VOPP1 promotes hepatocellular carcinoma proliferation through MAPK14 and RPS6KB1

Background: The present study aimed to investigate the role of VOPP1 in hepatocellular carcinoma (HCC). Methods: Immunohistochemistry(IHC), Western blot and Reverse-transcription polymerase chain reaction (RT-PCR) were used to analyze the expression of VOPP1 protein, the expression of VOPP1, MAPK14, RPS6KB1, CYLD and TWIST1 and the mRNA expression of VOPP1, MAPK14, RPS6KB1, CYLD and TWIST1. The cell proliferation and apoptosis were tested using Celigo cell imaging analyzer and annexin V-APC apoptosis detection kit respectively. Colony formation and tumor xenograft assays was performed to understand their roles in tumorigenicity. Results: The expression of VOPP1 in HCC samples was higher than that in adjacent noncancerous tissues by immunohistochemistry. In addition, the deletion of VOPP1 using shRNA inhibited cell proliferation and tumour growth, and induced cell apoptosis in vitro and in vivo. Furthermore, VOPP1 silencing decreased the expression of MAPK14 and RPS6KB1, indicating that the MAPK and mTOR signalling pathways might be involved in VOPP1-mediated cancer cell proliferation. Conclusion: The present data indicates that VOPP1 may play an important role in the progression of HCC by targeting the MAPK and mTOR signalling pathways, and that VOPP1 may potentially be a candidate as a novel molecular target for HCC therapy.