Xie Wenli, Liu Naifu, Wang Xiangyu, Wei Ling, Xie Wenyan, Sheng Xiugui
School of Medicine, Shandong University, Jinan, China.
Department of Gynecologic Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, China.
Front Oncol. 2021 Feb 16;11:598344. doi: 10.3389/fonc.2021.598344. eCollection 2021.
Cisplatin remains the mainstay of endometrial cancer (EC) chemotherapy. Wilms' tumor 1-associated protein (WTAP), playing a critical role in transcriptional and post-transcriptional regulation, has been reported as an oncogene, and its expression is elevated in multiple types of human tumors. Recent evidence has shown that the increased expression of WTAP is also closely related to chemo-resistance. However, its specific role in the susceptibility of human EC cells to cisplatin remains largely unexplored.
WTAP over-expression and WTAP depletion cell lines as well as their corresponding controls were constructed by transfection with lentivirus. Western blotting analysis and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to detect the expression of WTAP. Cell proliferation assay, colony formation assay, cell cycle assay, and apoptosis analysis were adopted to evaluate the effect of WTAP on the chemo-sensitivity of EC cells to cisplatin as well as its underlying mechanism. Immunofluorescence staining was used to assess the translocation of β-catenin. Moreover, a subcutaneous xenograft tumor model was established to assess the effect of WTAP on tumor growth after cisplatin treatment.
Depletion of WTAP in RL95-2 cells significantly enhanced the chemo-susceptibility of cells to cisplatin and increased the cell apoptosis, while WTAP over-expression in ARK-2 cells exhibited the opposite effects. Additionally, WTAP depletion significantly suppressed xenograft-tumor growth and enhanced sensitivity and apoptosis of tumor cells . Mechanistic analysis exhibited that WTAP over-expression facilitated the cytoplasm-to-nucleus translocation of β-catenin and enhanced the GSK3β phosphorylation at Ser9, while WTAP depletion revealed the opposite results, indicating that WTAP rendered chemo-resistance of EC cells to cisplatin by promoting the Wnt/β-catenin pathway.
WTAP might promote the chemo-resistance of EC cells to cisplatin through activating the Wnt/β-catenin pathway. Collectively, our findings offered novel insights into EC treatment.
顺铂仍然是子宫内膜癌（EC）化疗的主要药物。肾母细胞瘤1相关蛋白（WTAP）在转录和转录后调控中起关键作用，已被报道为一种癌基因，其在多种人类肿瘤中表达升高。最近的证据表明，WTAP表达的增加也与化疗耐药密切相关。然而，其在人类EC细胞对顺铂敏感性中的具体作用仍 largely未被探索。
通过慢病毒转染构建WTAP过表达和WTAP缺失细胞系及其相应对照。采用蛋白质免疫印迹分析和定量实时聚合酶链反应（qRT-PCR）检测WTAP的表达。采用细胞增殖试验、集落形成试验、细胞周期试验和凋亡分析来评估WTAP对EC细胞对顺铂化疗敏感性的影响及其潜在机制。采用免疫荧光染色评估β-连环蛋白的转位。此外，建立皮下异种移植瘤模型以评估WTAP对顺铂治疗后肿瘤生长的影响。
RL95-2细胞中WTAP的缺失显著增强了细胞对顺铂的化疗敏感性并增加了细胞凋亡，而ARK-2细胞中WTAP的过表达则表现出相反的效果。此外，WTAP的缺失显著抑制了异种移植瘤的生长并增强了肿瘤细胞的敏感性和凋亡。机制分析表明，WTAP的过表达促进了β-连环蛋白从细胞质到细胞核的转位并增强了Ser9位点的GSK3β磷酸化，而WTAP的缺失则显示出相反的结果，表明WTAP通过促进Wnt/β-连环蛋白途径使EC细胞对顺铂产生化疗耐药性。
WTAP可能通过激活Wnt/β-连环蛋白途径促进EC细胞对顺铂的化疗耐药性。总的来说，我们的研究结果为EC治疗提供了新的见解。
