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Biomedical subjects

M Talpaz

Publications and source records attributed to M Talpaz.

At least 181 records · Page 10Linked to original sources
PubMed1994

Inhibition of acute myelogenous leukemia progenitor proliferation by macrophage inflammatory protein 1-alpha.

Macrophage inflammatory protein-alpha (MIP-1 alpha), an 8-kDa peptide produced by stimulated macrophages, has been recently sequenced and cloned. In addition to its inflammatory effects, MIP-1 alpha inhibits proliferation of immature hematopoietic progenitors both in vitro and in vivo. Because the gene coding for MIP-1 alpha is expressed in peripheral blood cells obtained from patients with acute myelogenous leukemia (AML), we sought to evaluate the effect of MIP-1 alpha on AML precursors. We studied bone marrow samples from 21 AML patients using both the AML blast colony assay and the delta suspension culture assay. We found that recombinant human (rh) MIP-1 alpha significantly inhibits early and mature AML progenitors with sample-to-sample variability, by up to 79% at concentrations ranging from 40 to 1600 ng/ml. These results were obtained in the presence of fetal calf serum either alone or with granulocyte-macrophage colony-stimulating factor, granulocyte colony-stimulating factor, or interleukin-3. In contrast, rhMIP-1 alpha (400 ng/ml) did not significantly affect normal colony-forming unit granulocyte-macrophage (CFU-GM), or burst-forming unit-erythroid (BFU-E) proliferation. These data prompted us to delineate the inhibitory mechanism of MIP-1 alpha. Consequently, we used the thymidine suicide technique to measure DNA synthesis in AML progenitors and the enzyme-linked immunosorbent assay to quantify intracellular levels of interleukin-1 beta in AML blasts following incubation with MIP-1 alpha. We found that whereas MIP-1 alpha prevented AML progenitors from entering the proliferative phase of the cell cycle, it had no effect on interleukin-1 beta levels. Taken together, our data suggest that MIP-1 alpha may have clinical benefits in therapy for AML and should be considered for evaluation in a clinical setting.

Adolescent↗
PubMed1993

Heterogeneity in lineage derivation of Philadelphia-positive acute lymphoblastic leukemia expressing p190BCR-ABL or p210BCR-ABL: determination by analysis of individual colonies with the polymerase chain reaction.

The molecular hallmark of Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL) is the expression of 1 of 2 alternate forms of the aberrant BCR-ABL protein-p210BCR-ABL or p190BCR-ABL. The presence of BCR-ABL message provides a target for analyzing the lineage derivation of this disease. We, therefore, studied myeloid and erythroid progenitor involvement in Philadelphia chromosome-positive ALL. Bone marrow low-density cells from Philadelphia chromosome-positive ALL patients (5 with the p190BCR-ABL and 2 with the p210BCR-ABL anomaly) were cultured in the mixed colony culture assay. cDNA from individually plucked colony-forming unit-granulocyte-macrophage and burst-forming unit-erythroid colonies was then analyzed using the hybridization protection assay in conjunction with the polymerase chain reaction to detect BCR-ABL molecular aberrations. Colony-forming unit-granulocyte-macrophage and burst-forming unit-erythroid colonies from 1 of 5 p190BCR-ABL-positive patients and 1 of 2 p210BCR-ABL-positive patients expressed BCR-ABL transcripts, whereas colony-forming unit-granulocyte-macrophage and burst-forming unit-erythroid colonies from the other patients did not. Our study suggests that the origin of both p190BCR-ABL- and p210BCR-ABL-positive ALL is heterogenous with involvement of either a pluripotent precursor or a lymphoid lineage-committed hematopoietic progenitor.

Adolescent↗
PubMed1993

Serum interleukin 6 levels are elevated in lymphoma patients and correlate with survival in advanced Hodgkin's disease and with B symptoms.

Several cytokines including gamma-interferon, tumor necrosis factor alpha, interleukin 1 beta (IL-1 beta), and interleukin 6 (IL-6) are pyrogenic and can inhibit lipogenic processes. Because patients with lymphoma often suffer from fever, weight loss, and night sweats (B symptoms), the etiology of which is unknown, the authors investigated serum levels of these cytokines in normal volunteers and in patients with Hodgkin's and non-Hodgkin's lymphoma. Sixty serum samples from patients with Hodgkin's disease (28 patients) or non-Hodgkin's lymphoma (32 patients), as well as 20 samples from normal volunteers, were collected. The majority of patients had advanced (Stage III or IV) or relapsed disease. The assay for gamma-interferon was a specific and sensitive radioimmunoassay (lower limit of detection = 0.1 unit/ml); the assays for tumor necrosis factor alpha, IL-1 beta, and IL-6 were enzyme-linked immunoassays with lower limits of sensitivity of 10 pg/ml, 20 pg/ml, and 22 pg/ml, respectively. There were no statistically significant differences in gamma-interferon, tumor necrosis factor alpha, or IL-1 beta levels between lymphoma patients and normal subjects. In contrast, 20 of 57 patients (35%) with lymphoma as compared with 0 of 19 normal volunteers (0%) had detectable serum IL-6 levels (P < 0.005, chi 2 test). Interestingly, 17 of 29 lymphoma patients with B symptoms (59%) as opposed to 3 of 28 lymphoma patients without B symptoms (11%) had detectable serum IL-6 levels (P < 0.001, chi 2 test); the median IL-6 level was 28.9 pg/ml (B symptoms present) versus undetectable (no B symptoms) (P < 0.005, Mann-Whitney U test). Analyzing Hodgkin's and non-Hodgkin's lymphoma groups separately revealed similar results. IL-6 levels showed no significant correlation with time from diagnosis, beta 2-microglobulin, or lactate dehydrogenase levels. However, analysis by the method of Kaplan and Meir demonstrated that the median survival of Hodgkin's disease patients with detectable IL-6 levels (> or = 22 pg/ml) was 10 mo, whereas the median survival has not been reached at a median follow-up time of 37.5 mo in those patients with lower values (Wilcoxon P value = 0.0012). There were too few patients in each subset of non-Hodgkin's lymphoma to determine the correlation between IL-6 and survival but, considered as a single group, a statistically significant correlation was not found.(ABSTRACT TRUNCATED AT 400 WORDS)

Actuarial Analysis↗
PubMed1993

Lymphotoxin is an autocrine growth factor for Epstein-Barr virus-infected B cell lines.

Because human lymphotoxin (LT) was originally isolated from a lymphoblastoid cell line, we investigated the role of this molecule in three newly established Epstein-Barr virus (EBV)-infected human B cell lines. These lines were derived from acute lymphoblastic leukemia (Z-6), myelodysplastic syndrome (Z-43), and acute myelogenous leukemia (Z-55) patients who had a prior EBV infection. Each lymphoblastoid cell line had a karyotype that was different from that of the original parent leukemic cells, and all expressed B cell, but not T cell or myeloid surface markers. In all three lines, rearranged immunoglobulin heavy chain joining region (JH) bands were found, and the presence of EBV DNA was confirmed by Southern blotting. Z-6, Z-43, and Z-55 cell lines constitutively produced 192, 48, and 78 U/ml LT, respectively, as assessed by a cytotoxicity assay and antibody neutralization. Levels of tumor necrosis factor (TNF) were undetectable. Scatchard analysis revealed that all the cell lines expressed high-affinity TNF/LT receptors with receptor densities of 4197, 1258, and 1209 sites/cell on Z-6, Z-43, and Z-55, respectively. Furthermore, labeled TNF binding could be reversed by both unlabeled TNF, as well as by LT. Studies with p60 and p80 receptor-specific antibodies revealed that the three lines expressed primarily the p80 form of the TNF receptor. When studied in a clonogenic assay, exogenous LT stimulated proliferation of all three cell lines in a dose-dependent fashion at concentrations ranging from 25 to 500 U/ml. Similar results were obtained with [3H]TdR incorporation. Monoclonal anti-LT neutralizing antibodies at concentrations of 25-500 U/ml inhibited cellular multiplication in a dose-dependent manner. It is interesting that in spite of a common receptor, TNF (1,000 U/ml) had no direct effect on Z-55 cell growth, whereas it partially reversed the stimulatory effect of exogenous LT. In addition, TNF inhibited Z-6 and Z-43 cell proliferation, and its suppressive effect was reversed by exogenous LT. Both p80 and p60 forms of soluble TNF receptors suppressed the lymphoblastoid cell line proliferation and their inhibitory effect was partially reversed by LT. Our data suggest that (a) LT is an autocrine growth factor for EBV-transformed lymphoblastoid B cell lines; and (b) anti-LT antibodies, soluble TNF/LT receptors, and TNF itself can suppress the growth of lymphoblastoid cells, probably by modulating or competing with LT.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

Analysis of the effects of tumor necrosis factor inhibitors on human hematopoiesis.

Truncated soluble fragments of tumor necrosis factor (TNF) receptors have recently been isolated from human serum and urine. These shed forms of TNF receptors bind TNF-alpha and lymphotoxin and inhibit various effects of TNF in culture. In this study, we evaluated the role of these molecules in the hematopoietic system. TNF-alpha and lymphotoxin inhibited colony forming units granulocyte-macrophage (CFU-GM) and burst forming units-erythroid (BFU-E) in a dose-dependent fashion at concentrations ranging from 1 to 5,000 U/ml and 25 to 250 U/ml, respectively. TNF-alpha exerted a similar dose-dependent inhibitory effect on a CD34 enriched marrow cell population, suggesting that its effect is not mediated through CD34 accessory cells. Its suppressive effect was partially reversed by anti-TNF-alpha neutralizing antibodies, thus proving its specificity. Two shed forms of TNF receptors, TNF binding protein (TNF-bp) and TNF receptor fusion protein (TNFR-fc), had no significant effect on CFU-GM proliferation. Both molecules, however, significantly reversed the inhibitory effect of TNF-alpha (p < 0.015 and p < 0.03, respectively), whereas they had no effect on the lymphotoxin-induced CFU-GM growth inhibition. These results indicate that TNF-bp and TNFR-fc may modulate the inhibitory effects of TNF-alpha in the hematopoietic system.

Animals↗
PubMed1993

Molecular approaches to the diagnosis and treatment of cancer.

We have used autologous bone marrow transplantation (ABMT) as a setting to develop the genetic therapy of cancer in hematopoietic neoplasms based on the use of the bone marrow as a conduit through which to introduce regulatory molecules into the patient. This has involved three developmental phases: 1) learning how to develop genetic modification techniques; 2) learning how to develop in vivo selection techniques for the genetically modified cells; and 3) developing molecular vectors for modification of hematopoietic cells for therapy of cancer. These programs will be summarized in terms of their progress at the conference.

Bone Marrow Transplantation↗
PubMed1993

Growth factors controlling interleukin-4 action on hematopoietic progenitors.

We investigated the effect of interleukin-4 (IL-4) on human hematopoietic progenitors using low-density bone marrow cells from 29 hematologically normal donors. We found that IL-4 could either inhibit or stimulate cell growth, depending upon the other constituents of the culture medium. At concentrations ranging from 0.1 to 10.0 micrograms/ml, it significantly inhibited colony-forming units granulocyte-macrophage (CFU-GM) in the presence of either fetal calf serum alone, erythropoietin, leukocyte-conditioned medium prepared with phytohemagglutinin, granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-3 (IL-3), or stem cell factor (SCF), in a dose-dependent fashion. In contrast, IL-4 stimulated CFU-GM colony multiplication in the presence of granulocyte colony-stimulating factor (G-CSF). Similar but less significant inhibitory effects were exerted by IL-4 on burst-forming units-erythroid (BFU-E). The growth-suppressive effect of IL-4 was partially reversed by IL-1 beta, and to a lesser extent by IL-6. When tested by enzyme-linked immunosorbent assay (ELISA), IL-4 suppressed cellular IL-1 beta production, and, similar to IL-4, anti-IL-1 beta-neutralizing antibodies inhibited CFU-GM colony growth, suggesting that the inhibition of endogenous IL-1 beta is a factor in regulating the IL-4 effect. Furthermore, in the absence of exogenous growth factors, IL-4 inhibited CFU-GM colony growth when anti-G-CSF neutralizing antibodies were also present. Therefore, we tested the effect of IL-4 on G-CSF receptors and found that 6- or 24-h incubation of low-density marrow cells with 1.0 microgram/ml IL-4 resulted in up-regulation of G-CSF receptors. Taken together, these results suggest that IL-4 possesses a dual modulatory role in the hematopoietic system via interaction with various cytokines.

Antibodies, Monoclonal↗
PubMed1993

Interferon in chronic myeloid leukemia. A workshop report.

The therapeutic efficacy of interferon-alpha (IFN-alpha) in the treatment of chronic myeloid leukemia is currently being tested in a number of institutional, interinstitutional, and international trials. There is no doubt that responses are achieved in many patients, and in a small subset complete eradication of clonogenic cells may be possible. However, it has not yet been shown that overall survival of patients treated with IFN-alpha is better than that of those treated with conventional cytoreductive drugs. There are still controversial opinions on problems such as dosages and duration of treatment, combination with cytostatic agents, definition of responses, and relevance of cytogenic and molecular data. An international workshop discussed the data on interferon therapy and attempted to define the role of interferon today in the management of chronic myeloid leukemia.

Bone Marrow Transplantation↗
PubMed1993

Granulocyte-macrophage colony-stimulating factor as a cause of paraneoplastic leukaemoid reaction in advanced transitional cell carcinoma.

Increasing evidence suggests that paraneoplastic syndromes may be mediated by tumour-related cytokine release, although the specific factor(s) involved remain poorly defined. Colony-stimulating factors (CSF) and interleukins (IL) promote colony growth in semi-solid media and, when administered in recombinant form, increase blood counts in patients. However, normal serum CSF levels in individuals with physiologic blood counts and the relationship between specific serum CSF levels and paraneoplastic leukaemoid reaction are not well established. In this study, we found that normal serum levels of granulocyte-macrophage CSF (GM-CSF), as measured by ELISA, were generally < 55 pg ml-1; IL-3, < 30 pg ml-1; and granulocyte CSF (G-CSF), < 50 pg ml-1. In contrast, high levels of GM-CSF (132 pg ml-1), but not G-CSF or IL-3, were found in a patient with a transitional cell carcinoma of the renal pelvis and increased leukocytosis correlating with the tumour burden. The GM-CSF was biologically active, as demonstrated by its ability to stimulate colony growth in vitro. Based on these results it appears that autonomous production of GM-CSF is one possible pathophysiologic mechanism underlying leukaemoid reaction in cancer patients.

Aged↗
PubMed1993

Subcellular localization of Bcr, Abl, and Bcr-Abl proteins in normal and leukemic cells and correlation of expression with myeloid differentiation.

We used specific antisera and immunohistochemical methods to investigate the subcellular localization and expression of Bcr, Abl, and Bcr-Abl proteins in leukemic cell lines and in fresh human leukemic and normal samples at various stages of myeloid differentiation. Earlier studies of the subcellular localization of transfected murine type IV c-Abl protein in fibroblasts have shown that this molecule resides largely in the nucleus, whereas transforming deletion variants are localized exclusively in the cytoplasm. Here, we demonstrate that the murine type IV c-Abl protein is also found in the nucleus when overexpressed in a mouse hematopoietic cell line. However, in both normal and leukemic human hematopoietic cells, c-Abl is discerned predominantly in the cytoplasm, with nuclear staining present, albeit at a lower level. In contrast, normal endogenous Bcr protein, as well as the aberrant p210BCR-ABL and p190BCR-ABL proteins consistently localize to the cytoplasm in both cell lines and fresh cells. The results with p210BCR-ABL were confirmed in a unique Ph1-positive chronic myelogenous leukemia (CML) cell line, KBM5, which lacks the normal chromosome 9 and hence the normal c-Abl product. Because the p210BCR-ABL protein appears cytoplasmic in both chronic phase and blast crisis CML cells, as does the p190BCR-ABL in Ph1-positive acute leukemia, a change in subcellular location of Bcr-Abl proteins between cytoplasm and nucleus cannot explain the different spectrum of leukemias associated with p210 and p190, nor the transition from the chronic to the acute leukemia phenotype seen in CML. Further analysis of fresh CML and normal hematopoietic bone marrow cells reveals that p210BCR-ABL, as well as the normal Bcr and Abl proteins, are expressed primarily in the early stages of myeloid maturation, and that levels of expression are reduced significantly as the cells mature to polymorphonuclear leukocytes. Similarly, a decrease in Bcr and Abl levels occurs in HL-60 cells induced by DMSO to undergo granulocytic differentiation. The action of p210BCR-ABL and its normal counterparts may, therefore, take place during the earlier stages of myeloid development.

Animals↗
PubMed1993

Effect of prior interferon alfa therapy on the outcome of allogeneic bone marrow transplantation for chronic myelogenous leukemia.

PURPOSE: To determine whether prior interferon alfa (IFN-A) treatment affects the outcome of allogeneic bone marrow transplantation. PATIENTS AND METHODS: We analyzed the outcome of 77 patients with chronic myelogenous leukemia (CML) who received transplants from an HLA-identical donor using a total-body irradiation-containing preparative regimen. Engraftment, acute and chronic graft-versus-host disease (GVHD), survival, and disease-free survival were compared between patients who had previously received interferon (IFN+) to those who had not (IFN-). Forty-one patients were transplanted in chronic phase and 36 had more advanced CML. The IFN+ group had received IFN-A in doses of 3 to 5 x 10(6) U/m2 three times a week or more for at least 4 weeks anytime before transplantation. RESULTS: For patients in chronic phase, there were no significant differences between the IFN+ group and the IFN- group in regard to neutrophils recovery more than 1.0 x 10(9)/L (29 v 24), platelet recovery more than 50 x 10(9)/L (33 v 36), incidence of grade II to IV GVHD (23% v 28%), incidence of chronic GVHD (39% v 47%), disease-free survival (46% +/- 11% v 59% +/- 13%), relapse (9% v 11%), or 100-day transplant-related mortality (22% v 16%). In patients with more advanced stage disease, there was also no significant differences between the IFN+ group and the IFN- group in regard to these outcomes. CONCLUSION: Prior treatment with IFN-A did not adversely affect transplant outcome. Further studies are required to better understand the complementary roles of IFN-A and allogeneic bone marrow transplantation for the treatment of CML.

Adolescent↗
PubMed1993

All-trans retinoic acid: tolerance and biologic effects in myelodysplastic syndrome.

PURPOSE: We conducted a study to evaluate the tolerance to and biologic effects of all-trans retinoic acid in patients with myelodysplastic syndrome. PATIENTS AND METHODS: Thirty-nine patients with myelodysplastic syndrome were treated with oral all-trans retinoic acid for 6 weeks. Dose levels were 10, 25, 50, 100, 150, 200, and 250 mg/m2/d. At least three patients were treated on each dose level. RESULTS: The most common side effects were mucocutaneous dryness and erythema, and hypertriglyceridemia. Dose-limiting side effects were diverse and included dermatitic problems, sensorineural hearing loss, headaches, nausea and vomiting, myalgias, and dyspnea. The maximum-tolerated dose was 150 mg/m2/d. Only one response was seen among 29 patients considered assessable for response. CONCLUSION: All-trans retinoic acid can be safely administered to patients at doses up to 150 mg/m2/d for 6 weeks. However, as administered in this study, this compound does not appear to have significant activity in myelodysplastic syndromes.

Administration, Oral↗
PubMed1993

CML: mechanisms of disease initiation and progression.

Chronic myelogenous leukemia (CML) is a hematological stem cell disorder characterized by excessive proliferation of the myeloid lineage. It has a progressive course typified by the transition from the chronic phase to the accelerated phase and on to blast crisis. The hallmark of CML is the translocation between chromosomes 9 and 22 that results in the chimeric BCR-ABL gene encoding p210BCR-ABL. The oncogenic potential of this protein has been validated, and it is believed that it contributes in a critical way to the initiation of CML. However, the secondary genetic forces responsible for the transition from the chronic state to the fully blastic stage are not clear. Evidence for chromosomal instability includes the clonal evolution which characterizes advanced CML. In regard to specific genetic aberrations, sporadic reports have shown alterations in H-RAS, c-MYC, retinoblastoma, and P53 genes, as well as production of p190BCR-ABL during the progression of CML. In addition, we have recently found evidence for excessive interleukin-1 beta production, acting in an autocrine and/or paracrine manner, in the more advanced stages of the disease. Taken together, current data suggest that multiple molecular pathways lead to disease progression, and that distinct subsets of genetic alterations exist in blast crisis patients.

Blast Crisis↗
PubMed1993

Role of interleukin-1 inhibitory molecules in therapy of acute and chronic myelogenous leukemia.

The poor outcome of conventional therapy of acute and chronic myelogenous leukemias (AML and CML) has prompted several groups to investigate new therapeutic directions. Data from various laboratories, including our own, indicate that both normal and leukemia precursors proliferate in response to growth factors. Furthermore, it has been shown that AML blasts, low-density cells from CML patients with advanced disease, and cultured bone marrow-adherent layers from CML blast crisis patients produce interleukin 1 (IL-1); this molecule may play a pivotal role in driving leukemia cell proliferation through autocrine or paracrine pathways. We have therefore hypothesized that interruption of the IL-1-mediated growth-stimulatory mechanism may suppress leukemia precursor multiplication. In searching for IL-1-inhibitory molecules that may be used clinically, we have investigated the in vitro effects of various IL-1 inhibitors including IL-1 receptor antagonist, soluble IL-1 receptors, and interleukin 4. Our studies suggest that IL-1 inhibitors can suppress clonogenic growth of cultured AML and CML progenitors and may hence be exploitable in clinical trials.

Animals↗