Feng Lu, Zou Xinru, Tang Longyu, Yuan Yijun, He Tianwen, Su Bin, Tang Ying, Wang Jiang, Liu Kang, Li Jun
Department of Obstetrics and Gynecology, The Second Clinical Medical College of North Sichuan Medical College, Nanchong Central Hospital, Beijing Anzhen Nanchong Hospital of Capital Medical University, Nanchong, Sichuan, China.
The Second Clinical Medical College of North Sichuan Medical College, Institute of Tissue Engineering and Stem Cell Research, Nanchong Central Hospital, Beijing Anzhen Nanchong Hospital of Capital Medical University, Nanchong, Sichuan, China.
Front Pharmacol. 2025 Jun 24;16:1563869. doi: 10.3389/fphar.2025.1563869. eCollection 2025.
Platinum chemotherapy, particularly cisplatin, has been the standard treatment for ovarian cancer. However, the development of resistance to cisplatin is a significant challenge during treatment. Circular RNAs (circRNAs) are a class of non-coding RNAs with a circular structure and have been implicated in regulating ferroptosis and chemoresistance. Despite the increasing recognition of circRNAs in cancer progression, the role of circASH1L in ferroptosis and cisplatin resistance in ovarian cancer remains poorly understood.
RNA sequencing (RNA-seq) was utilized to identify differentially expressed circRNAs in ovarian cancer cells. Cell survival and invasion were assessed using CCK-8 and transwell assays, while apoptosis, cell cycle progression, and lipid peroxidation were analyzed by flow cytometry. Levels of GSH, MDA, and iron ions were measured using appropriate kits. qRT-PCR and Western blot analyses were performed to evaluate the expression of relevant RNAs and proteins. The clinical relevance of circASH1L/miR-515-5p/CDCA7 axis in ovarian cancer patients was analyzed using public datasets. Molecular interactions were confirmed through dual-luciferase reporter assays, RNA immunoprecipitation (RIP), and co-immunoprecipitation (Co-IP). , the effects of circASH1L on ferroptosis and chemoresistance were evaluated using a xenograft mouse model.
circASH1L expression was downregulated upon erastin treatment and significantly upregulated in cisplatin-resistant A2780/DDP and SKOV3/DDP cells. Silencing circASH1L reversed cisplatin resistance by reducing cell viability and invasion, while promoting apoptosis and ferroptosis. Mechanistically, circASH1L was found to act as a sponge for miR-515-5p, which in turn regulates the CDCA7/RRM2 axis. Rescue experiments demonstrated that inhibiting miR-515-5p or overexpressing CDCA7 blocked the effects of circASH1L silencing. Moreover, CDCA7 could interact with RRM2 and inhibit RRM2 degradation, which contributed to reducing cell cycle arrest and ferroptosis resistance. The clinical analysis showed circASH1L, and CDCA7/RRM2 expression was positive correlated with drug resistance and worse survival rate, while miR-515-5p expression was on the contrary. , silencing circASH1L enhanced cisplatin sensitivity by inducing ferroptosis.
Our study demonstrates that silencing circASH1L alleviates cisplatin resistance in ovarian cancer cells. The underlying mechanism involves the upregulation of miR-515-5p, which targets the CDCA7/RRM2 axis, leading to cell cycle modulation and the induction of ferroptosis. Targeting the circASH1L/miR-515-5p/CDCA7 pathway offers new insights into the relationship between ferroptosis and chemoresistance, presenting a promising strategy to overcome chemoresistance in ovarian cancer.
铂类化疗，尤其是顺铂，一直是卵巢癌的标准治疗方法。然而，顺铂耐药的发生是治疗过程中的一项重大挑战。环状RNA（circRNA）是一类具有环状结构的非编码RNA，与铁死亡调节和化疗耐药有关。尽管circRNA在癌症进展中的作用日益受到认可，但circASH1L在卵巢癌铁死亡和顺铂耐药中的作用仍知之甚少。
利用RNA测序（RNA-seq）鉴定卵巢癌细胞中差异表达的circRNA。使用CCK-8和Transwell实验评估细胞活力和侵袭能力，通过流式细胞术分析细胞凋亡、细胞周期进程和脂质过氧化。使用相应试剂盒测量谷胱甘肽（GSH）、丙二醛（MDA）和铁离子水平。进行qRT-PCR和蛋白质免疫印迹分析以评估相关RNA和蛋白质的表达。使用公共数据集分析circASH1L/miR-515-5p/CDCA7轴在卵巢癌患者中的临床相关性。通过双荧光素酶报告基因实验、RNA免疫沉淀（RIP）和免疫共沉淀（Co-IP）确认分子相互作用。此外，使用异种移植小鼠模型评估circASH1L对铁死亡和化疗耐药的影响。
在埃拉司亭处理后，circASH1L表达下调，而在顺铂耐药的A2780/DDP和SKOV3/DDP细胞中显著上调。沉默circASH1L可通过降低细胞活力和侵袭能力来逆转顺铂耐药，同时促进细胞凋亡和铁死亡。机制上，发现circASH1L作为miR-515-5p的海绵，进而调节CDCA7/RRM2轴。挽救实验表明，抑制miR-515-5p或过表达CDCA7可阻断circASH1L沉默的作用。此外，CDCA7可与RRM2相互作用并抑制RRM2降解，这有助于减少细胞周期停滞和铁死亡抗性。临床分析表明，circASH1L和CDCA7/RRM2表达与耐药性和较差的生存率呈正相关，而miR-515-5p表达则相反。此外，沉默circASH1L通过诱导铁死亡增强顺铂敏感性。
我们的研究表明，沉默circASH1L可减轻卵巢癌细胞中的顺铂耐药。潜在机制涉及miR-515-5p的上调，其靶向CDCA7/RRM2轴，导致细胞周期调节和铁死亡诱导。靶向circASH1L/miR-515-5p/CDCA7途径为铁死亡和化疗耐药之间的关系提供了新的见解，为克服卵巢癌化疗耐药提供了一种有前景的策略。
