A biomarker is an non-invasive fluid which acts as indicator in case of any biochemical, biological, changes ie it may increase or decrease or any response to a body .Mainly it indicates specific response in the body which might be a molecule or any type of secretion which is used for diagnosis .eg in cancer, biomarkers acts as a tool for cancer detection or preventive measures in patients1.this can be identified only by comparison studies of healthy indivual with disease patients which represents the absence of presence of markers2.oral cancer a type of cancer which occurs in mouth , tongue or nasal cavity .where any cancerous tissue or lesion develops. According to survey,90/ of them are considered as oral squamous cell carcinoma .when compared to all oral tumours3.in oral cancer ,biomarkers has the main advantage of easily identifying the primary( pre malignant) and secondary (malignant) lesions or cancerous agent and also determines the levels of all chemical or any DNA changes (structural functional and, chemical abbreation )etc which acts as a ready identification of oral cancer4
. Biomarkers are broadly classified into genomics, proteomics, metabolic s 5
.salivary biomarkers which is a invasive fluid acts as a primary detection since it has a direct contact with tissue or lesions present .where saliva contains protein such as m RNA DNA .so this becomes the potential biomarker6..
serum biomarkers in oral cancer act as a early prediction in some cases, this marker can be identified only when the tumor or lesion starts to develop .as the tumor grows ,serum changes it amount and molecules or proteins present becomes synthesized which gets released with components7.a study was to made to identify the serum immune levels in cancer patients. A comparative study was made on pre and post treatment with certain protein levels such as AGP and IGA .where these proteins elevated in cancer patients and did not change even after treatment8
.urinary biomarker another type of markers used for the screnning of oral cancer. where urine excreted product contains certain nicotine ,no2+no3 which are main chemicals present in tobacco products these are identified by methods such as hplc ,tlc .a study found these levels were significantly increased in oral cancer patients9
.proliferation markers such as ki -67 and p35 .considered as the evaluating agent for biological activities or changes take in oral cancer. This study was made by Histo pathological analysis( tumor size, metastasis, nodal size).where expression of markers were compared .so results concluded as useful marker 10.
So all Biomarkers in oral cancer is easily influenced by its risk factors ,sign and symptoms etc. this becomes another challenging opportunity for research in identifying specific , early marker and also detection of their stages(malignancy).so biomarkers acts as diagnosing agent11.
salivary biomarkers which is a invasive fluid acts as a primary detection since it has a direct contact with tissue or lesions present .where saliva contains protein and analytes such as m RNA, DNA so this becomes the potential biomarker6,12.saliva comprises 99 prcnt of the water ,inorganic and organic components. Inorganic species does not give much effect where organic species contain abnormal development take place with changes in chemical abbreations (DNA aneuploidy).this DNA changes directly links to stages of cancer and can be easily predicting its negative potency13.
There are 8 tumor markers present in saliva namely
These markers get abruptly decreased or increased and this is identified by salivary analysis methods. A study was made and compared among these marker to check their sensitivity and specificity . where five of the markers get increased and three becomes decreased . results concluded that sensitivity ranges from (58-100) and specificity ranges from (42-10.) which determines that. each markers have their own value14. A case study showed the comparison between salivary LDH and serum LDH in oral squamous cell carcinoma patients with control group. Results proved that only oral squamous cell carcinoma patients have a consistent increase in both serum and salivary LDH and their isoenzymes15. But however salivary Iso enzymes has been extensively used as their studies was done in oral lichens also. salivary Iso enzymes such as LDH4, LDH5.LDH3 .these Iso enzymes were found to be increases in oral lichen planus and the reason was LDH with its carcinogenic promoting activity in LDH16.
Two types of biomarkers are classified and divided in salivary markers
• Protein marker
• RNA based marker
Protein marker includes mainly three important markers
• Glutathione transferase
RNA roughly includes
• M RNA
• Micro RNA’S17.
SALIVARY RNA biomarker
Some Studies suggested that Human RNA is found in saliva. It is confirmed by two methods of microarray technique
• QPCR(Quantitative )
• High density nucleotide
This is done by collection of saliva sample which gets separated by centrifuge methods to get a supernant liquid .then the product is analysed by the above method . results proved that M RNA is present in saliva and becomes the detection / prevention in oral cancer18. Specificity and sensitivity of RNA was found to be 99 percentage for early prognosis19.
MIRNA found in saliva is determined by micro array technique. The MIRNA play a role as marker in saliva by abnormality changes or impairment with cancerous transformation. Apparently MIRNA consists of 23 components with different but particular gene between oral cancer and normal cells
Examination of cells expressed that eight molecules were increasing (
) and two molecules were decreasing the quality of cellular components which might be either RNA or proteins.
This specifically indicates a particular cell mir-10b which has the both activity of invading and migrating process. So this mir10-b actively participates in detection and early possibility of oral cancer20.