化疗诱导人肝癌细胞凋亡中p53和bcl-2基因的调控

目的 建立化疗药物丝裂霉素诱导肝癌细胞凋亡的模型，初步探讨在该凋亡过程 中重要凋亡相关基因ｐ５３和ｂｃｌ－２的调控作用。方法 用丝裂霉素诱导人肝癌细胞系ＨｅｐＧ２凋亡，我显微镜和透射电镜观察肝癌细胞的形态学改变，琼脂糖凝胶电泳检测凋亡细胞ＤＮＡ片段的梯状条带，用流式细胞仪免疫荧光法检测凋亡不同时期Ｐ５３和Ｂｃｌ－２蛋白的表达量。结果 ８ｍｇ／ｍｌ丝裂霉素作用１２，２４，４８ｈ后，Ｐ５３蛋白表达量明显增高，尤以１２ｈ明显，而后逐渐下降。Ｂｃｌ－２蛋白在整个凋亡过程中无明显变化。结论 在化疗药物丝裂霉素诱导肝癌细胞凋亡过程中，ｐ５３基因参与了调控，并为凋亡信号传导途径中的早期事件。丝裂霉素诱导的肝癌细胞凋亡途径为ｐ５３依赖方式，而在该凋亡过程中，ｂｃｌ－２基因的调控并不重要。

Regulation of p53 and bcl-2 genes in apoptosis of human liver cancer cells induced by chemotherapy

Objective To determine whether the important apoptosis related genes of p53 and bcl 2 participate in the regulation of apoptosis of human liver cancer cells by establishing the model of apoptosis of human liver cancer cells induced by mitomycin C (MMC). Methods The selected human liver cancer cell line HepG 2 was treated with 8mg/ml MMC. The morphological changes of the cells were observed using fluorescent and electron transmission microscopy and the DNA fragments of the cells analyzed by agarose gel electrophoresis to testify cell apoptosis. The expression of p53 and bcl 2 genes was detected by flow cytometry. Results The morphological observation and biochemical examination showed that MMC induced the HepG 2 cells to undergo apoptosis. After administration of MMC, the expression of p53 gene changed obviously while that of bcl 2 gene was not apparent. Conclusion p53 plays an important role in the regulation of apoptosis induced by MMC in HepG2 cells. This regulation may be an early event in apoptotic signal pathway. Meanwhile, the apoptosis of the cells is p53 dependent. However, bcl 2 gene may not participate in the control of this apoptosis.