中文摘要：

目的研究COX-2选择性抑制剂塞来昔布与多柔比星（doxorubicin,ADM）联合应用对乳腺癌MCF-7细胞和Sk-Br-3细胞的抗肿瘤作用,探讨塞来昔布是否对多柔比星具有减毒增效作用。方法实验分为对照组,塞来昔布组,多柔比星组和联合用药组。用MTT法检测药物对MCF-7细胞和Sk-Br-3细胞的生长抑制效应;Western blot测定MCF-7细胞和Sk-Br-3细胞bcl-2的表达;PI染色检测细胞凋亡;克隆形成法测定药物对MCF-7细胞和Sk-Br-3细胞系的细胞毒作用。结果 MTT结果显示,30μmol·L-1塞来昔布与0.625mg·L-1多柔比星联合作用于MCF-7细胞的72 h存活率为68.53%,作用于Sk-Br-3细胞的72 h存活率为32.66%,较多柔比星单用能明显降低乳腺癌细胞的存活率,且具有时间和剂量依赖性。流式细胞仪PI染色结果显示,联合用药诱导的细胞凋亡率分别为MCF-7细胞59.7%,Sk-Br-3细胞65.8%,较单用多柔比星诱导的凋亡率（MCF-7细胞25.9%,Sk-Br-3细胞28.7%）明显提高。Western blot结果显示单用多柔比星可以使蛋白bcl-2表达下调,合用后较单用下调更加明显。两者联合处理乳腺癌细胞后,caspases-3的活性明显增强。结论塞来昔布和多柔比星对乳腺癌MCF-7细胞和Sk-Br-3细胞有增殖抑制及促凋亡作用,两药联合表现为协同或相加作用。

英文摘要：

Aim To investigate the anti-tumor effects of COX-2 selective inhibitor celecoxib combined with doxorubicin on breast cancer MCF-7 cells and Sk-Br-3 cells and to discuss whether celecoxib has the functions of attenuating doxorubicin′s toxicity and enhancing its efficiency.Methods Cells were divided into control group,celecoxib group,doxorubicin group and combined group.MTT assay was used to detect growth inhibition induced by drugs in MCF-7 cells and Sk-Br-3 cells.Western blot were used to determine the expression of bcl-2 in MCF-7 cells and Sk-Br-3 cells.PI staining detected cell apoptosis.Clone forming determined drug′s cytotoxicity in MCF-7 cells and Sk-Br-3 cells.Results MTT results showed that 72 h after the action of 30 μmol·L-1 celecoxib combined with 0.625 mg·L-1 doxorubicin in MCF-7 cells,the survival rate was 68.53%,in Sk-Br-3 cells,the survival rate was 32.66%.The survival rate of breast cancer cells was significantly lower than that of doxorubicin group.Celecoxib combined with doxorubicin showed time and dose-dependent effect.PI staining by flow cytometry showed that celecoxib combined with doxorubicin induced apoptosis rate of MCF-7 cells was 59.7%,and that of Sk-Br-3 cells was 65.8%,which significantly increased apoptosis rate compared with doxorubicin alone（MCF-7 cells 25.9%,Sk-Br-3 cells 28.7%）.Western blot showed that doxorubicin alone could re-duce the expression of bcl-2 and the combined group reduced more than the single ones.Activity of caspase3 was increased by celecoxib combined with doxorubicin than that treated by doxorubicin alone.Conclusion Celecoxib and doxorubicin show proliferation inhibition and apoptosis promotion effects on breast cancer MCF-7 cells and Sk-Br-3 cells.The combination of the two shows synergistic or additive effect.