CD70在肝癌中的表达及其对淋巴细胞增殖抑制作用的研究

Expression of CD70 in hepatocellular carcinoma and its suppressive impact on the proliferation of lymphocytes

目的探讨CD70基因在肝癌中的表达及其在肝癌免疫逃逸中的作用。方法采用RT-PCR检测CD70在肝癌细胞系和肝癌组织的表达;构建CD70真核表达载体,瞬时转染HepG2细胞,与Jurkat细胞共培养,通过细胞增殖试剂(CCK8)检测对其淋巴细胞增殖的抑制作用。结果①肝癌细胞系BEL-7402、SMMC-7721中CD70表达呈阳性,HepG2细胞中CD70表达呈阴性;10例肝癌组织中3例CD70表达呈阳性,2例癌旁组织CD70表达均呈阴性;②成功构建CD70的真核表达载体,瞬时转染HepG2细胞,与活化的Jurkat细胞共培养。转染CD70后的HepG2与Jurkat共培养后,Jurkat增殖抑制率(65.03%)与空细胞对照组和空载体对照组(38.01%、30.15%)相比显著升高(P<0.01)。结论CD70基因在肝癌中呈阳性表达,并可抑制淋巴细胞的增殖活性,在肝癌细胞免疫逃逸中起了重要作用。

Objective To investigate the expression of the CD70 gene in hepatocellular carcinoma and its role in the immune escape of hepatocellular carcinoma. Methods CD70 expression was determined by RT-PCR. The eukaryotic expression vector （CD70-pcDNA3）was constructed and transiently transfected into the HepG2 cell line. After co-culturing HepG2 with Jurkat, the effects of CD70 on inhibiting lymphocyte proliferation were assessed by the Cell counting kit 8（CCK8）. Results ① CD70 gene presented in BEL-7402 and SMMC-7721 but not in HepG2. CD70 was positive in 3 cases of hepatocellular carcinoma while it was negative in 2 cases of liver tissues adjacent to cancer tissues. ② The eukaryotic expression vector （CD70-pcDNA3） was successfully constructed and transiently transfected into the HepG2 cell line. The HepG2 cell line transfected with the CD70 gene can significantly inhibit the proliferation of PHA-activated Jurkat cells. The proliferation inhibition rate of Jurkat cells co-cultured with HepG2 cells transfected by the CD70 gene was 65.03%, which was significantly higher than that of Jurkat cells and Jurka cells co-cultured with HepG2 cells （38.01% and 30.15%）. Conclusion The CDT0 gene is expressed in hepatocellular carcinoma and can inhibit the proliferation of lymphocytes. The CD70 gene may play an important role in the immune escape of hepatoma cells.