Targeting of β-Catenin Reverses Radioresistance of Cervical Cancer with the PIK3CA-E545K Mutation
Targeting of β-Catenin Reverses Radioresistance of Cervical Cancer with the PIK3CA-E545K Mutation
复制标题
DOI：
10.1158/1535-7163.mct-19-0309
复制
发表时间：
2020-02-01
影响因子：
5.7
通讯作者：
Yang, Huijuan
中科院分区：
文献类型：
--
作者：
Jiang, Wei;Wu, Yutuan;Yang, Huijuan
本研究旨在探讨宫颈癌中最常见的 PIK3CA 热点突变 E545K 是否赋予宫颈癌细胞放射抗性，以阐明其潜在机制，并开发有效的靶点。通过慢病毒转染建立具有 PIK3CA-WT 和 PIK3CA-E545K 的 SiHa 和 MS751 细胞。通过集落形成、细胞周期、细胞凋亡、DNA损伤和修复测定来评估放射敏感性。在体内评估异种移植肿瘤相关毒性的生长和免疫组织化学测定。这表明更多带有PIK3CA-E545K的细胞停滞在S期。在携带 PIK3CA-E545K 的 SiHa 和 MS751 细胞中，辐射 (IR) 导致更高的存活率、更少的细胞凋亡、更少的 pH2A.X 病灶以及更高的 Chk1/2 表达。从机械角度来看，IR后PIK3CA-E545K细胞中AKT/GSK3 β/β-catenin通路被高度激活，并且更多的β-catenin在细胞核中积累。此外，通过 shRNA 或 XAV939 靶向 β-连环蛋白可增强 PIK3CA-WT 和 PIK3CA-E545K 细胞的 IR 敏感性，而后者更为显着。 beta-Catenin shRNA 和 XAV939 通过高度激活的 p53/bcl2/bax 途径增加 IR 介导的集落形成抑制。 XAV939 在具有 PIK3CA-E545K 的 MS751 细胞中增强 IR 引起的细胞凋亡、DNA 损伤、克服 S 期停滞、DNA 修复并逆转 β-连环蛋白核积累。在体内，XAV939 增强了 PIK3CA-E545K 宫颈癌异种移植物的放射敏感性，且具有不可见的内脏毒性。研究结果表明，带有 PIK3CA-E545K 的宫颈癌细胞通过增强 β-连环蛋白的表达和核积累来抵抗 IR。靶向β-连环蛋白可逆转放射抗性，这表明抑制β-连环蛋白以增强宫颈癌放射敏感性的临床前研究的可能领域。
This study aims to explore whether E545K, the most common hotspot mutation of PIK3CA in cervical cancer, confers radioresistance to cervical cancer cells, to demonstrate the underling mechanism, and to develop the effective targets. SiHa and MS751 cells with PIK3CA-WT and PIK3CA-E545K were established by lentiviral transfection. The radiosensitivity was assessed by colony formation, cell cycle, cell apoptosis, DNA damage, and repair assay. The growth and immunohistochemical assay of xenograft tumor-related toxicity were evaluated in vivo. It was indicated that more cells with PIK3CA-E545K arrested in S phase. Irradiation (IR) led to more survival percentage, less apoptosis, fewer pH2A.X foci, and higher expression of Chk1/2 in SiHa and MS751 cells bearing PIK3CA-E545K. Mechanically, AKT/GSK3 beta/beta-catenin pathway was highly activated, and more beta-catenin was found accumulated in nucleus in cells with PIK3CA-E545K after IR. Furthermore, targeting beta-catenin by shRNA or XAV939 enhanced IR sensitivity in cells with PIK3CA-WT and PIK3CA-E545K, whereas it was more notably in the latter. beta-Catenin shRNA and XAV939 increased IR-mediated inhibition of colony formation with highly activated p53/bcl2/bax pathway. XAV939 enhanced IR-caused apoptosis, DNA damage, overcame S-phase arrest, DNA repair and reversed beta-catenin nuclear accumulation in MS751 cells with PIK3CA-E545K. In vivo, XAV939 enhanced the radiosensitivity of cervical cancer xenografts with PIK3CA-E545K with invisible viscera toxicity. The findings demonstrate that cervical cancer cells with PIK3CA-E545K are resistant to IR by enhancing the expression and nuclear accumulation of beta-catenin. Targeting beta-catenin reverses the radioresistance, which suggests possible areas for preclinical research on beta-catenin inhibition for strengthening the radiosensitivity of cervical cancer.