BACKGROUND: Imatinib mesylate (IM) resistance is an emerging problem for chronic myeloid leukemia (CML). Previous studies found that connexin 43 (Cx43) deficiency in the hematopoietic microenvironment (HM) protects minimal residual disease (MRD), but the mechanism remains unknown. METHODS: Immunohistochemistry assays were employed to compare the expression of Cx43 and hypoxia-inducible factor 1α (HIF-1α) in bone marrow (BM) biopsies of CML patients and healthy donors. A coculture system of K562 cells and several Cx43-modified bone marrow stromal cells (BMSCs) was established under IM treatment. Proliferation, cell cycle, apoptosis, and other indicators of K562 cells in different groups were detected to investigate the function and possible mechanism of Cx43. We assessed the Ca 2+ -related pathway by Western blotting. Tumor-bearing models were also established to validate the causal role of Cx43 in reversing IM resistance. RESULTS: Low levels of Cx43 in BMs were observed in CML patients, and Cx43 expression was negatively correlated with HIF-1α. We also observed that K562 cells cocultured with BMSCs transfected with adenovirus-short hairpin RNA of Cx43 (BMSCs-shCx43) had a lower apoptosis rate and that their cell cycle was blocked in G0/G1 phase, while the result was the opposite in the Cx43-overexpression setting. Cx43 mediates gap junction intercellular communication (GJIC) through direct contact, and Ca 2+ is the key factor mediating the downstream apoptotic pathway. In animal experiments, mice bearing K562, and BMSCs-Cx43 had the smallest tumor volume and spleen, which was consistent with the in vitro experiments. CONCLUSIONS Cx43 deficiency exists in CML patients, promoting the generation of MRD and inducing drug resistance. Enhancing Cx43 expression and GJIC function in the HM may be a novel strategy to reverse drug resistance and promote IM efficacy.
Animals ; Humans ; Mice ; Apoptosis ; Bone Marrow Cells ; Cell Communication ; Connexin 43/genetics* ; Gap Junctions/metabolism* ; Imatinib Mesylate/therapeutic use* ; K562 Cells ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology* ; Mesenchymal Stem Cells/metabolism* ; Tumor Microenvironment ; Calcium/metabolism*

Multiple myeloma (MM) is a malignant proliferative disease of plasma cells. Bone marrow mesenchymal stem cells (MSC) play an important role in the progression of MM. Compared with normal donor derived MSC (ND-MSC), MM patients derived MSC (MM-MSC) exhibit abnormalities in genes, signaling pathways, protein expression levels and cytokines secreted by themselves. Moreover, the exosomes of MM-MSC can interact with the bone marrow microenvironment. The above reasons can lead to MM cell proliferation, chemoresistance, impaired osteogenic differentiation of MM-MSC, and affect the immunomodulatory capacity of MM patients. In order to further understand the pathogenesis and related influencing factors of MM, this paper reviews the latest research progress of MM-MSC.
Humans ; Multiple Myeloma/pathology* ; Osteogenesis ; Mesenchymal Stem Cells ; Cell Differentiation ; Bone Marrow/metabolism* ; Bone Marrow Cells/metabolism* ; Tumor Microenvironment

Multiple myeloma (MM) is a common hematologic tumor characterized by malignant proliferation of clonal plasma cells, the exact pathogenesis of which is not yet fully understood. The extracellular vesicles (EV) are structures released by cells into their surroundings that do not have a functional nucleus and can communicate between cells or deliver biologically active proteins and nucleic acids to target cells. EV play an important role in the interaction between myeloma cells and the bone marrow microenvironment, and they can promote MM progression. In this paper, we summarize the recent research progress in the mechanism of action of EV on MM in order to provide inspiration for exploring new strategies for MM treatment and prognostic stratification.
Bone Marrow/metabolism* ; Extracellular Vesicles/pathology* ; Hematologic Neoplasms/metabolism* ; Humans ; Multiple Myeloma/pathology* ; Nucleic Acids/metabolism* ; Tumor Microenvironment

No abstract available.
Bone Marrow/pathology ; Chromosomes, Human, Pair 12 ; Chromosomes, Human, Pair 9 ; Core Binding Factor Alpha 2 Subunit/*genetics ; DNA/metabolism ; Gene Rearrangement ; Humans ; In Situ Hybridization, Fluorescence ; Karyotyping ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis/*genetics ; Male ; Middle Aged ; Oncogene Proteins, Fusion/*genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Translocation, Genetic

No abstract available.
Aged, 80 and over ; Base Sequence ; Bone Marrow/pathology ; DNA/chemistry/metabolism ; Female ; Fusion Proteins, bcr-abl/*genetics ; Humans ; Leukemia, Myelogenous, Chronic, BCR-ABL Positive/diagnosis/*genetics ; Multiplex Polymerase Chain Reaction ; Protein Isoforms/genetics ; Sequence Analysis, DNA

BACKGROUND: To the best of our knowledge, the association between pediatric AML and mitochondrial aberrations has not been studied. We investigated various mitochondrial aberrations in pediatric AML and evaluated their impact on clinical outcomes. METHODS: Sequencing, mitochondrial DNA (mtDNA) copy number determination, mtDNA 4,977-bp large deletion assessments, and gene scan analyses were performed on the bone marrow mononuclear cells of 55 pediatric AML patients and on the peripheral blood mononuclear cells of 55 normal controls. Changes in the mitochondrial mass, mitochondrial membrane potential, and intracellular reactive oxygen species (ROS) levels were also examined. RESULTS: mtDNA copy numbers were about two-fold higher in pediatric AML cells than in controls (P<0.0001). Furthermore, a close relationship was found between mtDNA copy number tertiles and the risk of pediatric AML. Intracellular ROS levels, mitochondrial mass, and mitochondrial membrane potentials were all elevated in pediatric AML. The frequency of the mtDNA 4,977-bp large deletion was significantly higher (P< 0.01) in pediatric AML cells, and pediatric AML patients harboring high amount of mtDNA 4,977-bp deletions showed shorter overall survival and event-free survival rates, albeit without statistical significance. CONCLUSIONS: The present findings demonstrate an association between mitochondrial genome alterations and the risk of pediatric AML.
Bone Marrow Cells/metabolism ; Case-Control Studies ; Child ; Cohort Studies ; DNA, Mitochondrial/chemistry/genetics/metabolism ; Female ; Flow Cytometry ; Gene Deletion ; Gene Dosage ; *Genome, Mitochondrial ; Humans ; Leukemia, Myeloid, Acute/genetics/mortality/*pathology ; Male ; Membrane Potential, Mitochondrial ; Minisatellite Repeats/genetics ; Odds Ratio ; Reactive Oxygen Species/metabolism ; Sequence Analysis, DNA ; Survival Rate

OBJECTIVETo investigate the IL-32 mRNA expression of bone marrow stromal cells and its correlation with apoptosis of bone marrow mononuclear cells in patients with myelodysplastic syndrome (MDS).

METHODSBone marrow samples from 26 MDS patients and 10 iron deficiency anemia (IDA, as control) patients were collected, RT-PCR was used to detect the IL-32 mRNA expression of bone marrow stromal cells, and the apoptosis of bone marrow mononuclear cells was detected by flow cytometry with Annexin V-FITC/PI dowble staining. The born marrow lymphocytes and NK cells were detected by means of direct immunofluorescence labeling whole blood hemolysis and flow cytometry.

RESULTSIL-32 mRNA expression of bone marrow stromal cells in the MDS patients was significantly higher than that of control group, the IL-32 mRNA expression of bone marrow stromal cells in patients with RA, RAS and RCMD was significantly higher than that in patients with RAEB. There was no obvious difference between RAEB and the control groups. The apoptosis of bone marrow mononuclear cells in MDS group was significantly higher than that in the control group, the apoptosis of bone marrow mononuclear cells in patients with RA, RAS and RCMD was significantly higher than that in RAEB. There was no significant difference between RAEB group and control group. The IL-32 mRNA expression in bone marrow stromal cells significantly correlated with the apoptosis of bone marrow mononuclear cells in MDS patients. The NK cell number in born marrow of MDS patients and the control group had no significant difference.

CONCLUSIONThe expression of IL-32 mRNA in bone marrow stromal cells significantly relates with the apoptosis of MDS cells, and the secretion of IL-32 by bone marrow stromal cells may be one of the reasons for the apoptosis of MDS bone marrow cells. It is speculated that the abnormal MDS bone marrow microenvironment is involved in the apoptosis of bone marrow cells.

Apoptosis ; Bone Marrow Cells ; metabolism ; Flow Cytometry ; Humans ; Interleukins ; metabolism ; Mesenchymal Stromal Cells ; metabolism ; Myelodysplastic Syndromes ; pathology ; RNA, Messenger ; metabolism

OBJECTIVETo investigate the role of Rheb (mTOR activator) in AML development by measuring Rheb expression in bone marrow of adult AML patients and in AML cell line HL-60.

METHODSReal-time PCR assay was used to measure the Rheb mRNA expression in 27 AML patients and 29 ITP patients as control. The relationship between Rheb mRNA expression and age, AML subtype, fusion gene, splenomegaly, hepatomegaly and survival of AML patients was analyzed and compared. In addition, HL-60 cell line over-expressing Rheb was established, and the HL-60 cells and HL-60 cells with overexpression of Rheb were treated with Ara-C of different concentrations, the proliferation level was detected by CCK-8 method, and the IC50 was calculated.

RESULTSThe mRNA level of Rheb in AML patients was similar to that in ITP patients (control). Interestingly, higher expression of Rheb was associated with better survival and was sensitive to Ara-C treatment. However, the expression level of Rheb was not associated with age, AML subtype, fusion gene, and hepatomegaly of patients. Lower expression level of Rheb was associated with splenomegaly. In vitro analysis of HL-60 line indicated that overexpression of Rheb could increased the cell sensitivity to Ara-C treatment (IC50=0.54 µmol/L) and caused HL-60 cell apoptosis.

CONCLUSIONThe lower Rheb expression is a poor prognostic indicator for AML patients, which is associated with AML splenomegaly, the patients and HL-60 cells with low expression of Rheb are insensitive to Ara-C treatment.

Adult ; Apoptosis ; Bone Marrow ; metabolism ; Cytarabine ; pharmacology ; HL-60 Cells ; Humans ; Leukemia, Myeloid, Acute ; genetics ; metabolism ; pathology ; Monomeric GTP-Binding Proteins ; genetics ; metabolism ; Neuropeptides ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Ras Homolog Enriched in Brain Protein ; Real-Time Polymerase Chain Reaction ; Spleen ; pathology

OBJECTIVETo compare the expression of C-C chemokine receptor type 5 (CCR5) on T cells between bone marrow grafts (G-BM) and peripheral blood grafts (G-PB) nobilized by recombinant human granulocyte colony-stimulating factor (rhG-CSF), and to analyze the correlation of CCR5+ T lymphocyte expression in the grafts with the occurrence of acute GVHD.

METHODSForty-six healthy donor and their recipient pairs of related allogeneic hematopoietic stem cell transplantation (allo-HSCT) were enrolled in this study. All the recipients were received the infusion of G-BM and G-PB. The relative proportion and quantity of CCR5+ T cell subset in G-BM and G-PB were detected and compared. Then the correlation of the quantity of infused CCR5+ T cells with the occurrence of acute GVHD was analyzed.

RESULTSAfter mobilization, the proportions of CD4+ CCR5+ and CD8+ CCR5+ T cells occupying T cells in G-PB were both lower than those in G-BM. However, the absolute counts in G-PB were 15-25 times more than those in the bone marrow. And the absolute counts could not predict the occurrence of acute GVHD after transplantation (P>0.05).

CONCLUSIONThe difference of CCR5+ subsets between G-PB and G-BM may partially explain that grafts from different sources have different immunologic characteristics. Besides, the quantity of CCR5+ T cells in the grafts are not related with the occurrence of acute GVHD. However, the relative proportion of CCR5+ T cell subset in the grafts may be predictive of acute GVHD.

Bone Marrow ; metabolism ; Bone Marrow Transplantation ; Graft vs Host Disease ; pathology ; Granulocyte Colony-Stimulating Factor ; pharmacology ; Hematopoietic Stem Cell Mobilization ; Hematopoietic Stem Cell Transplantation ; Humans ; Receptors, CCR5 ; metabolism ; T-Lymphocyte Subsets ; metabolism ; Tissue Donors

OBJECTIVETo explore the autophagy activity of CD34+ cells in bone marrow of MDS patients and its clinical significance.

METHODSThe activity of autophagy in bone marrow CD34+ cells from 20 MDS patients, 20 non-malignant anemia patients and 5 AML patients admitted in our hospital from October 2012 to March 2014 was detected by flow cytometry (FCM).

RESULTSThe autophagy activity in low risk MDS patients and non-malignant anemia patients were both significantly higher than that in both high risk MDS and AML patients (P<0.05), and more interestingly, the autophagy activity in MDS negatively correlated with World Health Organization classification-based prognostic system (WPSS) score (r=-0.877) .

CONCLUSIONThe autophagy activity CD34+ cells in the patients with MDS is higher than that in AML patients, and negatively correlated with WPSS scores, indicating that the decrease of autophagy activity maybe accelerate the genesis and development of MDS and relate with the prognosis of MDS patients.

Antigens, CD34 ; metabolism ; Autophagy ; Bone Marrow Cells ; cytology ; pathology ; Flow Cytometry ; Humans ; Leukemia, Myeloid, Acute ; pathology ; Myelodysplastic Syndromes ; pathology ; Prognosis