Knockdown of ubiquitin-specific peptidase 13 inhibits cell growth of hepatocellular carcinoma by reducing c-Myc expression.

Ubiquitin-specific peptidase 13 (USP13) has been reported to be involved in the tumorigenesis of several tumors, but its function in tumors is still controversial. In this study, the function of USP13 in hepatocellular carcinoma (HCC) was investigated, and we found that USP13 was significantly upregulated in both of primary HCC tumor tissues and cell lines. And HCC patients with high USP13 expression had a shorter overall survival or relapse-free survival than patients with low USP13 expression. In HCC cell lines, knockdown of USP13 by shRNAs markedly decreased HCC cell growth, and mechanistic investigations revealed that USP13 knockdown could markedly downregulate the expression levels of c-Myc. Moreover, overexpression of c-Myc could significantly attenuate the effects of shUSP13 on HCC cell growth inhibition. In addition, in vivo experiments showed that knockdown of USP13 could significantly inhibit xenograft tumor growth of HCC. Taken together, our present study provided the first evidence that USP13 acted as a novel driver in HCC tumorigenesis by regulating c-Myc expression, and targeting USP13 could be a promising strategy for HCC therapy.