Department of Oncology, 900TH Hospital of Joint Logistics Support Force, Fuzhou, P.R. China;
Medical Department, 900TH Hospital of Joint Logistics Support Force, Fuzhou, P.R. China.
Anticancer Res. 2023 Nov;43(11):4905-4914. doi: 10.21873/anticanres.16688.
BACKGROUND/AIM: Endometrial cancer (EC) is a frequent gynecological cancer. Studies have demonstrated that the sensitivity of EC toward 5-fluorouracil (5-FU) chemotherapy has decreased, leading to unsatisfactory treatment effects. There is an urgent need to investigate the reasons for the unsatisfactory treatment of EC with 5-FU. The purpose of the study was to investigate the effect of RAD51AP1 after being transcriptionally activated by E2F7 on the sensitivity of EC cells to 5-FU chemotherapy via the fatty acid metabolic pathway.
mRNA expression data on EC were downloaded from The Cancer Genome Atlas database, subjected to differential expression analysis, and the target genes were determined based on the bioinformatics analysis and literature consulting. The regulatory transcription factor upstream of RAD51AP1 in EC was predicted using the hTFtarget database. The expression of E2F7 and RAD51AP1 was measured by qRT-PCR and western blot. Then, the transcriptional activation relationship between E2F7 and RAD51AP1 was verified by chromatin immunoprecipitation (ChIP) and dual luciferase assays. The IC values of EC cells toward 5-FU were determined by the CCK-8 assay, and cell apoptosis was detected by flow cytometry. The expression of apoptosis-related and fatty acid metabolism-related proteins was evaluated by western blot.
Bioinformatics analysis showed that both E2F7 and RAD51AP1 were highly expressed in EC, and the possible binding sites between RAD51AP1 promoter and E2F7 were predicted. ChIP assay and dual luciferase assay confirmed the binding of E2F7 to RAD51AP1 promoter region. Cell experiments showed that overexpressing RAD51AP1 could facilitate the growth and fatty acid metabolism of EC cells, and suppress cell sensitivity to 5-FU, while silencing of E2F7 could reduce the effect of RAD51AP1 overexpression on EC cell growth and sensitivity toward 5-FU.
The E2F7/RAD51AP1 axis can promote the growth of EC cells and inhibit cell sensitivity to 5-FU by regulating fatty acid metabolism, suggesting that E2F7/RAD51AP1 axis may be a novel pathway for EC treatment.
背景/目的：子宫内膜癌（EC）是一种常见的妇科癌症。研究表明，EC 对 5-氟尿嘧啶（5-FU）化疗的敏感性降低，导致治疗效果不理想。因此，迫切需要研究导致 EC 对 5-FU 治疗效果不理想的原因。本研究旨在探讨 E2F7 转录激活 RAD51AP1 后通过脂肪酸代谢途径对 EC 细胞对 5-FU 化疗敏感性的影响。
从癌症基因组图谱数据库下载 EC 的 mRNA 表达数据，进行差异表达分析，并根据生物信息学分析和文献查阅确定靶基因。使用 hTFtarget 数据库预测 EC 中 RAD51AP1 的上游调控转录因子。通过 qRT-PCR 和 Western blot 测量 E2F7 和 RAD51AP1 的表达。然后，通过染色质免疫沉淀（ChIP）和双荧光素酶测定验证 E2F7 和 RAD51AP1 之间的转录激活关系。通过 CCK-8 测定确定 EC 细胞对 5-FU 的 IC 值，并通过流式细胞术检测细胞凋亡。通过 Western blot 评估凋亡相关和脂肪酸代谢相关蛋白的表达。
生物信息学分析表明，E2F7 和 RAD51AP1 在 EC 中均高表达，并预测了 RAD51AP1 启动子与 E2F7 之间可能的结合位点。ChIP 实验和双荧光素酶实验证实了 E2F7 与 RAD51AP1 启动子区域的结合。细胞实验表明，过表达 RAD51AP1 可促进 EC 细胞的生长和脂肪酸代谢，并抑制细胞对 5-FU 的敏感性，而沉默 E2F7 可降低 RAD51AP1 过表达对 EC 细胞生长和对 5-FU 敏感性的影响。
E2F7/RAD51AP1 轴可通过调节脂肪酸代谢促进 EC 细胞的生长并抑制细胞对 5-FU 的敏感性，提示 E2F7/RAD51AP1 轴可能是 EC 治疗的新途径。
