p21^(WAF1/CIP1)过表达对人肝癌细胞恶性表型和细胞凋亡的影响

Effects of overexpression of p21 WAF1/CIP1 on the malignant phenotype and apoptosis of human hepatocellular carcinoma cells

目的探讨ｐ２１ＷＡＦ１／ＣＩＰ１过表达对人肝癌细胞恶性表型和细胞凋亡的影响。方法用带有ｐ２１的真核表达载体ＰＣＥＰ，经基因转染，使其在有ｐ５３突变的人肝细胞癌细胞系（ＨＣＣ９２０４）中表达；通过流式细胞仪、透射电镜和ＤＮＡ电泳确定凋亡细胞。结果转基因后Ｇ１期细胞增加，并且在Ｇ１期前出现一凋亡峰，凋亡细胞占被检细胞总数的２２５％；电镜下可见部分细胞体积缩小，胞膜完整，有出芽现象，细胞器结构完整，致密的染色质边集于核膜内侧，呈明显的凋亡细胞的形态；琼脂糖凝胶电泳出现ＤＮＡ梯形条带。转染ｐ２１后，细胞的恶性表型发生了逆转，表现为细胞在软琼脂中克隆形成能力降低，ＢｒｄＵ掺入量Ａ值由对照组的１．３８±０．１１明显下降为０．７７±０．０６（Ｐ＜０．０５）。结论ＰＣＥＰｐ２１ＷＡＦ１／ＣＩＰ１能够抑制肝癌细胞的生长及诱导细胞凋亡。

Objective To study the effects of overexpression of p21 WAF1/CIP1 on the malignant phenotype and apoptosis of human hepatocellular carcinoma cells. Methods p21 WAF1/CIP1 gene was transfected into a human hepatocellular carcinoma cell line, HCC 9204 with p53 mutation. Flow cytometry (FLC), transmission electron microscopy (EM) and DNA electrophoresis were used to identify apoptosis. Results The transfected HCC 9204 showed increase in cell number in G 1 phase of cell cycle. Apoptosis was confirmed by the appearance of apoptotic peak on FLC, characteristic ultrastructural changes on EM and DNA laddering on electrophoresis. Apoptotic cells accounted for 22.5% of the total p21 transfected cells. An alteration of the malignant phenotype of cells was evidenced by the loss of anchorage independent growth in soft agar and reduction BrdU incorporation. Conclusion The results indicate that the p21 WAF1/CIP1 can inhibit proliferation and induce apoptosis of hepatocellular carcinoma cells with p53 mutation.