Circulating MicroRNA-21 Expression as a Novel Serum Biomarker for Oral Sub-Mucous Fibrosis and Oral Squamous Cell Carcinoma

Background: Circulating miRNAs (miRs) in the biofluids such as serum and plasma act as potential biomarkers for early diagnosis, treatment and prognosis. In the present study, an attempt made to see the expression of miR-21 in serum of 20 cases of Oral sub-mucous fibrosis (OSMF), 20 cases of Oral squamous cell carcinoma and 40 healthy volunteers. The expression of miR-21 was evaluated in relation to different demographical and clinicopathological features such as sex, tobacco, pan-masala, alcohol, smoking and clinical staging respectively with an aim to identify correlation with oral pre-cancer and cancer stages. Materials and Methods: The relative expression level of miR-21 was determined by quantitative real-time RT-PCR (qRT-PCR) in the sera of 20 OSCC, 20 OSMF patients and 40 healthy subjects as a control. Association between expression of miR-21 and OSCC clinical stages and demographical parameters such as sex, pan-masala, tobacco, smoking, alcohol have also been analyzed in detail. Results: The results obtained by t-test revealed significant increase in the expression level of miR-21 in OSCC as compared to OSMF. The study also revealed the positive correlation between higher miR-21 expression and pan-masala chewers as shown by t-test. The statistical test, ANOVA has also indicated a positive correlation between up-regulation of miR-21 in the clinical stages of the OSCC. Conclusion: The results of present study indicated up-regulation of circulating miR-21 in serum of OSCC as compared to OSMF (p=0.001), this study also elucidated the positive correlation between miR-21 expression in OSCC/OSMF patients, only one demographical parameter (Pan-masala) and negative correlation for other parameters such as sex, tobacco, smoking, alcohol etc. Other findings suggested a significant increase (p=0.000) in the expression of miR-21 in clinical staging (I-IV) of oral cancer. More studies are needed to validate it as potential diagnostic and prognostic biomarker for OSMF and OSCC for better management.