Abstract: Objective: To investigate the expression levels of miRNA-31 and STAT-3 in patients with tongue squamous cell carcinoma (TSCC) and their clinical significances. Methods: 137 tissue samples of TSCC were collected. The expression of miRNA-31 was detected by fluorescence in situ hybridization, and the expression of STAT-3 was detected by immunohistochemistry. Meanwhile, the expression levels of miRNA-31 and STAT-3 in TSCC patients at different differentiation were evaluated. Correlations between miRNA-31 and STAT-3 expressions with survival time were also analyzed. Results: The percentages of miRNA-31 positive cells in poorly differentiated, moderately differentiated and highly differentiated were 80.6±14.3, 58.5±15.7 and 23.7±9.4, respectively. For STAT-3, the percentages of positive cells were 85.9±12.7, 51.7±16.3 and 17.6±9.1, respectively. The expression levels of miRNA-31 and STAT-3 at various degrees of cell differentiation were significantly different (P<0.05). MiRNA-31 was positively correlated with the expression of STAT-3 in TSCC (r=0.614, P<0.05). The median survival periods were 37 and 38 months in TSCC patients with high expression levels of miRNA-31 and STAT-3, while 65 and 66 months in low expression group (P<0.001). Conclusion: In TSCC, the expression levels of miRNA-31 and STAT-3 were positively correlated, which were also correlated with the degree of cell differentiation and prognosis of patient.

Key words: Tongue squamous cell carcinoma, MiRNA-31, STAT-3, Expression, Correlation