基于三维细胞模型的氯乙基亚硝基脲耐药性研究

Drug Resistance of Chloroethylnitrosoureas Based on a Three-dimensional Cell Model

氯乙基亚硝基脲(CENUs)是临床上重要的抗癌烷化剂,然而O6-烷基鸟嘌呤-DNA-烷基转移酶(AGT)介导肿瘤细胞对CENUs产生耐药性是其临床应用中的重要问题;设计开发AGT抑制剂作为辅药与CENUs联合使用能够有效克服CENUs的耐药性。因此,合理地评价CENUs及其联合用药策略的耐药性对于CENUs的临床应用和新药开发具有重要意义。利用微孔纤维素支架培养人脑神经胶质瘤SF763细胞(AGT高表达)和SF126细胞(AGT低表达),建立了三维肿瘤细胞模型;并将其应用于对CENUs类药物尼莫司汀(ACNU)、卡莫司汀(BCNU)和洛莫司汀(CCNU)以及CENUs与AGT抑制剂联合用药的耐药性研究。结果表明,三维肿瘤细胞对各CENUs均表现出明显的耐药性,其IC50值为传统二维细胞组的1.7~3.5倍;在CENUs与AGT抑制剂联合用药组中,虽然二维细胞组的耐药性有所下降,但三维细胞组仍然表现出了明显的耐药性。由于体外三维肿瘤球比传统二维细胞更加接近体内实体瘤的生长状态及肿瘤微环境,因此,使用三维细胞模型评价药物的耐药性有利于得到更加准确的结果,从而为体内实验提供更可靠的参考。

Chloroethylnitrosoureas(CENUs)are important anticancer alkylating agents in clinics.However,the drug resistance of CENUs mediated by O6-alkylguanine-DNA-alkyltransferase(AGT)is a crucial problem in its clinical application.Designing and developing AGT inhibitors as adjuvants in combination with CENUs can effectively overcome the resistance of CENUs.Therefore,reasonable assessment of the resistance of CENUs and their combined drug strategies is of great significance for the clinical application of CENUs and the development of new drugs.In this study,a three-dimensional(3 D)tumor cell model was established by culture human brain glioma SF763 cells(highly expressing AGT protein)and SF126 cells(lowly expressing AGT protein)in microporous cellulose scaffolds.The 3 D cell model was used to investigate the drug resistance to CENUs,including nimustine(ACNU),carmustine(BCNU)and lomustine(CCNU),and their combination chemotherapy with AGT inhibitors.The results showed that the 3 D tumor cells showed obvious drug resistance to each CENUs with IC50 values 1.7~3.5 times of the 2 D cells.In the groups treated by CENUs in combination with AGT inhibitors,significant drug resistance to CENUs was observed in the 3 D cell groups although it was decreased in the 2 D cell groups.As the growing status and tumor microenvironment of in vitro 3 D tumor spheres are more similar to those of solid tumors in vivo compared to traditional 2 D cells,the application of 3 D cell model will be helpful in obtaining accurate results in the evaluation of drug resistance,which will thereby provide reliable reference for in vivo experiments.