RT - Journal Article T1 - Radiosensitizing effects of gemcitabine on aerobic and chronically hypoxic HeLa and MRC5 cells in-vitro JF - Int-J-Radiat-Res YR - 2012 JO - Int-J-Radiat-Res VO - 10 IS - 1 UR - http://ijrr.com/article-1-878-en.html SP - 11 EP - 18 K1 - Gemcitabine K1 - radiosensitizer K1 - hypoxia K1 - HeLa and MRC5 cells K1 - cytochalasin blocked micronucleus assay AB - Background: Gemcitabine (2′, 2′-difluoro-2′- deoxycytidine, an analogue of deoxycytidine) is a relatively new drug with wide range of anti-cancer activity. In this study, radiosensitizing effects of gemcitabine was investigated on HeLa and MRC5 human originated cell lines under both chronically hypoxic and normoxic conditions using the micronucleus (MN) assay. Materials and Methods: For induction of chronic hypoxia, the cell culture flasks were saturated with N2 gas. To evaluate the radiosensitizing effects, in the presence of the non-genotoxic concentration (1ng/ml) of gemcitabine, cells were exposed to different doses (0.5, 1, 2 Gy) of X-ray in both chronically hypoxic and normoxic conditions. Results: Results showed that there was no significant difference in MN induction under chronically hypoxic and normoxic condition when using 1 ng/ml gemcitabine alone, however in the absence of drug, MN induction was significantly different in irradiated cells (P LA eng UL http://ijrr.com/article-1-878-en.html M3 ER -