乳腺癌耐受蛋白介导的5-氟尿嘧啶耐受及机制

目的筛选乳腺癌耐受蛋白(BCRP)介导的耐受药物,探讨BCRP介导抗肿瘤药物耐受的机制,优化以BCRP表达检测结果为评价指标,为肿瘤临床化疗方案提供有价值的资料。方法不同浓度的抗肿瘤药物分别处理BCRP呈不同程度表达的PA317/Teton/TREBCRP细胞,经MTT法筛选出BCRP介导的耐受药物。高效液相色谱仪检测耐受药物在细胞内的相对剂量。采用核DNA染料Hochest33258荧光染色技术和流式细胞术检测耐受药物诱导的细胞凋亡。结果随着细胞BCRP表达的增高,PA317/Teton/TREBCRP细胞对5氟尿嘧啶(5Fu)、甲氨蝶呤、多柔比星、吡柔比星、依托泊苷、米托蒽醌等药物的耐药指数增高(P<0.05),而对如紫杉醇、顺铂、长春碱、丝裂霉素、长春地辛等药物均敏感。细胞的BCRP表达量与胞内5Fu浓度具有负相关性(r=-0.885,P<0.05)。随着细胞BCRP表达的增高,经5Fu处理后细胞凋亡率随之降低(P<0.05),而Ko143能显著提高BCRP表达细胞的凋亡率(P<0.05)。结论BCRP能增强细胞对5Fu所致的凋亡耐受。

Breast cancer resistance protein-mediated 5-fluorouracil resistance and its mechanism

AIM To screen breast cancer resistance protein(BCRP)-mediated resistant agents and investigate the mechanism, so as to provide valuable data for optimizing clinical scheme for tumor chemotherapy based on BCRP expression as an evaluation marker. METHODS MTT assay was used to screen BCRP-mediated resistant agents with PA317/Tet-on/TRE-BCRP cell of different expression level of BCRP after treated with different concentration anticancer agents. High performance liquid chromatography was applied to measure relative dose of intracellular retention resistance agents.Nuclear DNA fluorescence dye,Hochest 33258, staining and flow cytometry were adopted to detect apoptotic cells after treated with drugs. RESULTS The indexes of resistance(RI) to 5-fluorouracil, methotrexate, doxirubicin, pirarubicin, etoposide and mitoxantrone were increased along with increased expression of BCRP on PA317/Tet-on/TRE-BCRP cells(P<0.05), but the resistance to paclitaxel, cisplatin, vincristine, mitomycin and vindesine was decreased. There was significant negative correlation between the intracellular 5-fluorouracil content expression level of BCRP (r=-0.885, P< 0.05). Apoptotic rate decreased with increased cellular expression of BCRP after treated with 5-fluorouracil (P< 0.05). On the contrary, treatment with Ko143 elevated the apoptotic rate of BCRP expression cells. CONCLUSION Cell resistance to 5-fluorouracil-induced apoptosis could be reinforced by BCRP expression.