Li Peng, Zhao Qing-Li, Jawaid Paras, Rehman Mati Ur, Sakurai Hiroaki, Kondo Takashi
Department of Radiological Sciences, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan.
Department of Cancer Cell Biology, Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Sugitani 2630, Toyama, 930-0194, Japan.
Cell Stress Chaperones. 2016 Sep;21(5):873-81. doi: 10.1007/s12192-016-0712-6. Epub 2016 Jul 22.
KRAS mutant lung cancers have long been considered as untreatable with drugs. Transforming growth factor-β-activated kinase 1 (TAK1) appears to play an anti-apoptotic role in response to multiple stresses and has been reported to be a responsive kinase that regulates cell survival in KRAS-dependent cells. In this study, in order to find a useful approach to treat KRAS mutant lung cancer, we focused on the combined effects of 5Z-7-oxozeaenol, a TAK1 inhibitor, with hyperthermia (HT) in KRAS mutant lung cancer cell line A549. Annexin V-FITC/PI assay, cell cycle analysis, and colony formation assay revealed a significant enhancement in apoptosis induced by HT treatment, when the cells were pre-incubated with 5Z-7-oxozeaenol in a dose-dependent manner. The enhanced apoptosis by 5Z-7-oxozeaenol was accompanied by a significant increase in reactive oxygen species (ROS) generation and loss of mitochondrial membrane potential (MMP). In addition, western blot showed that 5Z-7-oxozeaenol enhanced HT-induced expressions of cleaved caspase-3, cleaved caspase-8, and HSP70 and decreased HT-induced expressions of Bcl-2, p-p38, p-JNK, and LC3. Moreover, 5Z-7-oxozeaenol pre-treatment resulted in a marked elevation of intracellular calcium level which might be associated with endoplasmic reticulum (ER) stress-related pathway. Taken together, our data provides further insights of the mechanism of action of 5Z-7-oxozeaenol and HT treatment, and their potential application as a novel approache to treat patients with KRAS mutant lung cancer.
KRAS 突变型肺癌长期以来一直被认为无法用药物治疗。转化生长因子-β 激活激酶 1（TAK1）似乎在应对多种应激时发挥抗凋亡作用，并且据报道它是一种在 KRAS 依赖性细胞中调节细胞存活的反应性激酶。在本研究中，为了找到治疗 KRAS 突变型肺癌的有效方法，我们聚焦于 TAK1 抑制剂 5Z-7-氧代玉米烯醇与热疗（HT）联合作用于 KRAS 突变型肺癌细胞系 A549 的效果。膜联蛋白 V-FITC/PI 检测、细胞周期分析和集落形成检测显示，当细胞以剂量依赖性方式预先与 5Z-7-氧代玉米烯醇孵育时，热疗诱导的细胞凋亡显著增强。5Z-7-氧代玉米烯醇增强的细胞凋亡伴随着活性氧（ROS）生成的显著增加和线粒体膜电位（MMP）的丧失。此外，蛋白质印迹显示 5Z-7-氧代玉米烯醇增强了热疗诱导的裂解型半胱天冬酶-3、裂解型半胱天冬酶-8 和热休克蛋白 70 的表达，并降低了热疗诱导的 Bcl-2、磷酸化 p38、磷酸化 JNK 和微管相关蛋白 1 轻链 3（LC3）的表达。此外，5Z-7-氧代玉米烯醇预处理导致细胞内钙水平显著升高，这可能与内质网（ER）应激相关途径有关。综上所述，我们的数据进一步揭示了 5Z-7-氧代玉米烯醇和热疗的作用机制，以及它们作为治疗 KRAS 突变型肺癌患者的新方法的潜在应用。
