胰腺癌细胞对5氟脲嘧啶和健择的获得性耐药机制的研究

The mechanism by which pancreatic cancer cells acquire drug resistance against 5-FU and gemcitabine

目的探讨胰腺癌细胞对 5氟脲嘧啶 (5 FU)和健择产生获得性耐药的机制。方法用磺酰罗丹明B蛋白染色法检测细胞毒性作用 ,根据药物剂量与细胞生存的关系计算 5 0 %抑制浓度(IC50 ) ;用RNA酶保护分析和Westernblot法来检测Bcl xL和mcl 1的表达水平。结果 5 FU和健择对 3株胰腺癌细胞均产生了细胞毒性作用。 5 FU长期作用后 ,Capan 1细胞IC50 上升了 2 1倍 (P <0 0 5 ) ;健择长期作用后 ,Capan 1细胞IC50 上升了 1 8倍 (P <0 0 5 ) ;而Mia Paca 2细胞在 5 FU和健择作用前后IC50 明显降低 (P <0 0 5 )。产生获得性耐药细胞的Bcl xL 和mcl 1的表达均上调。结论胰腺癌细胞对 5 FU相对耐药 ,而对健择较为敏感。化疗药物长期作用后 ,抑凋亡基因Bcl xL和mcl 1的表达上调 ,胰腺癌细胞产生了获得性耐药。

Objective To investigate the mechanism by which pancreatic cancer cells(PCC) acquire drug resistance against 5-FU and gemcitabine. Methods The cytotoxic effects of 5-FU and gemcitabine on PCC ( Panc-1, Mia-Paca-2 andCapan-1) were assessed by using Sulforhodamine B and the expression of anti-apoptotic genes of the Bcl-x L and mcl-1 were analyzed by RNase protection assay and Western blot. Results5-FU and gemcitabine effect cytotoxicity towards PCC. After repeated treatment with 5-FU, the IC 50 values in Capan-1 cells increased by 2.1 fold (P<0.05).In case of gemcitabine, the IC 50 in Capan-1 cells raised by 1.8 fold (P<0.05). RNase protection assay and Western blot analysis showed a negative correlation between Bcl-x L and mcl-1 expression and the sensitivity to 5-FU and gemcitabine after 5-FU and gemcitabine treatment. Conclusion Pancreatic cancer cell lines are generally more resistant to 5-FU than gemcitabine. The expression of Bcl-x L and mcl-1 was upregulated following repeated exposure to 5-FU or gemcitabine suggesting that the activation of anti-apoptotic genes Bcl-x L and mcl-1 contributes to the chemoresistance of pancreatic cancer cells.