Leukemia Decreased TREM-1 Expression In Hematopoiesis Stem/ Progenitor Cells

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 5166-5166
Author(s):  
Huiyu Li ◽  
Wenying Li ◽  
Xiaoling Yi ◽  
Shiang Huang ◽  
Wei Liu ◽  
...  
Keyword(s):  
Cord Blood ◽  
Progenitor Cells ◽  
Blood Cells ◽  
K562 Cells ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Control Group ◽  
Dependent Manner ◽  
Functional Link ◽  
Free Condition

Abstract Objectives Triggering receptor expressed on myeloid cells (TREM) -1 is a receptor expressed on the cell-surface of neutrophils, monocytes and macrophages. This receptor is a molecule crucial for the triggering and amplification of inflammatory responses. TREM-1 is shed from the membrane of activated macrophages and can be found as soluble TREM (sTREM)-1. Soluble TREM-1 is thought to negatively regulate TREM receptor signaling. In current study, we confirmed that TREM-1 were down-expressed in leukemic cells. The aims of this study was to investigate if there is a functional link between myelogenous leukemia cells and TREM-1 in hematopoiesis stem/progenitor cells. Methods 10 cord blood were collected from full-term normal cesarean-section infants. The study was approved by the ethic committee. Hematopoiesis stem/progenitor cells isolation started within 4h from partum. Plasma was used to evaluate sTREM-1. Set up a control group and leukemia cells induced group. Leukemia cells induced group processed as following: culture hematopoiesis stem/progenitor cells with 1:1 microvesicles-free leukemia cell line condition supernatant and DMEM medium with high glucose. Collect cells and condition supernatant from control group and leukemia cells induced group at 0h, 6h, 12h, and 24h. The expressions of TREM-1 on hematopoiesis stem/progenitor cells were measured by flow cytometry. sTREM-1 levels of condition supernatant were detected by the ELISA. Results In this study, our results provide the first evidence that TREM-1 was expressed in hematopoiesis stem/progenitor cells (CD34+/CD38-, CD34+/CD38+). The TREM-1 mean ratio of median fluorescence intensity (mean ratio of MFI) was 3.79 ± 0.96 and 9.51 ± 1.56 in hematopoiesis stem cells (CD34+/CD38- cells) and hematopoiesis progenitor cells (CD34+/CD38+ cells), respectively. The expression of TREM-1 in hematopoiesis stem cell was weaker than that in hematopoiesis progenitor cell. In addition, our results showed that sTREM-1 level was 6.04 ± 3.92 pg/mL in cord blood plasma. In order to assess a functional link between myelogenous leukemia cells and TREM-1 in hematopoiesis stem/progenitor cells, we separately cultured CD34+/CD38-, CD34+/CD38+ cells with 1:1 microvesicles-free condition medium from K562 cells and DMEM medium with high glucose for 48 hs. As a result, the TREM-1 mean ratio of MFI went from 3.79 ± 0.96 to 2.45 ± 1.29 in CD34+/CD38- cells and from 9.51 ± 1.56 to 4.22± 1.73 in CD34+/CD38+ cells in a period from 0 to 24 hours; The same results were obtained from cultured with 48h microvesicles-free condition medium from THP-1 cells. These suggested that the leukemia could induce the decreased expression of TREM-1 in hematopoiesis stem/progenitor cells in time-dependent manner. There was no obvious difference between 48h and 24h cultured with condition medium, TREM-1 expression of hematopoiesis stem/progenitor cells began to stabilize within 24 hours. Similarly, we cultured CD34+/CD38-, CD34+/CD38+ cells with conditional medium from differential number 48h microvesicles-free condition medium from K562 cells (K562 cells numberset six levels: 2*106, 1*106, 5*105, 2.5*105, 1*105, 5*104). As a result, the TREM-1 mean ratio of MFI went from 1.81±1.46 to 3.45±0.93 rising in turn in CD34+/CD38- cells and went from 3.49 ± 1.95 to 11.62 ± 3.60 rising in turn in CD34+/CD38+ cells. The same results were also obtained from THP-1 cells. These suggested that the leukemia cells could induce the decreased expression of TREM-1 in hematopoiesis stem/progenitor cells in number-dependent manner. The higher the number of leukemia cells, the more significant is in inhibition to TREM-1 expression in hematopoiesis stem/ progenitor cell. Furthermore, our results showed that sTREM-1 levels was increased in supernatants of normal cord blood cells cultured with conditional medium from K562 cells (6.04 ± 3.92 pg/mL for 0 hour; 17.51 ± 3.8 pg/mL for 48 hours, P < 0.05). Compared with quiescent cord blood cells, in vitro leukemia induced normal blood cells secreted high levels of sTREM-1. Conclusion In this study, our results provide the first evidence that TREM-1 was expressed in hematopoiesis stem/progenitor cells. The leukemia cells could induce the decreased expression of TREM-1 in hematopoiesis stem/progenitor cells and facilitates the generation of sTREM-1. Disclosures: No relevant conflicts of interest to declare.

Correction of Fanconi Anemia Type C Phenotypic Abnormalities Using a Clinically Suitable Retroviral Vector Infection Protocol

1996 ◽  
Vol 5 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Brian W. Freie ◽  
Parmesh Dutt ◽  
D. Wade Clapp
Keyword(s):  
Gene Transfer ◽  
Cord Blood ◽  
Cell Line ◽  
Progenitor Cells ◽  
Fanconi Anemia ◽  
Blood Cells ◽  
Myelogenous Leukemia ◽  
Transfer Efficiency ◽  
Gene Transfer Efficiency ◽  
Type C

Fanconi anemia (FA) is a complex autosomal recessive disease with hematologic manifestations characterized by a progressive hypoplastic anemia, hypersensitivity to clastogenic agents, and an increased incidence of acute myelogenous leukemia. The cDNA that corrects one of four FA complementation subtypes, named Fanconi anemia Type C (FAC) has recently been identified. We constructed a simplified recombinant retrovirus (vMFGFAC) encoding only the FAC cDNA, and tested its ability to correct the FAC defect in a lymphocytic cell line and primary mobilized blood progenitor cells. In addition, the gene transfer efficiency using a clinically applicable gene transfer protocol into normal primitive hematopoietic progenitor cells, high proliferating potential colony forming cells (HPP-CFC), derived from CD34+ purified cord blood cells was examined. The gene transfer efficiency was significantly enhanced when cells were transduced with supernatant while adherent to a 30/35 KD fragment of fibronectin, FN30/35, and was similar to efficiency obtained by coculture with retrovirus packaging cells. Transduction of an FAC deficient lymphoid cell line with vMFGFAC supernatant resulted in an enhanced cell viability, and G-CSF mobilized peripheral blood cells from an FAC-deficient patient transduced with the vMFGFAC virus demonstrated enhanced progenitor cell colony formation. These data indicate that the vMFGFAC virus allows functional complementation of FAC in lymphoblasts and primary hematopoietic progenitors, and that primitive cord blood hematopoietic stem/progenitor cells can be transduced at an efficiency comparable to protocols using cocultivation if adherent to FN 30/35 fragment.

Identification of human chronic myelogenous leukemia progenitor cells with hemangioblastic characteristics

Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2733-2740 ◽  
Author(s):  
Baijun Fang ◽  
Chunmei Zheng ◽  
Lianming Liao ◽  
Qin Han ◽  
Zhao Sun ◽  
...  
Keyword(s):  
Stem Cells ◽  
Endothelial Cells ◽  
Progenitor Cells ◽  
Chronic Myelogenous Leukemia ◽  
Blood Cells ◽  
Fusion Gene ◽  
Fetal Liver ◽  
Philadelphia Chromosome ◽  
Myelogenous Leukemia ◽  
Leukemic Cells

AbstractOverwhelming evidence from leukemia research has shown that the clonal population of neoplastic cells exhibits marked heterogeneity with respect to proliferation and differentiation. There are rare stem cells within the leukemic population that possess extensive proliferation and self-renewal capacity not found in the majority of the leukemic cells. These leukemic stem cells are necessary and sufficient to maintain the leukemia. Interestingly, the BCR/ABL fusion gene, which is present in chronic myelogenous leukemia (CML), was also detected in the endothelial cells of patients with CML, suggesting that CML might originate from hemangioblastic progenitor cells that can give rise to both blood cells and endothelial cells. Here we isolated fetal liver kinase-1–positive (Flk1+) cells carrying the BCR/ABL fusion gene from the bone marrow of 17 Philadelphia chromosome–positive (Ph+) patients with CML and found that these cells could differentiate into malignant blood cells and phenotypically defined endothelial cells at the single-cell level. These findings provide direct evidence for the first time that rearrangement of the BCR/ABL gene might happen at or even before the level of hemangioblastic progenitor cells, thus resulting in detection of the BCR/ABL fusion gene in both blood and endothelial cells.

scholarly journals Induction of apoptosis by Kola nut extract as a recent and promising treatment strategy for Leukemia

Bionatura ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 1725-1732
Author(s):  
Hamdah Alsaeedi ◽  
Rowaid Qahwaji ◽  
Talal Qadah
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Leukemia Cell ◽  
K562 Cells ◽  
Myelogenous Leukemia ◽  
Time Dependent ◽  
Leukemia Cell Line ◽  
Apoptotic Cells ◽  
Dependent Manner ◽  
Anti Cancer

Kola nut extracts have recently been reported to contain chemopreventive compounds providing several pharmacological benefits. This study investigated Kola nut extracts' anti-cancer activity on human immortalized myelogenous leukemia cell line K562 through apoptosis and cell cycle arrest. Fresh Kola nuts were prepared as powder and dissolved in DMSO. Different concentrations (50, 100, 150, 200, and 250 μg/ml) of working solutions were prepared. The K562 cells were treated with the different concentrations of Kola nut extract or vehicle control (10% DMSO) followed by incubation at 37°C for 24, 48, and 72 hours, respectively. Treatment activity was investigated in K562 cells; by Resazurin, and FITC/Propidium Iodide and 7-AAD stained cells to evaluate apoptotic cells and the cell cycle's progression. Inhibition of leukemia cell proliferation was observed. The extract effectively induced cell death, early and late apoptosis by approximately 30% after 24 and 48 hours incubation, and an increase in the rate of dead cells by 50% was observed after 72 hours of incubation. Also, cell growth reduction was seen at high dose concentrations (150 and 200 µg/ml), as evident by cell count once treated with Kola nut extract. The total number of apoptotic cells increased from 5.8% of the control group to 27.4% at 250 µg/ml concentration. Moreover, Kola nut extracts' effects on K562 cells increased gradually in a dose and time-dependent manner. It was observed that Kola nut extracts could arrest the cell cycle in the G2/M phase as an increase in the number of cells by 29.8% and 14.6 % were observed from 9.8% and 5.2% after 24 and 48 hours of incubation, respectively. This increase was detected in a dose and time-dependent manner. Kola nut extracts can be used as a novel anti-cancer agent in Leukemia treatment as it has shown significant therapeutic potential and therefore provides new insights in understanding the mechanisms of its action. Keywords: Kola nut extracts, Leukemia, K562 cell line, Apoptosis, Cancer.

scholarly journals Protective Effect of Silymarin against Rapamycin-induced Apoptosis and Proliferation Inhibition in Endothelial Progenitor Cells

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Peng Zhang ◽  
Guohua Han ◽  
Pei Gao ◽  
Kun Qiao ◽  
Yusheng Ren ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Endothelial Progenitor Cells ◽  
Mononuclear Cells ◽  
Control Group ◽  
Dependent Manner ◽  
Endothelial Progenitor ◽  
Concentration Dependent Manner ◽  
Inhibition Of Proliferation ◽  
And Migration ◽  
Proliferation And Migration

For this study, peripheral blood samples were collected from human volunteers. Mononuclear cells (MNC) were separated by density centrifugation and were induced to differentiate into endothelial progenitor cells (EPCs) in vitro. Different concentrations of rapamycin and silymarin were introduced to the EPCs over 24 hours and then EPCs were analyzed for proliferation, migration, apoptosis and angiogenesis. Compared with the control group, rapamycin (1, 10, 100 ng/mL) inhibited the proliferation and migration of EPCs in a concentration dependent manner ( P<0.05). Silymarin (50, 100 μg/mL) enhanced the proliferation and migration of EPCs and inhibited apoptosis in a concentration dependent manner ( P<0.05). By adding rapamycin (1 ng/mL) and silymarin (25, 50, 100 μg/mL) over 24 hours, silymarin inhibited the pro-apoptotic effect of rapamycin on EPCs, and reversed the inhibition of proliferation, migration and angiogenesis of EPCs by rapamycin ( P<0.05).

Slug Plays an Essential Role in the Radioprotection of Hematopoietic Progenitors In Vivo by Antagonizing p53-Mediated Apoptotic Pathways.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 31-31
Author(s):  
Wen-Shu Wu ◽  
Dong Xu ◽  
Stefan Heinrichs ◽  
A. Thomas Look
Keyword(s):  
Bone Marrow ◽  
Progenitor Cells ◽  
Leukemia Cells ◽  
Dependent Manner ◽  
Wild Type ◽  
Γ Irradiation ◽  
Aberrant Expression ◽  
Hematopoietic Stem ◽  
Myeloid Progenitors

Abstract An antiapoptotic role for Slug/Snail in mammals was suggested by studies in C. elegans, where CES-1/Scratch, a member of the Slug/Snail superfamily, was found to control the apoptotic death of NSM sister neurons by acting as a transcriptional repressor of EGL-1, a BH3-only proapoptotic protein. Identification of Slug as the target gene of the E2A-HLF oncoprotein in human pro-B leukemia cells led us to demonstrate its antiapoptotic function in IL-3-dependent murine pro-B cells. In contrast to its aberrant expression in pro-B leukemia cells, endogenous Slug is normally expressed in both LT-HSC and ST-HSC, as well as committed progenitors of the myeloid series, but not in pro-B and pro-T cells, implying its function in myelopoiesis. Using Slug−/− mice produced in our laboratory, we showed that these knockouts are much more radiosensitive than Slug+/− and wild-type mice, and that apoptotic cells increase significantly in the hematopoietic progenitor cells of Slug−/− mice as compared to wild-type mice following γ-irradiation, indicating a radioprotective function in vivo. We showed here that although the development of myeloid progenitors is not impaired under steady-state conditions, their repopulation is incomplete γ-irradiated in in Slug−/− mice. We demonstrate further the radiation-induced death of Slug−/− mice is exclusively a result of bone marrow failure with no apparent contribution from systemic injures to other tissues. By two-way bone marrow transplantation, we provide firm evidence that Slug protects mice from γ-irradiation-induced death in a cell-autonomous manner. Interestingly, regenerative capacity of hematopoietic stem cells (HSC) was retained in irradiated Slug−/− mice, which could be rescued by wild-type bone marrow cells after irradiation, indicating that Slug exerts its radioprotective function in myeloid progenitors rather than HSCs. Furthermore, we establish that Slug radioprotects mice by antagonizing downstream of the p53-mediated apoptotic signaling through inhibition of the p53-resposive proapoptotic gene Puma, leading in turn to inhibition of the mitochondria-dependent apoptotic pathway activated by γ-irradiation in myeloid progenitors. More interestingly, we observed that Slug is inducible by γ-irradiation in a p53-dependent manner. Together, our findings implicate a novel Slug-mediated feedback mechanism by which p53 control programmed cell death in myeloid progenitor cells in vivo in response to γ-irradiation.

Imatinib Mesylate (STI571) Abrogates the Resistance to Doxorubicin in K562 Chronic Myeloid Leukemia Cells by Inhibition of BCR/ABL Kinase-Mediated DNA Repair.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1525-1525
Author(s):  
Ireneusz Majsterek ◽  
Janusz Blasiak ◽  
Artur Slupianek ◽  
Tomasz Skorski
Keyword(s):  
Drug Resistance ◽  
Dna Repair ◽  
Imatinib Mesylate ◽  
Lymphoblastic Leukemia ◽  
Specific Inhibitor ◽  
K562 Cells ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Abl Kinase ◽  
Kinetics Of

Abstract Imatinib mesylate (STI571), a specific inhibitor of the BCR/ABL tyrosine kinase, exhibits potent antileukemic effects in the treatment of chronic myelogenous leukemia (CML). However, the precise mechanisms by which inhibition of BCR/ABL activity results in pharmacological responses remain unknown. BCR/ABL-positive human CML cells resistant to doxorubicin K562doxoR and their sensitive K562doxoS counterparts were used to determine the mechanism by which the STI571 inhibitor may overcome drug resistance. K562 wild type cells and CCRF-CEM lymphoblastic leukemia cells without BCR/ABL were used as controls. We examined kinetics of DNA repair after cell treatment with the drug by the alkaline comet assay. MTT assay was used to estimate resistance against doxorubicin and Western Blot analysis with Crk-L antibody was performed to evaluate BCR/ABL kinase inhibition by STI571. We provide evidence that treatment of CML-derived BCR/ABL-expressing leukemia K562 cells with STI571 results in the inhibition of DNA repair and abrogation of the resistance of these cells to doxorubicin. We found that doxorubicin-resistant K562doxoR cells exhibited accelerated kinetics of DNA repair in comparison to doxorubicin-sensitive K562doxoS cells. Inhibition of BCR/ABL kinase in K562doxoR cells with 1 μM STI571 decreased the kinetics of DNA repair and abrogated drug resistance. The results suggest that STI571-mediated inhibition of BCR/ABL kinase activity can affect the effectiveness of the DNA repair pathways, which in turn may enhance drug sensitivity of leukemia cells.

Dysregulated Expression of HSP70 Isoforms in Acute Myelogenous Leukemia (AML)

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1370-1370
Author(s):  
Krishan K. Sharma ◽  
Juan Felipe Rico ◽  
Duane C Hassane ◽  
Gabriela Chiosis ◽  
Monica L. Guzman
Keyword(s):  
Drug Resistance ◽  
Heat Shock ◽  
Cord Blood ◽  
Cell Lines ◽  
Blood Cells ◽  
Leukemia Cell ◽  
Leukemia Cells ◽  
Normal Cells ◽  
Leukemia Cell Lines ◽  
Cord Blood Cells

Abstract Abstract 1370 Stress-inducible heat shock protein 70 (HSP70) is a major cytoprotective factor and a molecular chaperone that interacts with HSP90 to form a multi-chaperone complex. Cancer cells are highly dependent on this complex due to their increased demand for protein synthesis. HSP70 overexpression inhibits apoptosis and has been associated with drug resistance. However, the contribution to drug resistance in AML of specific HSP70 isoforms remains unknown. As there is growing interest in therapeutically targeting HSP70, we investigated the expression of 7 different HSP70 isoforms in AML primary cells and leukemia cell lines and their response to a novel HSP70-inhbitor, YK5. A panel of 12 leukemia cell lines and 11 primary samples was used to determine the expression of HSP70 and their response to YK5. We also evaluated the changes to the HSP70 isoforms when exposed to either heat shock or YK5. We found MV4-11, MOLM-13, and U937 sensitive to YK5 (LD50 = 1.18μM, 1.03μM, and 2.31μM at 24 hours, respectively). In contrast, OCI-AML3, TUR and THP-1 were more resistant to the inhibitor. (LD50 = 9.92μM, 9.74μM, and 8.84μM at 24 hours, respectively). Non-tumor cells, however, were significantly less affected by treatment with YK5 (72% viable cord blood mononuclear cells after 24 hour treatment with 5μM YK5). We found that the cell surface expression of HSP70 was higher in both cell lines and primary samples when compared their normal counterparts. Furthermore, quantitative PCR revealed that cell lines with higher levels of HSPA1A and lower levels of HSPA6 demonstrated higher sensitivity to YK5. Interestingly, higher levels of HSPA1A and lower levels of HSPA6 were also found in primary AML samples when compared to CD34+ cord blood cells, consistent with the relative insensitivity of normal cells to YK5. We further discovered, mining publicly available databases, that high levels of HSPA1A were associated poorer prognosis (p = 0.004), suggesting that YK5 would be beneficial to patients presenting high HSP70 expression. We also evaluated the effect of YK5 on the gene expression of the various HSP70 isoforms. Quantitative PCR revealed the ability of YK5 to downregulate HSPA6 and HSC70 (HSPA8) in both cell lines and primary samples. Strikingly, all HSP70 isoforms exhibited similar fold changes upon heat shock in primary samples, CD34+ cord blood cells, and leukemia cell lines, indicating that the cellular stress response is not damaged in AML. However, the specificity of HSP70 inhibition to leukemia cells and not normal cells suggests a dysregulated set of client proteins and increased dependency on HSP70 to maintain leukemic homeostasis. In summary, we have found dysregulated expression of the HSP70 isoforms HSPA1A and HSPA6 in leukemia cells and that the expression levels of these isoforms correlate to the sensitivity of YK5-mediated HSP70 inhibition (HSPA1A: p=0.0012 and r2=0.801, HSPA6: p=0.0011 and r2=0.847). *KKS and JFR contributed equally to this project Disclosures: No relevant conflicts of interest to declare.

Biomarker for Benzopyrene Exposure Is Mitochondrial Mass and Mitochondrial DNA Copy in Blood Cells and Hematopoietic Tissues

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4889-4889
Author(s):  
Myung-Geun Shin ◽  
Hye-Ran Kim ◽  
Hyun-Jung Choi ◽  
Hwan-Young Kim ◽  
Dong-Kyun Han ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Mitochondrial Dna ◽  
Peripheral Blood ◽  
Blood Cells ◽  
Copy Number ◽  
Leukemia Cells ◽  
Dependent Manner ◽  
Mtdna Copy Number ◽  
Mitochondrial Mass ◽  
Dose Dependent

Abstract Abstract 4889 Benzopyrenes are well known pollutants and carcinogens. They can intercalate into DNA and interfere transcriptions, resulting in causing various human diseases. However, biomarkers of benzopyrene toxicity have not been comprehensively studied in blood and leukemia cells. The current study was investigated to discover biomarkers for benzopyrene exposure in blood cells and leukemia cell lines. Peripheral blood, peripheral blood hematopoietic stem cell and leukemia cells (THP-1, K562, Molt-4 and HL-60) were cultured in RPMI 1640 media with adding 0, 50, 100 and 200μM of benzopyrene. Viability and apoptosis were assessed by tryptophan blue dye exclusion test and flowcytometry using annexin V. Hydrogen peroxide was measured using enzyme immunoassay. Mitochondrial mass, membrane potential and mitochondrial DNA (mtDNA) copy number were measured using MitoTracker Green, Red probes and real time PCR, respectively. The number of cell remained constant for three weeks culture. Viability of four cell lines disclosed significant decrease after two weeks of benzopyrene treatment. Apoptosis was increased in time- and dose-dependent manner after two weeks of benzopyrene treatment. Mitochondrial contents and membrane potentials were dramatically increased in three-week culture at dose dependent manner. Hydrogen peroxide level was significantly elevated after two weeks treatment of benzopyrene compared to non-benzopyrene treatment group. The number of mtDNA copy increased gradually after exposure to benzopyrene. These results indicated that increased mitochondrial mass and mtDNA copy number were biomarkers for direct exposure of benzopyrene in blood cells and hematopoietic tissues. Disclosures: No relevant conflicts of interest to declare.

A Novel Non-Genetic Photostable Approach to Labelling Acute Myeloid Leukemia and Bone Marrow Cells with Quantum Dots

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 4818-4818
Author(s):  
Yanwen Zheng ◽  
Zhengwei Mao ◽  
Bin Yin
Keyword(s):  
Bone Marrow ◽  
Quantum Dots ◽  
Acute Myeloid Leukemia ◽  
Blood Cells ◽  
Myeloid Leukemia ◽  
Hematopoietic Cells ◽  
Leukemia Cell ◽  
Leukemia Cells ◽  
Dependent Manner ◽  
Acute Myeloid

Abstract Abstract 4818 Acute myeloid leukemia (AML) is a detrimental disease with difficult diagnosis and treatment. Understanding the biology of AML at the molecular and cellular levels would be essential to successful management of the disease. However, the notoriously known difficulty in manipulation of leukemia cells has long hindered the dissection of AML pathogenesis. The advent of CdSe/ZnS quantum dots (QDs) represents an important advancement in the research field of nanotechnology, which have recently also been applied for imaging of live cells. Here, we have introduced a non-genetic approach of marking blood cells, by taking advantage of QD technology. We compared QDs complexed with different vehicles, including a peptide Tat (QDs-Tat), cationic polymer Turbofect (QDs-Tf) and liposome Lipofectamine 2000 (QDs-Lip), in their abilities to mark cells. QDs-Tat showed the highest efficiency in delivery into hematopoietic cells, among the three vehicles. We then examined QDs-Tat labelling of leukemia cell lines, and found that QDs-Tat could label 293T, bone marrow (BM) cells, THP-1, MEG-01 and HL-60 with a decreasing efficiency. The efficiency of QDs-Tat delivery was dependent on the concentration of QDs-Tat applied, but not the length of incubation time. In addition, more uniform intracellular distributions of QDs in 293T and leukemia cells were obtained with QDs-Tat, compared with the granule-like formation obtained with QDs-Lip. Clearly, QD fluorescence was sharp and tolerant to repetitive photo excitations, and could be detected in 293T for up to one week following labelling. In summary, our results suggest that QDs have provided a photostable, non-genetic and transient approach that labels normal and malignant hematopoietic cells in a cell type-, vehicle-, and QD concentration-dependent manner. We expect for potentially wide applications of QDs as an easy and fast tool assisting investigations of various types of blood cells in the near future. Disclosures: No relevant conflicts of interest to declare.

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