三氯化镧对体外培养人肝癌细胞的抑制作用

Inhibitory effects of LaCl_3 on hepatocellular carcinoma

目的:研究三氯化镧(LaCl3)对人肝癌细胞株SMMC-7721生长的影响及其作用机理。方法:体外培养的人肝癌细胞SMMC-7721,给予LaCl3(0.05、0.10、0.50及1.00 mmol.L-1)培养不同时间(1、3、5和7 d),观察癌细胞生长曲线、集落抑制率、培养上清中甲胎蛋白(AFP)的变化。采用流式细胞术检测SMMC-7721细胞周期变化。免疫组织化学检测培养细胞CyclinD1、PCNA、CDK4及P16的表达情况。结果:MTT法显示0.50及1.00 mmol.L-1LaCl3对SMMC-7721生长具有明显的抑制作用,且具有剂量和时间的依赖性;0.10和0.50 mmol.L-1的LaCl3对肝癌细胞集落的形成抑制率分别为51%和67%(P<0.05),1.00 mmol.L-1LaCl3的集落形成抑制率达97%(P<0.01);不同剂量LaCl3作用SMMC-7721细胞3 d后,细胞周期发生明显变化,表现为G0/G1期细胞百分数增加,与对照组比较差异有显著性(P<0.01)。0.10、0.50及1.00 mmol.L-1LaCl3均可抑制AFP的分泌,其中以1.00 mmol.L-1LaCl3组作用最显著(P<0.01)。免疫细胞化学结果显示,LaCl3促进P16蛋白的表达,使Cyclin D1、PCNA和CDK4蛋白的表达下降。结论:LaCl3对SMMC-7721细胞生长具有明显的抑制作用,其机制可能与阻断细胞周期进程、降低细胞的恶性程度有关。

Objective To observe the inhibitory effect of LaCl3 on the growth of human hepatocellular carcinoma cell lines SMMC-7721 and its mechanism. Methods The cells were treated with different doses of LaCl3 and the growth curve, colony inhibitory rates, the levels of AFP of cultured cells were detected at 1, 3 , 5 and 7 days after they were dealed with LaCl3. The changes of cell cycle were detected by flow cytometry and the expressions of cell cycle protein CyclinD1, PCNA, CDK4 and P16 were observed by immunocytochemistry staining . Results MTT test showed that SMMC-7721 cell proliterating activity was obviously inhibited by LaCl3 in a time and dose related manner at concentrations of 0. 50 and 1.00 mmol· L^-1. The colony forming inhibitory rate of 0. 10, 0.50 and 1.00 mmol· L^- 1 LaCl3 were 51% , 67% and 97% （P〈0.05, P〈0.01 ） .Cell cycle progress of SMMC-7721 changed obviously when treated with different does of LaCl3, the percent of G0/G1 phase was higher and S phase lower, the difference was significant compared with control group （P〈0.01）. 0. 10, 0.50 and 1.00 mmol · L^-1 LaCl3 could decreased the levels of AFP, the effect of 1.00 mmol · L^ -1 LaCl3 was notable （P〈 0.01 ）. Immunocytochemistry showed that LaCl3 could enhance the expression of P16 protein and decrease the expressions of CyclinD1 , PCNA and CDK4. Conclusion LaCl3 could inhabit the growth of SMMC-7721 cell and its mechanism might be connected with the inhibition of cell cycle progress and decrease the degree of malignancy.