THE EFFECT OF CELECOXIB ON RADIOSENSITIVITY ENHANCEMENT OF CERVICAL CANCER HeLa CELLS

Objective To investigate the effect of celecoxib,an inhibitor of cyclooxygenase-2(COX-2),on radiosensitivity enhancement of human cervical cancer HeLa cells and its mechanism. Methods MTT assay was used to measure the proliferation inhibition of celecoxib on HeLa cells and determine the concentration IC50 of celecoxib.The cells were randomized to three groups: drug group(10,20,40,80 μmol/L),control group and blank group.The cells were treated in vitro with different doses of radiation alone(0,2,4,6,8 Gy),celecoxib(20% IC50) alone and radiation combined with celecoxib administrated.The clonogenic assay was performed to determine the radiosensitivity effect of celecoxib on HeLa cells with the concentration of 20% IC50.The cell cycle distribution was analyzed by flow cytometry(FCM) to compare control group with drug group. Results Inhibition of celecoxib on HeLa cell proliferation was dose and time dependent.Values of SF2,D0,Dq,SER displayed the group of radiation combined with celecoxib were significantly lower than those of radiation alone group.Cell population in G0/G1 phase increased and in S phase decreased. Conclusion Celecoxib can increase the radiosensitivity of HeLa cells in cancer of the cervix,which is probably associated with promotion of apoptosis,inhibition of sublethal damage of tumor cells and facilitation of redistribution of tumor cell cycle.