title: Radiosensitization by inhibiting complex I activity in human hepatoma HepG2 cells to X-ray radiation.
abstract: The purpose of this study is to investigate the influence of mitochondrial respiratory chain complex I inhibition on the radiosensitivity of HepG2 cells. The complex I inhibitor rotenone was used to inhibit complex I activity on HepG2 cells before X-ray irradiation. The cytotoxicity of rotenone was analyzed by MTT assay at various doses. Rotenone induced dissipation of mitochondrial membrane potential and increase of intracellular ROS production were observed. Intracellular ATP production level was determined using luciferin-luciferase assay kit. We further analyzed cell survival and cell cycle distribution of a combined treatment which HepG2 cells underwent 0.5 µM rotenone pretreatment firstly and irradiated with different doses of X-ray radiation afterwards. Our results suggest rotenone pretreatment prior to X-ray irradiation could induce a sensitizing effect on HepG2 cells by enhancing X-ray radiation induced proliferation inhibition and cell apoptosis.
authors.affiliation: Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Xin
authors.initials: X
authors.lastname: Zhou
authors.forename: Ruping
authors.initials: R
authors.lastname: Chen
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects*; D042967:Electron Transport Complex I / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D056945:Hep G2 Cells; D006801:Humans; D024101:Mitochondrial Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D011836:Radiation Tolerance / Q000187:drug effects*; D012402:Rotenone / Q000494:pharmacology*; D014475:Uncoupling Agents / Q000494:pharmacology; D014965:X-Rays
chemical_list: D024101:Mitochondrial Proteins; D014475:Uncoupling Agents; D012402:Rotenone; D042967:Electron Transport Complex I