Experimental research on radiosensitization mechanisms of the recombinant antisense adenovirus for EGFR in human breast cancer cells

Ojbective: To investigate the radiosensitization mechanisms of the recombinant antisense adenovirus for EGFR（AdE5） in human breast cancer MDA-MB-231cells.Methods: After seeded in culture dishs,MDA-MB-231 cells were treated respectively by X-ray irradiation,AdE5 infection and AdE5 infection combined with X-ray irradiation.Total cellular protein was prepared.The expression of Cyclin-A,Cyclin-D1 and CDK2 were detected by Western Blot to investigate the radiosensitization mechanisms of AdE5.Results: X-ray irradiation induced early Cyclin-A expression,and inhibited its expression later.AdE5 induced early CDK2 expression.Neither X-ray irradiation nor AdE5 affected cyclin-D1 expression.However,when cells were sequentially treated by AdE5 and X-ray irradiation,Cyclin-D1 expression augmented by 4 to 10 times as compared with controls.Conclusion: Recombinant EGFR antisense adenovirus may be able to speed up the G1-phase transition of human breast MDA-MB-231 cells and augment G2/M-phase proportion,so as to increase cellular radiosensitivity.