Department of Gastrointestinal Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan 450008, P.R. China.
Mol Med Rep. 2021 Apr;23(4). doi: 10.3892/mmr.2021.11879. Epub 2021 Feb 4.
Hyperthermia is one of the most widely employed adjuvant treatments for cancer, especially for hyperthermic intraperitoneal chemotherapy, and has few side effects. Gastric cancer has various hyperthermia sensitivities, but the exact molecular mechanisms remain to be elucidated. In the present study, western blotting was performed to detect differential expression of proteins that have been reported to be upregulated in gastric cancer. Following knockdown of these proteins, apoptosis was measured by Annexin V‑FITC/propidium iodide (PI) double staining and hyperthermia treatment was applied. To evaluate the effect of cyclin‑dependent kinase 6 (CDK6) on hyperthermia‑induced apoptosis, CDK6 was knocked down or inhibited by the addition of a specific inhibitor and subsequent PI staining and cell proliferation, migration and invasion assays were performed. Hyperthermia‑induced protein kinase B (AKT) expression and phosphorylation inhibition were detected. As demonstrated in the present study, the hyperthermia‑induced proteins kinesin family member 11 (KIF11), cyclin‑dependent kinase 6 (CDK6), stromal antigen 2, NIMA‑related kinase 2 and karyopherin subunit α 4 were highly expressed in gastric cancer cells, including SH‑10‑TC and HGC‑27 cells. Knockdown of KIF11 significantly increased apoptosis without hyperthermia treatment and CDK6 significantly increased hyperthermia‑induced apoptosis, prompting the present study to focus on CDK6. It was further confirmed that CDK6 activity was critical for decreasing hyperthermia‑induced apoptosis and for cell proliferation. Hyperthermia‑induced AKT expression and phosphorylation inhibition is potentially the main cause of CDK6 transcriptional upregulation. Taken together, these findings demonstrated that CDK6 is upregulated via hyperthermia‑induced AKT inhibition and subsequently protected gastric cancer cells from hyperthermia‑induced apoptosis, indicating that it is a potential therapeutic target to sensitize gastric cancer cells to hyperthermia‑based therapy.
热疗是癌症最广泛应用的辅助治疗方法之一，尤其适用于高热腹腔化疗，且副作用较少。胃癌具有多种热疗敏感性，但确切的分子机制尚待阐明。在本研究中，通过蛋白质印迹法检测已报道在胃癌中上调的差异表达蛋白。敲低这些蛋白后，通过 Annexin V-FITC/碘化丙啶（PI）双染法检测细胞凋亡，并进行热疗处理。为了评估周期蛋白依赖性激酶 6（CDK6）对热疗诱导凋亡的影响，通过添加特异性抑制剂敲低 CDK6，并进行 PI 染色和细胞增殖、迁移和侵袭实验。检测热疗诱导的蛋白激酶 B（AKT）表达和磷酸化抑制。如本研究所示，热疗诱导的蛋白驱动蛋白家族成员 11（KIF11）、周期蛋白依赖性激酶 6（CDK6）、基质抗原 2、NIMA 相关激酶 2 和核孔蛋白亚基α4 在胃癌细胞中高表达，包括 SH-10-TC 和 HGC-27 细胞。在没有热疗处理的情况下，敲低 KIF11 显著增加细胞凋亡，而敲低 CDK6 显著增加热疗诱导的细胞凋亡，这促使本研究专注于 CDK6。进一步证实，CDK6 活性对于降低热疗诱导的细胞凋亡和细胞增殖至关重要。热疗诱导的 AKT 表达和磷酸化抑制可能是 CDK6 转录上调的主要原因。综上所述，这些发现表明，CDK6 通过热疗诱导的 AKT 抑制而上调，从而保护胃癌细胞免受热疗诱导的凋亡，表明其是使胃癌细胞对基于热疗的治疗敏感的潜在治疗靶点。
