C1orf61 promotes hepatocellular carcinoma metastasis and increases the therapeutic response to sorafenib.

C1orf61 is a specific transcriptional activator that is highly up-regulated during weeks 4-9 of human embryogenesis, the period in which most organs develop. We have previously demonstrated that C1orf61 acts as a tumor activator in human hepatocellular carcinoma (HCC) tumorigenesis and metastasis. However, the underlying molecular mechanisms of tumor initiation and progression in HCC remain obscure. In this study, we demonstrated that the pattern of C1orf61 expression was closely correlated with metastasis in liver cancer cells. Gene expression profiling analysis indicated that C1orf61 regulated diverse genes related to cell growth, migration, invasion and epithelial-mesenchymal transition (EMT). Results showed that C1orf61 promotes hepatocellular carcinoma metastasis by inducing cellular EMT in vivo and in vitro. Moreover, C1orf61-induced cellular EMT and migration are involved in the activation of the STAT3 and Akt cascade pathways. In addition, C1orf61 expression improved the efficacy of the anticancer therapy sorafenib in HCC patients. For the first time, we report a regulatory pathway by which C1orf61 promoted cancer cell metastasis and regulated the therapeutic response to sorafenib. These findings increased our understanding of the molecular events that regulate metastasis and treatment in HCC.