Abstract

MICRORNAS AS PREDICTORS OF ORAL CANCER

Sushma P. S., Kaiser Jamil*, Uday Kumar P. and Ramakrishna M.

Abstract

Background: Oral cancer is defined as uncontrollable growth of cells seen in the oral cavity. It appears as a growth or sore in the mouth that does not cure. Oral cancer can affect the mouth, palate, sinuses, and pharynx. Squamous cell carcinoma is the most common type of oral cancer. MicroRNAs (miRNAs) have been shown to be involved in a wide range of biological processes. A significant role for miRNA in cancers is to target gene expression level through their respective signaling pathways. The current study analyzed gene expression profiles of a few microRNAs such as miR-21, miR-137, miR-200c and miR-205 in pathogenesis of oral squamous cell carcinoma(OSCC). Methods: Biopsy samples were collected from 50 patients recently diagnosed with oral cancer along with corresponding non malignant portions, with the approval of Institutional Ethics Committee. Quantitative real time PCR (qRT PCR) was used to quantify the levels of miRNAs expression. The association between miRNA expression levels and clinico-pathological parameters was analyzed using MedCalc software. Findings and interpretation: This study found miRNA-21 was up-regulated (in 54% cases) whereas miR-137 (48%), miR-200c (46%), miR-205 (42% of cases) was down-regulated in OSCC. Among these four microRNAs, only miR-137 was differently associated with the risk of OSCC, whereas all other microRNAs were found to be directly associated with OSCC. This study demonstrated an association of miR-21, miR-137, miR-200c and miR-205 in OSCC with altered gene expression, suggesting that in spite of varying expressions in miRNAs’ its role in the development of oral cancer was very much evident. It is suggested that these miRNAs could probably serve as biomarkers for oral cancer management.

Keywords: Oral cancer, microRNAs, Demographics, biomarkers, economic status, miR-21, miR-137, miR-200c, miR-205, Gene expression, qRTPCR, reverse transcription.