CYP2J2 promotes the development of hepatocellular carcinoma by increasing the EETs production to improve HIF-1α stability.

OBJECTIVE:This study aimed to explore the function and mechanism of Cytochrome P450 2J2 (CYP2J2) epoxygenase and epoxyeicosatrienoic acids (EETs) in the malignant development of hepatocellular carcinoma (HCC). METHOD:The expressional levels of EETs and CYP2J2 in HCC tissues and cell lines were quantified by ELISA, western blot and RT-qPCR, respectively. The effects of EET and CYP2J2 on HCC development were analyzed by CCK-8 assays, flow cytometry analysis, colony formation and transwell assays. The effect of CYP2J2-EET metabolism on stability of HIF-1α was detected by western blot experiments. HIF-1α inhibitor, YC-1, was used to probe the relationship between HIF-1α and metastasis of HCC cells. Finally, xenograft experiments were established to investigate the function of CYP2J2-EETs metabolism in HCC tumorigenesis in vivo. RESULT:CYP2J2, 11, 12-EET and 14, 15-EET were up-regulated in HCC tissues and Huh-7, HepG2 cell lines. Addition of exogenous 14, 15-EET accelerated proliferation and metastasis of HCC cells. Knockdown of CYP2J2 inhibited growth and metastasis of HCC cells and malignant xenograft, which was obviously reversed by addition of 14, 15-EET. Moreover, in Huh-7 and HepG2 cells, CYP2J2-EET metabolism elevated the expression of HIF-1α and its downstream factors including VEGFA, PDK1, GLUT1 and DDIT4 through suppressing the expression of PHD. Treatment of YC-1 remarkably suppressed the HCC cells proliferation and restored the effect of 14, 15-EET on tumor size in vivo. CONCLUSION:The up-regulated levels of CYP2J2 and 14, 15-EET in HCC cells improved the stability of HIF-1α thourgh inhibiting PHD expression, which further promoted the malignant development of HCC.