The biological effect of 125I seeds continuous low dose rate irradiation on H1299 cell line：comparison with 60Co γ-ray high dose rate irradiation / 介入放射学杂志

ABSTRACT

Objective To investigate the biological effect of 125I seeds continuous low dose rate (CLDR) irradiation and 60Co γ-ray high dose rate (HDR) irradiation on H1299 cell line of non-small cell lung cancer (NSCLC). Methods H1299 cells in exponential growth were separately irradiated with 125I seeds CLDR irradiation and 60Co γ-ray HDR irradiation. The cell survival fraction was inspected with clone formation experiment, the cell cycle and apoptosis rate was determined with flow cytometry, and the expressions of Bax and Bcl-2 proteins were measured by Western blot method. Results With the irradiation dose increasing, the anti-proliferation effect of 125I seeds CLDR irradiation on H1299 cells became more remarkable than that of 60Coγ-ray HDR irradiation. When the irradiation dose reached 4 Gy, the G2/M phase percentage and the apoptotic ratio of H1299 cells in 125I seeds CLDR irradiation group were 21.77±0.31%and 13.79±0.50% respectively, which were only 18.85±0.99% and 8.79±0.22% respectively in 60Co γ-ray HDR irradiation group, the difference was statistically significant (P<0.05). In 125I seeds CLDR irradiation group the expression of Bax protein was remarkably up-regulated, while the expression of Bcl-2 protein was down-regulated. Conclusion The inhibition effect of 125I seeds CLDR internal irradiation on the proliferation of H1299 cells is more obvious than that of 60Co γ-ray HDR irradiation. In 125I seeds CLDR irradiation group, the imbalance of Bcl-2/Bax ratio may play an important role in achieving the antitumor effect.