摘要目的 探讨化疗后残存乳腺癌组织乳腺癌耐药蛋白(BCRP/ABCG2)、P-糖蛋白表达及其与上皮间质转化(EMT)的相关性.方法 收集乳腺癌标本76例,免疫组织化学EnVision法检测化疗后残存乳腺癌组织ABCG2、P-糖蛋白的表达及EMT相关标志物E-cadherin及波形蛋白的表达.将乳腺癌MCF7细胞分为空白对照组、阳性对照(TGF-β1诱导)组和联合用药组,联合应用多西紫杉醇和表柔比星处理MCF7细胞获得药物筛选残存细胞(DSC);免疫荧光检测DSC细胞中E-cadherin和波形蛋白的表达;逆转录-聚合酶链反应(RT-PCR)和Western blot分别检测DSC细胞中ABCG2、P-糖蛋白、E-cadherin、波形蛋白的mRNA及其蛋白表达.结果 与化疗前乳腺癌组织比较,化疗后残存乳腺癌组织中高表达ABCG2和P-糖蛋白,并与波形蛋白表达呈显著正相关(r1=0.97,P1=0.000;r2=0.83,P2 =0.001);而与E-cadherin蛋白表达呈显著负相关(r3=-0.55,P3 =0.010;r4=-0.43,P4 =0.020).免疫荧光结果亦显示DSC中高表达波形蛋白,而低表达E-cadherin蛋白.RT-PCR显示DSC中高表达ABCG2及P-糖蛋白mRNA,且与波形蛋白的mRNA表达呈显著正相关(r1=0.99,r2=0.96,P＜0.05);与E-cadherin mRNA表达呈显著负相关(r3=-0.99,r4=-0.98,P＜0.05);Western blot结果显示DSC中高表达ABCG2及P-糖蛋白,且与波形蛋白表达呈显著正相关(r1=0.98,r2=0.89,P＜0.05);与E-cadherin蛋白表达呈负相关(r3=-0.47,r4=-0.33,P＜0.05).结论 化疗后残存乳腺癌组织ABCG2及P-糖蛋白与EMT相关标志物表达之间存在显著相关性,经历EMT可能是导致乳腺癌多药耐药的重要原因之一.

abstractsObjective To explore the expression of breast cancer resistance protein (ABCG2),p-glycoprotein (P-gp) in residual breast cancer tissue after chemotherapy and their correlation with epithelial mesenchymal transition (EMT).Methods Seventy-six cases of breast cancer were collected.The expression of ABCG2,P-gp and EMT markers E-cadherin and vimentin in residual breast cancer tissue after chemotherapy was detected by immunohistochemistry (EnVision method).MCF7 cells were divided into three group:untreated control group,positive control (TGF-β1 induced) group and drug surviving cells (DSC) group (selected viable MCF7 cells after docetaxel and epirubicin treatment).The expression of EMT markers E-cadherin and vimentin was detected by immunofluorescence.The mRNA and protein expression of ABCG2,P-gp and EMT markers were detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot,respectively.Results Compared with breast cancer tissue before chemotherapy,ABCG2,P-gp and vimentin protein were highly expressed in residual breast cancer tissue after chemotherapy.The expression of ABCG2 and P-gp correlated positively with vimentin protein (r1 =0.97,P1 =0.000; r2 =0.83,P2 =0.001) and negatively with E-cadherin protein (r3 =-0.55,P3 =0.010; r4 =-0.43,P4 =0.020) expression.RT-PCR results showed that ABCG2,P-gp and vimentin mRNA were highly expressed in residual breast cancer tissue after chemotherapy.The expression of ABCG2 and P-gp mRNA correlated positively with vimentin mRNA (r1 =0.99,r2 =0.96,P ＜ 0.05) but negatively with E-cadherin protein (r3 =-0.99,r4 =-0.98,P ＜ 0.05) ; Western blot showed that ABCG2,P-gp and vimentin protein were highly expressed in residual breast cancer tissue after chemotherapy.The expression of ABCG2 and P-gp protein correlated positively with vimentin protein (r1 =0.98,r2 =0.89,P ＜ 0.05) and negatively with E-cadherin protein (r3 =-0.47,r4 =-0.33,P ＜ 0.05).Conclusions The expression of resistance-associated proteins in the residual breast cancer tissue after chemotherapy is significantly correlated with EMT.The expression of EMT profile may be one of important mechanisms for multidrug resistance in breast cancer.