P糖蛋白在乳腺癌原发性耐药过程中的表达

P-glycoprotein expression in the development of primary multidrug resistance in breast carcinoma

目的:研究乳腺癌原发性耐药过程中P糖蛋白(P-glycoprotein,P-gp)的表达特征,初步探讨乳腺癌原发性耐药的发生机制.方法:采用免疫组织化学及逆转录多聚酶链反应技术,对25例接受术前新辅助化疗的乳腺癌患者、15例未接受术前化疗的乳腺癌患者、10例乳腺腺病患者组织标本内P-gp和MDR1mRNA的表达情况进行检测.结果:P-gp表达阳性率在乳腺癌术前化疗组患者和未化疗组患者中分别为84.0%(21/25)和46.7%(7/15),对照组未见P-gp表达;MDR1表达阳性率在三组则分别为84.0%(21/25)、53.3%(8/15)和10%(1/10),组间差异均显著(P<0.01).结论:部分乳腺癌细胞在恶性变的过程中同时伴有对化疗药物耐受能力的增加,肿瘤细胞内极低水平的MDR1mRNA表达即可导致多药耐药,MDR1/P-gp与乳腺癌的内源性耐药相关.

AIM： To study the expression and significance of P-glycoprotein （P-gp） in the development of multidrug resistance in breast cancer, METHODS： The expression of P-gp and MDR1 mRNA were detected by immunohistochemistry and reverse transcription-olymerase chain reaction （RT-PCR） in the specimens from 25 breast cancer patients with neoadjuvant chemotherapy （NAC group）, 15 breast cancer patients without neoadjuvant chemotherapy （non-NAC group） and 10 patients with breast adenosis （control group）. RESULTS： The positive rate of P-gp expression was 84.0% （21/25）, 46.7% （7/15） and 0 in NAC group, non-NAC group and control group, respectively. MDRI mRNA expression was 84.0% （21/25）, 53.3% （ 8/ 15） and 10% （1/10） in three groups respectively. Significant difference was found between the three groups （ P 〈 0.01 ）. CONCLUSION： Some tumor cells＇ tolerances to chemotherapeutics increase during the process of oncogenesis and the tolerances can be induced by an extremely low expression of MDR1/P-gp. MDR1/P-gp is associated with the intrinsic multidrug resistance in breast carcinoma.