mTOR up-regulation of SNRPA1 contributes to hepatocellular carcinoma development

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Recent studies showed that snRNPs were implicated in human cancer development. The role of SNRPA1, which is a member of U2 snRNPs, in HCC, remains undocumented. Here, we found that SNRPA1 was highly expressed in HCC tissue compared with normal adjacent liver tissues. Up-regulation of SNRPA1 was correlated with the clinical stage of HCC and the overall survival of HCC patients. In vitro and in vivo results showed that knockdown of SNPRA1 inhibited the cell proliferation, colony formation and xenografted tumorigenesis of HCC cells. Apoptosis was induced by SNPRA1 down-regulation. Mechanistically, SNPRA1 was stimulated by mTOR activation. In addition, whole-genome microarray analysis identified that 262 genes were up-regulated and 462 genes were down-regulated by SNPRA1 knockdown in HCC cells. qPCR analysis suggested that the fibroblast growth factor-2 (FGF2), Alpha-fetoprotein (AFP), β-catenin, Ki-67 and cyclin B1 were down-regulated and caspase 3, p53 as well as p21 were up-regulated after SNRPA1 knockdown. Taken together, our findings implicate that SNPRA1 functions as an oncogene in HCC.