AKR7A3 rs1738023 association with susceptibility to female hepatocellular carcinoma and its role in AFB1 metabolism and tumor.
BACKGROUND: Hepatocellular carcinoma (HCC) is one of the most common cancer worldwide. In this study, we performed a two-stage exome-chip association analysis and found that the aldo-keto reductase family7 member A3 (AKR7A3) rs1738023 may be a potential susceptibility locus for HCC in females. We aimed to explore its role and mechanism. METHODS: The association between genotype and phenotype was analyzed through GWAS method. The expression of AKR7A3 in cancer tissue and blood analysis by qRT-PCR. The relationship of AKR7A3 and aflatoxin B1 (AFB1) was also analyzed. The effect of AKR7A3 on the biological behavior of HCC cell line was investigated on proliferation and invasion. The potential mechanism was analyzed by transcriptome analysis and western blot. RESULTS: Through genome-wide association analysis (GWAS), AKR7A3 (rs1738023), KIF2C (rs4342887), and CYP3A5 (rs6977165 and rs4646450) were found to be associated with susceptibility to hepatocellular carcinoma (HCC) in women. Further expression quantitative trait loci (eQTL) analysis showed that only AKR7A3 (rs1738023) was significantly associated with gene expression. The expression of AKR7A3 was significantly lower in HCC than adjacent non-tumorous tissues (P < 0.001). The genotype of rs1738023 was significantly associated with AKR7A3 expression (P = 0.0085). Rs1738023[C] genotype had a low AKR7A3 expression level and limited detoxification ability of AFB1. Literature data showed that AKR7A3 is involved in the metabolism of aflatoxin B1 (AFB1). Functional experimental results showed that overexpression of AKR7A3 in the normal liver cell line HL-7702 could significantly reduce AFB1-induced ROS levels and DNA adduct formation, suggesting that it plays a protective role in AFB1 metabolic detoxification. Cell function test showed that overexpression of AKR7A3 inhibit the proliferation, migration and invasion of HCC cells, and block the cell cycle. Transcriptome sequencing and KEGG pathway enrichment analysis revealed that overexpression of AKR7A3 affected the PI3K signaling pathway and led to downregulation of HIF1A and its downstream VEGFA protein expression. The validation results were confirmed in HCC cell lines Huh-7 and SUN-387. CONCLUSION: Overexpression of AKR7A3 contributes to inhibition of HCC progression and reduction of aflatoxin toxicity. AKR7A3 may serve as a potential prognostic and therapeutic target for HCC patients, although further validation is needed.