化疗后残存乳腺癌组织中乳腺癌耐药蛋白、P-糖蛋白的表达及其与癌干细胞的相关性

摘要

Objective To compare the expression differences of breast cancer resistance protein (BCRP/ABCG2) and P-glycoprotein (P-gp) in breast cancer tissue before chemotherapy and in residual breast cancer tissue, and to explore its correlation with breast cancer stem cells. Methods Immunohistochemistry was used to detect the expression of ABCG2, P-gp, and breast cancer stem cells (BCSCs ) markers ( CD44 and CD24 ) in breast cancer tissue before chemotherapy and residual breast cancer tissue after chemotherapy. Immu-nofluorescence was applied for determination of the CD44 and CD24 protein expressions of BCSCs microspheres cells. The monoclone-forming ability of BCSCs microspheres cells was detected by limited dilution assay. The ex-pressions of ABCG2 , P-gp, CD44 , and CD24 proteins were detected by Western blot. Results Compared with those in breast cancer tissue before chemotherapy, the expression levels of ABCG2 and P-gp were positively correlated with the expression level of CD44 protein (χ2 = 41. 34 , r = 0. 83 ; χ2 = 22. 81, r = 0. 61 ) in residual breast cancer tissue after chemotherapy; meanwhile, they were negatively correlated with the expression of CD24 protein (χ2 = - 21. 25 , r = 0. 72; χ2 = - 17. 26 , r = 0. 65 ) ( all P < 0. 05 ) . The diameter of BCSCs micro-spheres were increased significantly after chemotherapy. The content of BCSCs increased by about 2. 5 times after chemotherapy. The expressions of ABCG2, P-gp and CD44 proteins significantly increased and that of CD24 protein significantly declined (P < 0. 05 ) . Conclusion Chemotherapy endows residual breast cancer tissue with cancer stem cells-like feastures, leading to multidrug resistance of breast cancer.%目的 通过对比化疗前乳腺癌组织和化疗后残存乳腺癌组织中乳腺癌耐药蛋白(ABCG2)、P-糖蛋白(P-gp)表达差异,探讨其与乳腺癌干细胞(BCSCs)的相关性.方法 免疫组织化学检测化疗前乳腺癌组织和化疗后残存乳腺癌组织ABCG2、P-gp及BCSCs标志物CD44及CD24蛋白的表达;免疫荧光检测"BCSCs微球体"细胞中CD44及CD24蛋白表达;有限稀释法检测"BCSCs微球体"细胞单克隆形成能力;Western blot检测"BCSCs微球体"细胞ABCG2、P-gp、CD44及CD24蛋白的表达.结果 与化疗前乳腺癌组织相比,化疗后残存乳腺癌组织ABCG2、P-gp表达与CD44蛋白表达呈正相关(χ2=41.34,r=0.83;χ2=22.81,r=0.61);而其与CD24蛋白表达呈负相关(χ2=-21.25,r=0.72;χ2=-17.26,r=0.65);差异均有统计学意义(P<0.05).化疗后残存乳腺癌组织中"BCSCs微球体"直径明显增加,且化疗后BCSCs含量是化疗前BCSCs含量的2.5倍;Western blot显示化疗后残存乳腺癌组织"BCSCs微球体"细胞ABCG2、P-gp及CD44蛋白表达明显升高(P<0.05),而CD24蛋白表达明显降低(P<0.05).结论 化疗赋予残存乳腺癌组织"癌干细胞样"特征,导致乳腺癌多药耐药产生.