NEWER TUMOR MARKERS

DR. BINA M. GADHIYA

ASSISTANT PROFESSOR

DEPT OF BIOCHEMISTRY

GMC AURANGABAD

TUMOR MARKER is a substance produced by a tumor or by the host in response to a tumor which is used to differentiate a tumor from normal tissue or to detect the presence of a tumor based on measurements in blood or secretions.

They are found in cells, tissues or body fluids.

Measured qualitatively or quantitatively by chemical immunological or molecular biological methods.

They are biochemical or immunologic counterparts of differentiation states of tumor.

Cancer a multigene disease (cluster of diseases)which arises as a result of mutational & epigenetic changes coupled with activation of complex signaling networks.

It involves alteration of three main classes of genes – 1)ProtoOncogenes 2)Tumor suppressor genes 3) DNA repair genes.

This contribute to development of cancer genotype & phenotype.

This alterations resist the natural & inherent death mechanisms embedded in cells(apoptosis) coupled with dysregulation of cell proliferation events.

Cancer

These genetic alterations include gene rearrangements, point mutations & gene amplifications leading to disturbances in molecular pathways regulating cell growth, survival & metastasis.

When these changes manifest in mazority of patients with specific type of tumour this can be used as tumour markers ( Biomarkers ) .

Can also be used for detection & developing targeted therapies besides predicting responses to treatment.

This new tumor markers include a broad range of biochemical entities such as:

1. nucleic acids

2. proteins

3. sugars

4. lipids

5. small metabolites

6. cytogenetic & cytokinetic parameters

7. whole tumor cells

8. cancer stem cells

Historical Background

1846 Bence-Jones protein

1940 Acid phosphatase

1960 Immunoassay

1963 Alpha-fetoprotein

1965 Carcinoembryonic antigen

1975 Monoclonal antibodies

1980 CA 125, PSA, Carbohydrate antigens

1970 Oncogenes

1980 Tumor Suppressor Genes

2001Microarrays, Mass Spectrometry, Neural Networks, Multiparametric Analysis

Highly specific i.e. detectable in only one tumor, not detectable in benign disease and healthy subjects

Highly sensitive i.e. detectable when only a few cancer cells are present

specific to a particular organ

Correlate with the tumour stage or tumour mass

correlate with the prognosis

have a reliable prediction value

But ideal tumour marker doesn’t exists

Ideal Tumour Marker should be….

CLINICAL APPLICATIONS OF TUMOUR MARKERS

Diagnosis

Prognosis

Monitor treatmen

t

Detection of

recurrence

Screening

In practice ,current tumour markers are useful for- evaluating progression of disease status after initial therapy & for monitoring subsequent treatment modalities.

CLASSIFICATION OF TUMOUR MARKERS

Hormones

Oncofetal Antigens Enzymes

Tumor-Associate

d Proteins

Receptors Genetic

ENZYMES AS TUMOR MARKERS

ALCOHOL DEHYRDROGENESE & ALDOLASE : LIVER CANCER

ALKALINE PHOSPHATASE :BONE, LIVER LEUKEMIA PROSTATIC ACID PHOSOHATASE :PROSTATE NEURON SPECIFIC ENOLASE : SMALL CELL LUNG

CANCER, NEUROBLASTOMA,MELANOMA

LACTATE DEHYDROGENES : LYMPHOMA , LEUKEMIA

PROSTATE SPECIFIC ANTIGEN :

Only marker used to screen for a common type of cancer –prostate cancer.

PSA is a single chain glycoprotein specific for prostatic tissue.

Gene encoding PSA has been sequenced & located on chromosome 19.

PSA is a serine protease of the kallikrein family.(KLK3).

Sandwich immunoassays are used to measure PSA.

UROKINASE PLASMINOGEN ACTIVATOR SYSTEM

Contains 1) UROKINASE PLASMINOGEN ACTIVATOR (uPA) A serine protease

2) uPA membrane bound receptor (uPAR)

3) uPA inhibitors ,PAI-1 & PAI-2

Cathepsins B & L activates uPA ,which interacts with its receptor ,uPAR & converts plasminogen to plasmin .

Plasmin degrades extracellular matrix (ECM) components & activates MMPs which further degrade the ECM & activate & release growth factors FGF & transforming growth factor –beta.

uPA IS the prognostic marker in breast cancer. ALSO in ovarian ,renal cervical & other cancers.

It is measured by ELISA & commercially available kits for detection of uPA & & PAI in tumor tissue.

CATHEPSINS Are lysosomal proteases.

Cathepsin B , D & L have role in tumor development & progression.

Expression & localization of CB & CD is altered in tumor tissue.

Increased expression is seen in –breast,gastric ,lung, prostate cancer & melanomas.

Altered localization is seen in –colon ,thyroid cancers ,-gliomas ,breast epithelial tumors .

They are involved in tissue invasion through ECM degradation & growth promotion by various growth factors –fibroblast growth factor ,Insulin like growth factor-1,Epidermal growth factor .

Increased expression ECM proteases is seen in stromal cells at the border between tumor cells & normal tissue .

Detection of CB & other growth factors in stromal cells & tumor tissue may have prognostic value.CB is detected by ELISA.

RIA is used to detect cytoplasmic CD in tumor tissue. It can be measured by western blot , immunohistochemistry & by activity.

MATRIX METALLO PROTEINASES

Zinc dependent endopeptidases capable of degrading components of ECM.

Involved in tissue remodeling & wound repair

Also associated with tumor growth ,invasion & metastasis.

Increased expression of MMP-2 & MMP-9 is associated with accelerated tumor progression in oral carcinoma ,lung adenocarcinoma ,papillary thyroid carcinoma .

MMP-7 correlates with tumor aggressiveness in esophageal carcinoma.

Expression of MMP-1 is associated with lymph node metastasis in cervical cancer & peritoneal metastasis in gastric cancer.

MMP inhibition may be therapeutic strategy for cancer.

MMPs are detected in tissue sections by immunohistochemistry using specific antibodies & in tissue extracts & serum by immunoassay.

ISOCITRATE DEHYDROGENASE 1

IDH1 can be used as a plasma biomarker for the diagnosis of NSCLCs, particularly lung adenocarcinoma, with relatively high sensitivity and specificity.

( Clin Cancer Res; 19(18); 5136–45. ©2013 AACR.)

HORMONES AS TUMOR MARKERS

ACTH :CUSHING’S SYNDROME,LUNG CANCER

ADH :LUNG , ADRENAL CORTEX,PANCREATIC

BOMBESIN :LUNG CALCITONIN :MEDULLARY CA THYROID VASOACTIVE INTESTINAL

PEPTIDE :PHEOCHROMOCYTOMA, NEUROBLASTOMA

HUMAN CHOROINIC GONADOTROPIN :CHORIOCARCINOMA, EMBRYONAL

ONCOFETAL ANTIGENS AFP : HEPATOCELLULAR ,GERM CELL

TUMOR, CARCINOFETAl FERRITIN : LIVER CEA : COLORECTAL, GASTROINTESTINAL,

LUNG, BREAST ,PANCREATIC SQUAMOUS CELL ANTIGEN : CERVICAL, LUNG,

SKIN, HEAD & NECK TENNESSEE ANTIGEN : COLON,

GASTROINTESTINAL, BLADDER CYTOKERATINS : 1)TISSUE POLYPEPTIDE

ANTIGEN : BREAST, COLORECTAL, OVARIAN, BLADDER 2)TISSUE POLYPEPTIDE SPECIFIC ANTIGEN 3) CYTOKERATIN 19 FRAGMENTS (CYFRA-21-1) -a prognostic marker for non small cell lung cancer.

Proteins as tumor markers BETA 2 MACROGLOBULIN : MULTIPLE MYELOMA,

CML, WALDENSTROM’S MACROGLOBULINEMIA C-PEPTIDE : INSULINOMA FERRITIN : LIVER, LUNG, BREAST, LEUKEMIA IMMUNOGLOBULINS : MULTIPLE MYELOMA,

LYMPHOMAS MELANOMA ASSOCIATED ANTIGEN : MELANOMA DES-GAMMA-CARBOXY PROTHROMBIN :

HEPATOCELLULAR SOLUBLE MESOTHELIN RELATED PEPTIDES :

MESOTHELIOMA, OVARIAN

TUMOR ASSOCIATED TRYPSIN INHIBITOR(TATI)

Acute phase reactant & induced under strong inflammatory conditions

Increased in gastrointestinal & urologic cancers .

Useful marker for pancreatic cancer . TATI in serum or urine is measured by

radioimmunoassay.

NUCLEAR MATRIX PROTEIN -22 : BLADDER CANCER

S-100 PROTEINS - MELANOMA AUTOANTIBODIES TO TUMOR ANTIGENS MARKERS OF ANGIOGENESIS : VASCULAR

ENDOTHELIAL GROWTH FACTOR (VEGF) , SOLUBLE Tie 2 RECEPTOR corelate with development of metastasis.

THYROGLOBULIN : THYROID CANCER CHROMOGRANINS : NEUROENDOCRINE

TUMORS

HEAT SHOCK PROTEINS

BREAST, ENDOMETRIAL CANCER, OSTEOSARCOMA

Physiopathological features of tumor micro environment (low glucose, oxygen) stimulate HSP induction.

HSP 27 EXPRESSION is associated with poor prognosis in gastric ,liver ,prostate carcinoma & osteosarcoma. Also associated with poor response to chemotherapy in leukemia patients.

HSP 70 is correlated with poor prognosis in breast, endometrial, uterine ,cervical & bladder carcinoma.

Implication of HSP in tumor progression & response to therapy has led to its successful targeting in therapy by use of HSP in anticancer vaccines exploiting their ability to act as immunological adjuvant.

MMP 13 –MATRIX METALLOPROTEIN 13 POTENTIALLY NEW TUMOR MARKER FOR

BREAST DIAGNOSIS. Gene expression using microarray technology

was studied in breast cancer patients .MMP 13 WAS 100% over expressed confirmed to be a secreted protein by western blot analysis of the culture medium .

(HE4) HUMAN EPIDIDYMIS PROTEIN 4

Marker for ovarian cancer . Gene for HE4 has been discovered using

microarrays to be overexpressed in epididymal tissue & later in ovarian cancer tissue.

The algorithm termed RISK OF MALIGNANCY INDEX (ROMI) incorporating HE4 & CA 125 was accurate in classifying a high percentage of women with epithelial ovarian cancer.

It is measured by enzyme immunoassay .

Ova1 1ST IVDMIA PROTEOMIC DIAGNOSTIC FOR OVARIAN CANCER. Qualitative serum test that conbines results of 5

immunoassays into a single numeric score.

5 markers are –CA 125, PREALBUMIN , Apo A1 , Transferrin & Beta 2 macroglobulin

Indicated in women who over age 18 & present with adnexal mass for which surgery is planned & yet not referred to oncologist .

OVA1 score is calculated using OvaCalc software.

Expected value for probability of malignancy -

in premenopausal women-1)HIGH –OVA 1≥ 5.0 2) LOW OVA1 < 5.0

In postmenopausal women -1)HIGH –OVA 1≥ 4.4 2) LOW OVA1 < 4.4

CARBOHYDRATE MARKERS or MUCIN TUMOR MARKERS

CA-125 : OVARIAN, ENDOMETRIAL CA-15-3 : BREAST, OVARIAN CA-549 : BREAST, OVARIAN CA-27.29 : BREAST MUCIN-LIKE CARCINOMA ASSOCIATED

ANTIGEN (MCA) : BREAST , OVARIAN DU-PAN-2 : PANCREATIC

BLOOD GROUP ANTIGEN RELATED MARKERS

CA 72-4 : NEWER TEST FOR OVARIAN, PANCREATIC & STOMACH CANCER . Studies of this marker are still in progress.

CA 19-9 : PANCREATIC, GASTROINTESTINAL, HEPATIC .best for pancreatic cancer.

CA 19-5 : PANCREATIC, GASTROINTESTINAL , OVARIAN

CA 50 : PANCREATIC, GASTROINTESTINAL, COLON CA 242 : PANCREATIC, GASTROINTESTINAL

RECEPTORS & OTHER TUMOR MARKERS

ESTROGEN & PROGESTERONE RECEPTORS : INDICATORS OF HORMONAL THERAPY IN BREAST CANCER.

ANDROGEN RECEPTORS : PROSTATE CANCER. HEPATOCYTE GROWTH FACTOR RECEPTOR (c-

MET) : COLORECTAL , HEPATOCELLULAR, BREAST, PROSTATE, CERVICAL CANCER.

EPIDERMAL GROWTH FACTOR RECEPTORS : OVER EXPRESSION HAS STRONG PROGNOSTIC VALUE.

CATECHOLAMINE METABOLITES - VMA, HVA ,METANEPHRINES :NEUROBLASTOMA , PHEOCHROMOCYTOMA

HYDROXYPROLINE : BONE METASTASIS ( BREAST ), MULTIPLE MYELOMA

LIPID ASSOCIATED SAILIC ACID : GASTROINTESTINAL ,LUNG ,RHEUMATOID

POLYAMINES LYSOPHOSPHATIDIC ACID : A POTENTIAL

BIOMARKER FOR OVARIAN & OTHER GYNEACOLOGICAL CANCERS.

Genetic markers Deviations from diploid chromosome to hypo

& hyper-diploidy as well as aneuploidy are noted in malignant tumors.

Sister chromatid exchanges & translocations give rise to structural aberrations are scored using various banding techniques. Philadelphia chromosome is associated with CML due to translocation between chromosomes 9 & 22.

Double minutes & homogenously stained regions indicative of gene amplifications are often observed in malignant cells that can serve as markers.

Somatic mutations are promising biomarkers for cancer risk as they can capture genetic events associated with malignant transformations.

Enhanced cell proliferation ,most important hallmark of cancer can be assessed by flow cytometric analysis of DNA Content ,which is automated, objective & rapid allowing large number of cells to be measured.

Identification of S phase cells & analysis of number of antigenic determinants of proliferation (PCNA, Ki67, NOR, etc ) are studied by molecular cell biology techniques which can be used as complementary markers.

Proteins encoded by mini chromosome maintenance genes (MCM) are also proposed as useful markers of proliferation ; with high levels of gene expression indicating poor prognosis.

Gene deletions can be discovered by PCR using microsatellite probes to various chromosomes & sites .

Random chromosomal abnormalities are associated with clinical cancer.

Mutations & loss of heterozygosity within several proto-oncogenes can lead to microsatellite instability . Detection of this MSI in pathological tissue samples & comparison with normal tissue represents a valuable tool for early detection , at pre neoplastic stage.

Establishment of biomarkers require a comprehensive understanding of molecular mechanisms & cellular processes underlying the initiation of cancer, especially focusing on how small changes in only a few regulatory genes or proteins can disrupt a variety of cellular functions.

In the post genomic era , with the availability of complete human genome sequence & recent technological advancement such as high throughput DNA sequencing , microarrays & mass spectrometry, the plethora of potentially informative cancer biomarkers has expanded dramatically.

Oncogenes

Oncogenes are derived from proto-oncogenes that may be activated by dominant mutations ,insertions , deletions, translocations , or inversions.

Most oncogenes code for proteins needed for proliferation , & their activation leads to cell division.

Most oncogenes are associated with hematologic malignancies ,such as leukemia & to a lesser extent solid tumors .

More than 40 proto oncogenes are recognized but only few are useful as tumor markers.

RAS GENES PROTEINS Coded by ras genes are located in inner face of

cellular membranes.

They bind to GDP/GTP & function as molecular switches that regulate mitogenic signals from growth factor to nucleus by signal transduction pathways .

This are activated in association with protein tyrosine kinase receptors

Mutated N RAS is critical step in carcinogenesis & is found in Neuroblastoma & Acute myeloid leukemia

Single point mutation in K RAS AT 12th position leads to change of amino acid from glycine to valine in p21 protein & is most frequently found in cancer & correlates with poor prognosis .

Mutations of ras oncogenes have been detected in DNA in stool of symptomatic & asymptomatic patients of colorectal cancer, suggesting a novel ,noninvasive paradigm for population screening.

ASCO in 2009 has formalized that diagnosis of metastatic colorectal cancer with wild type KRAS tumors are likely to benefit from monoclonal antibody treatments targeting the EGFR pathways such as CETUXIMAB & PANITUMUMAB.

C- myc gene

Binds to DNA & is involved in transcription regulation.

Gene product p62 is located in nucleus of transformed cells.

Translocation results in activation of this gene & is associated with poor prognosis. Increased expression is seen in T & B cell lymphoma ,sarcoma .

Over expression of p62 is also seen in70 to 100% of primary breast cancers & can be detected with immunohistochemistry.

Her-2/neu (ERBB2)-

This gene codes for EGF family of tyrosine kinase receptors which are involved in cell proliferation , differentiation & survival.

Amplification of this gene is found in Breast, Ovarian & gastrointestinal tumors.

HERCEPTIN treatment is administered only to those breast cancer patients who have Her-2/neu amplification.

Immunohistochemistry is used to detect increased expression of this protein.

FISH is used for detection of HER-2/neu gene amplification.

BCL-2 GENE

BCL-2 oncogene codes for a protein which inhibits apoptosis, especially lymphoma & leukemia cells.

Activation of this BCL-2 gene is due to 14:18 translocation resulting in formation of BCL-2 protein.

Overexpression of BCL-2 gene is associated with development of resistance to cytotoxic cancer chemotherapy .

BCR-ABL FUSION GENE A balanced translocation between

chromosomes 9 & 22 creating BCR- ABL fusion gene ( Philadelphia chromosome )seen in 90% of CML patients.

Protein derived from this fusion is active tyrosine kinase that activates several signaling pathways, leading to uncontrolled growth , inhibition of apoptosis & neoplastic transformation.

Detection of BCR-ABL gene by RT-PCR is useful in diagnosing CML & monitoring residual disease in patients who have undergone bone marrow transplantation.

Several strategies target the BCR-ABL gene by oligonucleotides or the BCR-ABL kinase domain by tyrosine kinase inhibitor ST1571 (GLEEVEC OR IMATINIB MESYLATE )

Tumor suppressor genes This genes are isolated from many solid tumors . The oncogenicity of tumor suppressor genes is

derived from loss of genes . Deletion or monosomy leads to loss of tumor suppressor genes

P53 Gene activates molecular processes that delay the cell cycle progression of proliferating cells & stimulate DNA repair process.

Mutant p53 gene is useful biomarker for predicting prognosis & patients response to therapy.

Gene replacement therapies targeting p53 aims at restoration of p53 function in cancer cells by introduction of exogenous p53.

APC gene is deactivated in many tumors (oesaphageal adenocarcinoma & squamous cell carcinoma.) hypermethylated APC gene in the blood is associated with poor survival.

Mutations in BRCA 1 & BRCA 2 gene have an inherited predisposition to develop breast & ovarian cancer.

In colon cancer ,deletion or reduced expression of DCC gene correlates with increasing stage & poor prognosis.

PTEN mutation or loss of expression is associated with more advanced stage & is a poor prognostic indicator in various cancers, including breast, cervical, hepatocellular & endometrial.

Epigenetic markers

Epigenetic modifications occur directly through DNA methylation of genes or indirectly by methylation ,acetylation or phosphorylation of histones & other proteins around which DNA is wound to form chromatin.

Activity of DNA methyl transferases are altered in tumor cells & are associated with developmental abnormalities.

Genomic hypo methylation leads to genomic instability & stronger gene expression .

Local promoter CpG island hypermethylation induces functional silencing of tumor suppressor genes.

Hypermethylation of p16 promoter in the circulating serum DNA correlate well with recurrent colorectal cancer.

Aberrant methylation of p16Ink4 & MGMT promoters can be detected in DNA from the sputum of patients with squamous cell carcinoma nearly 3 years before clinical diagnosis.

Alterations in methylation patterns of group of genes in sputum samples may be an effective & non invasive approach for identifying smokers at risk of developing lung cancer.

The development of therapeutics that reverse epigenetic alterations in cancer cells along with prognostic & diagnostic assays on gene methylation patterns are promising new avenues for future improvements in patient care.

Cells as BiomarkersCirculating Tumor Cells [CTCs] : They provide early and reliable indication of

disease progression and survival of patients on systemic therapy for metastatic breast cancer as early as 3-4 weeks after initiation of therapy.

Superior to standard tumor markers in predicting prognosis.

Can be used as an early predictor of treatment efficacy and extremely in sparing patients from futile therapy.

Can be detected by immunocytometry.

T-regulatory cells [CD4+,CD25+,Foxp3] : These are important in inducing and

maintaining peripheral self-tolerance and thus preventing immune pathologies.

Increased T regulatory activity is associated with poor response to tumor antigens and contribute to immune dysfunction resulting in tumor growth.

T-regulatory cells may serve as surrogate immune marker of cancer progression and perhaps prognosis.

It is also useful as a predictor of response to therapies.

CD 90 IS A DIAGNOSTIC MARKER TO DIFFERENTIATE BETWEEN MALIGNANT PLEURAL MESOTHELIOMA & LUNG CARCINOMA WITH IMMUNO HISTOCHEMISTRY .

Cancer Stem Cells [CSC] : Subpopulation of cancer cells which resemble the

developmental hierarchy of the normal tissue from which the tumor arose.

Evidence for existence of CSC initially came from studies of AML.

CSC are now demonstrated in many solid tumors including glioblastoma, medulloblastoma, breast cancer, melanoma and prostate cancer.

CSC are resistant to chemotherapy and radiation therapy. Eradication is the critical determinant in achieving cure.

Identifying and characterizing CSC for every possible tumor is of paramount importance and will likely lead to new therapeutic avenues.

Viral Biomarkers

Hepatocellular cancer – HBV promotes carcinogenesis through genetic

instability generated by its common integration in host DNA .

These markers include :

1. Analysis of viral DNA or proteins or antibodies produced against the viral proteins.

2.HBsAG

3.HBeSG

4.anti-HBV core-antigen.

5.anti-HBeAG, anti-HbsAG.

Cervical Cancer : Persistent infection of high-risk type of human

papilloma virus. HPV-viral load in biopsy specimen. Antibodies against HPV-E6 and E7 serves as

markers of an invasive HPV associated malignancy. 2 new HPV Vaccines “Gardasil” and “Cervarix” are

highly immunogenic and effective in preventing infections with high risk-HPV types 16 & 18.

EBV has been directly implicated in pathogenesis of Burkitt’s lymphoma, NHL, nasopharyngeal carcinoma.

Detection of quantification of plasma EBV-DNA serves as a useful molecular marker for diagnosis monitoring and prediction of relapse in patients with nasopharyngeal carcinoma and Hodgkin’s lymphoma.

(PCA 3) PROSTATE CANCER ANTIGEN 3 GENE

It is a new gene based test carried out on urine sample .

PCA 3 is highly specific to prostate cancer & not increased in benign enlargement or inflammation of prostate.

This testing holds potential in men with elevated PSA levels but no cancer on initial biopsy.

PCA 3 urine test will decide whether a new biopsy is needed.

Mitochondrial Markers

Mutations in mitochondrial DNA particularly in D-loop region have found in many cancers .

Mutated mt DNA has been detected in body fluids of cancer patients & is much more abundant than mutated nuclear p53 DNA.

Metabolic Biomarkers

Bio-energetic index of cell has been suggested for classification and prognosis of cancer, besides predicting the response to therapy.

Positron emission tomography allows non invasive and quantitative analysis of various biologic process.

It uses a glucose analogue [2-deoxy-D-glucose] labelled with positron emitter Fluorine 18.

FDG that is partially metabolized and trapped as its phosphate [2-DG-6-P] in the tumor tissue, thus, localizing the tumor

Extent of increase in glucose utilization measured by FDG-PET has been co-related with degree of malignancy in some tumors.

Glycolytic inhibitors like 2-deoxy-D-glucose are selectively cytotoxic to tumor cells sensitizing it to ionizing radiations. 2-DG has the potential to enhance the efficacy of chemotherapy.

Clinical trials in patients with malignant brain tumors using a hypo fraction radio-therapy protocol combined with 2DG have been very encouraging.

Studying cancer through metabolomics could reveal new biomarkers for cancer that could be useful for its future prognosis ,diagnosis & therapy.

Therapeutic Biomarkers

Targeted therapies display greater selectivity for tumor cells. Eg : Small molecule drugs that inhibit the activity of tyrosine kinases [ Eg : Imatinib and Erlotinib targeting ABL & EGFR].

Antibody bevacizumab targets a growth factor that stimulates tumor blood vessel growth.

Telomerase

One of the best markers for human cancer associated with only malignant tumors.

Telomerase enzyme ensures the maintenance of telomere and thereby protecting the cell from degradation and cell death.

In cancer cells telomerase shuttling system is impaired.

The TRAP (telomeric repeat amplification protocol) assay is used for detection of telomerase activity.

It has been a target for anti-cancer therapeutics that turn off telomerase and there by inhibit tumor growth.

Currently two clinical trials : one using a vaccine [GRNVAC1] and the other a lapidated drug [GRN163L] are under way to evaluate the efficacy of telomerase inhibitors.

Histone deacetylases [HDACs]

HDACs are associated with oncogenesis by regulating the expression of certain tumor suppressor genes leading to excessive proliferation and tumorogenesis.

They have recently been the attractive targets for cancer therapeutics.

HDAC inhibitors are currently under clinical investigation in a number of hematological malignancies and solid tumors.

Mammalian target of rapamycin Evolutionarily conserved serine threonine protein

kinase that belongs to PIKK (phosphoinositide 3 kinase (PI3K) –related kinase ) family .

Plays an important role regulating cell growth & proliferation .

Upon activation mTOR increases phosphorylation levels of its downstreams targets that include P70S6K & 4EBP1, which leads to increased levels of translation , ribosome biogenesis & reorganization of actin cytoskeleton & inhibition of autophagy .

A no. of m TOR inhibitors have potent anti-proliferative properties which make them useful for cancer chemotherapy particularly of advanced solid tumors showing higher levels of expressions of phosphorylated S6.

PIN1 Peptidyl-Prolyl-Isomerase [PPIase], PIN1 regulates

post phosphorylation event which is in the form Cis and Trans isomerization of phosphoserine/threonine – proline peptide bonds at selective sides.

Over expression of PIN1 has been reported in human breast cancer cell lines and tissues, and its expression closely correlates with the level of cyclin D1 in tumors.

PIN1 opens a new target for the development of specific therapeutics as phosphorylated p53 is known substrates of PIN1.

Inhibition of PIN1 induces mitotic arrest and apoptosis in tumor cell lines

Recent studies with PIN1 inhibitor Juglone delays the growth of various tumor cell lines.

Proteomics analysis of saliva Non invasive method for identifying biomarkers for

human cancers 4 proteins in saliva have been found to be useful

markers of oral cancers with 90% sensitivity & 83% specificity for oral squamous cell carcinoma .

Calcium binding protein MRP 14 CD 59 –overexpressed on tumor cells that enables

them to escape from complement dependent & antibody mediated immune responses.

Profilin 1 a protein involved in several signaling pathways ,secreted in tumor microenvironments during the early progressive stage of tumorogenesis.

Catalase, a member of antioxidative system is involved in carcinogenesis & tumor progression .

ADIPONECTIN & LEPTIN – IN BREAST CANCER

Adiponectin & leptin are involved. Studies show that leptin m RNA expression is higher

than adiponectin m RNA expression in cancer cells. Adiponectin inhibits proliferation of cancer cells.

Leptin stimulates growth of cancer cells. Adiponectin inhibits leptin induced cell proliferation.

ADHESION MOLECULES & METASTASIS Cell adhesion molecules, including Integrins,

Selectins & Cadherins regulate many steps of metastatic process.

Increased serum levels of E selectin, Inter cellular adhesion molecule (ICAM) & Vascular adhesion molecule (VCAM) indicate late stage of Breast cancer or the occurrence of metastasis & hence a poor prognosis.

Stress & cancer

Under normal circumstances trigerring ATF 3 gene in stressfull conditions protects the body from harm by causing normal cells to commit suicide .

Cancer cells are able to switch on ATF 3 GENE in immune cells & causes malfunction of immune cells & allows cancer cells to escape from the tumor & spread to other parts of the body.

MICROARRAY BASED MARKERS

Amplichip p450 – Roche diagnostics Oncotype Dx - Genomic health inc. Mammaprint - Agendia inc. Tissue of origin test – Pathwork diagnostics . Bioplat-a software for human cancer biomarker

discovery Micro array based analytes will revolutionize the

future of cancer therapy by providing biomarkers on their genetic makeup.

THE PRECLINICAL STRATEGY OF CANCER BIOMARKER DISCOVERY ARE SENSITIVE & SPECIFIC ENOUGH

-FOR EARLY CANCER DETECTION

-FOR MONITORING DISEASE PROGRESSION &

-FOR PROPER TREATMENT SELECTION,

PAVING THE WAY TO INDIVIDUALIZED CANCER TREATMENT.

NEW ERA IN CLINICAL ONCOLOGY WILL BE GUIDED BY MOLECULAR ATTRIBUTES OF INDIVIDUAL PATIENTS THAT WILL ALSO ANSWER ABOUT BIOLOGIC BEHAVIOR OF TUMORS .

Thank You

REFERENCES- Cancer Biomarkers – Current Perspectives. [Indian J Med Res

132, August 2010, pp 129-149.

Teitz Textbook of clinical chemistry and molecular diagnostics.

MMP13 is potentially a new tumor marker for breast cancer diagnostic. [PubMed – indexed for MEDLINE]

BioPlat- a software for human cancer biomarker discovery.[Bioinformatics. 02/2014]

Involvement of adiponectin and leptin in breast cancer: clinical and in vitro studies.[ENDOCR RELAT CANCER, 2009 December;16(4): 1197-210]

Detecting cancer through markers (Dr. Mohini Bhargava- Express Healthcare)

Cancer biomarker discovery : current status & future perspectives.

( International journal of Radiation Biology ).

Stress fuels cancer spread by triggering master gene :ATF 3.