TY - JOUR T1 - Epigallocatechin-3-gallate Enhances Radiation Sensitivity in Colorectal Cancer Cells Through Nrf2 Activation and Autophagy JF - Anticancer Research JO - Anticancer Res SP - 6247 LP - 6252 DO - 10.21873/anticanres.12980 VL - 38 IS - 11 AU - TUMENJIN ENKHBAT AU - MASAAKI NISHI AU - KOZO YOSHIKAWA AU - HIGASHIJIMA JUN AU - TAKUYA TOKUNAGA AU - CHIE TAKASU AU - HIDEYA KASHIHARA AU - DAICHI ISHIKAWA AU - MASAHIDE TOMINAGA AU - MITSUO SHIMADA Y1 - 2018/11/01 UR - http://ar.iiarjournals.org/content/38/11/6247.abstract N2 - Background/Aim: Epigallocatechin-3-gallate (EGCG) is a major polyphenolic component of green tea. EGCG plays a potential role in radio-sensitizing cancer cells. The combined effect of EGCG and radiation was investigated in a colorectal cancer cell line, focusing on nuclear factor (erythroid-derived 2)-like 2 (Nrf2) autophagy signalling. Materials and Methods: HCT-116 cells were treated with 12.5 μM EGCG for different periods of time, 2 Gy radiation, or both. Cell viability was determined with the WST-8 assay. The number of colonies was determined with the colony formation assay. mRNA expression of LC3 and caspase-9 was analyzed with quantitative real-time polymerase chain reaction. Results: Combination treatment with EGCG and radiation significantly decreased the growth of HCT-116 cells. The number of colonies was reduced to 34.2% compared to the control group. Immunofluorescence microscopy images showed that nuclear translocation of Nrf2 was significantly increased when cells were treated with the combination of EGCG and radiation compared to the control and single-treatment groups. Combined treatment with EGCG and radiation significantly induced LC3 and caspase-9 mRNA expression. Conclusion: EGCG increased the sensitivity of colorectal cancer cells to radiation by inhibiting cell proliferation and inducing Nrf2 nuclear translocation and autophagy. ER -