Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

The molecular mechanism of autocrine regulation of vascular endothelial growth factor (VEGF) in chronic lymphocytic leukemia (CLL) B cells is unknown. Here, we report that CLL B cells express constitutive levels of HIF-1alpha under normoxia. We have examined the status of the von Hippel-Lindau gene product (pVHL) that is responsible for HIF-1alpha degradation and found it to be at a notably low level in CLL B cells compared with normal B cells. We demonstrate that the microRNA, miR-92-1, overexpressed in CLL B cells, can target the VHL transcript to repress its expression. We found that the stabilized HIF-1alpha can form an active complex with the transcriptional coactivator p300 and phosphorylated-STAT3 at the VEGF promoter and recruit RNA polymerase II. This is initial evidence that pVHL, without any genetic alteration, can be regulated by microRNA and explains the aberrant autocrine VEGF secretion in CLL.

Original publication

DOI

10.1182/blood-2008-10-185686

Type

Journal article

Journal

Blood

Publication Date

28/05/2009

Volume

113

Pages

5568 - 5574

Keywords

B-Lymphocytes, Cell Culture Techniques, Cell Nucleus, Cells, Cultured, Gene Expression Regulation, Leukemic, Humans, Hydroxylation, Hypoxia-Inducible Factor 1, Leukemia, Lymphocytic, Chronic, B-Cell, MicroRNAs, Mixed Function Oxygenases, Protein Binding, Protein Processing, Post-Translational, STAT3 Transcription Factor, Signal Transduction, Vascular Endothelial Growth Factor A, Von Hippel-Lindau Tumor Suppressor Protein, p300-CBP Transcription Factors