Significantly enhanced tumor cellular and lysosomal hydroxychloroquine delivery by smart liposomes for optimal autophagy inhibition and improved antitumor efficiency with liposomal doxorubicin
Significantly enhanced tumor cellular and lysosomal hydroxychloroquine delivery by smart liposomes for optimal autophagy inhibition and improved antitumor efficiency with liposomal doxorubicin
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智能脂质体显着增强肿瘤细胞和溶酶体羟氯喹的递送，以实现最佳的自噬抑制并提高脂质体阿霉素的抗肿瘤效率
DOI：
10.1080/15548627.2016.1162930
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发表时间：
2016-01-01
期刊：
影响因子：
13.3
通讯作者：
He, Qin
中科院分区：
文献类型：
--
作者：
Wang, Yang;Shi, Kairong;He, Qin
羟氯喹（HCQ）抑制自噬，因此可以使某些癌细胞对化疗敏感，但所需的高剂量限制了其临床应用。在这里，我们表明，加载HCQ到脂质体（HCQ/Lip）修饰的pH敏感的TH-RGD靶向肽（HCQ/Lip-TR）可以集中HCQ在B16 F10肿瘤细胞和溶酶体。由于HCQ/Lip-TR能够结合肿瘤细胞表面上高度表达的ITGAV-ITGB 3/整联蛋白αvβ3受体，并经历电荷逆转，从pH 7.4的阴离子变为pH 6.5的阳离子，因此HCQ/Lip-TR被有效内化。在pH6.5的体外研究表明，与用游离HCQ处理培养物相比，用HCQ/Lip-TR处理培养物后，细胞内HCQ浓度高35.68倍，溶酶体HCQ浓度高32.22倍。在携带B16 F10肿瘤的小鼠中观察到的相应增强在肿瘤细胞内为15.16倍，在溶酶体内为14.10倍。与游离HCQ相比，HCQ/Lip-TR与轻度贫血和轻度肌抑制性白色血细胞和血小板计数减少相关，以及小肠中的蓄积较少，这可能降低肠道副作用的风险。此外，HCQ/Lip-TR与游离多柔比星（DOX）或脂质体DOX的共递送改善了DOX抑制肿瘤生长的能力。生化、电镜和免疫荧光实验证实HCQ/Lip-TR阻断了肿瘤细胞的自噬流。我们的研究结果表明，将HCQ装载到Lip-TR脂质体中可以增加肿瘤细胞中抑制剂的有效浓度，从而允许使用更少的毒性剂量。
ABSTRACT Hydroxychloroquine (HCQ) inhibits autophagy and therefore can sensitize some cancer cells to chemotherapy, but the high doses required limit its clinical use. Here we show that loading HCQ into liposomes (HCQ/Lip) decorated with a pH-sensitive TH-RGD targeting peptide (HCQ/Lip-TR) can concentrate HCQ in B16F10 tumor cells and lysosomes. HCQ/Lip-TR was efficiently internalized as a result of its ability to bind ITGAV-ITGB3/integrin αvβ3 receptors highly expressed on the tumor cell surface and to undergo charge reversal from anionic at pH 7.4 to cationic at pH 6.5. Studies in vitro at pH 6.5 showed that the intracellular HCQ concentration was 35.68-fold higher, and lysosomal HCQ concentration 32.22-fold higher, after treating cultures with HCQ/Lip-TR than after treating them with free HCQ. The corresponding enhancements observed in mice bearing B16F10 tumors were 15.16-fold within tumor cells and 14.10-fold within lysosomes. HCQ/Lip-TR was associated with milder anemia and milder myosuppressive reductions in white blood cell and platelet counts than free HCQ, as well as less accumulation in the small intestine, which may reduce risk of intestinal side effects. In addition, co-delivering HCQ/Lip-TR with either free doxorubicin (DOX) or liposomal DOX improved the ability of DOX to inhibit tumor growth. Biochemical, electron microscopy and immunofluorescence experiments confirmed that HCQ/Lip-TR blocked autophagic flux in tumor cells. Our results suggest that loading HCQ into Lip-TR liposomes may increase the effective concentration of the inhibitor in tumor cells, allowing less toxic doses to be used.