Division of Gynecologic Oncology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Department of Gynecologic Oncology, Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing 100006, P.R. China.
Int J Oncol. 2023 Sep;63(3). doi: 10.3892/ijo.2023.5551. Epub 2023 Jul 28.
Endometrial cancer is the most common gynecologic cancer and one of the only cancers for which incidence and mortality is steadily increasing. Although curable with surgery in the early stages, endometrial cancer presents a significant clinical challenge in the metastatic and recurrent setting with few novel treatment strategies emerging in the past fifty years. Ipatasertib (IPAT) is an orally bioavailable pan‑AKT inhibitor, which targets all three AKT isoforms and has demonstrated anti‑tumor activity in pre‑clinical models, with clinical trials emerging for many cancer types. In the present study, the MTT assay was employed to evaluate the therapeutic efficacy of IPAT or IPAT in combination with paclitaxel (PTX) in endometrial cancer cell lines and primary cultures of endometrial cancer. The effect of IPAT and PTX on the growth of endometrial tumors was evaluated in a transgenic mouse model of endometrial cancer. Apoptosis was assessed using cleaved caspase assays and cellular stress was assessed using ROS, JC1 and tetramethylrhodamine ethyl ester assays. The protein expression levels of markers of apoptosis and cellular stress, and DNA damage were evaluated using western blotting and immunohistochemistry. IPAT significantly inhibited cell proliferation, caused cell cycle G1 phase arrest, and induced cellular stress and mitochondrial apoptosis in a dose dependent manner in human endometrial cancer cell lines. Combined treatment with low doses of IPAT and PTX led to synergistic inhibition of cell proliferation and induction of cleaved caspase 3 activity in the human endometrial cancer cell lines and the primary cultures. Furthermore, IPAT effectively reduced tumor growth, accompanied by decreased protein expression levels of Ki67 and phosphorylation of S6 in the mouse model of endometrioid endometrial cancer. The combination of IPAT and PTX resulted in increased expression of phosphorylated‑H2AX and KIF14, markers of DNA damage and microtubule dysfunction respectively, as compared with IPAT alone, PTX alone or placebo‑treated mice. The results of the present study provide a biological rationale to evaluate IPAT and the combination of IPAT and PTX in future clinical trials for endometrial cancer.
子宫内膜癌是最常见的妇科恶性肿瘤之一，也是发病率和死亡率稳步上升的唯一癌症之一。尽管在早期阶段通过手术可以治愈，但在转移性和复发性疾病中，子宫内膜癌仍然是一个重大的临床挑战，在过去五十年中几乎没有出现新的治疗策略。Ipatasertib（IPAT）是一种口服生物可利用的泛 AKT 抑制剂，可靶向所有三种 AKT 同工型，并已在临床前模型中显示出抗肿瘤活性，许多癌症类型的临床试验正在涌现。在本研究中，采用 MTT 法评估了 IPAT 或 IPAT 联合紫杉醇（PTX）在子宫内膜癌细胞系和子宫内膜癌原代培养物中的治疗效果。在子宫内膜癌转基因小鼠模型中评估了 IPAT 和 PTX 对子宫内膜肿瘤生长的影响。采用 cleaved caspase 测定法评估细胞凋亡，采用 ROS、JC1 和 tetramethylrhodamine ethyl ester 测定法评估细胞应激。采用 Western blot 和免疫组化法评估凋亡和细胞应激标志物以及 DNA 损伤的蛋白表达水平。IPAT 显著抑制细胞增殖，在一定剂量范围内引起细胞周期 G1 期阻滞，并诱导人子宫内膜癌细胞系中的细胞应激和线粒体凋亡。低剂量 IPAT 和 PTX 联合治疗导致人子宫内膜癌细胞系和原代培养物中细胞增殖的协同抑制和 cleaved caspase 3 活性的诱导。此外，IPAT 有效抑制肿瘤生长，同时降低小鼠子宫内膜样子宫内膜癌模型中 Ki67 的蛋白表达水平和 S6 的磷酸化。与 IPAT 单药治疗、PTX 单药治疗或安慰剂治疗的小鼠相比，IPAT 和 PTX 联合治疗导致磷酸化 H2AX 和 KIF14 的表达增加，分别为 DNA 损伤和微管功能障碍的标志物。本研究结果为评估 IPAT 和 IPAT 与 PTX 联合治疗子宫内膜癌的未来临床试验提供了生物学依据。
