Background Cervical cancer (CC) is the third most common gynecological malignancy around the world. Cisplatin is an effective drug, but cisplatin resistance is a vital factor limiting the clinical usage of cisplatin. Enhancer of mRNA decapping protein 4 (EDC4) is a known regulator of mRNA decapping, which was related with genome stability and sensitivity of drugs. This research was to investigate the mechanism of EDC4 on cisplatin resistance in CC. Two human cervical cancer cell lines, HeLa and SiHa, were used to investigate the role of EDC4 on cisplatin resistance in vitro. The knockdown or overexpression of EDC4 or replication protein A (RPA) in HeLa or SiHa cells was performed by transfection. Cell viability was analyzed by MTT assay. The growth of cancer cells was evaluated by colony formation assay. DNA damage was measured by γH2AX (a sensitive DNA damage response marker) immunofluorescent staining. The binding of EDC4 and RPA was analyzed by immunoprecipitation. Results EDC4 knockdown in cervical cancer cells (HeLa and SiHa) enhanced cisplatin sensitivity and cisplatin induced cell growth inhibition and DNA damage. EDC4 overexpression reduced DNA damage caused by cisplatin and enhanced cell growth of cervical cancer cells. EDC4 could interact with RPA and promote RPA phosphorylation. RPA knockdown reversed the inhibitory effect of EDC4 on cisplatin-induced DNA damage. Conclusion The present results indicated that EDC4 is responsible for the cisplatin resistance partly through interacting with RPA in cervical cancer by alleviating DNA damage. This study indicated that EDC4 or RPA may be novel targets to combat chemotherapy resistance in cervical cancer. Graphical abstract

中文翻译：

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mRNA 去帽蛋白 4 (EDC4) 的增强子与复制蛋白 a (RPA) 相互作用并通过减轻 DNA 损伤促进宫颈癌顺铂耐药

背景 宫颈癌 (CC) 是全球第三大常见妇科恶性肿瘤。顺铂是一种有效的药物，但顺铂耐药性是限制顺铂临床应用的重要因素。mRNA去帽蛋白4（EDC4）增强子是已知的mRNA去帽调节因子，与基因组稳定性和药物敏感性有关。本研究旨在探讨EDC4对CC顺铂耐药的机制。两种人宫颈癌细胞系 HeLa 和 SiHa 用于研究 EDC4 在体外对顺铂耐药性的作用。EDC4 或复制蛋白 A (RPA) 在 HeLa 或 SiHa 细胞中的敲低或过表达是通过转染进行的。通过MTT测定分析细胞活力。通过集落形成试验评估癌细胞的生长。DNA 损伤是通过 γH2AX（一种敏感的 DNA 损伤反应标记）免疫荧光染色来测量的。通过免疫沉淀分析 EDC4 和 RPA 的结合。结果 宫颈癌细胞（HeLa 和 SiHa）中的 EDC4 敲低增强了顺铂敏感性和顺铂诱导的细胞生长抑制和 DNA 损伤。EDC4 过表达减少了顺铂引起的 DNA 损伤并增强了宫颈癌细胞的细胞生长。EDC4 可以与 RPA 相互作用并促进 RPA 磷酸化。RPA 敲低逆转了 EDC4 对顺铂诱导的 DNA 损伤的抑制作用。结论 目前的结果表明，EDC4 通过减轻 DNA 损伤与宫颈癌中的 RPA 相互作用，部分导致顺铂耐药。该研究表明，EDC4 或 RPA 可能是对抗宫颈癌化疗耐药的新靶点。图形概要