Mine the Stability of the G2/M Checkpoint to Break Down Acute Lymphoblastic Leukemia Defenses Against Antineoplastic Drugs

Abstract Although impressive developments have been made in the treatment of Acute Lymphoblastic Leukemia (ALL) patients, the overall survival is still very poor. With the exception of novel therapeutic strategies based on monoclonal antibodies (Bi-specific T-cell engagers, BiTEs) or immunogenic cells (CART cells), the therapeutic approaches for adult ALL patients are still base on non-selective chemotherapy or on tyrosine kinase inhibitors (TKIs) for the patients harboring the BCR-ABL1 fusion transcript. In addition a large percentage of initial successfully treated patients frequently develop relapses. Thus there is a need to improve the efficacy of conventional therapies, in particular those related to TKIs and to DNA damaging agents, in order to reduce the off-target toxicity and avoid relapses. In the present study we evaluated the in vitro, ex vivo and in vivo efficacy of MK-1775, a specific Wee1 inhibitor, in single agent and in combination with different therapeutic agents normally used for the treatment of B-/T-ALL. We firstly started by evaluated the efficacy of the compound in single agent on a panel of human B and T ALL cell lines (n=8) and on primary cells isolated from the bone marrow of adult B-ALL patients (n=8). The inhibition of Wee1 deeply reduced the cell viability and the proliferation rate, induced the apoptosis and increased the DNA damages of both leukemic cell lines and primary cells. Further cell-cycle analysis showed that in leukemic cell lines the treatment increased the number of cell in late S and G2/M phase. Light microscopy analyses, looking for nuclei morphology, confirmed that MK-1775 increased the number of mitotic cells but it interfered with normal mitotic division (induction of aberrant mitosis as showed by the increment of DNA bridges and micro-nuclei). The effects of the compound on the cell cycle profile and on the G2/M checkpoint were confirmed also in immunoblotting analyses, by the increment of phospho-HH3(ser10) and of Myt1 (mitotic isoform), and by gene expression analysis looking to specific genes involved in the G2/M checkpoints (PrimePcr DNA damage assay, Biorad). In particular genes like GADD45A and CCNB1/CCNB2 were significantly up-regulated between treated and untreated samples. Finally using a T-ALL mouse model we evaluated the effect of MK-1775 in single agent. Although no significative differences were seen between treated and un-treated samples, due to a very aggressive phenotype of the disease (all animal died after only 18 days from the engraftment), molecular analyses confirmed that the treatment induced DNA damages (increase of H2A.X and p-Chk1 ser317) and inhibited Wee1 functionality (reduction of pCDC2) on leukemic blasts isolated from both spleens and bone marrows. To evaluate if the inhibition of the G2/M checkpoint could sensitize leukemic cells to the toxicity of antineoplastic drugs, Philadelphia-negative ALL cell lines and primary leukemic cells (n=9) where treated with increasing concentration of MK-1775 and increasing concentration of the nucleotide analogue, clofarabine. Statistical analyses (Combination index value) confirmed the synergy of the combination in the reduction of the cell viability, in the inhibition of the proliferation and in the induction of the apoptosis. Similar results were seen on Philadelphia-positive ALL cell lines and primary cells (n=3) combining the MK-1775 with the TKI, bosutinib. The simultaneously inhibition of the Wee1 and the BCR-ABL downstream pathway resulted in a synergic inhibition of the cell viability, reduction of the proliferation and induction of apoptosis. In our opinion the pre-clinical results of this study are the basis for a future clinical evaluation of MK-1775 for the treatment of ALL patients. Acknowledgments: ELN, AIL, AIRC, progetto Regione-Università 2010-12 (L. Bolondi), Fondazione del Monte di Bologna e Ravenna, FP7 NGS-PTL project. Disclosures Martinelli: Novartis: Speakers Bureau; BMS: Speakers Bureau; Amgen: Consultancy, Speakers Bureau; Roche: Consultancy, Speakers Bureau; MSD: Consultancy; Pfizer: Consultancy, Speakers Bureau; Ariad: Consultancy, Speakers Bureau; Genentech: Consultancy; Celgene: Consultancy, Speakers Bureau.

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Expression and Function of the CXCR7 Chemokine Receptor in Leukemias

Blood ◽

10.1182/blood.v112.11.2423.2423 ◽

2008 ◽

Vol 112 (11) ◽

pp. 2423-2423

Author(s):

Sergej Konoplev ◽

Hongbo Lu ◽

Michael A Fiegl ◽

Zhihong Zeng ◽

Wenjing Chen ◽

...

Keyword(s):

Flow Cytometry ◽

Cell Lines ◽

Lymphoblastic Leukemia ◽

Leukemic Cell ◽

Leukemic Cells ◽

Human Leukemia ◽

Rt Pcr ◽

Hematopoietic Stem ◽

Leukemic Cell Lines ◽

And Function

Abstract Background: Bone marrow produced stromal-derived factor-1a (SDF-1a) is a key chemokine involved in chemotaxis, homing, mobilization, and expansion of hematopoietic stem and progenitor cells. While the majority of well-defined functions of SDF-1a are mediated via its receptor CXCR4, recent studies have characterized CXCR7 as an alternative receptor capable of binding SDF-1a. Although the functions of CXCR7 are still incompletely understood, the receptor was reported to promote migration and adhesion in certain cell types and function as a pro-survival factor in breast cancer cells. CXCR7 expression and function in human leukemia cells has not been characterized. In this study, we examined CXCR7 expression in leukemia cell lines and primary samples from patients with acute lymphoblastic leukemia (ALL) and utilized a small molecule inhibitor of CXCR7 to probe CXCR7’s function. Materials and methods: CXCR4 and CXCR7 expression was determined by flow cytometry, real-time PCR (RT-PCR) and immunocytochemistry (ICC) in leukemic cell lines including AML (OCI-AML2, OCI-AML3, HL60, U937 NB4, Molm13), ALL (REH, Raji, RS4; 11, Nalm6, Molt4) and CML (KBM5, K562) cells. In primary ALL patient samples, CD34+CD19+ gating was applied to detect CXCR7 expression on pre-B leukemic cells by flow cytometry. The migration of leukemic cells towards SDF-1a was studied using a transwell system. CXCR4 inhibitor AMD3100 was purchased from Sigma, and CXCR7 inhibitor CCX-733 was provided by ChemoCentryx Inc., Mountain View, CA. Results: CXCR4 was found to be ubiquitously expressed on the cell surface of all leukemic cell lines tested. CXCR7 mRNA and protein expression was detectable only in Burkitt lymphoma Raji cells, as analyzed by flow cytometry (clone 11G8, R&D systems), RT-PCR and ICC. Curiously, CXCR7 expression was significantly induced in MOLM13 cells under hypoxic (6% O2) conditions (p=0.01). Low levels of surface CXCR7 were found in 8 of the 9 primary ALL samples by flow cytometry. To determine the respective roles of CXCR4 and CXCR7 in migration of leukemic cells, we utilized CXCR4 inhibitor AMD3100 and CXCR7 inhibitor CCR733 in Raji (CXCR7 positive) and RS4;11 (CXCR7 negative) cells. AMD3100 at 25μM significantly inhibited SDF-1a induced migration (from 38.5% to 12%); CCR733 at 10μM also inhibited SDF-1a induced migration (from 38.5% to 24%) and the combination of AMD3100 and CCR733 resulted in 81% inhibition of migration (from 38.5% to 7.2%). AMD3100 blocked SDF-1a induced migration of CXCR4+CXCR7− RS4;11 cells (from 36.5% to 15.8%), while CCR733 had no effect (36.5% and 39.2%). In conclusion, these studies demonstrate functional expression of the SDF-1 receptor CXCR-7 on Raji and primary ALL cells and suggest that CXCR7 plays an active role in the migration of leukemic cells. CXCR-7 may serve as an alternative receptor to CXCR4. Studies addressing the role of CXCR7 in adhesion, SDF-1a-mediated signaling and survival of leukemic cells are in progress.

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The Inhibition of Checkpoint Kinase 1 As a Promising Strategy to Increase the Effectiveness of Different Treatments in Acute Lymphoblastic Leukemia

Blood ◽

10.1182/blood.v126.23.2478.2478 ◽

2015 ◽

Vol 126 (23) ◽

pp. 2478-2478

Author(s):

Andrea Ghelli Luserna Di Rora ◽

Ilaria Iacobucci ◽

Enrica Imbrogno ◽

Enrico Derenzini ◽

Anna Ferrari ◽

...

Keyword(s):

Cell Cycle ◽

Acute Lymphoblastic Leukemia ◽

Cell Viability ◽

Cytotoxic Activity ◽

Cell Lines ◽

Propidium Iodide ◽

Lymphoblastic Leukemia ◽

Single Agent ◽

Dna Damages ◽

Checkpoint Kinase

Abstract Nowadays the effectiveness of the treatments for adult Acute Lymphoblastic Leukemia (ALL) patients is still inadequate and frequently many patients after years of response to treatments develop relapses. Thus there is a need to find novel targets for specific therapies and to maximize the effect of the actual treatments. Recently different Checkpoint Kinase (Chk)1/Chk2 inhibitors has been assessed for the treatment of different type of cancers but only few studies have been performed on hematological diseases. We evaluated the effectiveness of the Chk1 inhibitor, LY2606368, as single agent and in combination with tyrosine kinase inhibitors (imatinib and dasatinib) or with the purine nucleoside antimetabolite clofarabine in B-/T- acute lymphoblastic leukemia (ALL) cell lines and in primary blasts. Human B (BV-173, SUPB-15, NALM-6, NALM-19 and REH) and T (MOLT-4, RPMI-8402 and CEM) ALL cell lines were incubated with increasing concentrations of drug (1-100 nM) for 24 and 48 hours and the reduction of the cell viability was evaluated using WST-1 reagent. LY2606368 deeply reduced the cell viability in a dose and time dependent manner in all the cell lines, with the BV-173 (6.33 nM IC50 24hrs) and RPMI-8402 (8.07 nM IC50 24hrs) being the most sensitive while SUP-B15 (61.4 nM IC50 24hrs) and REH (96.7 nM IC50 24hrs) being the less sensitive cell lines. Moreover the sensitivity to the compound was no correlated with the different sub-type of ALL or with the mutational status of p53, which is a marker of the functionality of the G1/S checkpoint. The cytotoxic activity was confirmed by the significant increment of apoptosis cells (Annexin V/Propidium Iodide), by the increment of gH2AX foci and by the activation of different apoptotic markers (Parp-1 and pro-Caspase3 cleavage). To understand the relationship between the activation of apoptosis and the effect on cell cycle and to identify hypothetical mechanisms of death, different cell cycle analyses were performed (Propidium Iodide staining). The inhibition of Chk1, deeply changed the cell cycle profile. Indeed in all the cell lines the percentage of cells in S phase and in G2/M phase were reduced by the treatment while the numbers of cells in sub-G1 and G1 phase were increased. The hypothetical function of LY2606368 as a chemosensitizer agent was evaluated combining the compound with different drugs normally used in clinical trials. For each drugs the combination strongly reduced the cell viability when compared to the cytotoxic effect of the single drugs. Moreover the combination showed an additive efficacy in term of induction of DNA damages as showed by the increase number of gH2AX foci and the activation of pChk1 (ser 317). The results found on the cell lines were confirmed also using primary leukemic blast isolated from adult Philadelphia-positive ALL patients. Indeed LY2606368 as single agent or in combination with the Tki, imatinib, was able to deeply reduce the cell viability and to induce DNA damages (gH2AX foci). In conclusion LY2606368 showed a strong cytotoxic activity on B-/T-All cell lines and primary blasts as single agent and in combination with other drugs. In our opinion this data are the basis for a future clinical evaluation of this compound in the treatment of leukemia. Supported by ELN, AIL, AIRC, progetto Regione-Università 2010-12 (L. Bolondi), FP7 NGS-PTL project. Disclosures Soverini: Novartis, Briston-Myers Squibb, ARIAD: Consultancy. Cavo:JANSSEN, CELGENE, AMGEN: Consultancy. Martinelli:ROCHE: Consultancy; Novartis: Consultancy, Speakers Bureau; BMS: Consultancy, Speakers Bureau; Pfizer: Consultancy; Ariad: Consultancy; AMGEN: Consultancy; MSD: Consultancy.

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Targeting High Dynamin2 Expression By Restoring Ikaros Function in Acute Lymphoblastic Leukemia

Blood ◽

10.1182/blood.v128.22.2713.2713 ◽

2016 ◽

Vol 128 (22) ◽

pp. 2713-2713

Author(s):

Zheng Ge ◽

Jianyong Li ◽

Baoan Chen ◽

Sinisa Dovat ◽

Chunhua Song

Keyword(s):

Cell Proliferation ◽

Acute Lymphoblastic Leukemia ◽

Lymphoblastic Leukemia ◽

Leukemic Cell ◽

Leukemic Cells ◽

Primary Cells ◽

Proliferation Assay ◽

High Relapse Rate ◽

Leukemic Cell Lines ◽

Ck2 Inhibitor

Abstract Background: Dynamin-2 (DNM2) is a GTPase essential for intracellular vesicle formation and trafficking, cytokinesis and receptor endocytosis. Mutations in DNM2 are common in early T-cell precursor acute lymphoblastic leukemia (ALL). However, DNM2 expression in other types of ALL is not reported. Ikaros, encoded by IKZF1, is a transcriptor factor functioned as a tumor suppress gene, and its dysfunction is associated with poor survival and high relapse rate in ALL. Casein Kinase II (CK2) inhibition could restore Ikaros function in high-risk leukemia and CK2 inhibitor-CX4945 showed the therapeutic efficacy on high-risk leukemia with human-derived xenograft mouse model. It is still undetermined if Ikaros regulates DNM2 expression in the leukemic cells. Methods: The 151 patients' and 30 volunteers' BM samples were collected between June 2008 and June 2014 at the First Affiliated Hospital of Nanjing Medical University. The ALL diagnosis was made according to the morphologic, Immunophenotypic, cytogenetic, and molecular criteria of WHO Diagnosis and Classification of ALL (2008).Cytogenetic and molecular analyses as previously reported. The DNM2 expression was determined by qPCR in the patients. All the patients were divided into high or low DNM2 expression groups (Q4 vs Q1-3) and the cutoff was determined by SPSS 17.0. For quantitative parameters, overall differences between the cohorts were evaluated using a Mann - Whitney U -test. For qualitative parameters, overall group differences were analyzed using a χ2 test. All statistical analyses were performed using the SPSS 17.0 and P<0.05 was considered statistically significant. The effect of Ikaros on DNM2 gene expression was observed by qPCR in the leukemic cells expressed Ikaros or Ikaros ShRNA. Ikaros binding with promoter of DNM2 was evaluated by chromatin immunoprecipitation assay following quantitative real-time PCR in leukemic cells. The effect of DNM2 inhibitor on cell proliferation was performed by WST-1 cell proliferation assay, and the synergy of Casein Kinase inhibitor which restores Ikaros function with DNM2 inhibitor on cell proliferation of leukemic cells was analyzed by CalcuSyn. Results: We studied DNM2 mRNA level in adults with B- and T-cell ALL, and found DNM2 is more highly expressed compared with normals in both forms of ALL. High DNM2 expression is significantly associated with poor overall survival (OS), high relapse rate, and leukaemia cell proliferation markers particularly in B-ALL. DNM2 expression is significantly higher in the patients with IKZF1 deletion compared to that of without deletion. Ikaros directly binds the DNM2 promoter in Nalm6 (B-ALL) and CEM (T-ALL) leukemic cells. Ikaros suppresses the transcription of DNM2 with luciferase reporter assay. Retroviral transduction of Ikaros results in the down-regulation of DNM2 in the leukemic cells. CK2 inhibitor, TBB increases Ikaros binding to promoter of DNM2 and suppresses DNM2 expression in an Ikaros-dependent manner in both leukemic cell lines and primary cells. TBB induced-increase of H3K9me3 binding on the promoter of DNM2 was also observed in leukemic cell lines and primary cells. Finally, DNM2 inhibitor-MiTMAB significantly suppresses the cell proliferation of Nalm6 and CEM cells with the WST-1 cell proliferation assay and has significantly synergistic effect with Ck2 inhibitor, CX-4945 in the cells. Conclusion: High DNM2 expression is associated with Ikarosdys-regulation, revealing their potential roles on the development of ALL. DNM2 inhibitor MiTMAB inhibits cell proliferation and has synergistic effect with CK2 inhibitor CX4945 in leukemic cells. Disclosures No relevant conflicts of interest to declare.

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Hydrocortisone does Not Influence in Vitro Glucocorticoid Sensitivity of Acute Lymphoblastic Leukemia Blasts

Blood ◽

10.1182/blood.v124.21.5228.5228 ◽

2014 ◽

Vol 124 (21) ◽

pp. 5228-5228

Author(s):

Lidewij T. Warris ◽

Marry M. van den Heuvel-Eibrink ◽

Ingrid M. Ariës ◽

Rob Pieters ◽

Erica L.T. van den Akker ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

Side Effects ◽

Cell Lines ◽

Fluorescence Intensity ◽

Lymphoblastic Leukemia ◽

Leukemic Cell ◽

Leukemic Cells ◽

Glucocorticoid Sensitivity ◽

Leukemic Cell Lines

Abstract Introduction: Dexamethasone-induced neuropsychological side effects on mood, behavior and cognition seriously affect quality of life in children with acute lymphoblastic leukemia (ALL) during a long treatment period. Based on recent studies in animals, we hypothesized that these neuropsychological side effects are mediated by dexamethasone-induced cortisol depletion of the mineralocorticoid receptor (MR) in the brain. Therefore, we hypothesize that these side effects could be ameliorated by an intervention with hydrocortisone. For clinical application settings however, an absolute prerequisite is that MR activation does not interfere with the efficacy of the glucocorticoids, dexamethasone and prednisolone, on ALL cells. Materials and Methods: To investigate responsiveness of leukemic cell lines and fresh patients’ leukemic cells to dexamethasone and prednisolone in the presence of hydrocortisone, MTT-assays were performed. In addition MR and the glucocorticoid receptor (GR) expression on leukemic cells of different ALL subtypes was studied with a microarray-based gene expression profiling and validated by quantitative real-time PCR. Results: Leukemic cells expressed the MR at a very low level with a significantly higher (P≤0.001) expression in ETV6-RUNX1+ patients (median: 160.7 [AU] of fluorescence intensity, range: 38.1 - 760.6 [AU]) versus other ALL subtypes (median: 41.8 [AU] of fluorescence intensity, range: 25.1 - 276.2 [AU]). MR expression did not differ between glucocorticoid resistant and sensitive patients’ cells. Hydrocortisone addition did not affect glucocorticoid sensitivity of leukemic cell lines and patients’ leukemic cells of different leukemic subtypes also including ETV6-RUNX1+. Glucocorticoid sensitive patients’ cells became significantly more sensitive by hydrocortisone addition (prednisolone: P≤0.01, dexamethasone: P≤0.05). Conclusion: This present study shows that hydrocortisone does not interfere with efficacy of dexamethasone and prednisolone in vitro. These findings support a clinical randomized trial to study whether addition of hydrocortisone decreases the neuropsychological side effects of dexamethasone in children with ALL. Acknowledgments: The financial support of the KiKa® (Kinderen Kankervrij) foundation is highly appreciated. Disclosures No relevant conflicts of interest to declare.

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A Novel Peptide Derived from Ginger Induces Apoptosis through the Modulation of p53, BAX, and BCL2 Expression in Leukemic Cell Lines

Planta Medica ◽

10.1055/a-1408-5629 ◽

2021 ◽

Author(s):

Chawalit Chatupheeraphat ◽

Sittiruk Roytrakul ◽

Narumon Phaonakrop ◽

Kamolchanok Deesrisak ◽

Sucheewin Krobthong ◽

...

Keyword(s):

Cell Viability ◽

Cell Lines ◽

Mononuclear Cells ◽

Raji Cell ◽

Leukemic Cell ◽

B Cell Lymphoma ◽

Leukemic Cells ◽

Peripheral Blood Mononuclear ◽

Normal Peripheral Blood ◽

Peptide Fraction

AbstractDespite the efficacy of chemotherapy, the adverse effects of chemotherapeutic drugs are considered a limitation of leukemia treatment. Therefore, a chemotherapy drug with minimal side effects is currently needed. One interesting molecule for this purpose is a bioactive peptide isolated from plants since it has less toxicity to normal cells. In this study, we extracted protein from the Zingiber officinale rhizome and performed purification to acquire the peptide fraction with the highest cytotoxicity using ultrafiltration, reverse-phase chromatography, and off-gel fractionation to get the peptide fraction that contained the highest cytotoxicity. Finally, a novel antileukemic peptide, P2 (sequence: RALGWSCL), was identified from the highest cytotoxicity fraction. The P2 peptide reduced the cell viability of NB4, MOLT4, and Raji cell lines without an effect on the normal peripheral blood mononuclear cells. The combination of P2 and daunorubicin significantly decreased leukemic cell viability when compared to treatment with either P2 or daunorubicin alone. In addition, leukemic cells treated with P2 demonstrated increased apoptosis and upregulation of caspase 3, 8, and 9 gene expression. Moreover, we also examined the effects of P2 on p53, which is the key regulator of apoptosis. Our results showed that treatment of leukemic cells with P2 led to the upregulation of p53 and Bcl-2-associated X protein, and the downregulation of B-cell lymphoma 2, indicating that p53 is involved in apoptosis induction by P2. The results of this study are anticipated to be useful for the development of P2 as an alternative drug for the treatment of leukemia.

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Differential expression of a novel proline-rich homeobox gene (Prh) in human hematolymphopoietic cells

Blood ◽

10.1182/blood.v85.5.1237.bloodjournal8551237 ◽

1995 ◽

Vol 85 (5) ◽

pp. 1237-1245 ◽

Cited By ~ 51

Author(s):

G Manfioletti ◽

V Gattei ◽

E Buratti ◽

A Rustighi ◽

A De Iuliis ◽

...

Keyword(s):

Cell Lines ◽

Constitutive Expression ◽

Leukemic Cell ◽

Leukemic Cells ◽

Maturation Stage ◽

Lymphoid Tissues ◽

Specific Cell ◽

B Cell Differentiation ◽

Leukemic Cell Lines

Proline-rich homeobox (Prh) is a novel human homeobox-containing gene recently isolated from the CD34+ cell line KG-1A, and whose expression appears mainly restricted to hematopoietic tissues. To define the pattern of Prh expression within the human hematopoietic system, we have analyzed its constitutive expression in purified cells obtained from normal hematopoietic tissues, its levels of transcription in a number of leukemia/lymphoma cell lines representing different lineages and stages of hematolymphopoietic differentiation, and its regulation during in vitro maturation of human leukemic cell lines. Prh transcripts were not detected in leukemic cells of T-lymphoid lineage, irrespective of their maturation stage, and in resting or activated normal T cells from peripheral blood and lymphoid tissues. In contrast, high levels of Prh expression were shown in cells representing early stages of B lymphoid maturation, being maintained up to the level of circulating and tissue mature B cells. Terminal B-cell differentiation appeared to be conversely associated with the deactivation of the gene, since preplasmacytic and plasmocytoma cell lines were found not to express Prh mRNA. Prh transcripts were also shown in human cell lines of early myelomonocytic, erythromegakaryocytic, and preosteoclast phenotypes. Prh expression was lost upon in vitro differentiation of leukemic cell lines into mature monocyte-macrophages and megakaryocytes, whereas it was maintained or upregulated after induction of maturation to granulocytes and osteoclasts. Accordingly, circulating normal monocytes did not display Prh mRNA, which was conversely detected at high levels in purified normal granulocytes. Our data, which show that the acquisition of the differentiated phenotype is associated to Prh downregulation in certain hematopoietic cells but not in others, also suggest that a dysregulated expression of this gene might contribute to the process of leukemogenesis within specific cell lineages.

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Effect of nordihydroguaiaretic acid on cell viability and glucose transport in human leukemic cell lines

FEBS Open Bio ◽

10.1002/2211-5463.12106 ◽

2016 ◽

Vol 6 (10) ◽

pp. 1000-1007 ◽

Cited By ~ 7

Author(s):

David Leon ◽

Daniela Parada ◽

Mauricio Vargas‐Uribe ◽

Alejandra A. Perez ◽

Lorena Ojeda ◽

...

Keyword(s):

Cell Viability ◽

Glucose Transport ◽

Cell Lines ◽

Leukemic Cell ◽

Nordihydroguaiaretic Acid ◽

Human Leukemic Cell ◽

Leukemic Cell Lines

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Signal transduction and glycophosphatidylinositol-linked proteins (lyn, lck, CD4, CD45, G proteins, and CD55) selectively localize in Triton- insoluble plasma membrane domains of human leukemic cell lines and normal granulocytes

Blood ◽

10.1182/blood.v87.9.3783.bloodjournal8793783 ◽

1996 ◽

Vol 87 (9) ◽

pp. 3783-3794 ◽

Cited By ~ 134

Author(s):

I Parolini ◽

M Sargiacomo ◽

MP Lisanti ◽

C Peschle

Keyword(s):

Signal Transduction ◽

G Proteins ◽

Cell Lines ◽

Tyrosine Kinases ◽

Leukemic Cell ◽

Receptor Activation ◽

Leukemic Cells ◽

Human Leukemic Cell ◽

Leukemic Cell Lines ◽

B Lymphoid

Src-family nonreceptor protein tyrosine kinases (NRPTK) are associated with cell surface receptors in large detergent-resistant complexes: in epithelial cells, yes is selectively located in vesicle structures containing caveolin (“caveolae”). These formations are typically also endowed with glycophosphatidylinositol (GPI)-anchored proteins. In the present study, we observed lck, lyn, src, hck, CD4, CD45, G proteins, and CD55 (decay-accelerating factor) expression in the buoyant low- density Triton-insoluble (LDTI) fraction of selected leukemic cell lines and granulocytes. We provide a detailed analysis of the two most highly expressed NRPTK, p53/p56lyn and p56lck, which are involved in the transduction of signals for proliferation and differentiation of monocytes/B lymphocytes and T lymphocytes, respectively. We show that lyn is selectively recovered in LDTI complexes isolated from human leukemic cell lines (promyelocytic [HL-60], erythroid [K562] and B- lymphoid [697]) and from normal human granulocytes, and that lck is recovered from LDTI fractions of leukemic T- and B-lymphoid cell lines (CEM, 697). In LDTI fractions of leukemic cells, lck and lyn are enriched 100-fold as compared with the total cell lysates. Analysis of these fractions by electron microscopy shows the presence of 70- to 200- nm vesicles: lyn and lck are homogenously distributed in the vesicles, as revealed by an immunogold labeling procedure. These novel results propose a role for these vesicles in signal transduction mechanisms of normal and neoplastic hematopoietic cells. In support of this hypothesis, we further observed that molecules participating in B- and T-cell receptor activation cofractionate in the LDTI fractions, CD45/lyn (B cells) and CD45/lck/CD4 (T cells).

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Loss of suppression of normal bone marrow colony formation by leukemic cell lines after differentiation is induced by chemical agents

Blood ◽

10.1182/blood.v65.1.100.100 ◽

1985 ◽

Vol 65 (1) ◽

pp. 100-106 ◽

Cited By ~ 9

Author(s):

HN Steinberg ◽

AS Tsiftsoglou ◽

SH Robinson

Keyword(s):

Bone Marrow ◽

Cell Lines ◽

Colony Formation ◽

Leukemic Cell ◽

K562 Cells ◽

Leukemic Cells ◽

Cell Phenotype ◽

Normal Bone Marrow ◽

Normal Bone ◽

Leukemic Cell Lines

Abstract The human leukemic cell lines K562 and HL-60 were cocultured with normal bone marrow (BM) cells. Coculture with 10(4) K562 or HL-60 cells results in 50% inhibition of normal CFU-E and BFU-E colony formation. However, when the same number of K562 and HL-60 cells is first treated for two to five days with agents that induce their differentiation, a gradual loss in their capacity to inhibit CFU-E and BFU-E colony formation is observed. The inhibitory material in K562 cells is soluble and present in conditioned medium from cultures of these cells. The degree to which leukemic cell suppression of CFU-E and BFU-E growth is reversed is correlated with the time of exposure to the inducing agent. Suppression is no longer evident after five days of prior treatment with inducers. In fact, up to a 90% stimulation of CFU-E growth is observed in cocultures with K562 cells that have been pretreated with 30 to 70 mumol/L hemin for five days. K562 cells treated with concentrations of hemin as low as 30 mumol/L demonstrate increased hemoglobin synthesis and grow normally, but no longer have an inhibitory effect on CFU-E growth. Hence, reversal of normal BM growth inhibition must be caused by the more differentiated state of the K562 cells and not by a decrease in the number of these cells with treatment. Thus, induction of differentiation in cultured leukemic cells not only alters the malignant cell phenotype but also permits improved growth of accompanying normal marrow progenitor cells. Both are desired effects of chemotherapy.

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Pioglitazone Inhibits the Growth of Human Leukemic Cell Lines and Primary Leukemic Cells in Vitro.

Blood ◽

10.1182/blood.v104.11.4493.4493 ◽

2004 ◽

Vol 104 (11) ◽

pp. 4493-4493 ◽

Cited By ~ 1

Author(s):

Yoshihiro Hatta ◽

Minoru Saiki ◽

Yuko Enomoto ◽

Shin Aizawa ◽

Umihiko Sawada ◽

...

Keyword(s):

Cell Lines ◽

Colony Formation ◽

Mononuclear Cells ◽

Hematopoietic Cells ◽

Leukemic Cell ◽

Leukemic Cells ◽

Peroxisome Proliferator ◽

Leukemic Cell Lines ◽

Ppar Γ

Abstract Troglitazone and pioglitazone are one of thiazolidinediones that are high affinity ligand for the nuclear receptor called peroxisome proliferator-activated receptor gamma (PPAR-γ). Troglitazone is a potent inhibitor of clonogenic growth of acute myeloid leukemia cells when combined with a retinoid. However, the effect of pioglitazone to neoplastic cells and normal hematopoietic cells has not been studied yet. Adult T-cell leukemia (ATL), prevalent in western Japan, is a highly aggressive malignancy of mature T lymphocyte. Therefore, we studied antitumor effect of pioglitazone against leukemic cells including ATL as well as normal hematopoietic cells. With 300 μM of pioglitazone, colony formation of ATL cell lines (MT1, MT2, F6T, OKM3T, and Su9T01) was completely inhibited. Colony formation of HUT102, another ATL cell line, was 12 % compared to untreated control. Clonogenic cells of other leukemic cell lines (K562, HL60, U937, HEL, CEM, and NALM1) was also inhibited to 0–30% of control. Colony formation of primary leukemic cells from 5 AML patients was decreased to 15 %. However, normal hematopoietic cells were weakly inhibited with 300 μM pioglitazone; 77 % of CFU-GM, 70 % of CFU-E, and 33 % of BFU-E survived. Cell cycle analysis showed that pioglitazone decreased the ratio of G2/M phase in HL60 cells, suggesting the inhibition of cell division. By Western blotting, PPAR-γ protein level was similar in all leukemic cells and normal bone marrow mononuclear cells. Taken together, pioglitazone effectively eliminate leukemic cells and could be used as an antitumor agent in vivo.

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