Tan Xiaojie, Zheng Shaoling, Liu Wenbin, Liu Yan, Kang Zhengchun, Li Zishuai, Li Peng, Song Jiahui, Hou Jianguo, Yang Bo, Han Xue, Wang Fubo, Jing Chunxia, Cao Guangwen
Department of Epidemiology, Second Military Medical University Shanghai 200433, China.
Department of Epidemiology, School of Medicine, Jinan University Guangzhou 510632, China.
Am J Cancer Res. 2021 Sep 15;11(9):4347-4363. eCollection 2021.
Human apolipoprotein B mRNA editing enzyme, catalytic polypeptide (APOBEC) 3 cytidine deaminases are the prominent drivers of somatic mutations in cancers. However, the effect of functional polymorphisms on the development of renal cell carcinoma (RCC) remains unknown. Five genetic polymorphisms affecting the expression of APOBEC3A (A3A), APOBEC3B, and APOBEC4 and uracil DNA glycosylase (UNG) were genotyped in 728 RCC patients and 1500 healthy controls. The effects of tumor necrosis factor-α (TNFα) and interleukin-6 on the activity of the promoter with rs12157810-A or -C in four RCC cell lines (786-O, A498, Caki2, ACHN) and two colorectal cancer cell lines (HCT116, SW620) were evaluated using dual-luciferase assays. Transcriptional repressors to the promoter were identified by chromatin immunoprecipitation-quantitative PCR. The proapoptotic effect of on RCC cells was evaluated using cytometry. The prognostic values of A3A and ETS1 were evaluated by the Cox regression analysis. The expressions of A3A and ETS1 were evaluated in clear cell RCC (ccRCC) specimens with different polymorphic genotypes using quantitative RT-PCR and immunohistochemistry. Of those functional polymorphisms, CC genotype at rs12157810 in the promoter was significantly associated with a decreased risk of ccRCC, compared to the AA genotype (odds ratio adjusted for age and gender, 0.41, 95% confidence interval [CI], 0.28-0.57). Other polymorphic genotypes were not associated with the risk of RCC. The activity of the promoter with rs12157810-C was significantly higher than that with rs12157810-A in the four RCC cell lines and two colorectal cancer cell lines. The activity of the promoter with rs12157810-C was greatly up-regulated by TNFα and predominantly inhibited by a transcriptional repressor ETS1. The binding of ETS1 to the promoter with rs12157810-C was looser than that with rs12157810-A. Ectopic expression of significantly promoted apoptosis in ccRCC cells, rather than in colorectal cancer cells. Higher ETS1 expression predicted a favorable prognosis in ccRCC, with a hazard ratio of 0.58 (95% CI, 0.43-0.78). Rs121567810-C up-regulates the promoter activity, possibly due to higher response to TNFα and looser transcriptional repression by ETS1. Up-regulation of A3A increases apoptosis, thus decreasing ccRCC risk in those carrying rs121567810-C.
人类载脂蛋白B信使核糖核酸编辑酶催化多肽（APOBEC）3胞苷脱氨酶是癌症体细胞突变的主要驱动因素。然而，功能多态性对肾细胞癌（RCC）发生发展的影响仍不清楚。对728例RCC患者和1500例健康对照者进行基因分型，检测影响APOBEC3A（A3A）、APOBEC3B、APOBEC4和尿嘧啶DNA糖基化酶（UNG）表达的5种基因多态性。使用双荧光素酶测定法评估肿瘤坏死因子-α（TNFα）和白细胞介素-6对四种RCC细胞系（786-O、A498、Caki2、ACHN）和两种结肠癌细胞系（HCT116、SW620）中具有rs12157810-A或-C的启动子活性的影响。通过染色质免疫沉淀-定量PCR鉴定启动子的转录抑制因子。使用细胞术评估其对RCC细胞的促凋亡作用。通过Cox回归分析评估A3A和ETS1的预后价值。使用定量逆转录-聚合酶链反应和免疫组织化学在具有不同多态性基因型的透明细胞RCC（ccRCC）标本中评估A3A和ETS1的表达。在这些功能多态性中，与AA基因型相比，启动子中rs12157810的CC基因型与ccRCC风险降低显著相关（年龄和性别校正后的优势比为0.41，95%置信区间[CI]为0.28-0.57）。其他多态性基因型与RCC风险无关。在四种RCC细胞系和两种结肠癌细胞系中，具有rs12157810-C的启动子活性显著高于具有rs12157810-A的启动子活性。具有rs12157810-C的启动子活性被TNFα大大上调，并主要被转录抑制因子ETS1抑制。ETS1与具有rs12157810-C的启动子的结合比与具有rs12157810-A的启动子的结合更松散。异位表达显著促进ccRCC细胞凋亡，而不是结肠癌细胞凋亡。较高的ETS1表达预测ccRCC预后良好，风险比为0.58（95%CI为0.43-0.78）。Rs121567810-C上调启动子活性，可能是由于对TNFα的反应更高以及ETS1的转录抑制更松散。A3A的上调增加细胞凋亡，从而降低携带rs121567810-C者的ccRCC风险。
