Zhao Chun-Bo, Shi Lei, Pu Hai-Hong, Zhang Qing-Yuan
Department of Radiation Oncology, the Third Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, 150086, China.
Department of Radiation Oncology, the Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang Province, China.
Pathol Oncol Res. 2017 Jan;23(1):47-53. doi: 10.1007/s12253-016-0076-3. Epub 2016 Jun 24.
We aimed to investigate the influence of radiation on hypoxia-treated breast cancers cells and its underlying mechanism. We mimicked the hypoxic response in MCF-7 cells by the treatment of CoCl. Meanwhile, hypoxic MCF-7 cells induced by CoCl or untreated MCF-7 cells were treated with or without radiation, and then treated with or without hypoxia inducible factors-1α (HIF-1α) inhibitor. Subsequently, glucose update and lactate release rate were determined by commercial kits, as well as the expressions of HIF-1α and the glucose metabolic pathway related genes, including fructose biphoshatase 1 (FBP1), glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA), hexokinase 2 (HK2), and isocitrate dehydrogenase 2 (IDH20) were detected by western blotting and/or RT-PCR. The results showed that glucose uptake rate and lactate release rate were increased in cells under hypoxia and/or radiation condition compared with untreated cells (p < 0.05), while the addition of HIF-1α inhibitor decreased these rates in hypoxia + radiation treated cells (p < 0.05). In addition, compared with untreated cells, the mRNA and protein levels of HIF-1α were significantly increased under hypoxia and radiation condition (p < 0.05), while which decreased after the addition of HIF-1α inhibitor (p < 0.05). Similar content changing trends (all p < 0.05) were observed in FBP1, IDH2, GLUT1, and LDHA but not HK2. In conclusion, the combination of radiation and hypoxia could promote the glucose metabolism. Furthermore, HIF-1α might inhibit the promoting effect of radiation on glycolysis in hypoxic MCF-7 cells by regulating the glucose metabolic pathway.
我们旨在研究辐射对缺氧处理的乳腺癌细胞的影响及其潜在机制。我们通过氯化钴处理模拟MCF-7细胞中的缺氧反应。同时，用或不用辐射处理由氯化钴诱导的缺氧MCF-7细胞或未处理的MCF-7细胞，然后用或不用缺氧诱导因子-1α（HIF-1α）抑制剂处理。随后，通过商业试剂盒测定葡萄糖摄取和乳酸释放率，以及通过蛋白质印迹和/或逆转录聚合酶链反应检测HIF-1α和葡萄糖代谢途径相关基因的表达，包括果糖双磷酸酶1（FBP1）、葡萄糖转运蛋白1（GLUT1）、乳酸脱氢酶A（LDHA）、己糖激酶2（HK2）和异柠檬酸脱氢酶2（IDH20）。结果表明，与未处理的细胞相比，缺氧和/或辐射条件下的细胞中葡萄糖摄取率和乳酸释放率增加（p<0.05），而添加HIF-1α抑制剂可降低缺氧+辐射处理细胞中的这些比率（p<0.05）。此外，与未处理的细胞相比，缺氧和辐射条件下HIF-1α的mRNA和蛋白质水平显著增加（p<0.05），而添加HIF-1α抑制剂后其水平降低（p<0.05）。在FBP1、IDH2、GLUT1和LDHA中观察到类似的含量变化趋势（均p<0.05），但在HK2中未观察到。总之，辐射和缺氧的联合作用可促进葡萄糖代谢。此外，HIF-1α可能通过调节葡萄糖代谢途径抑制辐射对缺氧MCF-7细胞糖酵解的促进作用。
