ABSTRACT
AIM:To investigate the efficiency of 2-methoxyestradiol (2-ME) as radiosensitizing agent for the treatment of lung cancer cells. METHODS:Cell line A549 and GLC-82 originated from human non-small cell lung cancer were cultured in vitro. Study group (2-ME in different concentrations) and control group without 2-ME were set up. Cell proliferation was measured by MTT assay that lung cancer cells were treated with 2-ME for 24 h,then the cells were exposed from 0 to 8Gy radiation,and the survival fraction was determined by clone forming test. Flow cytometry was used to measure the effects of 2-ME on cell cycle distribution. RESULTS:MTT assay showed minimum effective concentration value was 0.15625×10~(-6) mol/L in GLC-82 and 1.25×10~(-6) mol/L in A549 cells. Compared to control group,exposed GLC-82 cells or A549 cells to minimum effective concentration of 2-ME for 24 h before irradiation resulted in an enhancement of radiation. The protection enhancement factor was 1.98 and 2.06 in GLC-82 and A549 cells,respectively. Flow cytometry analysis of cell cycle progression demonstrated G_2/M phase arrest in both cells in a dose dependent manner. No obvious change of CDK2 activity in both GLC-82 cells and A549 cells was observed. CONCLUSION:2-ME enhances radiosensitivity by G_2/M phase arrest in the cell cycle.