低剂量率^(32)Pβ射线与高剂量率^(60)Coγ射线对肿瘤细胞杀伤效应对比研究

A comparison study on of tumor cell-killing effects between low-dose-rate β-irradiation of ^(32)Pand γ-irradiation of^(60)Co

探索和比较低剂量率持续β射线和高剂量率γ射线两种不同的照射方式抑制肿瘤细胞增殖特点及其可能的机制。辐射源采用Pβ射线和Coγ射线;;肿瘤细胞采用人宫颈癌HeLa细胞系;;辐射后生物效应用台3260盼蓝排除法、流式细胞周期检测。低剂量率Pβ射线持续照射抑制细胞增殖为渐进性;;允许多数的细胞在倍32增一个或几个细胞周期后死亡;;高剂量率Coγ射线照射对细胞的抑制作用直接、迅速。32Pβ射线对细胞周60期阻滞程度低、时间长;;而Coγ射线则相反。32Pβ低剂量率照射以缓慢持续的抑制肿瘤细胞增殖的特点不60同于Coγ射线照射。持续照射对细胞损伤、修复机制的破坏和对辐射相对敏感的G2期持续阻滞可能是其作60用机制。

The paoer is to elucidate radiobiological charicateristics and radiobiological mechanism in killing tumor cells with low dose rate β?rays and high dose rate γ-rays. HeLa cells were exposed to low?rate β?irradiation of 32P or high?dose?rate γ?irradiation of 60Co. Cell response?patterns were compared between two the types of radiations in terms of their inhibition of cell proliferation and cell cycle blockage, evaluated by typanblue excluded method and flow cytometry, respectively. Results show that there is a different way in growth inhibition effect on HeLa cells between low?dose?rate irradiation of P and high?dose?rate irradiation of Coγ. In exposure to P, the 32 60 32 inhibition of cell proliferation in HeLa cell was a prolong course, whereas and the effect was in a more serious and quick way in Co irradiation. Cell cycle arrest in G2 phase induced by P was lower and more prolong than that 60 32 induced by Co. The inhibition effect on tumor cells between the two types of radiations is different. Impaired DNA 60 repair system by continuous low?dose?rate radiation might contribute to the final radiation effect of P. 32