IMPACT, Institute for Innovation in Physical and Mental Health and Clinical Translation, School of Medicine, Deakin University, Geelong, VIC 3216, Australia.
Telethon Kids Institute, University of Western Australia, Perth, WA 6009, Australia.
Biomolecules. 2022 Nov 3;12(11):1623. doi: 10.3390/biom12111623.
Doxorubicin is the most frequently used chemotherapeutic agent for the treatment of hepatocellular carcinoma. However, one major obstacle to the effective management of liver cancer is the drug resistance derived from the cancer stem cells. Herein, we employed a CD133 aptamer for targeted delivery of doxorubicin into liver cancer stem cells to overcome chemoresistance. Furthermore, we explored the efficacy of autophagy inhibition to sensitize liver cancer stem cells to the treatment of CD133 aptamer-doxorubicin conjugates based on the previous observation that doxorubicin contributes to the survival of liver cancer stem cells by activating autophagy. The kinetics and thermodynamics of aptamer-doxorubicin binding, autophagy induction, cell apoptosis, and self-renewal of liver cancer stem cells were studied using isothermal titration calorimetry, Western blot analysis, annexin V assay, and tumorsphere formation assay. The aptamer-cell binding andintracellular accumulation of doxorubicin were quantified via flow cytometry. CD133 aptamer-guided delivery of doxorubicin resulted in a higher doxorubicin concentration in the liver cancer stem cells. The combinatorial treatment strategy of CD133 aptamer-doxorubicin conjugates and an autophagy inhibitor led to an over 10-fold higher elimination of liver cancer stem cells than that of free doxorubicin in vitro. Future exploration of cancer stem cell-targeted delivery of doxorubicin in conjunction with autophagy inhibition in vivo may well lead to improved outcomes in the treatment of hepatocellular carcinoma.
多柔比星是治疗肝细胞癌最常用的化疗药物。然而，癌症干细胞的耐药性是有效治疗肝癌的主要障碍之一。在此，我们采用 CD133 适体将多柔比星靶向递送至肝癌干细胞，以克服化疗耐药性。此外，我们还探索了自噬抑制的效果，以提高肝癌干细胞对 CD133 适体-多柔比星缀合物治疗的敏感性，这是基于先前的观察结果，即多柔比星通过激活自噬来促进肝癌干细胞的存活。我们使用等温滴定量热法、Western blot 分析、膜联蛋白 V 检测和肿瘤球形成检测研究了适体-多柔比星结合、自噬诱导、细胞凋亡和肝癌干细胞自我更新的动力学和热力学。通过流式细胞术定量测定适体-细胞结合和多柔比星在细胞内的积累。CD133 适体引导的多柔比星递送至肝癌干细胞，可使肝癌干细胞内的多柔比星浓度更高。与游离多柔比星相比，CD133 适体-多柔比星缀合物与自噬抑制剂联合的组合治疗策略可使肝癌干细胞的清除率提高 10 倍以上。未来在体内探索针对癌症干细胞的多柔比星靶向递药与自噬抑制的联合应用，可能会改善肝细胞癌的治疗效果。
