关键词: 结肠癌细胞(HCT-8), 细胞周期

Abstract: Abstract:Objective To study the effects of low dose radiation(LDR) on cell cycle and the expression of its related proteins of HCT-8 cells and provide theoretical basis for clinical application of LDR.Methods Human colon carcinoma cells(HCT-8) cultivated in vitro were divided into seven groups:sham radiation group(0 mGy),LDR groups(25,50,75,100 and 200 mGy) and high dose radiation group(1000 mGy).The proliferation rate was detected with the method of cell count and MTT, the ratios of G₀/G₁,S,G₂/M in cell cycle were determined with flow cytometry after LDR,The cell cycle and expressions of related signal proteins were analyzed with protein assay system.Results The results of cell count and MTT showed that there were no significant differentes of proliferation rate of HCT-8 cells between 25,50,75,100,200 mGy LDR groups and sham radiation group(P>0.05);compared with high dose radiation group,there were significant differences(P<0.05).The result of flow cytometry showed that the ratio of G₀/G₁ phase of HCT-8 cells increased (P>0.05),the ratio of S phase decreased significantly(P<0.05),and the ratio of G₂/M phase increased obviously(P<0.05) 12 and 24 h after 75 mGy radiation compared with sham radiation group.There were no significant differences of the ratios of G₀/G₁,S,and G₂/M phases of HCT-8 cells 48 h after radiation compared with sham radiation group(P>0.05).The protein assay result indicated that the expressions of AKt,PCNA,p27,CDK2,cyclin E,EGFR,ERK1/2,p-ERK,p-GSK-32/β in HCT-8 cells after LDR decreased compared with sham radiation group.Conclusion LDR has no stimulating effect on HCT-8 cells.However,to some extent LDR suppress the expressions of some proteins related to proliferation and cell cycle.

Key words: colon carcinoma cell(HCT-8), cell cycle