B7-H3对小鼠Lewis肺癌细胞生长的影响

目的观察B7-H3对Lewis肺癌(LLC)细胞生长的影响并探讨其作用机制。方法采用40只C57BL/6小鼠，右腋下接种Lewis肺癌细胞悬液，建立皮下种植瘤模型，随机分为4组，在瘤体附近皮下围绕瘤体分别注射多西他赛、B7-H3及多西他赛+B7-H3，以注射空质粒作为对照。注射后第1、3、7、14天测量肿瘤的大小，计算肿瘤的体积；采用免疫组织化学及Western blot检测瘤组织中B7-H3的表达；采用ELISA检测小鼠血清IL-12的水平。结果多西他赛和B7-H3均能分别抑制肿瘤的生长，两者联合则抑制作用增强，多西他赛组、B7-H3组及多西他赛+B7-H3组的抑瘤率分别为32.98%、28.59%和4595%，上述处理后肿瘤细胞凋亡率均比对照组明显提高(P<0.01)；B7-H3组及多西他赛+B7-H3组肿瘤组织中B7-H3的表达下调，但差异无统计学意义(P>0.05)；小鼠血清中IL-12的表达在B7-H3组及多西他赛+B7-H3组均较对照组水平升高(P<0.05)。结论 B7-H3能抑制小鼠Lewis肺癌细胞的生长，其机制可能与通过IL-12诱导激活细胞毒性T细胞而产生抗肿瘤免疫应答有关。

Effect of B7-H3 on Growth of Lewis Lung Carcinoma Cell

Objective To study the inhibitive effect of B7-H3 on the growth of Lewis lung carcinomas(LLC) cell.Methods Forty C57BL/6 mice were subcutaneously inoculated with LLC cells suspension(1×107/ml) in the right armpit.The tumor-bearing mice were randomly divided into four groups:empty plasmid(as control),docetaxel,B7-H3 and docetaxel+B7-H3 were injected subcutaneously around the tumor.Tumor sizes were valued at the first,third,seventh and fourteenth day after injection.B7-H3 expression was detected by immunohistochemistry and Western blot.The level of serum IL-12 was detected by ELISA.Results Tumor was inhibited by docetaxel and B7-H3.The inhibitory rates in the groups of docetaxel,B7-H3 and docetaxel+B7-H3 were 32.98%,28.59% and 45.95%,respectively.The apoptosis rate of tumor cells after treatment was significantly increased(P<0.01).B7-H3 expression in tumor tissue decreased in the groups of B7-H3 and docetaxel+B7-H3,although the difference was not significant(P> 0.05).The level of serum IL-12 increased in the groups of B7-H3 and docetaxel+B7-H3 than that in control group(P<0.05).Conclusion B7-H3 can inhibit the growth of murine Lewis lung cancer cell,and promote cytotoxic T cells induced by IL-12 leading to anti-tumor immune response.