NK细胞对不同人肝癌细胞株的杀伤作用

Activated NK cells against human hepatocellular carcinoma cell lines in vitro and in vivo

目的:观察自然杀伤(NK)细胞对不同肝癌细胞株的体内外抑瘤作用,并检测肝癌细胞MHC-I类链相关蛋白(MIC蛋白)的表达。方法:抽取志愿者外周血50 mL,分离单个核细胞,置入NK细胞试剂盒行孵化及逐级扩增。计算NK细胞对人白血病细胞株K562及人肝癌细胞株BEL7402、HepG2、SMMC7721的杀伤率。接种建立人肝癌细胞株裸鼠移植瘤,进行NK细胞瘤内及瘤周注射;计算各组裸鼠移植瘤的体积,绘制各组肿瘤生长曲线;处死裸鼠,称瘤重,计算NK细胞对各组肿瘤抑制率。检测人肝癌细胞表面MIC蛋白表达。结果:NK细胞对K562细胞杀伤最强,BEL-7402次之,SMMC-7721细胞株杀伤敏感性最低。裸鼠抑瘤实验结果显示NK细胞对于BEL-7402细胞株的抑瘤效果最好,而对于SMMC-7721细胞株的抑瘤效果较差。BEL-7402及HepG2细胞株表面表达MIC,而SMMC-7721则很少表达。结论:NK细胞对于不同人肝癌细胞株体内外抑瘤作用不同,其差异可能和不同肝癌细胞株MIC的表达有关。

AIM： To evaluate the role of natural killer（NK） cells against a variety of human hepatocellular carcinoma（HCC） cell lines in vitro and in vivo,and to investigate the expression of MHC class I chain-related protein（MIC protein） in these HCC cell lines.METHODS： Peripheral blood mononuclear cells（PBMC） were isolated from 50 mL peripheral blood donored by a healthy volunteer and cultured in the NK cell kit followed by amplification and cytokine activation.The release of lactate dehydrogenase（LDH） was detected by lysis experiment.Animal experiments were performed following vaccination with HCC cell lines（BEL7402,HepG2 and SMMC7721） in BALB/c-nu/nu mice.The diameters of the tumors were measured and the growth curves of difference cell lines were delineated.Three weeks later,these mice were sacrificed and the weight of the transplanted tumors was also detected.Furthermore,the expression of MIC protein was determined.RESULTS： The obvious differences of lysis effects of NK cells on different cell lines were observed,in which the lysis effect of NK cells on K562 cells was the strongest,the effect on BEL7402 cells was in the middle and the effect on SMMC7721 cells was the weakest.In animal experiments,NK cells also showed obvious and different restraining effects on a variety of HCC cell line-transplanted tumors in nude mice.The tumor inhibitory rates of NK cells were 43.5% in BEL-7402 cell-transplanted tumor,40.7% in HepG2 cell-transplanted tumor and 36.0% in SMMC-7721 cell-transplanted tumor.The protein expression of MIC was 48.7%,32.8% and 0.9% in the 3 cell lines,respectively.CONCLUSION： The lysis effects of NK cells on a variety of human HCC cell lines are different.The expression of MIC in the tumor cells may play distinct role in evaluating these differences.