Inhibition of xenograft human glioma tumor growth by lentivirus-mediated gene transfer of alphastatin

Alphastatin-Loaded Chitosan Nanoparticle Preparation and Its Antiangiogenic Effect on Lung Carcinoma

Alphastatin is a 24-amino acid peptide and can suppress tumor angiogenesis by inhibiting both the migration and tubule formation of vascular endothelial cells. However, the anticancer effect of Alphastatin is limited due to the short half-life and degradation in the body. In this study, Alphastatin-loaded chitosan nanoparticles (AsCs NPs) were prepared with an initial concentration of 2 mg/ml for chitosan and 1 mg/ml for Alphastatin. AsCs NPs presented the encapsulation efficiency of 32.4%, the mean particle size of 387.4 nm, the polydispersity index of 0.223, and the zeta potential of +28.1 mV. AsCs NPs have a sustained release for 6 days and were stable in serum for at least 24 hours. And the NPs could preserve the integrity of encapsulated Alphastatin and released Alphastatin for 24 hours. In a subcutaneous LA975 lung carcinoma xenograft T739 mouse model, AsCs NPs significantly inhibited the tumor growth, tumor volume, and microvessel density (MVD), and the antitumor effect was even stronger than that of Alphastatin. In addition, the VEGF-induced tube formation of HUVEC could be inhibited by AsCs NPs in vitro and the serum containing AsCs NPs, and the protein level of SphK1 in HUVEC was also decreased by AsCs NPs, suggesting an inhibitory effect of AsCs NPs on the SphK1-S1P signaling pathway. Furthermore, hemolysis assay showed a safety on blood compatibility of AsCs NPs. Our study indicated that AsCs NPs inhibited the SphK1-S1P signaling pathway and enhanced the antiangiogenic effect of Alphastatin both in vitro and in vivo.

Knockdown of ILK inhibits glioma development via upregulation of E-cadherin and downregulation of cyclin D1

Integrin-linked kinase (ILK) is a highly conserved serine-threonine protein kinase that interacts with cytoplasmic domains of integrin subunits in tumor tissues. However, the relationship between gliomas and ILK is elusive. The present study aimed to investigate the role of ILK in a human glioma cell line (U251). ILK stable expressing vector, U251ILK-PGFP-V-RS-shRNA, was established and named as U251-si. The empty-PGFP-V-RS-shRNA (U251-N) was employed as the control. Quantitative real-time PCR and western blot analysis were used to detect ILK and E-cadherin mRNA and protein expression, respectively. Cell cycle analysis was employed to examine the cell cycle distribution. Cell migration was detected using a wound healing assay, and cell invasion was detected using a Transwell invasion assay. Tumor size and weight were also examined. The results indicated that ILK was expressed at a lower level at both the mRNA and protein levels in the U251-si group compared with the U251-N group (p<0.01). ILK knockdown suppressed cell proliferation of the glioma cells. Knockdown of ILK reduced the migratory and invasive potentials of the glioma cells. Inhibition of ILK expression upregulated E-cadherin and downregulated cyclin D1 in the glioma cells compared to the U251-N group (p<0.05). Knockdown of ILK in the U251 cells attenuated the ability of U251 cells to form tumors in nude mice and impaired glioma cell in vivo tumorigenicity. In conclusion, knockdown of ILK inhibits glioma cell migration, invasion and proliferation through upregulation of E-cadherin and downregulation of cyclin D1. Our results suggest that ILK may serve as a promising therapeutic target for glioma.