The Medical School, Nankai University, Tianjin, China.
Department of Oncology, Nanyang First People's Hospital, Henan, China.
J Appl Toxicol. 2022 Dec;42(12):1937-1947. doi: 10.1002/jat.4365. Epub 2022 Jul 25.
A hypoxic microenvironment results in significantly elevated hypoxia-inducible factor-1 (HIF-1) level in pancreatic cancer. HIF-1 functions to maintain the survival of cancer cells. The present study was performed to investigate whether inhibition of HIF-1α expression was involved in the in vitro antitumor effect of rhein in pancreatic cancer cells and to explore the underlying mechanism. sh-RNA knockout technique and western blotting were used to investigate the role of HIF-1α in autophagy activation in MiaPaCa-2 and PANC-1 cells. The survival and glycolysis were assessed using MTT assay and colorimetric kits, respectively. Apoptosis was evaluated by detecting the levels of apoptosis-related proteins using western blotting. Among the five pancreatic cancer cell lines, MiaPaCa-2 and PANC-1 cells were more sensitive to hypoxia-induced autophagy. HIF-1α regulated hypoxia-induced autophagy in MiaPaCa-2 and PANC-1 cells. Treatment with rhein inhibited the survival and suppressed glycolysis in MiaPaCa-2 and PANC-1 cells exposed to hypoxia. Bafilomycin A1 enhanced the suppressive effects of rhein on cell survival and glycolysis under hypoxia. Treatment with rhein, but not bafilomycin A1, significantly reduced HIF-1α expression. In conclusion, inhibition of HIF-1α-mediated autophagy enhances the in vitro antitumor activity of rhein in pancreatic cancer cells under hypoxia.
缺氧微环境导致胰腺癌中缺氧诱导因子-1（HIF-1）水平显著升高。HIF-1 的功能是维持癌细胞的存活。本研究旨在探讨抑制 HIF-1α 表达是否参与了大黄素在胰腺癌细胞中的体外抗肿瘤作用，并探讨其潜在机制。sh-RNA 敲除技术和 Western blot 用于研究 HIF-1α 在 MiaPaCa-2 和 PANC-1 细胞中自噬激活中的作用。使用 MTT 测定法和比色试剂盒分别评估细胞存活和糖酵解。通过 Western blot 检测凋亡相关蛋白的水平评估细胞凋亡。在五种胰腺癌细胞系中，MiaPaCa-2 和 PANC-1 细胞对缺氧诱导的自噬更为敏感。HIF-1α 调节 MiaPaCa-2 和 PANC-1 细胞中缺氧诱导的自噬。在缺氧条件下，大黄素处理抑制 MiaPaCa-2 和 PANC-1 细胞的存活并抑制糖酵解。Bafilomycin A1 增强了大黄素在缺氧下对细胞存活和糖酵解的抑制作用。大黄素处理而非 Bafilomycin A1 显著降低了 HIF-1α 的表达。总之，抑制 HIF-1α 介导的自噬增强了大黄素在缺氧条件下对胰腺癌细胞的体外抗肿瘤活性。
