State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
Medical and Healthy Analytical Center, Peking University, Beijing 100191, China.
Biomaterials. 2014 Jul;35(20):5347-5358. doi: 10.1016/j.biomaterials.2014.03.036. Epub 2014 Apr 13.
A novel therapeutic strategy combining mTOR inhibitor rapamycin (RAPA) and doxorubicin (DOX)-loaded cyclic octapeptide liposomes for targeting integrin α3 was expected to combat the triple-negative breast cancer (TNBC). RAPA was loaded into PEG-PCL polymer micelles (M-RAPA) to realize solubilization. Flow cytometry analysis and laser confocal microscopy were used to evaluate the in vitro cellular uptake. The in vivo tumor targeting and bio-distribution were investigated by living fluorescence imaging. As the results, LXY modification significantly enhanced the cellular uptake of liposomal DOX in integrin α3 overexpressed TNBC cells (MDA-MB-231) in vitro and accordingly improved the tumor accumulation of liposomes in vivo. When used alone or in combination with LXY-LS-DOX, M-RAPA could greatly inhibit the expression of HIF-1α protein, which is always highly expressed in malignant cancers and involved in tumor angiogenesis, proliferation, therapeutic resistance and poor prognosis. Meanwhile, the improved efficacy of combined targeted therapy with LXY-LS-DOX and M-RAPA was demonstrated by the in vitro cytotoxicity against model TNBC cells and in vivo anti-tumor activity against mouse bearing TNBC model. These results suggested that the targeted combinational therapy based on LXY-LS-DOX and M-RAPA systems may provide a rational strategy to improve therapeutic outcomes of TNBC.
一种新型的治疗策略,结合 mTOR 抑制剂雷帕霉素(RAPA)和载多柔比星(DOX)的环状八肽脂质体,用于靶向整合素 α3,有望治疗三阴性乳腺癌(TNBC)。RAPA 被载入 PEG-PCL 聚合物胶束(M-RAPA)中以实现溶解。通过流式细胞术分析和激光共聚焦显微镜评估细胞内摄取。通过活体荧光成像研究体内肿瘤靶向和生物分布。结果表明,LXY 修饰显著增强了整合素 α3 过表达的 TNBC 细胞(MDA-MB-231)中脂质体 DOX 的细胞摄取,从而增加了脂质体在体内的肿瘤蓄积。当单独使用或与 LXY-LS-DOX 联合使用时,M-RAPA 可以大大抑制缺氧诱导因子 1α(HIF-1α)蛋白的表达,HIF-1α 蛋白在恶性肿瘤中经常高度表达,参与肿瘤血管生成、增殖、治疗抵抗和预后不良。同时,LXY-LS-DOX 和 M-RAPA 的联合靶向治疗的体外对 TNBC 细胞的细胞毒性和体内对携带 TNBC 模型的小鼠的抗肿瘤活性证明了联合靶向治疗的疗效有所提高。这些结果表明,基于 LXY-LS-DOX 和 M-RAPA 系统的靶向联合治疗可能为提高 TNBC 的治疗效果提供一种合理的策略。