[Show abstract][Hide abstract] ABSTRACT: DNA methyltransferase 3A (DNMT3A) mutations were considered to be independently associated with unfavorable prognosis in adults with de novo acute myeloid leukemia (AML), however, there are still debates on this topic. Here, we aim to further investigate the association between DNMT3A mutations and prognosis of patients with AML.
PLoS ONE 01/2014; 9(6):e93353. · 3.53 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The promyelocytic leukemia (PML) gene, as an important tumor-suppressor, has been proven to regulate stem cell function in multiple tissues; however its role in human mesenchymal stem cells (hMSCs) remains unclear. In the present study, the effect of PML on regulating the proliferation and osteogenic differentiation of hMSCs was explored. New downstream genes that may be responsible for the regulation of PML were found, and possible mechanisms were analyzed. The lentiviral vector which encodes full-length human PML cDNA or shRNA against PML was transfected into hMSCs. RT-PCR and western blotting were used to detect mRNA and protein expression. Flow cytometry was used to analyze apoptosis and the cell cycle distribution. Osteogenic differentiation of hMSCs was induced by osteo-inductive medium for 7 to 14 days. cDNA microarray was used to scan the gene expression profile and to identify significant changes in gene expression. In the present study, we found that PML was stably expressed in hMSCs, and the expression was increased time-dependently along with cell osteogenic differentiation. Overexpression of PML inhibited hMSC proliferation by inducing apoptosis and arresting the cell cycle. However, PML enhanced the osteoblast differentiation potential of hMSCs. PML-overexpressing hMSCs had a significant increase in mineralized matrix production and ALP activity on day 7 under osteogenic or non-osteogenic differentiation conditions. Upregulation of integrin-binding sialoprotein (IBSP, bone sialoprotein) induced by PML overexpression was found. Our data indicate that PML regulates hMSCs as an inhibitor of cell proliferation but a promoter of osteogenic differentiation.
[Show abstract][Hide abstract] ABSTRACT: Abstract T-cell acute lymphoblastic leukemias (T-ALLs) are clonal lymphoid malignancies with poor prognosis, and still lack of effective treatment. Here we examined the interactions between the mammalian target of rapamycin (mTOR) inhibitor rapamycin and idarubicin (IDA) in series of human T-ALL cell lines Molt-4, Jurkat, CCRF-CEM, and CEM/C1. Co-exposure of cells to rapamycin and IDA synergistically induced T-ALL cells growth inhibiton and apoptosis mediated by caspase activation via intrinsic mitochondrial pathway and extrinsic pathway, Combined treatment with rapamycin and IDA down-regulate Bcl-2 and Mcl-1, inhibit the activation of PI3K/ mTOR and extracellular signal-related kinase (ERK). They also played synergistic pro-apoptotic roles in the drug-resistant microenvironment simulated by mesenchymal stem cells (MSCs) as a feeder layer. In addition, MSCs protect T-ALL cells from IDA cytotoxicity by up-regulating ERK phosphorylation, while rapamycin efficiently reversed this protective effect. Taken together, we confirm the synergistic antitumor effects of rapamycin and IDA, and provide an insight into the potential future clinical applications of combined rapamycin-IDA regimens for treating T-cell malignancies.
[Show abstract][Hide abstract] ABSTRACT: Background. Recently, several important polymorphisms have been identified in T-cell activation and effector pathway genes and reported to be associated with inter-patient variability in alloimmune responses. The present study was designed to assess the impact of these genetic variations on the outcomes of allogeneic hematopoietic stem cell transplantation. Design and Methods. We first investigated 10 single nucleotide polymorphisms in 6 genes: CD28, inducible co-stimulator, cytotoxic T-lymphocyte antigen 4, Granzyme B, Fas and Fas ligand, in 138 pairs of patients and their unrelated donors and a second cohort of 102 pairs of patients and their HLA-identical sibling donors. Results. We observed that patients receiving stem cells from a donor with the cytotoxic T-lymphocyte antigen 4 gene CT60 variant allele (AA genotype) had a reduced incidence of grades II-IV acute graft-versus-host disease, however, they experienced early cytomegalovirus infection and relapse more frequently, which suggested an interaction between the donor cytotoxic T-lymphocyte antigen 4 gene CT60 AA genotype and reduced T-cell alloreactivity. Furthermore, an unrelated donor with the Granzyme B +55 variant genotype (AA) was an independent risk factor for development of grades II-IV acute graft-versus-host disease (p=0.024, RR=1.811). Acute myelogenous leukemia patients with the Fas -670 TT genotype were at higher risk of relapse (p=0.003, RR=3.823). The presence of those susceptible alleles in donor and/or patient resulted in worse overall survival (54.9% vs. 69.5%, p=0.029). Conclusions. Our data suggest that genotype analysis of T-cell activation and effector pathway genes can be used for risk assessment for patients with hematological malignancies before hematopoietic stem cell transplantation.
[Show abstract][Hide abstract] ABSTRACT: Graft-versus-host disease (GVHD) is a common complication after allogeneic hematopoietic stem cell transplantation. Much of our knowledge regarding GVHD comes from experiments on the mouse hematopoietic system due to ethical and technical constraints. Thus, in vivo GVHD models of the human immune system are required. In this study, we report an effective and reliable protocol for xenogeneic GVHD (xeno-GVHD) model induction using NOD/SCID mice, in which mice underwent a conditioning regimen consisting of intraperitoneal injection of cyclophosphamide and anti-CD122, followed by transfusion of phytohemagglutinin-activated human peripheral blood mononuclear cells containing 1 × 10(7) T cells, which has not been reported previously. The present model can be utilized to study human immune cell function in vivo and elucidate the mechanisms underlying the pathogenesis of human GVHD. In addition, this model system can help researchers to rapidly determine whether proposed therapeutic strategies for GVHD are efficient in vivo and will elucidate the underlying mechanisms of drugs and cells to be investigated. Furthermore, such a protocol will undoubtedly be very helpful to laboratories that have no available sources of irradiation.
Annals of Hematology 06/2012; 91(11):1803-12. · 2.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The efficient commitment of a specialized cell type from induced pluripotent stem cells (iPSCs) without contamination from unknown substances is crucial to their use in clinical applications. Here, we propose that CD34+ progenitor cells, which retain hematopoietic and endothelial cell potential, could be efficiently obtained from iPSCs derived from human bone marrow mesenchymal stem cells (hBMMSC-iPSCs) with defined factors. By treatment with a cocktail containing mesodermal, hematopoietic, and endothelial inducers (BMP4, SCF, and VEGF, respectively) for 5 days, hBMMSC-iPSCs expressed the mesodermal transcription factors Brachyury and GATA-2 at higher levels than untreated groups (P<0.05). After culturing with another hematopoietic and endothelial inducer cocktail, including SCF, Flt3L, VEGF and IL-3, for an additional 7-9 days, CD34+ progenitor cells, which were undetectable in the initial iPSC cultures, reached nearly 20% of the total culture. This was greater than the relative number of progenitor cells produced from human-skin-fibroblast-derived iPSCs (hFib-iPSCs) or from the spontaneous differentiation groups (P<0.05), as assessed by flow cytometry analysis. These induced cells expressed hematopoietic transcription factors TAL-1 and SCL. They developed into various hematopoietic colonies when exposed to semisolid media with hematopoietic cytokines such as EPO and G-CSF. Hematopoietic cell lineages were identified by phenotype analysis with Wright-Giemsa staining. The endothelial potential of the cells was also verified by the confirmation of the formation of vascular tube-like structures and the expression of endothelial-specific markers CD31 and VE-CADHERIN. Efficient induction of CD34+ progenitor cells, which retain hematopoietic and endothelial cell potential with defined factors, provides an opportunity to obtain patient-specific cells for iPSC therapy and a useful model for the study of the mechanisms of hematopoiesis and drug screening.
PLoS ONE 01/2012; 7(4):e34321. · 3.53 Impact Factor