Site specificity and expression profile of miR-21 in oral squamous cell carcinoma

BACKGROUND: Oral Squamous Cell Carcinoma (OSCC) is the most common epithelial malignancy of the oral cavity which has evolved globally as a grave and growing health problem. It shares a wide geographic variation with respect to the incidence rate and exhibits anatomic adaptation to oral environment with varied clinical presentation along with a spectrum of histological mélange. Besides, in recent cancer research, both genetics and epigenetics add on at the molecular level and accounts for this diversification and tumor heterogeneity of OSCC and thereby substantiates to the miRNA expression profiling in OSCC. AIMS AND OBJECTIVES: In the present study, subsite specificity of miR-21 expression in tissue specimens of OSCC of Tongue, Buccal mucosa, and Gingivo buccal (GB) sulcus were analyzed. MATERIALS AND METHODS: Quantification of miR-21 was done on 30 tissue samples of OSCC using real-time polymerase chain reaction (RT-PCR). RESULTS: Results indicated that miR-21 expression was significantly expressed at the subsites. Out of 30 samples, 22 showed upregulation, and 8 showed down-regulation with reference to endogenous control. The comparative Ct method was used to analyze the differences in subsite specific expression of miR-21 in OSCC cases. It was significantly upregulated in the buccal mucosa (p=0.002), followed by GB sulcus (p=0.01) and Tongue (p=0.25). CONCLUSION: In conclusion, the study could identify the differential miR-21 expression at sub-sites, indicating that it may serve as a diagnostic marker with further elaboration on a larger sample size..