Myosin18B predicts favorable prognosis of cutaneous squamous-cell carcinoma.

Background Myosin18 family, including Myosin18A (MYO18A) and Myosin18B (MYO18B), are newly-identified Myosins in Myosin superfamily. The expression and function of Myosin18 family in cancer progression is still controversial, and in cutaneous squamous-cell carcinoma (cSCC) is totally unknown. Objective To investigate the expression and prognostic significance of Myosin18 family in cSCC. Methods In this study, the expressions of MYO18 family, including MYO18A and MYO18B were detected in six pairs of cSCCs and corresponding normal tissues with qRT-PCR. MYO18A and MYO18B expressions and intracellular locations in 80 cSCCs were detected with immunohistochemistry. The clinical significance was evaluated by analyzing the correlation between MYO18 family and clinicopathological factors. The prognostic significance of MYO18 family was estimated by univariate analysis with log-rank test, and by multivariate analysis by Cox-regression model. Results The percentages of high MYO18A and MYO18B in cSCC were 43.75% and 36.25%, respectively. High expression of MYO18A (P = 0.035) and MYO18B (P = 0.032) were both associated with less tumor size. MYO18A had no significant influence on sSCC prognosis (P = 0.686), but low expression of MYO18B was proved to be significantly associated with poor outcome of cSCC (P = 0.014). MYO18B was confirmed as an independent prognostic biomarker of cSCC (P = 0.002), indicating the favorable outcome. Conclusion The expression of MYO18B was an independent prognostic biomarker of cSCC, predicting the favorable prognosis independently. Investigating the expression of MYO18B can help stratify the subset of high-risk cSCC patients for more potent treatment and post-operational surveillance.