Dragowska Wieslawa H, Singh Jagbir, Wehbe Mohamed, Anantha Malathi, Edwards Katarina, Gorski Sharon M, Bally Marcel B, Leung Ada W Y
Department of Experimental Therapeutics, BC Cancer, Vancouver, BC V5Z 1L3, Canada.
Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC V6T 1Z7, Canada.
Pharmaceutics. 2024 Dec 30;17(1):42. doi: 10.3390/pharmaceutics17010042.
Preclinical studies have shown that the anti-malarial drug hydroxychloroquine (HCQ) improves the anti-cancer effects of various therapeutic agents by impairing autophagy. These findings are difficult to translate in vivo as reaching an effective HCQ concentration at the tumor site for extended times is challenging. Previously, we found that free HCQ in combination with gefitinib (Iressa, ZD1839) significantly reduced tumor volume in immunocompromised mice bearing gefitinib-resistant JIMT-1 breast cancer xenografts. Here, we sought to evaluate whether a liposomal formulation of HCQ could effectively modulate autophagy in vivo and augment treatment outcomes in the same tumor model. We developed two liposomal formulations of HCQ: a pH-loaded formulation and a formulation based on copper complexation. The pharmacokinetics of each formulation was evaluated in CD1 mice following intravenous administration. An efficacy study was performed in immunocompromised mice bearing established JIMT-1tumors. Autophagy markers in tumor tissue harvested after four weeks of treatment were assessed by Western blot. The liposomal formulations engendered ~850-fold increases in total drug exposure over time relative to the free drug. Both liposomal and free HCQ in combination with gefitinib provided comparable therapeutic benefits ( > 0.05). An analysis of JIMT-1 tumor tissue indicated that the liposomal HCQ and gefitinib combination augmented the inhibition of autophagy in vivo compared to the free HCQ and gefitinib combination as demonstrated by increased LC3-II and p62/SQSTM1 (p62) protein levels. The results suggest that liposomal HCQ has a greater potential to modulate autophagy in vivo compared to free HCQ; however, this did not translate to better therapeutic effects when used in combination with gefitinib to treat a gefitinib-resistant tumor model.
临床前研究表明，抗疟药物羟氯喹（HCQ）通过损害自噬作用来增强各种治疗药物的抗癌效果。由于长时间在肿瘤部位达到有效的HCQ浓度具有挑战性，这些研究结果难以在体内得到验证。此前，我们发现游离HCQ与吉非替尼（易瑞沙，ZD1839）联合使用可显著减小携带吉非替尼耐药的JIMT-1乳腺癌异种移植瘤的免疫缺陷小鼠的肿瘤体积。在此，我们试图评估HCQ脂质体制剂是否能在体内有效调节自噬，并增强同一肿瘤模型的治疗效果。我们开发了两种HCQ脂质体制剂：一种pH负载制剂和一种基于铜络合的制剂。静脉注射后，在CD1小鼠中评估了每种制剂的药代动力学。在携带已形成JIMT-1肿瘤的免疫缺陷小鼠中进行了疗效研究。治疗四周后收集的肿瘤组织中的自噬标志物通过蛋白质印迹法进行评估。相对于游离药物，脂质体制剂随时间推移使总药物暴露增加了约850倍。脂质体HCQ和游离HCQ与吉非替尼联合使用均提供了相当的治疗益处（>0.05）。对JIMT-1肿瘤组织的分析表明，与游离HCQ和吉非替尼联合使用相比，脂质体HCQ和吉非替尼联合使用在体内增强了对自噬的抑制作用，这通过LC3-II和p62/SQSTM1（p62）蛋白水平的升高得以证明。结果表明，与游离HCQ相比，脂质体HCQ在体内调节自噬的潜力更大；然而，在与吉非替尼联合用于治疗吉非替尼耐药肿瘤模型时，这并没有转化为更好的治疗效果。
