This ppt will provide you a brief yet effective information about major types of biomarkers, their definitions, their significance in disease dignosis & treatment, how they are being & are developed to be used as an effective dignostic tool for Cancer & their other future implications in other fields of medicine.
B.Sc. (H) Medical
Types Of Biomarkers
There are mainly four types of molecular biomarkers :
Genomic biomarkers: based on the analysis of DNA
(deoxyribonucleic acid) profiles, especially the analysis of
SNPs (single nucleotide polymorphisms), i.e. identification
of punctual variations in genomic DNA.
Transcriptomic biomarkers: based on the analysis of RNA
Proteomic or Protein biomarkers: based on the analysis
of the protein profiles.
Metabolomic biomarkers: based on the analysis of
metabolites (metabolites are the inter-mediates and
products of metabolism).
Genomic Or DNA Biomarkers
A measurable DNA characteristic that is an indicator of
normal biologic processes, pathogenic processes, and/or
response to therapeutic or other interventions.
Scientists have discovered that virtually all cancers carry
somatic DNA mutations. Unlike hereditary mutations that
are passed from parent to child and are present in every cell
in the body, somatic mutations form in the DNA of
individual cells during a person's life. Because these
somatic mutations are only present in tumor cell DNA,
they provide an extremely specific biomarker that can be
detected and tracked.
Mutations in oncogenes, tumour-suppressor genes, and
mismatch-repair genes can serve as DNA biomarkers.
In a new study published in Science Translational Medicine
Journal scientists have discovered that dying tumor cells
release small pieces of their DNA into the bloodstream.
These pieces are called cell-free circulating tumor DNA
(ctDNA). This study examines the potential of screening
ctDNA for somatic mutations as a way to detect and follow
the progression of a patient's tumor.
Mutations in other cancer-related genes, such as the RAS
oncogene or the tumour-suppressor genes CDKN2A (cyclin
dependent kinase inhibitor A, which encodes p16INK4A),
APC (the adenomatous polyposis coli gene) and RB1 (the
retinoblastoma gene), also have the potential as markers
for prognosis or selection of therapy.
The transcriptome is the set of all RNA molecules,
including mRNA, rRNA, tRNA, and other non-coding
RNA produced in one or a population of cells. It differs
from the exome in that it includes only those RNA
molecules found in a specified cell population, and usually
includes the amount or concentration of each RNA
molecule in addition to the molecular identities.
RNA-based biomarkers undergoing clinical evaluation
consist of multi-gene molecular patterns or ‘fingerprints’.
For example, pattern-based RNA expression analysis of
clinical breast cancers has identified previously unknown
molecular subtypes that are associated with differences in
That analysis has also provided increased prognostic capability,
predicted response to neo-adjuvant therapy, predicted the likelihood of
metastasis in lymph-node negative patients and correctly predicted
tumour grade from laser-capture microdissected specimens.
Gene expression profiling offers an unparalleled opportunity to develop
biomarkers that are useful in diagnosis and prognosis and in helping to
achieve the goal of individualized cancer treatment.
Transcriptomic biomarkers use in
Cancer drug discovery
Proteomics is the large-scale study of proteins,
particularly their structures and functions.
Proteomics technologies are emerging as a useful tool
in the discovery of cancer biomarkers.
These advances overcome in part the complexity and
heterogeneity of the human proteome, permitting the
quantitative analysis and identification of protein
changes associated with tumor development. With the
advent of new and improved proteomic technologies,
it is possible to discover new biomarkers for the early
detection and treatment of cancer.
Ongoing & anticipated implications of
Proteomics biomarkers in medicine
Proteomic-based approaches for
biomarker investigation can be
employed in different aspects of
medicine, such as –
1. elucidation of pathways affected
2. identification of individuals who
are at a high risk of developing,
3. identification of individuals who
are most likely to respond to
interventions, and prediction of
which patients will develop
specific side effects
Proteomics biomarkers use an
effective Dignostic Biomarker
Metabolomics is the "systematic study of the unique chemical
fingerprints that specific cellular processes leave behind", the
study of their small-molecule metabolite profiles.
Metabonomics, was introduced to refer specifically to the
analysis of metabolic responses to drugs or diseases.
Metabonomics has become a major area of research; it is
the complex system biological study, used as a method to
identify the biomarker for various disease.
In general, in most disease cases, a metabolic pathway had or has
been either activated or deactivated - this parameter can thus be
used as a marker for some diseases.
For eg., Serotonin production pathways, activated in a person
who has recently consumed alcohol for instance, can be a
metabolic marker of recent alcohol consumption.
The feasibility of metabolomics for biomarker discovery is
supported by the assumption that metabolites are
important players in biological systems and that diseases
cause disruption of biochemical pathways. In fact,
metabolomics, has shown to have benefits in various
Compared to classical diagnostic approaches and
conventional clinical biomarkers, metabolomics offers
potential advantages in sensitivity and specificity.
Despite its potential, metabolomics still retains several
intrinsic limitations which have a great impact on its