Preliminary study on K562 cells' proliferation inhibition induced by ionizing radiation / 肿瘤研究与临床

ABSTRACT

Objective To investigate the dose response relationship for K562 cells' loss of proliferation ability induced by 60Co γ ray irradiation. K562 cell morphological change and Egr-1 expression level are also investigated. Methods 3H-TdR incoporation assay, Giemsa Staining, RT-PCR were used in this study.Results It was noted that the proliferation inhibition is positively dose-dependent. K562 cells showed extensive changes in both morphology and Giemsa staining characteristics after radiation exposure. The irradiated cells acquired characteristics which the high differentiated cells had only. In the early stage after exposure to 5 Gy 60Co γ ray irradiation. A transient transcriptional upregulation of Egr-1 gene which was related to apoptosis and differentiation was observed.The transcriptional level reached its top on time point of 0.5 ～1 hours after exposure. Eight hours after exposure, the transcriptional level was below normal.Conclusions The proliferation inhibition of K562 cell is positively dose dependent. Egr-1 gene can be rapidly activated after exposure to 5 Gy 60Coγ ray. After exposure to 60Co γ ray irradiation, K562 cells entered into a more mature stage on differentiation of morphological