en قلب Heart پژوهشي Research <p><strong>Background: </strong>VHL (von Hippel-Lindau), Runx-3 (Runt-related transcription factor 3), E-cadherin (Epithelial cadherin), P15 (INK4a, cyclin dependent kinase inhibitor), and P16 (INK4b) genes are essential in hematopoiesis. The aim of this study was to explore the correlation between gene expression and promoter methylation in CD34+ stem cells before and after differentiation to erythroid lineage.</p> <p><strong>Materials and Methods: </strong>CD34+ hematopoietic stem cells were separated from umbilical cord blood using MidiMacs (positive selection) system. Expanded CD34+ stem cells were differentiated into erythroid lineage with human recombinant erythropoietin (EPO). DNA extraction was done by QIAamp DNA Mini Kit. RNA was extracted using RNase Mini plus Kit. MSP (Methylation specific PCR) technique was done for methylation assay. Methylation status and expression assay was done for VHL, Runx-3, E-cadherin, P15, and P16 genes&nbsp; on both CD34+ stem cells and differentiated erythroid cells.</p> <p><strong>Results: </strong>The results showed that, before differentiation, P15 had comparative methylation pattern and average expression and it remained unchanged after differentiation (p=0.01). concerning P16, results revealed no methylation pattern and complete expression in absence of EPO and with EPO it changed to comparative status (p=0.01). E-cad and Runx-3 genes had relative methylation pattern and fully expression before and after differentiation but their expression after that, was increased and decreased&nbsp; Respectively (p=0.04). VHL gene had no significant methylation status before or after differentiation and its expression was complete (p=0.01).</p> <p><strong>Conclusion: </strong>The obtained results indicated that promoter methylation of P15, P16, VHL, Runx3 and E-cad was one of the definitive expression control mechanism of these genes.</p> <p></p> Differentiation, EPO, Hematopoietic Stem Cells 172 181 http://ijpho.ssu.ac.ir/browse.php?a_code=A-10-70-93&slc_lang=en&sid=1 Fatemeh Eskandari No Department of Hematology, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran دانشگاه علوم پزشکی تربیت مدرس Hoda Pourkarim No Department of Hematology, Allied Medical School, Tehran University of Medical Sciences, Tehran, Iran دانشگاه علوم پزشکی تهران Mehdi Sahmani No Department of Clinical Biochemistry, Cellular and Molecular Research Center, Qazvin, Iran Mehdi Goudarzi No Department of Microbiology, School of Medicine, Shahid Beheshti University of Medical Science, Tehran, Iran Naser Mobarra No Stem cell Research Center, School of Medicine, Golestan University of Medical Sciences, Gorgan, Iran Ali Dehghanifard No Cell Research Center, Sarem Women’s Hospital, Tehran, Iran Gholamreza Khamisipour No Department of Hematology, Faculty of Allied Medicine, Bushehr University of Medical Sciences, Bushehr, Iran Nasim Kalantari No Department of Hematology, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran Hanieh Rahmani No Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran Mehdi Azad Yes Department of Medical laboratory sciences, Faculty of Allied Medicine, Qazvin University of Medical Sciences, Qazvin, Iran