Radiosensitivity of A549 cells transfected by effective STAT3 antisense oligodeoxynucleotides

Objective: To investigate the influence of effective STAT3 antisense oligodeoxynucleotides (AS10) on radiosensitivity of A549 cells. Methods: Oligodeoxynucleotides were tansfected into A549 cells. Cell viability was assessed using CCK-8 assay. Apoptotic assay was performed using Hoechst 33258 staining and Annexin V/PI with FACS analysis, the expressions of STAT3, P-STAT3, Bcl-X1 and Cyclin D1, were measured by Western blot. Results: The expression of STAT3, P-STAT3, Bel-X1 and Cyclin D1 were downregulated. Cell viability was decreased significantly in those groups transfected with AS10 followed by different dose of γ irradiation. Fraction of early apoptosis was increased when combined AS10 transfection with irradiation compared with those cells treated with irradiation alone or NS transfection with subsequent exposure to irradiation. Conclusion: These results indicate that effective STAT3 antisense oligodeoxynucleotides(AS10) can enhance the therapeutic effect of γ-irradiation to A549 cells, which support the role of STAT3 as a potential molecular target for tumor therapies, and also a potential molecular target for enhancement of radiosensitivity of radioresistant tumors. (authors)