Department of Surgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, 600 Yishan Road, Shanghai 200233, China.
Mol Biol Rep. 2011 Mar;38(3):1769-75. doi: 10.1007/s11033-010-0291-z. Epub 2010 Sep 14.
Our previous study established the human multi-drug-resistant cholangiocarcinoma cell line QBC939/ADM. In this study, we investigate further the ability of tamoxifen (TAM) to reverse drug-resistance to chemotherapeutics using QBC939/ADM cells. Cell growth inhibition was determined by the MTT assay, while cell cycle progression, apoptosis and the intra-cellular concentration of adriamycin (ADM) were all determined by flow cytometry. P-glycoprotein (P-gp) protein and mRNA expression was determined by Western blotting and real-time PCR. Growth inhibition and apoptosis induced by ADM, mitomycin (MMC), or vindesine (VDS) were enhanced after pre-treatment with 5 or 10 μM TAM, while only VDS increased cell numbers in the G(2)/M phase. The intra-cellular concentration of ADM rose after pre-treatment with 10 μM TAM, but not 5 μM TAM. Furthermore, real-time PCR and western blot analysis revealed down-regulation of P-gp expression in QBC939/ADM cells after TAM pre-treatment. The enhanced effects of TAM on growth inhibition, apoptosis, and intra-cellular concentration and the down-regulation of P-gp expression were blocked by an anti-P-gp antibody. TAM (10 μM) may reverse the multi-drug-resistance (MDR) of QBC939/ADM and enhance the chemotherapeutic effects on cholangiocarcinoma, by competitively inhibiting over-expressed P-gp.
我们之前建立了人多药耐药性胆管癌细胞系 QBC939/ADM。在这项研究中，我们进一步研究了他莫昔芬（TAM）逆转 QBC939/ADM 细胞中化学治疗药物耐药性的能力。通过 MTT 测定法测定细胞生长抑制，通过流式细胞术测定细胞周期进程、细胞凋亡和阿霉素（ADM）的细胞内浓度。通过 Western blot 和实时 PCR 测定 P-糖蛋白（P-gp）蛋白和 mRNA 表达。用 5 或 10 μM TAM 预处理后，ADM、丝裂霉素（MMC）或长春新碱（VDS）诱导的生长抑制和细胞凋亡增强，而仅 VDS 增加 G(2)/M 期的细胞数。用 10 μM TAM 预处理后，ADM 的细胞内浓度增加，但 5 μM TAM 则不然。此外，实时 PCR 和 Western blot 分析显示，TAM 预处理后 QBC939/ADM 细胞中 P-gp 表达下调。TAM（10 μM）可能通过竞争性抑制过表达的 P-gp 逆转 QBC939/ADM 的多药耐药性（MDR）并增强对胆管癌的化学治疗作用。
