Effect of Dioxin (TCDD) on Gene Transcription of Human CD34+ Hematopoietic Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4033-4033
Author(s):  
Nicola S. Fracchiolla ◽  
Federica Servida ◽  
Pier A. Bertazzi ◽  
Paolo Corradini ◽  
Antonio Colombi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cardiovascular Disease ◽  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Expression Profiles ◽  
Juvenile Myelomonocytic Leukemia ◽  
Human Cd34 ◽  
Cd34 Cells ◽  
Hodgkin's Lymphomas ◽  
Vitro Effect

Abstract 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) binds to aryl hydrocarbon receptor (AhR), a member of the erb-A family, allowing, after DNA binding, gene expression regulation. TCDD has a large number of biological effects, as skin and cardiovascular disease, diabetes and cancer. An increase in myeloid leukemia, Hodgkin’s and non-Hodgkin’s lymphomas, was observed after 15 years in the population exposed to TCDD after the 1976 accident in Seveso, Italy. In the present study, we analyzed the in vitro effect of TCDD exposure on human CD34+ progenitor cells from G-CSF stimulated leukapheresis of 4 normal donors. Gene expression modulation induced by TCDD was analysed on highly purified (>96%) CD34+ cells, after exposure to 10 nM of TCDD for 12 hrs. Gene expression profiles have been generated by high-density oligonucleotide arrays (Affymetrix GeneChip U133A) and subsequently analyzed with a supervised approach (DNA-Chip Analyzer, dChip 2006). The differential expression of 257 transcripts (150 up regulated and 106 down-regulated) distinguished the 4 TCDD treated from the 4 untreated control samples. Interestingly, a number of the differentially expressed genes were involved in skin and cardiovascular diseases, diabetes, and different cancers, all of which have been associated with TCDD exposure. Among skin diseases, defects in laminin beta 3, ALOX12B and keratin 2a, all downregulated in TCDD exposed CD34+ cells, are associated with development of epidermolysis bullosa, erythroderma ichthyosiform, and Siemens ichthyosis bullosa, respectively. As far as diabetes and cardiovascular disease pathogenesis are concerned, defects of SLC2A4 gene, dowregulated by TCDD, is associated with the development of non insulin dependent diabetes, while epoxide hydrolase 2 and EGR2 are associated with cardiovascular disease. Among cancer related genes, ARHGAP26 and ABL2 are associated with juvenile myelomonocytic leukemia and acute myeloid leukemia with eosinophilia, respectively. Nevertheless, the expression of numerous other genes potentially involved in hemopoiesis/leukemogenesis, was modulated by TCDD exposure. Among these examples are c-kit ligand, LIF receptor, pre B lymphocyte gene 1, piwi-like 2, FLT3 ligand, chemokine ligands 14 and 15, and cdk2, that were all up regulated, while MLL4, wnt inhibitory factor 1, chemokine ligand 7, and lymphoid blast crisis oncogene, were down regulated. In conclusion, the gene expression pattern induced by TCDD exposure on the CD34+ normal progenitor cells is consistent with the spectrum of TCDD induced toxicities/diseases. In particular, it provides the basis for a possible role of TCDD in the neoplastic transformation of hemopoietic stem cells and support the epidemiologic data of increased hematologic cancer risk in the population exposed accidentally to the substance.

Genotypic Representation of Myelodysplastic/Myeloproliferative Neoplasms in Nrg, Nrg-3GS and Srg-W41 Mice with Transgenic Expression of Human Cytokines

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 2038-2038
Author(s):  
Hein Than ◽  
Naoto Nakamichi ◽  
Anthony D. Pomicter ◽  
John O'Shea ◽  
Orlando Antelope ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Myeloid Leukemia ◽  
Myeloproliferative Neoplasms ◽  
Model Systems ◽  
Juvenile Myelomonocytic Leukemia ◽  
Functional Screening ◽  
Human Cd34 ◽  
Cd34 Cells ◽  
Significant Difference ◽  
Myelomonocytic Leukemia

Abstract Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are complex clonal hematopoietic stem cell malignancies with overlapping dysplastic and proliferative features. Genomic analyses have charted the somatic mutation spectrum of MDS/MPN and revealed a major role for epigenetic dysregulation in their pathogenesis. No disease-modifying therapies are currently available, as progress has been hampered by a lack of genetically faithful in vivo model systems suitable for the preclinical development of new strategies. Yoshimi et al (Blood. 2017;130:397-407) recently showed that patients' chronic myelomonocytic leukemia (CMML) and juvenile myelomonocytic leukemia (JMML) cells transplanted into NOD/SCID-IL2Rγ-/-mice expressing human IL3, GM-CSF and SCF transgenes (NSG-3GS mice) produced xenografts that had mutations characteristic of the input cells. Since we had demonstrated a superior level of chimerism achieved from transplants of normal human CD34+cord blood cells in SirpaNOD/Rag1-/-/IL2rγc-/-/W41/41mice with c-KIT deficiency (with an otherwise mixed NOD-C57Bl/6 background - SRG-W41 mice) compared to conventional NSG or NRG hosts (Miller et al. Exp Hematol. 2017;48:41-49), it was of interest to explore their use as hosts of samples from patients with MDS/MPN: CMML, atypical chronic myeloid leukemia (aCML) and secondary acute myeloid leukemia (sAML) progressed from CMML or aCML. Heparinized blood or bone marrow samples were obtained from patients treated at Huntsman Cancer Institute after informed consent. Diagnoses included CMML (n=5), aCML (n=2), and sAML (n=2). Unseparated cells were shipped by overnight courier to Vancouver and CD34+cells isolated on the same day were injected intravenously into sub-lethally irradiated female NRG mice or SRG-W41 mice, or in some cases the same sex and strains also carrying the human 3GS transgenes (NRG-3GS or SRG-W41-3GS mice) in accordance with British Columbia Cancer Agency institutional guidelines. Occasionally when mice were not immediately available, or large numbers of cells were available, cells were viably cryopreserved and transplanted later after thawing. Mice were observed for up to 36 weeks after xenotransplantation with .05 to 1.1x106 human CD34+cells. Engraftment of human CD45+cells in xenografts was evaluated by immunophenotyping, and a median of 90% human chimerism (range: 1% - 95%) was achieved at the time of bone marrow harvest from xenografts. Variant allele frequencies (VAF) were determined in genomic DNA extracted from both the patient samples (CD34+cells) and matching fluorescence-activated cells (FACS)-sorted human CD45+cells (hCD45+cells) purified from xenografts (1-5 xenografts per patient sample). DNA samples were subjected to PCR amplification with extension primers and analyzed using a MALDI-TOF mass spectrometer (MassArray, Agena Bioscience, San Diego, CA). Each mutation call was assigned by the software based on the molecular weight of the extended primer. Analysis of hCD45+cells from eight xenograft samples so far demonstrated a strong correlation of VAF between the patient samples and hCD45+cells from xenografts, in both SRG-W41-3GS (R2=0.94, p<0.01) and NRG-3GS (R2=0.97, p<0.01) models (Figure 1). This tight correlation of VAF was illustrated in hCD45+cells from xenografts transplanted with CMML, aCML or sAML cells. The majority of mutations detected were those in epigenetic regulator genes, such as ASXL1, EZH2 and TET2. No significant difference in VAF was observed between CD34+and CD34- compartments within the hCD45+cells. Additional samples, including specimens from patients with the related myeloproliferative neoplasm, chronic neutrophilic leukemia (CNL) are being analyzed and will be presented. These findings demonstrate the utility of SRG-W41-3GS as well as NRG-3GS as receptive hosts of primary human MDS/MPN cells with genetic evidence of their growth in these mice closely recapitulating the mutational profiles of the transplanted cells. These new strains may facilitate the development of functional screening and pre-clinical testing of novel therapeutic strategies for a range of human MDS/MPN and related myeloid disorders. Disclosures Deininger: Pfizer: Consultancy, Membership on an entity's Board of Directors or advisory committees; Blueprint: Consultancy.

Evaluation of Human and Rhesus CD34+CXCR4+ and CD34+CXCR4- Subpopulations

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1007-1007
Author(s):  
Naoya Uchida ◽  
Yu Tian ◽  
Ping Jin ◽  
Aylin C. Bonifacino ◽  
Mark E. Metzger ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Population ◽  
Human Cell ◽  
Peripheral Blood ◽  
Conflicts Of Interest ◽  
Expression Profiles ◽  
Human Cells ◽  
Egfp Expression ◽  
Human Cd34 ◽  
Cd34 Cells

Abstract Abstract 1007 CXCR4 is an α-chemokine receptor specific for the ligand stromal-derived-factor-1 (SDF-1). CXCR4 is expressed on several cell types, including CD34+ cells. In this study, we sought to evaluate the difference between subpopulations of human and rhesus CD34+ cells that express CXCR4. Rhesus CD34+ cells were mobilized using a five day course of G-CSF (10mcg/kg SQ) and a single dose (1mg/kg SQ) of the CXCR4 antagonist, AMD3100, on the 5th day. Leukapheresis was performed two hours following the last dose of G-CSF and AMD3100 and CD34+ cells were isolated by immunoselection from the product. Human CD34+ cells were collected by leukapheresis and immunoselection following a 5 day course of 480 mcg G-CSF SQ. CXCR4+ and CXCR4- fractions in the CD34+ cells were separated by cell sorting. Rhesus and human CD34+CXCR4+ and CD34+CXCR4- cells were used for microarray analysis as well as cultured and transduced with an EGFP-expressing lentiviral vector. On average (SD) 21.6 ± 4.4% of AMD3100+G-CSF mobilized rhesus (n=6) and 39.3 ± 4.3% of G-CSF mobilized human (n=3) CD34+ cells express CXCR4. Two days following in vitro culture, rhesus CD34+CXCR4+ cells showed greater numbers of adherent spindle-shaped cells (56.4 ± 7.4%) when compared to CXCR4- cells (1.3 ± 0.4%, p<0.01) and bulk CD34+ cells (21.0 ± 2.0%, p<0.01). Following transduction, the rhesus CD34+CXCR4+ derived cells also had significantly lower EGFP expression (7.0 ± 0.3%) when compared to their CD34+CXCR4- counterpart (25.4 ± 1.2%, p<0.01) and bulk CD34+ cells (22.6 ± 2.2%, p<0.01). In CFU assay, human CD34+CXCR4+ cells showed fewer colony numbers (Erythroid (E): 6.2 ± 1.7/1000 cells, Myeloid (M): 7.0 ± 0.0/1000 cells) when compared to CD34+CXCR4- derived cells (E: 21.5 ± 7.9/1000 cells, ns, M: 24.7 ± 4.8/1000 cells, p<0.05) and bulk CD34+ cells without lentiviral transduction (E: 37.3 ± 1.2/1000 cells, p<0.05, M: 24.7 ± 4.8/1000 cells, p<0.01). To determine whether the CD34+CXCR4+ or CD34+CXCR4- subpopulation contained hematopoietic repopulating cells, human CD34+CXCR4+ cells (4×10e4 cells/mouse) and CD34+CXCR4- cells (4×10e4 cells/mouse or 2×10e6 cells/mouse) with lentiviral gene-marking were transplanted into NOD/SCID/IL2Rγ null mice. Human cell chimerism and %EGFP in the peripheral blood cells were analyzed every 4 weeks for over 6 months (Figure). CD34+CXCR4+ cell-transplanted mice showed no engraftment of human cells (less than 1% of human CD45+ cells) at all time points, while human cells were detected in the peripheral blood of the CD34+CXCR4- cell-transplanted mice (4×10e4 cells/mouse) until 12 weeks after transplantation. The CD34+CXCR4- cell-transplanted mice (2×10e6 cells/mouse) showed human cell engraftment for over 6 months. These data suggest that the CD34+CXCR4- cell population contain hematopoietic repopulating cells. To evaluate the nature of the CD34+CXCR4+ cell population, global microarray gene expression analysis was performed both on human and non-human primate CD34+CXCR4+ cells. Microarray signatures showed different gene profiles between CD34+CXCR4+ and CD34+CXCR4- populations in both human and rhesus CD34+ cells. Both human and rhesus CD34+CXCR4+ populations demonstrated strong monocyte- and neutrophil-mediated inflammatory response gene expression profiles, suggesting that the CD34+CXCR4+ subpopulation in both human and non-human primates contain progenitors instrumental in the innate immune response. These results indicate that while the addition of AMD3100 to G-CSF mobilization protocols may increase the number of CD34+ cells mobilized, some of these cells may not be as potent for gene therapy and transplantation applications and support the design of immunoselection protocols which target specific subpopulations of CD34+ cells for therapeutic applications in the future. Disclosures: No relevant conflicts of interest to declare.

NFκB-Mediated Up-Regulation of Transcription Factors Related to More Primitive State of Hematopoietic Progenitor Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 1246-1246
Author(s):  
Rodrigo A. Panepucci ◽  
Lucila H.B. Oliveira ◽  
Dalila L. Zanette ◽  
Greice A. Molfetta ◽  
Rita C.V. Carrara ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Progenitor Cells ◽  
Real Time ◽  
Quantitative Pcr ◽  
Expression Profiles ◽  
Hematopoietic Progenitor Cells ◽  
Hematopoietic Progenitor ◽  
Cd34 Cells ◽  
Primitive State

Abstract We have previously shown that a distinctive feature of umbilical cord blood (UCB) CD34+ hematopoietic progenitor cells (HSPC) as compared to bone marrow (BM) CD34+ is a higher expression of transcription targets and components of the nuclear factor kappa B (NF-κB) pathway. NFKB2 and RELB are sub-units of the transcription factor (TF) that specifically mediates the constitutive NF-κB signaling pathway and their increased levels could be related with the primitive state of the newborn’s HSPC. However, BM and UCB CD34+ HSPC differ in their sub-population compositions, and a higher proportion of more primitive cells among the CD34+ cells could account for those differences. CD133 is a surface marker expressed on a more primitive sub-population of CD34+ cells that are highly enriched in long-term culture-initiating cells, NOD/SCID-repopulating cells. We used flow cytometry, oligonucleotide microarray gene expression profiling and real time quantitative PCR to better characterize immunomagnetically sorted CD34+ and CD133+ HSPC derived from BM and UCB. We found that UCB CD34+ cells contain a larger proportion of CD133+ cells (around 70%), differing from BM CD34+ cells (around 30%). Cluster analysis of the expression profiles, encompassing 10.000 genes, showed that UCB CD133+ are more similar to UCB CD34+ than to BM CD133+ cells. Furthermore, a statistically significant higher expression of NFKB2 and RELB was demonstrated by quantitative PCR on UCB CD133+ HSPC, compared to BM. Overall this indicates that despite distinct compositions of the cells from UCB or BM, UCB HSPC display intrinsic molecular differences related to their ontological age. The comparison of the gene expression profiles of the CD133+ with the CD34+ populations revealed the higher expression of many well known factors related to more primitive HSPC and hemangioblasts. In fact, TFs such as RUNX1/AML1, GATA3, USF1, TAL1/SCL, HOXA9 and HOXB4 were all present at higher levels in CD133+ HSPC. In an attempt to identify a key TF that could be responsible for the expression of these important factors, we carried a promoter analysis for the set of highly expressed TF found in the CD133 cells. A frequency of TF binding sites significantly higher than the expected was observed for the NF-κB TFs, including potential NF-κB targets such as RUNX1, GATA3 and USF1. Measurements of GATA3, NFKB2 and RELB expression by real-time PCR showed a higher expression of the three genes in CD133+ samples (both from BM and UCB), as well as a correlation of the expression levels of NFkB2 and RELB with one another and with GATA3 (Sperman’s correlation), indicating that GATA3 could be, in fact, regulated by NF-κB. To further test this hypothesis, we used interference RNA (RNAi) against NFKB2 in HSPC. Levels of NFKB2, GATA3 and RELB (a known target of NFKB2/RELB dimmers) were down-modulated, in comparison with cells transfected with control RNAi. Taken together, our data indicates that constitutive NF-κB signaling may act up-regulating transcription factors related to a more primitive state of HSPC.

scholarly journals Global gene expression profiles of hematopoietic stem and progenitor cells from patients with chronic myeloid leukemia: the effect of in vitro culture with or without imatinib

2017 ◽  
Vol 6 (12) ◽  
pp. 2942-2956 ◽  
Author(s):  
Sócrates Avilés-Vázquez ◽  
Antonieta Chávez-González ◽  
Alfredo Hidalgo-Miranda ◽  
Dafne Moreno-Lorenzana ◽  
Lourdes Arriaga-Pizano ◽  
...  
Keyword(s):  
Gene Expression ◽  
Chronic Myeloid Leukemia ◽  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Global Gene Expression ◽  
Hematopoietic Stem ◽  
Stem And Progenitor Cells

Repression of BMI1 in normal and leukemic human CD34+ cells impairs self-renewal and induces apoptosis

Blood ◽  
2009 ◽  
Vol 114 (8) ◽  
pp. 1498-1505 ◽  
Author(s):  
Aleksandra Rizo ◽  
Sandra Olthof ◽  
Lina Han ◽  
Edo Vellenga ◽  
Gerald de Haan ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Myeloid Leukemia ◽  
Oxygen Species ◽  
Self Renewal ◽  
Human Cd34 ◽  
Bmi1 Expression ◽  
Cd34 Cells ◽  
Stem And Progenitor Cells ◽  
Cord Blood Cd34

Abstract High expression of BMI1 in acute myeloid leukemia (AML) cells is associated with an unfavorable prognosis. Therefore, the effects of down-modulation of BMI1 in normal and leukemic CD34+ AML cells were studied using a lentiviral RNA interference approach. We demonstrate that down-modulation of BMI1 in cord blood CD34+ cells impaired long-term expansion and progenitor-forming capacity, both in cytokine-driven liquid cultures as well as in bone marrow stromal cocultures. In addition, long-term culture-initiating cell frequencies were dramatically decreased upon knockdown of BMI1, indicating an impaired maintenance of stem and progenitor cells. The reduced progenitor and stem cell frequencies were associated with increased expression of p14ARF and p16INK4A and enhanced apoptosis, which coincided with increased levels of intracellular reactive oxygen species and reduced FOXO3A expression. In AML CD34+ cells, down-modulation of BMI1 impaired long-term expansion, whereby self-renewal capacity was lost, as determined by the loss of replating capacity of the cultures. These phenotypes were also associated with increased expression levels of p14ARF and p16INK4A. Together our data indicate that BMI1 expression is required for maintenance and self-renewal of normal and leukemic stem and progenitor cells, and that expression of BMI1 protects cells against oxidative stress.

The Transcriptional Profile of PV Displays Limited Similarity to EPO Stimulated Progenitor Cells: Evidence That JAK2 V617F Confers a Novel Program to Malignant Hematopoietic Stem Cells.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 120-120
Author(s):  
Windy Berkofsky-Fessler ◽  
Melanie J. McConnell ◽  
Kai Huang ◽  
Monica L. Bailey ◽  
Dwayne L. Barber ◽  
...  
Keyword(s):  
Gene Expression ◽  
Progenitor Cells ◽  
Cross Validation ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Jak2 V617f ◽  
Jak2 Mutation ◽  
Data Set ◽  
Cd34 Cells ◽  
Normal Human

Abstract Polycythemia vera (PV) is a myeloproliferative disorder characterized by accumulation of mature red cells (RBC). Recent evidence indicates that a mutation of JAK2, V617F, is found in virtually all patients with PV. This allele encodes a constitutively active form of JAK2 and represents a likely pathogenic lesion. JAK2 is required for normal RBC development and is activated by erythropoietin (EPO) during erythroid maturation. Hence the JAK2 mutation may phenocopy EPO stimulation of hematopoietic progenitor cells (HPC). This hypothesis predicts that gene expression profiles of EPO-stimulated normal human CD34+ cells should closely correlate with gene expression found in malignant PV progenitors. We tested this idea using our dataset of human HPC from 8 normals and 9 PV patients and a recently published data set (Ebert et al., Blood 2005) of normal human HPC treated with EPO. In addition, we examined our other data sets to obtain the murine transcriptional program of EPO stimulation, including BaF3-EPO-R cells, HCD-57 cells, fetal liver cells, and phenylhydrazine-primed splenic erythroblasts all treated with EPO. Using low sensitivity direct sequencing we detected the JAK2 V617F mutation in one third of our PV patients and are now using high sensitivity allele-specific PCR to document the mutation in all patients. Further, the gene expression profiles across all of our PV specimens is uniform; hence the PV progenitors in this study are likely representative of JAK2 mutant cells. The human and mouse experiments, pre- and post-EPO treatment, were queried to produce a transcriptional profile of EPO stimulation, i.e. genes that significantly (p≤0.05) changed at least 2x between no drug and EPO treatment after multiple testing correction. A support vector machine selected 31 of 47 EPO- regulated human genes which correctly identified 16 of 17 samples as PV or normal upon leave-one-out cross-validation. This shows similarities exist between normal EPO/JAK2 signaling and PV. However the gene expression signature of EPO stimulated progenitors had very little overlap with the expression profile of PV specimens. Only 3 genes were present in both sets, KLF4, RGC32, SKIP1. Even when the restrictions were eased to a 1.5x change between PV and normal, only 5 genes were common to the PV and EPO sets (KLF4, MCL1, RGC32, SUI1, SKIP1), representing 2.6% of the total. Interestingly, these five genes alone are sufficient to predict EPO treatment in humans and PV status. Analysis of the murine data set yielded an even smaller overlap with PV, 1.1% (2 genes of 177). 38 EPO-regulated murine genes, distinct from the human set, predicted all PV samples correctly and performed with 60% accuracy on cross-validation. We conclude that expression of 5 genes may represent the common action of mutant and wild-type JAK2. The divergence in gene expression pattern between EPO treated cells and PV indicates that the JAK2 mutation in PV progenitors also affects genes distinct from the usual EPO targets during normal hematopoiesis. Genes affected by mutant JAK2 in PV may represent novel therapeutic targets in this disease. We are further testing this hypothesis by expression profiling of normal CD34+ cells expressing the mutant JAK2.

Gene expression profiling identifies significant differences between the molecular phenotypes of bone marrow–derived and circulating human CD34+ hematopoietic stem cells

Blood ◽  
2002 ◽  
Vol 99 (6) ◽  
pp. 2037-2044 ◽  
Author(s):  
Ulrich Steidl ◽  
Ralf Kronenwett ◽  
Ulrich-Peter Rohr ◽  
Roland Fenk ◽  
Slawomir Kliszewski ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Stem Cells ◽  
Bone Marrow ◽  
Dna Synthesis ◽  
Progenitor Cells ◽  
Hematopoietic Stem ◽  
Human Cd34 ◽  
Cd34 Cells ◽  
Stem And Progenitor Cells

Abstract CD34+ hematopoietic stem cells are used clinically to support cytotoxic therapy, and recent studies raised hope that they could even serve as a cellular source for nonhematopoietic tissue engineering. Here, we examined in 18 volunteers the gene expressions of 1185 genes in highly enriched bone marrow CD34+(BM-CD34+) or granulocyte–colony-stimulating factor–mobilized peripheral blood CD34+(PB-CD34+) cells by means of cDNA array technology to identify molecular causes underlying the functional differences between circulating and sedentary hematopoietic stem and progenitor cells. In total, 65 genes were significantly differentially expressed. Greater cell cycle and DNA synthesis activity of BM-CD34+ than PB-CD34+ cells were reflected by the 2- to 5-fold higher expression of 9 genes involved in cell cycle progression, 11 genes regulating DNA synthesis, and cell cycle–initiating transcription factor E2F-1. Conversely, 9 other transcription factors, including the differentiation blocking GATA2 and N-myc, were expressed 2 to 3 times higher in PB-CD34+ cells than in BM-CD34+cells. Expression of 5 apoptosis driving genes was also 2 to 3 times greater in PB-CD34+ cells, reflecting a higher apoptotic activity. In summary, our study provides a gene expression profile of primary human CD34+ hematopoietic cells of the blood and marrow. Our data molecularly confirm and explain the finding that CD34+ cells residing in the bone marrow cycle more rapidly, whereas circulating CD34+ cells consist of a higher number of quiescent stem and progenitor cells. Moreover, our data provide novel molecular insight into stem cell physiology.

Distinctive gene expression profiles of CD34 cells from patients with myelodysplastic syndrome characterized by specific chromosomal abnormalities

Blood ◽  
2004 ◽  
Vol 104 (13) ◽  
pp. 4210-4218 ◽  
Author(s):  
Guibin Chen ◽  
Weihua Zeng ◽  
Akira Miyazato ◽  
Eric Billings ◽  
Jaroslaw P. Maciejewski ◽  
...  
Keyword(s):  
Gene Expression ◽  
Molecular Mechanisms ◽  
Expression Profiles ◽  
Small Sample ◽  
Hematopoietic Progenitor Cell ◽  
Molecular Characteristics ◽  
Hematopoietic Progenitor ◽  
Trisomy 8 ◽  
Monosomy 7 ◽  
Cd34 Cells

Abstract Aneuploidy, especially monosomy 7 and trisomy 8, is a frequent cytogenetic abnormality in the myelodysplastic syndromes (MDSs). Patients with monosomy 7 and trisomy 8 have distinctly different clinical courses, responses to therapy, and survival probabilities. To determine disease-specific molecular characteristics, we analyzed the gene expression pattern in purified CD34 hematopoietic progenitor cells obtained from MDS patients with monosomy 7 and trisomy 8 using Affymetrix GeneChips. Two methods were employed: standard hybridization and a small-sample RNA amplification protocol for the limited amounts of RNA available from individual cases; results were comparable between these 2 techniques. Microarray data were confirmed by gene amplification and flow cytometry using individual patient samples. Genes related to hematopoietic progenitor cell proliferation and blood cell function were dysregulated in CD34 cells of both monosomy 7 and trisomy 8 MDS. In trisomy 8, up-regulated genes were primarily involved in immune and inflammatory responses, and down-regulated genes have been implicated in apoptosis inhibition. CD34 cells in monosomy 7 showed up-regulation of genes inducing leukemia transformation and tumorigenesis and apoptosis and down-regulation of genes controlling cell growth and differentiation. These results imply distinct molecular mechanisms for monosomy 7 and trisomy 8 MDS and implicate specific pathogenic pathways.

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