6 research outputs found
Leukemia cell microvesicles promote survival in umbilical cord blood hematopoietic stem cells
Microvesicles can transfer their contents, proteins and RNA, to target cells and thereby transform them. This may induce apoptosis or survival depending on cell origin and the target cell. In this study, we investigate the effect of leukemic cell microvesicles on umbilical cord blood hematopoietic stem cells to seek evidence of apoptosis or cell survival. Microvesicles were isolated from both healthy donor bone marrow samples and Jurkat cells by ultra-centrifugation and were added to hematopoietic stem cells sorted from umbilical cord blood samples by magnetic associated cell sorting (MACS) technique. After 7 days, cell count, cell viability, flow cytometry analysis for hematopoietic stem cell markers and qPCR for P53 gene expression were performed. The results showed higher cell number, higher cell viability rate and lower P53 gene expression in leukemia group in comparison with normal and control groups. Also, CD34 expression as the most important hematopoietic stem cell marker, did not change during the treatment and lineage differentiation was not observed. In conclusion, this study showed anti-apoptotic effect of leukemia cell derived microvesicles on umbilical cord blood hematopoietic stem cells
LY86, LRG1 and PDE9A genes overexpression in umbilical cord blood hematopoietic stem progenitor cells by acute myeloid leukemia (M3) microvesicles
Background
Microvesicles as a new device of cell–cell communication are potentially able to induce some phenotypes and genotypes of an origin cell in a target cell. We evaluate the role of leukemia microvesicles on the leukemia stem cells (LSCs)-specific genes expression in healthy hematopoietic stem progenitor cells (HSPCs).
Methods
HL-60 and NB-4 cell lines were selected for microvesicles isolation by ultracentrifugation. Healthy HSPCs were obtained by magnetic association cell sorting (MACS) and CD-34 micro-beads from umbilical cord blood samples and then, were treated with 20 and 40 μg/ml leukemia microvesicles for 10 days, respectively. LY86, LRG1 and PDE9A genes expression as LSC specific genes were analyzed by QRT-PCR. Surface CD-34 antigen as stemness marker was measured by flow cytometry technique.
Results
Healthy HSPCs showed a significant increase in LSC specific genes expression after treatment with both 20 and 40 μg/ml leukemia microvesicles at day 10. All studied groups showed more than 70% surface CD-34 antigen at the last day of experiment which proved HSPCs stemness.
Conclusion
Our results suggest that healthy HSPCs can be transformed genetically by leukemia microvesicles to over express LSC specific genes. This may be further evidence of leukemia-like transformation by leukemia microvesicles.
Keywords: Microvesicles, Hematopoietic stem progenitor cells, Leukemia, Cell communicatio
Association of FXII 5’UTR 46C>T polymorphism with FXII activity and risk of thrombotic disease
Objective: Thrombotic diseases are caused by genetic and environmental factors. There are a number of well-characterized genetic defects that lead to increased risk of thrombosis. Results from previous studies have indicated that FXII is involved in the pathogenesis of thrombophilic diseases. However, the results in this regard are highly controversial. One of the most important determinants of Plasma FXII level is 46CgT polymorphism in the FXII gene. In the present study, the risk of thrombophilic diseases related to this polymorphism was investigated in a case-control study. Material and Methods: One hundred and sixty subjects were studied: 120 patients diagnosed with thrombophilia (96 venous thromboembolism, 24 arterial thrombosis), and 40 age-gender-matched controls. For each subject, FXII activity level was measured by a one-step clotting assay with FXII-deficient plasma, and 46CγT polymorphism was genotyped using a restriction fragment length polymorphism (RFLP) method. Results: In this study, the previous observation that individuals with different genotypes for the 46 CγT polymorphism show significant differences in FXII activity levels was confirmed. Most importantly, FXII activity ≤68% was associated with an increased risk of venous thrombosis with an adjusted odds ratio (OR) of 4.7 (95% confidence interval [CI]: 1.03-21.1, p=0.04). However, it was not a risk factor for arterial thrombosis with adjusted OR of 5 (95% CI: 0.91-27.1, p=0.09). In CT and TT genotype, the adjusted ORs were 2 (95% CI: 0.9-4.4, p=0.11) and 2.3 (95% CI: 0.45-11, p=0.48), respectively, for patients with venous thrombosis compared with the controls. Similarly, the adjusted ORs in arterial thrombosis were 1.2 (95% CI: 0.4-3.6, p=0.76) for CT and 1.8 (95% CI: 0.2-14.9, p=0.59) for TT genotype. Thus, we did not find any association of the mutated T allele in the heterozygous or homozygous state with an increased risk of venous or arterial thrombosis. Conclusion: Lower FXII activity is not a risk factor; rather, it simply represents a risk marker for thrombosis
MicroRNA-21 over expression in umbilical cord blood hematopoietic stem progenitor cells by leukemia microvesicles
Microvesicles are able to induce the cell of origin's phenotype in a target cell. MicroRNA-21, as an oncomir, is up-regulated in almost all cancer types such as leukemia which results in cell proliferation. In this study, we examine the ability of leukemia microvesicles to induce proliferation in hematopoietic stem progenitor cells (HSPCs) via microRNA-21 dysregulation. Herein, leukemia microvesicles were isolated from HL-60 and NB-4 cell lines by ultracentrifugation, and then their protein content was measured. Normal HSPCs were isolated from umbilical cord blood samples by a CD-34 antibody. These cells were treated with 20 and 40 μg/mL leukemia microvesicles for 5 and 10 days, respectively. Cell count, CD-34 analysis, and a microRNA-21 gene expression assay were done at days 5 and 10. HSPCs showed a significant increase in both microRNA-21 gene expression and cell count after treating with leukemia microvesicles compared with the control group. CD-34 analysis as stemness proof did not show any difference among the studied groups. This data suggests that HSPC proliferation followed by microRNA-21 gene over expression can be another evidence of a leukemia-like phenotype induction in a healthy target cell by leukemia microvesicles
Altered Expression of CD44, SIRT1, CXCR4, miR-21, miR-34a, and miR-451 Genes in MKN-45 Cell Line After Docetaxel Treatment
Purpose: Today it is known that the gene expression profile of cancer stem cells differs from other cancer cells, which may lead to the resistance to routine treatments. The aim of this study was to investigate the effect of docetaxel (DOC) treatment on CD44+ cell frequency in human gastric cancer (GC) MKN-45 cell line and its effect on expression levels of SIRT1, CXCR4, microRNA (miR)-21, miR-451, and miR-34a that are closely correlated with the chemoresistance or self-renewal of cancer stem cells (CSCs). Methods: The cytotoxic effect of DOC on MKN-45 cell line was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT)-assay. The frequency of CD44+ cells was measured by flow cytometry in the treated and control groups. The expression level of SIRT1, CXCR4, miR-21, miR-451, and miR-34a was assessed in DOC-treated and non-treated cells using quantitative real-time PCR. Data were analyzed using Statistical Package for the Social Sciences (SPSS) software. Results: The half-maximal inhibitory concentration (IC50) of DOC was 10 μg/ml after 48 h. Flow cytometry showed a significant increase in CD44+ cells after treatment with DOC (94.3) when compared with non-treated cells (84.6) (P < 0.01). The expression of SIRT1, CXCR4, and miR-21 was up-regulated (1.4-fold, 6.7-fold, and 1.22-fold, respectively, P < 0.05) in DOC-treated cells relative to non-treated cells, while miR-451 and miR-34a were down-regulated (0.14-fold and 0.36-fold, respectively, P < 0.05). Conclusion: DOC treatment affected CD44+ cell frequency in MKN-45 cell line and induced significant changes in the expression of SIRT1, CXCR4, miR-21, miR-451, and miR-34a that are implicated in stemness and chemo-radioresistance, which might offer new insights for future GC therapies