全反式维甲酸诱导胰腺癌细胞凋亡机制研究

目的 维甲酸类药物调节肿瘤细胞生长、分化和凋亡是其防治肿瘤的基础。本研究观察全反式维甲酸(ATRA)诱导体外胰腺癌细胞凋亡的可能机制。方法 胰腺癌细胞Patu8988与ATRA共同孵育。通过DNA断裂分析、TUNEL标记证实凋亡存在，并用流式细胞仪检测凋亡细胞比例。用RT-PCR和Western blot方法检测凋亡诱导过程中p53、bcl-2和bax基因的水平及其表达变化。结果 ATRA处理组细胞凋亡比例明显增加。TUNEL标记和DNA断裂分析发现典型凋亡特征。ATRA处理组bax和phospho-p53(Ser 46)表达上调，但bcl-2表达下调。结论 ATRA能诱导胰腺癌细胞凋亡，其分子机制可能与bcl-2/bax和p53的表达相关。

The mechanisms of the apoptosis of pancreatic cancer cells induced by all-trans retinoic acid

Objective The aim of this study was to observe the effects of all trans retinoic acid (ATRA) on cell growth in vitro and the signal pathway during apoptosis of pancreatic cancer cells induced by ATRA. Methods Pancreatic adenocarcinoma cell line Patu 8988 cells were treated by ATRA. Apoptosis was detected by flow cytometry, DNA degradation assay and TUNEL respectively, and the exprssion of p53 and bcl 2/bax mRNA was assessed by RT PCR, and bcl 2, bax and phospho p53 protein was detected by Western blot. Results After the treatment with ATRA, the apoptotic rates of Patu 8988 cells were increased compared with that in the control. TUNEL assay showed a strong positive reactions occurred after the treatment at 72hr. DNA degradation assay also showed a typical DNA ladder pattern consistent with apoptosis. Apoptosis of Patu 8988 cells was accompanied by the upregulation of bax and phospho p53 (Ser 46) expression, but the expression of bcl 2 is down regulated compared with that in the untreated cells. Conclusions ATRA is able to induce the apoptosis of pancreatic cancer cells, and the upregulated expression of bcl 2/bax and p53 is contributed to the apoptosis of the cells induced by ATRA.