Multiple receptor tyrosine kinases regulate HIF-1alpha and HIF-2alpha in normoxia and hypoxia in neuroblastoma: implications for antiangiogenic mechanisms of multikinase inhibitors.
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Multiple receptor tyrosine kinases regulate HIF-1alpha and HIF-2alpha in normoxia and hypoxia in neuroblastoma: implications for antiangiogenic mechanisms of multikinase inhibitors.

Oncogene. 2010 Mar 8;

Authors: Nilsson MB, Zage PE, Zeng L, Xu L, Cascone T, Wu HK, Saigal B, Zweidler-McKay PA, Heymach JV

Novel treatment approaches are needed for children with advanced neuroblastoma. Studies with neuroblastoma cells have indicated the presence of a hypoxia-driven vascular endothelial growth factor (VEGF)/VEGF receptor (VEGFR)-1 autocrine loop modulating hypoxia-inducible factor-1alpha (HIF-1alpha). Whether other receptor tyrosine kinases (RTKs) are capable of modulating HIF-1alpha levels and whether RTKs can regulate HIF-2alpha as well is largely unknown. We evaluated neuroblastoma cell lines for expression of various RTKs. Although cell lines were heterogeneous in the expression of VEGFR-1, -3, c-Kit and RET, most cells expressed PDGFR-alpha and -beta. Ligand-induced activation of multiple RTKs upregulated HIF-1alpha levels, whereas activation of VEGFR-1 alone upregulated HIF-2alpha. Multitargeted tyrosine kinase inhibitor sunitinib reduced hypoxia-induced rises in HIF-1alpha and HIF-2alpha through mechanisms involving effects on both mRNA levels and protein stability. In addition, sunitinib and sorafenib had direct effects on tumor cell viability in vitro. In a neuroblastoma xenograft model, tumor growth inhibition by sunitinib was associated with inhibition of angiogenesis and reduced HIF-1alpha levels. These findings show that multiple RTKs may regulate the HIF axis in normoxia and hypoxia and suggest that multikinase inhibitors may exert antiangiogenic effects not only by direct effects on endothelial cells, but also by blocking compensatory hypoxia- and ligand-induced changes in HIF-1alpha and HIF-2alpha.Oncogene advance online publication, 8 March 2010; doi:10.1038/onc.2010.60.

PMID: 20208561 [PubMed - as supplied by publisher]

Read the complete post at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?tmpl=NoSidebarfile&db=PubMed&cmd=Retrieve&list_uids=20208561&dopt=Abstract

Posted 9 Mar 2010 4:38 AM by pubmed: neuroblastoma
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There is nothing quite as devastating as hearing that word - neuroblastoma. In seconds your world is turned upside down and your normal life is but a distant memory. You are thrust into a confusing world full of fear. Your child has cancer.

We know. We have been there. The Neuroblastoma Foundation is here for you.

Welcome to our website. It is a place for you to find answers and ask questions. One of the primary goals of the Neuroblastoma Foundation is to ensure that parents, patients and health care professionals find the information they need to make the best treatment decisions possible for children and adults affected by neuroblastoma. There is a vast amount of information throughout the internet, much of which is encapsulated in medical jargon that is so complex that even many medical professionals have difficulty in interpreting its meaning. We are here to help to decipher this information and to make sure you (and your oncologist) understand exactly what it means to you. From treatment decisions to side effects we have parents and experts that have experienced it all and are willing to distill it for you.