EGCG enhances cancer cells sensitivity underCoγ radiation based on miR-34a/Sirt1/p53.
Food Chem Toxicol. 2019 Sep 5 ;133:110807. Epub 2019 Sep 5. PMID: 31494133
Ionizing radiation (IR) resistance and toxicity to normal cells are the main problems in radiotherapy for cancer. In this study, we demonstrated that epigallocatechin gallate (EGCG) could inhibit effectively IR-induced damage to mouse normal hepatic cells AML-12, and improve dramatically the radiosensitivity of mouse hepatoma cells H22 toCoγ. In addition, the different effects of EGCG and underlying molecular mechanisms based on microRNA-34a (miR-34a) and apoptosis-related proteins were investigated by cells viability analysis, quantitative realtime PCR (qRT-PCR), Western blot and cells transfection. The results indicated EGCG playedthe key role of radiosensitization on H22 cells by activating the miR-34a/Sirt1/p53 signaling pathway. Besides, EGCG could down-regulate the expression of anti-apoptotic protein Bcl-2, and up-regulate the expression of pro-apoptotic proteins Bax and Caspase-3 in H22 cells. Interestingly, EGCG showed contrary results on AML-12 cells. Therefore, radiation protection and radiosensitization of EGCG were associated with apoptosis regulated by miR-34a/Sirt1/p53 signaling pathway.