Enhanced activity of AZD5582 and SM-164 in rabies virus glycoprotein-lactoferrin-liposomes to downregulate inhibitors of apoptosis proteins in glioblastoma

Abstract

Upregulated proliferation of neoplastic cells from suppressing apoptotic signals associated with the inhibitors of apoptosis proteins (IAP) makes difficult the achievement of therapeutic efficiency against glioblastoma multiforme. Studies in the last few years have witnessed a paradigm focusing on targeting IAP using its antagonists, such as Smac mimetics, to restrain tumor malignancy. A Smac mimetic compound needs to penetrate the blood-brain barrier (BBB), and must be internalized into cerebral tumor for improved chemotherapy. Rabies virus glycoprotein (RVG) and lactoferrin (Lf)-grafted liposomes were developed in this study to carry two IAP antagonists, AZD5582 and SM-164, across the BBB and to induce apoptosis in U87 MG and human brain cancer stem cells (HBCSCs). Liposomes modified with RVG slightly reduced BBB tightness and enhanced capability of AZD5582 and SM-164 for traversing the barrier because of their brain-targeting ability. Immunofluorescence and western-blot results revealed that AZD5582- and SM-164-encapsulated liposomes facilitated mutual curative intensity, effectively triggered apoptosis of U87 MG and HBCSCs, reduced the expression of cellular IAP 1 (cIAP1) and X-linked IAP (XIAP), and enhanced the expression of caspase-3. Hence, RGV-Lf-liposomes carrying AZD5582 and SM-164 can be promising formulations to activate apoptosis of U87 MG and HBCSCs, and this functionalized drug delivery system targeting cIAP and XIAP is a potential strategy to cure glioblastoma in clinical cancer management.

Keywords: Human brain cancer stem cell; Inhibitor of apoptosis protein; Lactoferrin; Liposome; Rabies virus glycoprotein.