RNF12 Activates PI3K-AKT Signaling To Promote The Progression Of Liver Cancer By Interacting With EGFR

Objective: RNF12,also known as RLIM,is an X chromosome-linked E3 ubiquitin ligase that targets LIM homeodomain.Meantime,RNF12 could also function as a co-transcription factor to bind to DNA to regulate the expression of downstream genes.However,the roles of RNF12 in Liver cancer have not been explored in detail.Methods: Western blot and immunohistochemical(IHC)staining was used for the detection of the expression of RNF12 in paired liver cancer and normal tissues.CCK-8,colony formation,xenograft and orthotopic implantation model were used to investigate the effects of RNF12 on the growth of liver cancer cells in vitro and vivo.Transwell migration and invasion,wound healing assays and mouse pulmonary metastasis model were used to investigate the effects of RNF12 on the invasion of liver cancer cells in vitro and vivo.Immunoprecipitation and mass spectrometry analyses were used to identify binding partners of RNF12.Immunofluorescence confocal microscopy and flow cytometry were used to detect the internalization of EGFR.Western blotting was used to detect the effect of RNF12 on the changes of the level of phosphorylated EGFR and downstream regulatory proteins of EGF/EGFR signaling.Results: High RNF12 expression was found in liver cancer,in correlation with more severe clinicopathological features and poorer prognosis.Meantime,RNF12 promoted the growth,invasion and migration of liver cancer in vitro and in vivo.Mechanistically,RNF12 was found to interact with EGFR and decrease its internalization to activate the EGF/EGFR signaling pathway.Meantime,the central region of RNF12(aa206-409)mediates its interaction with EGFR.And AKT inhibitor MK2206 could reverse RNF12 mediated cell proliferation and migration in liver cancer.Conclusions: RNF12 exerts a vital role in the progression of liver cancer.It was found to activate PI3K-AKT signaling to promote cancer progression in liver cancer by interacting with EGFR.