Angiogenic factors are increased in circulating granulocytes and CD34(+) cells of myeloproliferative neoplasms

It has been shown that angiogenesis and inflammation play an important role in development of most hematological malignancies including the myeloproliferative neoplasm (MPN). The aim of this study was to investigate and correlate the levels of key angiogenic molecules such as hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF) and endothelial nitric oxide synthase (eNOS) in peripheral blood and bone marrow cells of MPN patients, along with JAK2V617F mutation allele burden and effects of therapy. HIF-1α and VEGF gene expression were decreased, while eNOS mRNA levels were increased in granulocytes of MPN patients. Furthermore, positively correlated and increased VEGF and eNOS protein levels were in negative correlation with HIF-1α levels in granulocytes of MPN patients. According to immunoblotting, the generally augmented angiogenic factors demonstrated JAK2V617F allele burden dependence only in granulocytes of PMF. The angiogenic factors were largely reduced after hydroxyurea therapy in granulocytes of MPN patients. Levels of eNOS protein expression were stimulated by Calreticulin mutations in granulocytes of essential thrombocythemia. Immunocytochemical analyses of CD34(+) cells showed a more pronounced enhancement of angiogenic factors than in granulocytes. Increased gene expression linked to the proinflammatory TGFβ and MAPK signaling pathways were detected in CD34(+) cells of MPN patients. In conclusion, the angiogenesis is increased in several cell types of MPN patients supported by the transcriptional activation of inflammation-related target genes, and is not limited to bone marrow stroma cells. It also appears that some of the benefit of hydroxyurea therapy of the MPN is mediated by effects on angiogenic factors. This article is protected by copyright. All rights reserved.

Molecular carcinogenesis. 2016 Jun 24 [Epub ahead of print]

Tijana Subotički, Olivera Mitrović Ajtić, Bojana B Beleslin-Čokić, Ronny Nienhold, Miloš Diklić, Dragoslava Đikić, Danijela Leković, Tanja Bulat, Dragana Marković, Mirjana Gotić, Constance T Noguchi, Alan N Schechter, Radek C Skoda, Vladan P Čokić

Institute for Medical Research, University of Belgrade, Belgrade, Serbia., Institute for Medical Research, University of Belgrade, Belgrade, Serbia., Clinic for endocrinology, Diabetes and Metabolic Diseases, Genetic Laboratory, Clinical Center of Serbia, Belgrade, Serbia., Department of Biomedicine, Experimental Hematology, University Hospital Basel, Basel, Switzerland., Institute for Medical Research, University of Belgrade, Belgrade, Serbia., Institute for Medical Research, University of Belgrade, Belgrade, Serbia., Clinic of Hematology, Clinical Center of Serbia, Belgrade, Serbia., Institute for Nuclear Sciences "Vinča", University of Belgrade, Belgrade, Serbia., Institute for Medical Research, University of Belgrade, Belgrade, Serbia., Clinic of Hematology, Clinical Center of Serbia, Belgrade, Serbia., Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD., Molecular Medicine Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD., Department of Biomedicine, Experimental Hematology, University Hospital Basel, Basel, Switzerland., Institute for Medical Research, University of Belgrade, Belgrade, Serbia.