An Efficient Bivalent Cyclic RGD-PIK3CB siRNA Conjugate for Specific Targeted Therapy against Glioblastoma In Vitro and In Vivo

• Main Authors: Bohong Cen (Author), Yuanyi Wei (Author), Wen Huang (Author), Muzhou Teng (Author), Shuai He (Author), Jianlong Li (Author), Wei Wang (Author), Guolin He (Author), Xin Bai (Author), Xiaoxia Liu (Author), Yawei Yuan (Author), Xinghua Pan (Author), Aimin Ji (Author)
• Format: Book
• Published: Elsevier, 2018-12-01T00:00:00Z.
• Subjects: article
• Online Access: Connect to this object online.

Summary

The PI3K-AKT-mTOR-signaling pathway is frequently activated in glioblastoma (GBM). Inhibition of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta (PIK3CB)/p110β (a PI3K catalytic isoform) by RNAi substantially suppresses GBM growth with less toxicity to normal astrocytes. However, insufficient and non-specific small interfering RNA (siRNA) delivery may limit the efficacy of RNAi-based therapies against GBM. Here we prepared a novel methoxy-modified PIK3CB siRNA molecule (siPIK3CB) that was covalently conjugated to a [cyclo(Arg-Gly-Asp-D-Phe-Lys)-Ahx]2-Glu-PEG-MAL (biRGD) peptide, which selectively binds to integrin αvβ3 receptors. The αvβ3-positive U87MG cell line was selected as a representative for GBM. An orthotopic GBM xenograft model based on luciferase-expressing U87MG was established and validated in vivo to investigate bio-distribution and anti-tumor efficacy of biRGD-siPIK3CB. In vitro, biRGD-siPIK3CB specifically entered and silenced PIK3CB expression in GBM cells in an αvβ3 receptor-dependent manner, thus inhibiting cell cycle progression and migration and enhancing apoptosis. In vivo, intravenously injected biRGD-siPIK3CB substantially slowed GBM growth and prolonged survival by reducing tumor viability with silencing PIK3CB expression. Furthermore, biRGD-siPIK3CB led to mild tubulointerstitial injury in the treatment of GBM without obvious hepatotoxicity, whereas co-infusion of Gelofusine obviously alleviated this injury without compromising anti-tumor efficacy. These findings revealed a great translational potential of biRGD-siPIK3CB conjugate as a novel molecule for GBM therapy. Keywords: siRNA delivery, gene silencing, orthotopic glioblastoma, tumor targeting

Item Description

2162-2531
10.1016/j.omtn.2018.09.002