Bryostatin 1: differentiating agent from the depths.
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Biomedical subjects
Publications and source records attributed to R M Stone.
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PURPOSE: To determine the treatment outcome of standard acute myeloid leukemia (AML)-type chemotherapy in a subset of patients with newly diagnosed myelodysplastic syndromes (MDS) compared with that of patients with de novo AML as defined using French-American-British (FAB) criteria. In addition, to determine the pretreatment variables having prognostic significance for treatment outcome in patients with MDS. PATIENTS AND METHODS: Nine hundred seven newly diagnosed patients with no history of cytopenias having a local institutional de novo AML successfully karyotyped and treated on Cancer and Leukemia Group B (CALGB) protocols for AML from 1984 to 1992. Thirty-three of the 907 patients were reclassified as having MDS on central pathology review using FAB criteria and form the basis of this analysis. RESULTS: The treatment outcomes for patients with MDS and AML were similar; the complete remission (CR) rate was 79% and 68%, respectively (P = .37); median CR duration was 11 and 15 months, respectively (P = .28); and median survival was 13 and 16 months, respectively (P = .72). For the MDS patients, there were no prognostic variables for CR rate identified. For CR duration, only the Sanz classification had prognostic value. The prognostic factors for survival in a univariate analysis included age, WBC count, Sanz classification, and percent blood blasts. In a proportional hazards analysis of survival, age greater than 60 years and WBC less than 2.6 x 10(9)/L were adverse prognostic factors. CONCLUSION: In patients with no known history of cytopenias who are treated intensively at diagnosis, the FAB distinctions between MDS (refractory anemia with excess blasts and refractory anemia with excess blasts in transformation) and AML appear to have little therapeutic relevance.
BACKGROUND: Elderly patients with primary acute myelogenous leukemia (AML) are less likely to enter remission than younger adults, in part because of a higher mortality rate related to severe myelosuppression. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to shorten the duration of neutropenia and decrease infectious complications when administered after chemotherapy to patients with lymphomas and solid tumors. METHODS: We randomly assigned 388 patients 60 years of age or older who had newly diagnosed primary AML to receive placebo or GM-CSF (5 micrograms per kilogram of body weight per day intravenously over a period of six hours) in a double-blind manner, beginning the day after the completion of three days of daunorubicin (45 mg per square meter of body-surface area per day) and seven days of cytarabine (200 mg per square meter per day by continuous intravenous infusion). If leukemia cells persisted in the marrow three weeks after the initiation of chemotherapy, further daunorubicin (two days) and cytarabine (five days) were administered. GM-CSF or placebo was given daily until the neutrophil count was at least 1000 per cubic millimeter, there was evidence of the regrowth of leukemia, or severe toxic effects attributable to the study infusion occurred. Patients who had a complete remission were then randomly assigned to receive one of two intensification regimens. RESULTS: Of 388 patients (median age, 69 years), 193 were randomly assigned to receive GM-CSF and 195 to placebo. The rate of complete remission was 51 percent (95 percent confidence interval, 44 to 59 percent) among those assigned to GM-CSF and 54 percent (95 percent confidence interval, 47 to 61 percent) among those assigned to receive placebo (P = 0.61). The reasons for failure (early death, death during marrow hypoplasia, and persistent leukemia), the incidence of severe or lethal infection, and the incidence of the regrowth of leukemia (2 percent overall) were similar in the two groups. The median duration of neutropenia was slightly shorter (P = 0.02) in the patients who received GM-CSF (15 days) than in those who received placebo (17 days), but the clinical importance of this result was minimal because the growth factor failed to lower the treatment-related mortality rate or improve the rate of complete remission. CONCLUSIONS: GM-CSF, in the dose and schedule we used, does not stimulate the regrowth of leukemia, but it also does not decrease the severe myelosuppressive consequences of initial chemotherapy or improve the response rate in patients 60 years of age or older with primary AML. It should not be recommended for use in such patients.
The goal of this phase II multicenter clinical trial was to evaluate a new intensive chemotherapy program for adults with untreated acute lymphoblastic leukemia (ALL) and to examine prospectively the impact of clinical and biologic characteristics on the outcome. One hundred ninety-seven eligible and evaluable patients (16 to 80 years of age; median, 32 years of age) received cyclophosphamide, daunorubicin, vincristine, prednisone, and L-asparaginase; 167 patients (85%) achieved a complete remission (CR), 13 (7%) had refractory disease, and 17 (9%) died during induction. A higher CR rate was observed in younger patients (94% for those < 30 years old, 85% for those 30 to 59 years old, and 39% for those > or = 60 years old, P < .001) and in those who had a mediastinal mass (100%) or blasts with a T-cell immunophenotype. Eighty percent of B-lineage and 97% of T-cell ALL patients achieved a CR (P = .01). The coexpression of myeloid antigens did not affect the response rate or duration. Seventy percent of those with cytogenetic or molecular evidence of the Philadelphia (Ph) chromosome and 84% of those without such evidence achieved a CR (P = .11). Patients in remission received multiagent consolidation treatment, central nervous system prophylaxis, late intensification, and maintenance chemotherapy for a total of 24 months. After a median follow-up time of 43 months, the median survival for all 197 patients is 36 months; the median remission duration for the 167 CR patients is 29 months. Favorable pretreatment characteristics relative to remission duration or survival are younger age, the presence of a mediastinal mass or lymphadenopathy, a white blood cell count (WBC) less than 30,000/microL, L1 morphology, T or TMy immunophenotype, and the absence of the Ph chromosome. The estimates of the proportion surviving at 3 years are 69% for patients less than 30 years old, 39% for those 30 to 59 years old, 89% for those who had a mediastinal mass, 59% with WBC less than 30,000/microL, 63% with L1 morphology, 69% for T or TMy antigen expression, and 62% for those who lack the Ph chromosome. Fifteen patients (8%) had no unfavorable prognostic factors and have an estimated probability of survival at 5 years of 100% (95% confidence interval, 77% to 100%). This intensive chemotherapy regimen produces a high remission rate and a high proportion of durable remissions in adults with ALL.
We report two patients with a distinctive biphenotypic hematologic disorder characterized by lymphoblastic lymphoma (LBL), eosinophilia, and myeloid malignancy and/or hyperplasia associated with a t(8;13)(p11;q11) chromosomal translocation in both bone marrow and lymph node specimens. Both patients presented with lymphadenopathy pathologically classified as LBL with a T-cell immunophenotype, myeloid hyperplasia of the bone marrow, and peripheral blood eosinophilia. The first patient achieved clinical complete remission after receiving several regimens of chemotherapy and remains disease-free 16 months after undergoing allogeneic bone marrow transplantation. The second patient developed progressive lymphadenopathy despite several courses of chemotherapy directed against non-Hodgkin's lymphoma. Eight months after his initial presentation, he developed acute myelogenous leukemia that was refractory to therapy. Comparison of these patients with four similar cases recently reported in the literature suggests that this constellation of findings constitutes a distinctive clinicopathologic syndrome. Molecular analysis of the t(8;13) translocation breakpoint may identify genes located in this region and provide insight into the pathogenesis of this interesting biphenotypic hematologic malignancy.
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Treatment of human HL-60 leukemic cells with 12-O-tetradecanoylphorbol-13-acetate (TPA) is associated with activation of protein kinase C (PKC) and induction of monocytic differentiation. An HL-60 variant cell line, termed HL-525, derived from long-term exposure to TPA (Homma et al, Proc Natl Acad Sci USA 83: 7316, 1986) is resistant to TPA-induced differentiation and displays decreased PKC beta expression compared with the HL-60 parent line. However, this variant exhibits features of granulocytic differentiation, including nitroblue tetrazolium reduction, when exposed to all-trans retinoic acid (ATRA). Whereas treatment of HL-525 cells with ATRA or TPA alone had no effect on features of monocytic differentiation, these agents in combination resulted in cellular adhesion, nonspecific esterase staining, and induction of the c-fms (monocyte growth factor receptor) gene. In order to measure PKC expression associated with the reversal of TPA resistance by ATRA, we exposed HL-525 cells to ATRA and analyzed PKC-mRNA and protein levels. Exposure of HL-525 cells to ATRA for 3 days resulted in induction of PKC beta transcripts, whereas there was little change in PKC alpha mRNA levels. ATRA treatment was also associated with an increase in PKC activity and an induction of cytosolic PKC beta protein levels. These findings are consistent with the hypothesis that ATRA reverses TPA resistance in HL-525 cells by enhancing the expression of PKC.
To determine whether neural crest-derived neuroblastoma cells may release cytokines which regulate the function of leukocytes, we found that neuroblastoma (HTB-11) cells did not constitutionally express IL-1 beta, TNF alpha, or IL-8 mRNA. However, TNF alpha, which induced HTB-11 cells to differentiate to perineurium-like cells, induced expression of IL-8 mRNA in a dose- and time-dependent fashion. In contrast, pentoxifylline (1 mM), which promoted HTB-11 cells to differentiate to polygonal neuron-like cells, did not induce IL-8 mRNA expression. As determined by enzyme-linked immunoassay, high levels of IL-8 were detectable in the culture supernatants from TNF alpha-treated neuroblastoma cells, but not pentoxifylline-treated neuroblastoma cells (19.60 +/- 2.34 vs 0.10 +/- 0.06 ng/ml). Culture supernatants obtained from TNF alpha-treated neuroblastoma cells induced chemotaxis of neutrophils and lymphocytes that was significantly blocked by anti-IL-8 neutralizing antibodies. Detection of a leukocyte chemotactic factor was not observed in the culture supernatants from pentoxifylline-treated cells. These results suggest that neural crest-derived perineurium-like cells, but not neuron-like cells, may release a leukocyte chemotactic factor or factors such as IL-8 which could be involved in leukocyte recruitment seen in inflammatory diseases affecting peripheral nerves.
We conducted a Phase I-II trial of recombinant human erythropoietin-beta (rhEPO) in patients with myelodysplastic syndrome (MDS). Patients with anemia and pathologically confirmed MDS were eligible for the study. Treatment consisted of rhEPO by subcutaneous injection thrice weekly for 6 weeks at one of three dose levels (100 U/kg (three patients), 200 U/kg (three patients) and 400 U/kg (14 patients)). Ferrous sulfate (325 mg po tid) was also administered if the transferrin saturation was below 30% (two patients). Patients were monitored with weekly CBC, white cell differential, and reticulocyte counts. Bone marrow examinations were performed at the conclusion of the treatment period and after a 2 week washout period. Patients who responded to therapy were continued on rhEPO at the same dose for 6 additional months. Response criteria included: 50% reduction in transfusion requirements compared with the 6 week pre-study period; doubling of reticulocyte count that was maintained on two determinations at least 1 week apart; or an increase in hemoglobin by at least 1.2 gm/dl without transfusions. Pre-treatment factors potentially predictive of response were analyzed by univariate analysis and in a multivariate fashion by classification and regression trees. Seven of the twenty patients sustained an untransfused rise in serum hemoglobin > or = 1.2 gm/dl. Four of the sixteen patients (including three of seven patients experiencing a rise in serum hemoglobin) who were transfusion-dependent prior to the study achieved a reduction or elimination of their transfusion requirements. Five of thirteen patients who received rhEPO during the extension phase had a continued response. A low baseline erythropoietin level (< 50 mU/ml) was the best predictor of hemoglobin response when controlling for other variables. rhEPO has a role in the treatment of certain patients with MDS, particularly in those whose endogenous serum erythropoietin levels are not markedly elevated.
PURPOSE: To determine the incidence, natural history, and risk factors associated with myelodysplastic syndrome (MDS) occurring as a late complication following autologous bone marrow transplantation for patients with non-Hodgkin's lymphoma. METHODS: We retrospectively reviewed the charts of all 262 patients who underwent autologous bone marrow transplantation for non-Hodgkin's lymphoma at the Dana-Farber Cancer Institute from 1982 through 1991. Although patients received a variety of treatments before they were eligible for transplant, identical myeloablative therapy (cyclophosphamide 60 mg/kg/d for 2 days plus total-body irradiation twice daily for 3 days) was administered in each case. By collecting data on pretransplant and early posttransplant variables, we attempted to identify risk factors for the development of MDS. RESULTS: The crude overall incidence of posttransplant MDS or acute myeloid leukemia (AML) was 7.6%. The actuarial risk at 6 years was 18% +/- 9%. The median time of onset was 31 months (range, 10 to 101) after transplant or 69 months (range, 27 to 141) after initial treatment for lymphoma. Pretreatment variables predictive for the development of MDS (univariate analysis) included prolonged interval between initial treatment and the transplant procedure (P = .003), increased duration of exposure to chemotherapy (P = .019) or to alkylating agents (P = .045), and use of radiation therapy (P = .032) or pelvic radiation (P = .003) before transplant. CONCLUSION: MDS is a potential complication of autologous bone marrow transplantation for non-Hodgkin's lymphoma; bone marrow stem-cell damage sustained before the transplant may be the most important risk factor.
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Nine patients (median age, 58; range: 37-74) with relapsed de novo acute myeloid leukemia (AML) (3), AML after prior myelodysplastic syndrome (MDS) (4), or MDS (2) were treated with 2-20 x 10(6) U/m2/day (1-10 mg/m2/day) of recombinant human interferon gamma (rIFN gamma; Biogen) on a 14-day continuous intravenous infusion schedule. The two patients who received the initial dose of 20 x 10(6) U/m2/day (1.0 mg/m2/day) could only tolerate 6 days of therapy because of severe hepatotoxicity. Two patients who received the revised starting dose of 10 x 10(6) U/m2/day also could not complete a full course of rIFN gamma due to renal failure in one case and pulmonary deterioration in the other. A reversible dose-related rise in SGOT was seen in six patients. All patients developed a severe flu-like syndrome characterized by myalgias and fevers. These toxicities were not associated with detectable serum levels of tumor necrosis factor (TNF). Although blasts from three of five assessable patients displayed increased expression of the Ia (HLA-DR) antigen, there were no hematological responses. Steady-state rIFN gamma plasma levels in patients who tolerated a complete infusion were < 40 U/ml, a concentration below that required to induce differentiation of myeloid leukemic cell lines in vitro. We conclude that continuous infusions of rIFN gamma at doses as low as 2 x 10(6) U/m2/day are poorly tolerated in patients with AML and MDS; the maximum tolerated dose is approximately 2 x 10(6) U/m2/day.
Acute myeloid leukemia (AML) in elderly patients is more likely to result from stem cell dysfunction at an earlier stage of myeloid maturation in the bone marrow than AML in younger individuals. The intensive therapy thought necessary to successfully treat such a relatively resistant leukemia is poorly tolerated in older patients who have more limited ability to withstand the myelosuppressive and end-organ toxicities of standard induction programs. While the administration of hematopoietic growth factors may stimulate leukemic cell growth, such a strategy could serve to ameliorate the prolonged myelosuppression associated with intensive chemotherapy, thereby outweighing this risk and offering the potential to more safely deliver such treatment to elderly patients with AML.
All-trans-retinoic (ATRA) treatment of patients with acute promyelocytic leukemia results in differentiation of the malignant cells and a high complete remission rate. ATRA treatment induced granulocytic differentiation in HL-60 cells as assessed by nitroblue tetrazolium (NBT) reduction, but had no effect on non-specific esterase (NSE) straining, as expected in cells maturing along the monocytic lineage. However, our results demonstrate that ATRA (0.1-10 microM) induces expression of the c-fms (monocyte colony-stimulating factor receptor) gene in HL-60 cells. This effect was detectable after 2 days and expression was maximal at 5 days. Similar results were obtained during treatment with cis-retinoic acid (CRA), hexamethylene bisacetamide (HMBA), or dimethyl sulfoxide (DMSO). The results also demonstrate that ATRA-induced c-fms expression is potentiated by exposure to tumor necrosis factor alpha (TNF alpha) or dibutyryl cyclic adenosine monophosphate (cAMP). The induction of c-fms transcripts by ATRA is associated with induction of M-CSF-binding ability, suggesting cell surface expression of the monocyte growth factor receptor. Our results indicate that retinoic acid can induce features of both monocytic and granulocytic differentiation in HL-60 cells.
Recent studies suggest that the administration of intensive post-remission therapy, which includes high-dose cytarabine, results in a longer period of disease-free survival when compared with lower dose treatment. In view of these improved results, it is uncertain currently whether younger patients with acute myeloid leukemia (AML) in first remission should be offered such intensive chemotherapy or either allogeneic or autologous bone marrow transplantation. Currently ongoing clinical trials, laboratory-based prognostic factor analysis, and attempts at better understanding the pathophysiology of acute leukemia may provide more precise guidelines for choosing the best treatment among these alternatives for any given individual with AML in first remission.
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Picibanil (OK432), an extract from streptococci, has been widely utilized to treat malignant ascites and pleural effusions. The antitumor mechanism is believed to include complement-mediated neutrophil activation. Employing a flow-cytometric analysis of actin polymerization as an indicator of cell activation as well as a tumor proliferation assay, we have found that monocyte-derived neutrophil-activating factors were involved in OK432-induced neutrophil activation as well as antitumor activity. OK432-stimulated (0.1 KE/ml; 0.01 mg/ml) monocyte supernatants (OKMS) induced neutrophil actin polymerization and chemotaxis. OKMS were responsible for neutrophil-mediated inhibition of human leukemic (CEM) cell proliferation and stimulated neutrophils to produce superoxide in the presence of CEM leukemic cells at an effector/target ratio higher than 20/1. In contrast, OK432 alone, OK432-stimulated lymphocyte supernatants, or OK432-stimulated neutrophil supernatants had no effect on neutrophil activation or suppression of tumor cell proliferation. OK432 in combination with mononuclear cells also had no effect on the inhibition of CEM cell proliferation. Pretreatment of OKMS at 56 degrees C for 30 min did not affect its ability to activate neutrophils, implying that complement activation is not responsible for the neutrophil activation. Supernatants from OK432-stimulated mononuclear cells, as determined by enzyme-linked immunosorbent assays and radioimmunoassays, contained high levels of interleukin-8 (IL-8; 1567 +/- 145 pg/ml) and tumor necrosis factor (TNF alpha; 2105 +/- 152 pg/ml), low levels of leukotriene B4 (800 +/- 45 pg/ml) and IL-1 beta (180 +/- 22 pg/ml), but interferon gamma was not detectable. IL-1 beta, IL-8, and TNF alpha transcripts, undetectable in untreated monocytes, increased significantly after 30-60 min exposure to OK432. These results suggest that neutrophil-activating factors from monocytes or resident macrophages may play an important role in the OK432-induced neutrophil activation and antitumor activity.