Taken together, our data suggest that PMF monocytes induce myelofibrosis-like phenotype in immunodeficient mice and that PMF and normal BM-derived CD14+/CD34- monocytes give rise to megakaryocyte progenitor cells.
We recently described the upregulation of MAF (v-maf avian musculoaponeurotic fibrosarcoma oncogene homolog) in PMFCD34+ hematopoietic progenitor cells (HPCs) compared to healthy donor.
Since we recently uncovered the upregulation of miR-34a-5p in PMFCD34+ hematopoietic progenitor cells (HPCs), in order to elucidate its role in PMF pathogenesis here we unravelled the effects of miR-34a-5p overexpression in HPCs.
Additionally, high LGALS1 expression was found in CD34(+) cells but not in leucocytes from patients with PMF, in absence of JAK2 V617F mutation, and also in SET-2 cells treated with JAK inhibitor.
In addition, LCP4 treatment resulted in the depletion of the number of MF HPCs that were JAK2V617F(+) Moreover, the degree of human cell chimerism and the proportion of malignant donor cells were significantly reduced in immunodeficient mice transplanted with MFCD34(+) cell grafts treated with LCP4.
The ROC curve analysis showed that a number of CD34+ <10/μl excludes the diagnosis of primary myelofibrosis with a sensitivity of 97 % and a specificity of 90 % (area under the curve: 0.93 [0.89-0.98]; p < 0.001).
Our data indicate that the MF splenic microenvironment is characterized by increased levels of intact, functional CXCL12, which contributes to the localization of MFCD34(+) cells to the spleen and the establishment of extramedullary hematopoiesis.
A histone deacetylase inhibitor, panobinostat, significantly increased MIRLET7 expression and reduced variant 1 of HMGA2 mRNA expression, but not variant 2, in both U937 cells and PMF-derived CD34(+) cells.
Because the validation of miRNA-target interactions unveiled JARID2/miR-155-5p as the strongest relationship in the network, we studied the function of this axis in normal and PMFCD34(+) cells.
Treatment of polycythemia vera (PV) and primary myelofibrosis (PMF) CD34(+) cells with low doses of RG7112 and Peg-IFNα 2a before their transplantation into immune-deficient mice decreased the degree of donor-derived chimerism as well as the JAK2V617F allele burden, indicating that these drugs can each alone or in combination deplete MPN HSCs.
Here, we show that treatment with the dual phosphoinositide-3-kinase (PI3K)/AKT and mTOR inhibitor BEZ235 attenuated PI3K/AKT and mTOR signaling, as well as induced cell-cycle growth arrest and apoptosis of the cultured human JAK2-V617F-expressing HEL92.1.7 (HEL), UKE1 cells, and primary CD34+ myelofibrosis (MF)-MPN cells.
In this study we evaluated the apoptosis-related gene and protein expression of BCL2 family members in bone marrow CD34+ hematopoietic stem cells (HSC) and peripheral blood leukocytes from ET and PMF patients.
Two to 6 months after the transplantation of CMAs treated JAK2V617F(+) PMFCD34(+) cells into nonobese diabetic/severe combined immunodeficient (SCID)/IL-2Rγ(null) mice, the percentage of JAK2V617F/JAK2(total) in human CD45(+) marrow cells was dramatically reduced.
Moreover, a marked augmentation in HR activity was found in CD34(+)-derived cells isolated from patients with polycythemia vera or primitive myelofibrosis compared with control samples.
CD34(+) cell JAK2(V617F) clonal dominance, defined as coherence between the CD34(+) cell and neutrophil JAK2(V617F) allele burdens, was present in 24% of ET, 56% of PV, and 93% of PMF patients, and was independent of the CD34(+) cell JAK2(V617F) genotype.
In conclusion, molecular profiling of IMCD34(+) cells uncovered a limited number of genes with altered expression that, beyond their putative role in disease pathogenesis, are associated with patients' clinical characteristics and may have potential prognostic application.
The enumeration of CD34-positive cells in the peripheral blood and the presence of circulating endothelial progenitor cells are the new important ancillary tests for the diagnosis of a small subset of patients with CIMF with atypical presentation.
The predictive power of these genes was verified by applying the algorithm to an unknown test set containing expression data from eight additional CD34+ samples (four AMM, four control).
The myeloproliferation is characterized by an increased number of circulating CD34+ progenitors with the prominent amplification of dystrophic megakaryocytic (MK) cells and myeloid metaplasia in the spleen and liver.
We describe a variant form, French-American-British (FAB) M3v, of acute promyelocytic leukemia (APL; FAB M3) with atypical morphocytochemical features, immature antigens (CD34 and HLA-DR) and marked myelofibrosis (MF).