Browse views: by Year, by Function, by GLF, by Subfunction, by Conference, by Journal

The IGFR1 inhibitor NVP-AEW541 disrupts a pro-survival and pro-angiogenic IGF-STAT3-HIF1 pathway in human glioblastoma cells

Gariboldi, Marzia B. and Ravizza, Raffaella and Monti, Elena (2010) The IGFR1 inhibitor NVP-AEW541 disrupts a pro-survival and pro-angiogenic IGF-STAT3-HIF1 pathway in human glioblastoma cells. Biochemical Pharmacology, 80 (4). pp. 455-462. ISSN 00062952

Abstract

Inappropriate activation of the IGF (insulin-like growth factor) system has been implicated in the growth and progression of a number of tumor types. Recent evidence indicates a possible role for the IGF system in modulating/mediating tumor cell response to hypoxia, a common occurrence in solid tumors, and particularly in malignant gliomas, causing tumor cells either to die, or to mount a pleiotropic adaptive response that is mainly orchestrated through activation of the hypoxia-inducible transcription factor HIF1. Experimental evidence suggests possible links between IGF- and HIF1-dependent signaling pathways, as well as a role for activated STAT3 in mediating their activities. Interestingly, igf2 is among the target genes transactivated by HIF1, thereby providing the missing link in a hypothetical autocrine self-amplifying circuit. The present study investigates the presence of the IGF-HIF1-VEGF axis in the human glioma cell line U-87 MG, and characterizes its molecular effectors. Our results show that exogenous IGF-I causes IGF1R and STAT3 activation, and increases HIF1a protein levels and HIF1 transcriptional activity, inducing VEGF release; a similar response, mediated by IGF-II release, is observed following HIF1a stabilization. The existence of an autocrine loop is confirmed by its down-regulation following inactivation of IGF1R (using the IGF1R-specific tyrosine kinase inhibitor NVP-AEW541), STAT3 (transfecting the cells with an expression vector encoding a dominant negative form of STAT3), or HIF1 (using the small molecule inhibitor YC-1). The ability of NVP-AEW541 to block this circuit could be beneficial in suppressing the growth and angiogenic potential of hypoxic glial tumors.

Item Type: Article
Keywords: Insulin-like growth factors, Hypoxia-inducible factor-1, STAT3, Glioblastoma, IGF-1 receptor inhibitor
Date Deposited: 13 Oct 2015 13:16
Last Modified: 13 Oct 2015 13:16
URI: https://oak.novartis.com/id/eprint/3192

Search

Email Alerts

Register with OAK to receive email alerts for saved searches.