乳腺癌细胞耐药过程中p38MAPK活性与细胞凋亡的关系

目的研究乳腺癌细胞耐药过程中p38MAPK活性与细胞凋亡的关系，探讨p38MAPK信号转导途径在其中的作用。方法 以p38MAPK特异性抑制剂SB203580处理乳腺癌耐药细胞MCF-7／ADM，采用流式细胞技术分析对细胞凋亡的影响；MTT检测MCF-7／ADM细胞对阿霉素的半数药物抑制浓度（IC50）；Western blot检测SB203580处理MCF-7／ADM和MCF-7两株细胞后p38MAPK蛋白表达水平；RT—PCR检测细胞内MDR-1 mRNA水平。结果SB203580（10μmol／L）干预24h后MCF-7／ADM细胞的凋亡率为（26．73±4．90）％，与未干预组和对照组凋亡率相比差异有显著统计学意义（F=143．80，P〈0．001）；MCF-7／ADM细胞对阿霉素的敏感性明显提高（F=148927．10，P〈0．001），相对逆转率达68．45％；与对照组和未干预组相比，干预组的MDR1 mRNA（F=9139．24，P〈0．001）及p38MAPK（F=685．42，P〈0．001）蛋白表达水平明显降低。结论p38MAPK信号转导途径与乳腺癌耐药密切相关，其可能机制为p38MAPK保护人乳腺癌耐药细胞（MCF-7／ADM）逃避凋亡，阻断该通路可增强乳腺癌耐药细胞发生凋亡。

Relationship between p38MAPK activity and apoptosis during drug resistance of breast carcinoma cell lines

Objective To investigate the relationship between p38MAPK activity and eell apoptosis and the effect of p38MAPK signal transduetion pathway during drug resistance of breast carcinoma cell lines. Methods Flow cytometry （ FCM ） was used to analyze the effect of p38MAPK inhibitor SB203580 on the apoptosis of MCF-7/ADM cell, a drug resistant human breast cancer cell. The inhibition concentration 50% （ IC50 ） of adriamycin on MCF-7/ADM was determined by MTT method in vitro. The MDR-1 mRNA level and p38MAPK protein expression in each group were detected by RT-PCR and Western Blot, respectively. Results After SB203580 action for 24 hours, the apoptosis rate of MCF-7/ADM was （26.73 ± 4.90） % , which was significantly lower than that of the control group and the untreated group （ F = 143. 80, P 〈 0. 001 ）. The relative reverse rate of the sensitivity of MCF-7/ADM to adriamycin in the SB203580 treated group was 68.45 %. The p38MAPK protein （ F = 685.42,P 〈 0. 001 ） and MDR-1 mRNA expression （ F = 913 9.24, P 〈 0. 001） after 24-hour SB203580 action were markedly lower than the control group and the untreated group. Conclusion p38MAPK signal pathway plays an important role in drug resistance of breast carcinoma cell. p38MAPK can protect MCF-7/ADM cells from apoptosis, and blocking the p38MAPK signal pathway can increase the apoptosis in drug resistant breast carcinoma cell lines.