Gene expression evaluation of antioxidant enzymes in patients with hepatocellular carcinoma: RT-qPCR and bioinformatic analyses

Abstract Any condition leading to chronic liver disease is a potential oncogenic agent for hepatocellular carcinoma (HCC). Alterations in the expression of antioxidant enzymes could alter the redox balance. Our aim was to evaluate the expression of the genes GPX1, GPX4, SEP15, SELENOP, SOD1, SOD2, GSR, CAT, and NFE2L2 in patients with HCC. Differential gene expression analysis was performed using RNA-Seq data from the TCGA and GTEx databases, and RT-qPCR data from HCC patient samples. Bioinformatic analysis revealed significant differential expression in most genes. GPX4 expression was significantly increased (p=0.02), while SOD2 expression was significantly decreased (p=0.04) in experimental data. In TCGA samples, alpha-fetoprotein levels (mg/dL) were negatively correlated with the expression of SEP15 (p<0.001), SELENOP (p<0.001), SOD1 (p<0.001), SOD2 (p<0.001), CAT (p<0.001), and NFE2L2 (p=0.004). Alpha-fetoprotein levels were positively correlated with the expression of GPX4 (p=0.02) and SELENOP (p=0.01) in the experimental data. Low expression of GPX1 (p=0.006), GPX4 (p=0.01), SELENOP (p=0.006), SOD1 (p=0.007), CAT (p<0.001), and NFE2L2 (p<0.001), and higher levels of GSR, were associated with low overall survival at 12 months. These results suggest a significant role for these antioxidant enzymes in HCC pathogenesis and severity.

摘要 任何引发慢性肝病的病症，均为肝细胞癌（Hepatocellular carcinoma, HCC）的潜在致癌因素。抗氧化酶表达异常可扰乱氧化还原稳态。本研究旨在探究肝细胞癌患者体内GPX1、GPX4、SEP15、SELENOP、SOD1、SOD2、GSR、CAT及NFE2L2基因的表达情况。研究采用TCGA与GTEx数据库的RNA测序（RNA-Seq）数据，以及肝细胞癌患者样本的逆转录实时定量PCR（RT-qPCR）数据，开展差异基因表达分析。生物信息学分析结果显示，多数基因呈现显著差异表达。实验队列数据中，GPX4的表达量显著上调（p=0.02），而SOD2的表达量显著下调（p=0.04）。在TCGA样本中，甲胎蛋白水平（单位：mg/dL）与SEP15（p<0.001）、SELENOP（p<0.001）、SOD1（p<0.001）、SOD2（p<0.001）、CAT（p<0.001）及NFE2L2（p=0.004）的基因表达呈显著负相关。而在实验数据中，甲胎蛋白水平与GPX4（p=0.02）及SELENOP（p=0.01）的基因表达呈显著正相关。GPX1（p=0.006）、GPX4（p=0.01）、SELENOP（p=0.006）、SOD1（p=0.007）、CAT（p<0.001）及NFE2L2（p<0.001）的低表达，以及GSR的高表达，均与12个月总生存期缩短显著相关。上述结果表明，这些抗氧化酶在肝细胞癌的发病机制与疾病严重程度中发挥着关键作用。