Related Experiment Video
Updated: Jul 13, 2026
Pan-myeloid Differentiation of Human Cord Blood Derived CD34+ Hematopoietic Stem and Progenitor Cells
Published on: August 9, 2019
Effects of chromatin-modifying agents on CD34+ cells from patients with idiopathic myelofibrosis
Jun Shi1, Yan Zhao, Takefumi Ishii
1Section of Hematology/Oncology, Department of Medicine, University of Illinois College of Medicine, Chicago, Illinois 60612, USA.
Abstract:
Idiopathic myelofibrosis (IM) is likely the consequence of both the acquisition of genetic mutations and epigenetic changes that silence critical genes that control cell proliferation, differentiation, and apoptosis. We have explored the effects of the sequential treatment with the DNA methyltransferase inhibitor, decitabine [5-aza-2'-deoxycytidine (5azaD)], followed by the histone deacetylase inhibitor, trichostatin A (TSA), on the behavior of IM CD34(+) cells. Unlike normal CD34(+) cells where 5azaD/TSA treatment leads to the expansion of CD34(+) cells and marrow-repopulating cells, treatment of IM CD34(+) cells results in a reduction of the number of total cells, CD34(+) cells, and assayable hematopoietic progenitor cells (HPC). In IM, HPCs are either heterozygous or homozygous for the JAK2V617F mutation or possess wild-type JAK2 in varying proportions. Exposure of IM CD34(+) cells to 5azaD/TSA resulted in a reduction of the proportion of JAK2V617F-positive HPCs in 83% of the patients studied and the reduction in the proportion of homozygous HPCs in 50% of the patients. 5azaD/TSA treatment led to a dramatic reduction in the number of HPCs that contained chromosomal abnormalities in two JAK2V617F-negative IM patients. IM is characterized by constitutive mobilization of HPCs, which has been partly attributed to decreased expression of the chemokine receptor CXCR4. Treatment of IM CD34(+) cells with 5azaD/TSA resulted in the up-regulation of CXCR4 expression by CD34(+) cells and restoration of their migration in response to SDF-1. These data provide a rationale for sequential therapy with chromatin-modifying agents for patients with IM.
Insights
Sequential treatment with decitabine and trichostatin A reduces harmful cells in idiopathic myelofibrosis (IM). This approach targets JAK2V617F mutations and chromosomal abnormalities, offering a potential new therapy for IM patients.
Area of Science:
- Hematology
- Cancer Biology
- Epigenetics
Background:
- Idiopathic myelofibrosis (IM) involves genetic mutations and epigenetic changes silencing key genes.
- CD34(+) cells and hematopoietic progenitor cells (HPCs) are central to IM pathogenesis.
- JAK2V617F mutation is a common genetic driver in IM.
Purpose of the Study:
- To investigate the effects of sequential decitabine (5azaD) and trichostatin A (TSA) treatment on IM CD34(+) cells.
- To evaluate the impact of 5azaD/TSA on JAK2V617F-positive and chromosomally abnormal HPCs in IM.
- To assess the modulation of CXCR4 expression and SDF-1-mediated migration by 5azaD/TSA in IM CD34(+) cells.
Main Methods:
- Treatment of IM CD34(+) cells with sequential DNA methyltransferase inhibitor (decitabine) and histone deacetylase inhibitor (trichostatin A).
- Flow cytometry analysis to quantify CD34(+) cells, HPCs, and JAK2V617F mutation status.
- Assessment of chromosomal abnormalities in HPCs.
- Measurement of CXCR4 expression and SDF-1-induced cell migration.
Main Results:
- Sequential 5azaD/TSA treatment reduced total cells, CD34(+) cells, and HPCs in IM samples, unlike in normal cells.
- The proportion of JAK2V617F-positive HPCs decreased in 83% of patients, with homozygous HPCs reduced in 50%.
- 5azaD/TSA significantly reduced chromosomally abnormal HPCs in JAK2V617F-negative IM patients.
- Treatment upregulated CXCR4 expression on IM CD34(+) cells and restored SDF-1-mediated migration.
Conclusions:
- Sequential decitabine and trichostatin A therapy demonstrates anti-proliferative effects on IM CD34(+) cells and HPCs.
- This treatment strategy reduces malignant cell populations, including those with JAK2V617F mutations and chromosomal abnormalities.
- The restoration of CXCR4 expression and SDF-1 responsiveness suggests a potential mechanism for improving homing and engraftment.
- These findings support the rationale for using sequential chromatin-modifying agents in idiopathic myelofibrosis treatment.
