The prognostic significance and biological effects of CYP27A1 in hepatocellular carcinoma
Objective To analyze the prognostic significance and biological effects of cytochrome P450 family 27 subfamily A member 1(CYP27A1)in hepatocellular carcinoma(HCC),and to preliminarily explore its molecular mechanism of regulating the malignant growth of HCC.Methods The Cance Genome Atlas(TCGA)database was used to analyze the expression level of CYP27A1 and its prognostic effect on HCC patients.The samples were divided into CYP27A1 high-expression group(n=170)and low-expression group(n=170)based on the median expression of CYP27A1 in HCC,gene set enrichment analysis(GSEA)was performed to investigate gene sets associated with CYP27A1 expression.The subcellular localization of CYP27A1 was detected by immunofluorescence staining and search database.The over-expression plasmid of CYP27A1 was constructed and then transfected into the HCC cells MHCC-97H and HCCLM3 cell lines,including two groups,namely control group(transfecting empty vector)and CYP27A1 over-expression group(transfecting CYP27A1 over-expressed vector).CCK-8,flow cytometer,and reactive oxygen species(ROS)fluorescence probe were applied to detect the effects of CYP27A1 over-expression on cell viability,apoptosis and ROS levels in HCC cells.Combining bioinformatics to analyze the correlation between CYP27A1 and the expression of ROS generation-related genes and HCC proliferation-related genes.Results Compared with the normal liver tissue,the expression level of CYP27A1 mRNA in HCC tissue was significantly reduced(P<0.01).The expression of CYP27A1 was significantly correlated with sex,T stage,tumor grade and tumor stage of HCC patients(P<0.05).Compared to the CYP27A1 high-expression group,patients in CYP27A1 low-expression group had lower survival rate(P<0.01).GSEA enrichment analysis revealed that the levels of HCC stem cell-related gene clusters and HCC proliferation gene clusters were remarkably increased in CYP27A1 low-expression group.The immunofluorescence showed that CYP27A1 was mainly located in nucleus in MHCC-97H and HCCLM3,whereas CYP27A1 was mainly located in mitochondria in HepG2.CYP27A1 over-expression attenuated cell viability(P<0.01),and reduced the ROS levels(P<0.05),whereas it had no effects on the apoptosis in HCC cells(P>0.05).The expression of CYP27A1 and the expression of inhibiting ROS generation-related genes were positively correlated(P<0.05),while the expression of inhibiting ROS generation-related genes and the expression of HCC proliferation-related genes were negatively correlated(P<0.05).Conclusions The expression of CYP27A1 was decreased in HCC,and down-regulated CYP27A1 promoted cell growth by enhancing ROS generation,although the precise mechanism requires future educidation.
hepatocellular carcinomacytochrome P450 family 27 subfamily A member 1malignant growth