations are called mutagens.
● The mutagens are different types such as (induced mutation ) physical
mutagens ,chemical mutagens and also biological mutagens, spontaneous
mutation .
● Site at which mutation occurs is also a reason for cancer formation, if
mutation occurs nucleotide sequence ( p53 or TP53) which is inside the
cells nucleus. affects the genes not to perform its function.
● Mutation may transfer through generations ,so it is heredity may be it not
may expressive in some generations.
9.
10. Types of mutagens
Physical mutagen mainly include ionizing radiation, such as X-rays, gamma rays
and alpha particles. Ultraviolet radiations can also behave as potential mutagens
because these have short wavelength and high energy so they have ability to cause
mutation .people working in uranium extraction mines.
.medical imaging sources play a role in source of physical mutagens.and moreover
sunlight is best source for these harmful physical mutagens .
Chemical mutagens :there are hundreds of mutagen ,the intake of chemicals which
make changes in the dna are known as chemical mutagens.
Biological mutagens: mutation caused by living microorganisms is known as biological
mutations. for example viruses and bacteria.
Mutation caused by virus:They can directly cause DNA damage (mutations) by
inserting their genomes into the DNA of the host cell.
11. ● Some viruses actually carry altered versions of genes that they have picked up
from previous host cells. These altered genes no longer function properly, and
when they are inserted into a new host cell, they cause dysregulation and can
lead to cancerous growth.
Chemical mutagens: In the day to day life chemicals comes to our contact ,
some harmful chemicals can mutate the dna which leads to cancer.
Methylcholanthrene : is a powerful carcinogen and a chemical mutagen only
nanograms are sufficient to produce a tumor in a mouse.
aflatoxins:They are a group of chemically related compounds synthesized by the fungi
are common carcinogens in our environment.
Smoking :Cigarette contains many carcinogens,the most important group being
benzo(a)pyrenees
12. ● Within a lung cell, benzo[a]pyrene is converted to an epoxide. The epoxide reacts
readily with guanine (G) positions of the DNA helix. If not corrected by the cell's
DNA repair mechanism, this guanine is misread as a thymine by the DNA
polymerase Ultimately, the original G-C base pair may be replaced by a T-A base
pair, a mutation called a transversion.
● Moreover, a non-smoking spouse of a heavy smoker will have 5 times more
probability to get lung cancer than a non-smoker.
● In the lifespan of smokers (GST) Glutathione-S-transferase plays a major role by
detoxification of various carcinogens, including cigarette smoke. About 5% of the
population are lacking in GST.
● Smokers who are devoid of GST are more prone to develop lung cancer.
● Oral cancer is strongly associated with chewing of tobacco.
14. Concern on cancer.
Cancer is known worldwide ,why this important is given to this
disease ,is cancer leads to dead?
Cancer kills by invading key organs like the intestines, lungs, brain, liver, and
kidneys and interfering with body functions that are necessary to live. Untreated
cancer commonly causes death.Cancer is the second leading cause of death globally.
Based on organs the names of cancer varies: Mouth Cancer,Thyroid
Cancer,Melanoma,Lung Cancer, Esophageal Cancer,Liver Cancer and
Retinoblastoma.
The WHO took cancer serious and initiated a new organisation under their control
called UICC ( UNION FOR INTERNATIONAL CANCER CONTROL), role of uicc is
create awareness and helps cancer affected people in many ways.
15. Developmental process of cancer
From starting developmental process of cancer is divided into three
stages
1. Initiation
2. Promotion
3. Progression
Initiation :mutagens and carcinogens are the initiators , the initiators
damage the nucleotide sequence ,and makes the nucleotide sequence
no to perform its function in body.Once a particular cell has been
affected by an initiator it is susceptible to promotion until its
death.and it is irreversible.initiation is the result of permanent genetic
change, any daughter cells produced from the division of the mutated
cell will also carry the mutation.
16. Promotion :Once a cell has been mutated by an initiator, it is susceptible to
the effects of promoters. Promoters initiates proliferation of the cell and
produces more daughter cells with mutation.promoting agent do not make
relationship within the dna ,they make relationship with the Cell receptors on
the surface affect the cell pathways and increase the rate of proliferation.
Example of promoter is benzopyrene.
progression: it is the last stage of cancer development.in this stage the
tumor cell or cancer cell due to activity of the progressive agent the cancer
cell gets increased speed of cancer cell division and invasion to other organs.in
this stage the mutated cell gets malignant potential .
17.
18. What happens to the immune system in case of cancer ?
Our immune system ready to fight with invading disease causing
microorganisms and protect us ,but in case of cancer our immune system
is weaken in many ways
In certain type of cancer such as lymphoma, leukaemia the bone marrow is
captivated by cancer cells and the immune system get weaker without
production of T cells and b cells .
In certain cases the treatment taken for cancer make the immune system
weak for certain period. For example : chemotherapy ,radiotherapy ,high
dose of steroids
Some cells of the immune system can recognise cancer cells as abnormal
and kill them .but this may not be enough to get rid of cancer altogether.
19. Tumor suppressor and oncogenes.
Other than immune system ,to control cancer our body regulatory mechanism
has tumor suppressor gene and proto oncogene.
Tumor suppressor gene :is a gene that regulates a cell during cell division and
replication.and it tries to repair dna in case of mutation, tumor suppressor gene code
for metastasis suppressor proteins. Prevent loss of contact inhibition .it this gene is
mutated cell proliferation takes place in cancer formation. In every case of cancer
short arm of chromosome 17 is mutated where the tumour suppressor gene is present.
Proto oncogenes: it is a normal gene w hich regulate cell division and cell apoptosis,but
when they get mutated,they get converted into oncogene which in turn promotes the
cancer.
Tumor suppressor and proto oncogene does not function properly in case of cancer.
20. Diagnosis methods for cancer.
Biopsy :A biopsy is a sample of tissue taken from the body in order to examine it
more closely. A doctor should recommend a biopsy when an initial test suggests an
area of tissue in the body isn't normal.
Endoscopy: is the insertion of a long, thin tube directly into the body to observe
an internal organ or tissue in detail.
Imaging studies: mammogram, MRI .
Treatment for cancer :
Chemotherapy : it involves intake of chemical drugs to kill the fast growing
cancer cells.it is one of the way to treat all types of cancer.it is also used after
surgical method kill remaining cancer cells after surgical removal.how ever
chemotherapy has short term and long term side effects.based on type and
stage of cancer ,overall health the type of drugs will be prefered.
21. The chemotherapy drugs will be given in different types.
They can be infused intravenously ,through pills,through injection
,chemotherapy creams .
Radiation therapy : it involves use of high energy x rays to kill cancer
cells. Radiation therapy has many types such as Three-dimensional
conformal radiation therapy (3D-CRT), .proton beam therapy. Doctors have
used it in a safer way ,but it has side effects one of it is it affects normal
healthy cells in nearby place damage the cell.
Iummnotheraphy : it involves activating or suppressing of our body’s immune
system to kill and stop growth of cancer cells.
Immune check inhibitors :drugs that block immune checkpoints. These
checkpoints are a normal part of the immune system and keep immune
responses from being too strong. By blocking them, these drugs allow immune
cells to respond more strongly to cancer.
22. T cell theraphy:it is a treatment that boosts the natural ability of your T cells
to fight against cancer. In this treatment, immune cells are taken from your
tumor. Those selected cells are changed in the lab to better attack your
cancer cells, grown in large batches, and put back into your body through a
needle in a vein.
Role of monoclonal antibody in cancer:monoclonal antibody acts as marker ,
it marks the cancer cell and helps the immune system to identify the cancer
cell precisely.
Monoclonal antibodies mainly blocks the signals from cancer.and limits the
growth and stops formation of blood vessels around cancer.
We all known that prevention is better than cure , so not only cancer from
other diseases also.
