Effects of baicalin on the apoptosis and cell cycle of colorectal cancer cells in orthotopic transplantation mice model with mismatch repair gene deficient / 中华消化外科杂志

ABSTRACT

Objective To study the effect of baicalin on the apoptosis and cell cycle of colorectal cancer cells in orthotopic transplantation mice model with mismatch repair gene hMLH1 deficient.Methods Sixty orthotopic transplantation mice models of human colorectal cancer cell line HCT1 16 expressing green fluorescent protein (GFP) were established,and were randomly divided into the control group and the 50,100,200 mg/kg baicalin groups according to the random number table.Mice in the 50,100,200 mg/kg baicalin groups received intragastric infusion of baicalin at the corresponding dosages twice a day,while mice in the control group received intragastric infusion of 5％ NaHCO3.Cell cycles and apoptotic rates of the HCT116-GFP cells were detected by flow cytometry and TUNEL method respectively.Differences between the 2 groups were analyzed using the analysis of variance or chi-square test,and differences within each group were analyzed using the LSD-t test.Results The orthotopic transplantation mice models of human colorecta] cancer were successfully constructed,and there was no significant difference in the body weight of the mice and tumor size among the 4 groups (F =0.343,0.107,P ＞0.05).The proportion of HCT116-GFP cells in the G2/M phase in the 50,100,200 mg/kg baicalin groups were 22％±6％,18％±7％ and 19％±6％,which were significantly higher than 7％ ±5％ of the control group (t =5.421,3.483,3.575,P ＜0.05).There were no significant differences in the proportion of HCT116-GFP cells in the G2/M phase among the 50,100,200 mg/kg baicalin groups (F =1.291,P ＞ 0.05).The apoptotic rates of HCT116-GFP cells in the 50,100,200 mg/kg baicalin groups were significantly higher than the control group (t =7.163,3.703,2.688,P ＜0.05).The apoptotic rate of the 50 mg/kg baicalin group was significantly higher than that of the 200 mg/kg baicalin group (t =2.259,P ＜ 0.05).Conclusions Baicalin significantly inhibits tumor growth in the orthotopic transplantation mice model with mismatch repair gene hMLH1 deficient.After treated with baicalin,the cell cycle is arrested at the G2/M phase,thus the tumor growth is inhibited.