中文摘要：

目的初步探讨耐药胰腺癌细胞株的耐药性对其放射敏感性的影响。方法选取人胰腺癌细胞株SW1990经氟尿嘧啶（5-FU）、阿霉素和吉西他滨诱导后建立三株耐药细胞亚株（SW1990／FIL1、SW1990／ADM、SW1990／GZ），通过流式细胞仪及直线加速器照射后进行细胞周期及放射生物学相关参数检测。结果细胞周期分析显示，与亲本株SW1990相比，SW1990／FU与SW1990／Gz的Go／G。期比例增高，G2／M期比例明显降低；SW1990／ADM各细胞周期百分比变化不大。集落实验结果表明，与亲本株SW1990相比，SW1990／FU及SW1990／GZ的存活分数（sir2）分别升高26．9％（P＜0．01）和14．4％（P＜0．01），差异有统计学意义；SW1990／ADM的sir2升高1．1％，差异不明显。结论耐药胰腺癌细胞株的耐药性对其放射敏感性具有一定影响，胰腺癌耐药细胞株放射敏感周期G2／M期比例降低，从而导致其放射敏感性降低，耐放射性增加。

英文摘要：

Objective To investigate the impact of the drug resistance on the radioresistance in human pancreatic cancer cell lines. Methods Three drug resistant pancreatic caner cell sublinos induced by fluorouracil （5-FU）, adriamycin （ADM） and gemcitabine respectively, SWI990/FU, SW1990/ADM and SW1990/Gz, were tested for the cell cycle and radio-sensitivity with flow cytometry and clonogenic assay. Results Compared with SW1990, the cell cycle assay indicated higher G0/G1 period percentage in SW1990/FU and SW1990/Gz, but the G2/M period percentage decreased; SW1990/FU had the same while SW1990/Gz had lower S period percentage. SW1990/ADM almost had a similar cell cycle with SW1990. Clonogenic assay showed both SW1990/FU and SW1990/Gz had greater survival fraction （SF2 ） than SW1990, but SW1990/ADM had seemingly similar SF2 as SW1990. Conclusion Drug resistant pancreatic cancer cell lines have reduced G2/M period percentage and increased radioresistance.