Kang Qingjie, Hu Xiaoyu, Chen Zhenzhou, Liang Xiaolong, Xiang Song, Wang Ziwei
Department of Gastrointestinal Surgery, The First Affiliated Hospital of Chongqing Medical University, No. 1 Youyi Road, Yuzhong District, Chongqing, 400016, China.
Chongqing Medical University, Chongqing, 400016, China.
Mol Cell Biochem. 2025 Mar;480(3):1865-1889. doi: 10.1007/s11010-024-05116-8. Epub 2024 Sep 17.
Colorectal cancer (CRC) remains a significant clinical challenge, with 5-Fluorouracil (5-FU) being the frontline chemotherapy. However, chemoresistance remains a major obstacle to effective treatment. METTL3, a key methyltransferase involved in RNA methylation processes, has been implicated in CRC carcinogenesis. However, its role in modulating CRC sensitivity to 5-FU remains elusive. In this study, we aimed to investigate the role and mechanisms of METTL3 in regulating 5-FU chemosensitivity in CRC cells. Initially, we observed that 5-FU treatment inhibited cell viability and induced apoptosis, accompanied by a reduction in METTL3 expression in HCT-116 and HCT-8 cells. Subsequent assays including drug sensitivity, EdU, colony formation, TUNEL staining, and flow cytometry revealed that METTL3 depletion enhanced 5-FU sensitivity and increased apoptosis induction both in vitro and in vivo. Conversely, METTL3 overexpression conferred resistance to 5-FU in both cell lines. Moreover, knockdown of METTL3 in 5-FU-resistant CRC cell lines HCT-116/FU and HCT-15/FU significantly decreased 5-FU tolerance and induced apoptosis upon 5-FU treatment. Mechanistically, we found that METTL3 regulated 5-FU sensitivity and apoptosis induction by modulating TRAP1 expression. Further investigations using m6A colorimetric ELISA, dot blot, MeRIP-qPCR and RNA stability assays demonstrated that METTL3 regulated TRAP1 mRNA stability in an m6A-dependent manner. Additionally, overexpression of TRAP1 mitigated the cytotoxic effects of 5-FU on CRC cells. In summary, our study uncovers the pivotal role of the METTL3/TRAP1 axis in modulating 5-FU chemosensitivity in CRC. These findings provide new insights into the mechanisms underlying CRC resistance to 5-FU and may offer potential targets for future therapeutic interventions.
结直肠癌（CRC）仍然是一个重大的临床挑战，5-氟尿嘧啶（5-FU）是一线化疗药物。然而，化疗耐药性仍然是有效治疗的主要障碍。METTL3是一种参与RNA甲基化过程的关键甲基转移酶，与CRC的致癌作用有关。然而，其在调节CRC对5-FU敏感性方面的作用仍不清楚。在本研究中，我们旨在探讨METTL3在调节CRC细胞对5-FU化疗敏感性中的作用及机制。首先，我们观察到5-FU处理抑制细胞活力并诱导凋亡，同时HCT-116和HCT-8细胞中METTL3表达降低。随后的实验，包括药物敏感性、EdU、集落形成、TUNEL染色和流式细胞术，表明METTL3缺失增强了5-FU敏感性，并在体外和体内增加了凋亡诱导。相反，METTL3过表达使两种细胞系对5-FU产生耐药性。此外，在5-FU耐药的CRC细胞系HCT-116/FU和HCT-15/FU中敲低METTL3显著降低了5-FU耐受性，并在5-FU处理后诱导凋亡。机制上，我们发现METTL3通过调节TRAP1表达来调节5-FU敏感性和凋亡诱导。使用m6A比色ELISA、斑点印迹、MeRIP-qPCR和RNA稳定性分析的进一步研究表明，METTL3以m6A依赖的方式调节TRAP1 mRNA稳定性。此外，TRAP1的过表达减轻了5-FU对CRC细胞的细胞毒性作用。总之，我们的研究揭示了METTL3/TRAP1轴在调节CRC对5-FU化疗敏感性中的关键作用。这些发现为CRC对5-FU耐药的机制提供了新的见解，并可能为未来的治疗干预提供潜在靶点。
