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Biomedical subjects

D L Longo

Publications and source records attributed to D L Longo.

At least 109 records · Page 6Linked to original sources
PubMed1996

Antitumor effects of human recombinant interleukin-1 alpha and etoposide against human tumor cells: mechanism for synergism in vitro and activity in vivo.

Recombinant human interleukin 1 alpha (rh IL-1 alpha) and etoposide (VP-16) synergize for direct growth inhibition of several human tumor cell lines in vitro. Our previous studies demonstrated that VP-16 increased the number of membrane-associated IL-1 receptors (IL-1Rs) and also enhanced the internalization of receptor-bound rh IL-1 alpha. The purposes of this study were to test our hypotheses that these events were critical to the synergy between rhIL-1 alpha and VP-16, to determine whether rhIL- 1 alpha and VP-16 synergize to increase superoxide (SO) anion radical production in vitro since SO anion has been implicated in the toxic effects of IL-1, and to investigate the antitumor efficacy of the combination against tumors in vivo. A375/C6 melanoma cells and OVCAR-3 ovarian carcinoma cells were tested with IL-1 receptor antagonist (IL-1 ra) before exposure to rhIL-1 alpha, VP-16 and rhIL-1 alpha plus VP-16. The synergistic or antagonistic effects were assessed by MTT assay. SO production was measured by reduction of cytochrome C. Athymic female mice bearing the A375/C6 melanoma were treated by rhIL-1 alpha, VP-16, and rhIL- 1 alpha+VP-16. The antitumor effects were evaluated by quantitating tumor growth and survival time. Pretreatment with the IL-1ra abrogated the synergistic effects of rhIL-1 alpha and VP-16. The production of SO radical by A375/C6 cells was increased 2.5 fold by the combination of rhIL-1 alpha and VP-16, and the addition of exogenous SOD blocked the synergy between rhIL-1 alpha and VP-16. However, when A375/SOD15 cells which over-expressed manganese superoxide dismutase (MnSOD) after MnSOD cDNA transfection were exposed to rhIL-1 alpha and VP-16, in vitro antagonism was observed. In vivo studies demonstrated that the combination of rhIL-1 alpha and VP-16 delayed tumor growth better than either agent alone, although long-term survival was not improved because of substantial toxicity. Our results suggest that the synergistic antitumor effects of IL-1 alpha and VP-16 may be due to IL-1R modulation and increased internalization of IL-1-IL-1R complex by VP-16 treatment, as well as to a subsequent increase in SO anion radical production from the tumor cells exposed to both drugs. Thus, the combination of IL-1 alpha and VP-16 might prove useful for the treatment of malignant disease in vivo, if the increased toxicity can be reduced or managed.

Animals↗
PubMed1996

Treatment of relapsed Hodgkin's disease.

High-dose chemotherapy with peripheral stem cell or bone marrow transplantation has quickly become accepted as the standard of care for patients with Hodgkin's disease (HD) who are chemotherapy induction failures or who relapsed after a short initial remission. The majority of studies would indicate that high-dose therapy is most effective when used early. As a result of promising pilot studies, high-dose therapy is also being used more frequently in patients at initial relapse after a long remission. Future approaches to improve the efficacy of high-dose therapy in marrow transplantation will require more effective chemotherapeutic agents. Recent studies with the taxanes and camptothecins suggest that these agents may be useful (Devizzi et al, 1994). Biological approaches with CD30 based antibodies and immunotoxins may also be helpful adjuncts to conventional-dose debulking regimens. Radio-immunoconjugates may augment the delivery of myelo-ablative doses of radiation therapy selectively to tumours. When patients relapse after high-dose therapy, there has been no standard approach to management. However, single agent chemotherapy (e.g. weekly low-dose vinblastine) has the potential for significant palliation, occasionally for prolonged periods.

Antineoplastic Agents↗
PubMed1996

Chemotherapy alone in the treatment of patients with early stage Hodgkin's disease.

Studies employing chemotherapy in early stage Hodgkin's disease suggest that this approach is at least comparable to radiation therapy in treatment outcome. Since the long-term disease-free survival in early stages approaches 90%, it is unlikely to further improve these results substantially. Thus, the major goal is the reduction of toxicity. The future choice of therapy will be influenced by the long-term toxicity of these approaches which has to be monitored carefully.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1996

Ly-49 G2+ NK cells are responsible for mediating the rejection of H-2b bone marrow allografts in mice.

NK cells can mediate the specific rejection of bone marrow but not solid tissue allografts in lethally irradiated mice. NK cells are also responsible for the phenomenon of "hybrid resistance' in which F1 hybrid H-2 heterozygous mice can reject parental H-2 homozygous bone marrow grafts. Ly-49C and Ly-49 G2 are markers identified on subsets of NK cells. While Ly-49C+ NK cells have been demonstrated to mediate the specific rejection of H-2d bone marrow allografts, the role of the Ly-49 G2+ NK subset is unclear because depletion of this subset in vivo did not affect splenic NK activity against tumor targets. Through bone marrow transplantation typing studies, we demonstrate that Ly-49 G2+ NK cells complement Ly-49C+ NK cells in that they specifically mediate the rejection of H-2b bone marrow allografts in lethally irradiated mice. In support of this, depletion of the Ly-49C+ NK subset in vivo also enhanced the ability of the mice to reject H-2b bone marrow cells suggesting that the depletion was augmenting the ability of the Ly-49 G2+ NK cells to reject the marrow allografts. Depletion of Ly-49 G2+ NK cells in F1 hybrid mice abrogated their ability to reject parental H-2b but not H-2d bone marrow grafts. Therefore, Ly-49 G2 denotes a subset of NK cells that appears to play a critical role in the recognition of H-2b bone marrow cells in allogeneic and F1 hybrid mice.

Animals↗
PubMed1996

Immunotherapy for non-Hodgkin's lymphoma.

Humanized monoclonal anti-CD20 has impressive activity and radioimmunoconjugates. Targeting the same molecule has led to prolonged remissions in both moderate and myeloablative doses. Idiotype-based vaccination has produced an apparent prolongation in disease-free and overall survival in selected patients with follicular lymphoma. Adoptive cellular therapy is active in the setting of Epstein-Barr virus-induced lymphoma after allogenic bone marrow transplantation. Improvements in each of these developments are readily in sight.

Animals↗
PubMed1996

Differential in vitro and in vivo antitumor effects mediated by anti-CD40 and anti-CD20 monoclonal antibodies against human B-cell lymphomas.

The antitumor effects of CD40 and CD20 monoclonal antibodies (mAbs) were compared on various human B-cell lymphomas by using both in vitro and in vivo assays. Anti-CD40 directly inhibited the proliferation of human B-cell lymphomas in vitro, whereas anti-CD20 exerted no inhibitory effects on the growth of any lymphoma tested. These lymphomas were then injected into immunodeficient mice to examine the antitumor efficacy of these unconjugated mAbs in vivo. This xenogeneic model was used in the evaluation of various potential therapeutic agents against human cancers in an in vivo setting. Surprisingly, in contrast to its negligible effects on lymphoma growth in vitro, anti-CD20 was more efficacious than anti-CD40 in promoting the survival of mice bearing some but not all lymphoma lines. To determine whether the antitumor effects of these mAbs were direct or indirect in vivo, we concurrently treated tumor-bearing mice with mAbs to the murine Fc receptor to block antibody-dependent cell-mediated cytotoxicity (ADCC). When these neutralizing antibodies against Fc receptors were administered at the same time as mAb treatment, the antitumor effects of anti-CD20 in vivo were completely abrogated, whereas anti-CD40 treatment, although also diminished, still provided significant antitumor effects. These results indicate that the in vivo antitumor activity of the murine anti-human CD20 mAb was primarily due to ADCC by murine effector cells, which may not translate into comparable effects in humans. By contrast, anti-CD40 may be of potential clinical use in the treatment of lymphomas in humans because of its additional direct anti-proliferative effects. The results also demonstrate a possible difficulty in accurately evaluating the potential clinical efficacy of murine antibodies against human tumors in a human/mouse model system. Murine monoclonal anti-human antibodies may produce greater effects in human/mouse xenogeneic models, in which they are more likely to elicit host effector systems than when used in vivo in humans.

Animals↗
PubMed1996

Endocrine effects of IL-1 alpha and beta administered in a phase I trial to patients with advanced cancer.

Previous primate and rodent studies suggested that interleukin-1 alpha (IL-1 alpha) caused changes in the secretion of pituitary, adrenal, thyroid, and gonadal hormones, as well as acute-phase reactants. Plasma samples were obtained after IL-1 alpha and beta treatment in cancer patients to document the changes in endocrine function suggested by the animal models. Successive groups of patients were treated at IL-1 alpha doses of 0.01, 0.03, 0.1, 0.3, and 1.0 microgram/kg, given daily as a 15-min intravenous bolus. IL-1 beta was given at 0.1 microgram/kg by the same route and time course. After the first dose of IL-1, statistically significant elevations of a.m. and p.m. cortisol, growth hormone (GH), and prolactin (PRL) occurred. Thyroid-stimulating hormone (TSH) and C-reactive protein (CRP) were elevated by the sixth treatment day. Testosterone decreased significantly in male patients. Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) were more variable but decreased in most patients. The changes in cortisol, GH, PRL, TSH, CRP, FSH, LH, and testosterone resolved after treatment and did not result in clinically apparent endocrinopathies. Bolus doses of IL-1 alpha and beta cause significant changes in many endocrine laboratory parameters and influence the in vivo activities of multiple homeostatic endocrine functions in human beings.

Acute-Phase Proteins↗
PubMed1996

Influence of interleukin-2 regimens on circulating populations of lymphocytes after adoptive transfer of anti-CD3-stimulated T cells: results from a phase I trial in cancer patients.

The adoptive transfer of anti-CD3-stimulated T killer (T-AK) cells was tested with different bolus and infusional interleukin-2 (IL-2) regimens, and anti-CD3 stimulation procedures to determine immunologic and antitumor effects in patients with a variety of advanced cancers. Indium-111 labeling was used to observe traffic patterns of the infused T-AK. Autologous peripheral blood mononuclear cells were obtained by leukapheresis. Cyclophosphamide (300 mg/m2) was given to most patients immediately after leukapheresis. The harvested cells were activated ex vivo with anti-CD3 overnight or for 4 days, at which time cells were reinfused and an IL-2 regimen was begun. Treatment was repeated 28 days later. This treatment regimen induced significant increases in leukocytes, lymphocytes, and eosinophils in patients in most treatment cohorts. Circulating lymphocytes were predominantly CD3+ T cells with preferential expansion of the CD8+ subset. Patients receiving cells stimulated in vitro for 4 days had significant T-cell lymphocytosis with either infusional or bolus plus infusional IL-2 regimens. T-cell viability was decreased in culture after a second 4-day stimulation with anti-CD3 at day 28; this decrease could be prevented by adding IL-2 to the culture media. Cells stimulated overnight required both bolus and infusional IL-2 to show an atypical lymphocytosis in vivo. Overnight-stimulated T-AK did not show decreases in in vitro viability at the day 28 restimulation. Indium-III-labeled cells trafficked to the liver, spleen, and bone marrow. No increase in uptake was observed in tumor deposits. There were 2 patients with partial responses, 5 with minor responses, 19 with stable disease, and 88 with progressive disease. The length of in vitro anti-CD3 stimulation, and the dose and timing of IL-2 administration in vivo results in different circulating leukocyte populations after adoptive T-AK infusion. Generally, the CD8+ T-cell subset was preferentially expanded by this treatment approach. Repeated ex vivo stimulation with anti-CD3 may cause cell death.

Adolescent↗
PubMed1996

Adoptive immunotherapy involving recombinant human M-CSF and R24 anti-melanoma antibody induces human T-cell infiltration into human melanoma xenografts.

Directed motion toward and infiltration of tumor masses by effector cells is essential for successful adoptive immunotherapy. A human/SCID mouse chimeric system was used to examine whether an antitumor antibody and recombinant human monocyte colony-stimulating factor (rhM-CSF) could promote human T-cell infiltration of a human tumor in vivo. Fourteen days after subcutaneous injection of the human melanoma cell line M-14 into SCID recipients, several adoptive immunotherapy regimens were initiated using activated human T cells, an anti-melanoma monoclonal antibody (MoAb) (R24), and rhM-CSF. Effects on tumor growth and human T-cell infiltration into the tumor were assessed. Compared with other treatment groups, only mice treated with the combination of activated human T cells, anti-tumor MoAb, and rhM-CSF demonstrated a significant cellular infiltrate in the melanoma. Immunohistology demonstrated human T cells present in the tumor up to 7 days after injection. Groups treated with rhRANTES or rmGM-CSF in place of rhM-CSF exhibited markedly less human T-cell infiltration. Additionally, only mice treated with human T cells, R24, and rhM-CSF demonstrated a significant antitumor response in vivo. This model suggests that activated human T cells can be specifically targeted to in vivo tumor sites by combined treatment with an antitumor antibody and rhM-CSF.

Animals↗
PubMed1996

A phase I randomized study of subcutaneous adjuvant IL-2 in combination with an autologous tumor vaccine in patients with advanced renal cell carcinoma.

We performed a prospective, randomized study to determine whether subcutaneous administration of interleukin-2 (IL-2) in combination with an autologous renal cell vaccine is feasible and can potentiate antitumor immunity. Seventeen patients with metastatic renal cell carcinoma underwent surgical resection with preparation of an autologous tumor cell vaccine. Patients were vaccinated intradermally twice at weakly intervals with 10(7) irradiated tumor cells plus bacillus Calmette-Guérin, and once with 10(7) tumor cells alone. Patients were randomized to one of three groups: no adjuvant IL-2, low-dose IL-2 (1.2 x 10(6) IU/m2), or high-dose IL-2 (1.2 x 10(7) IU/m2). IL-2 was administered subcutaneously on the day of vaccination and the subsequent 4 days. Immune response was monitored by delayed-type hypersensitivity (DTH) response to tumor cells as compared with normal autologous renal cells. Sixteen of 17 patients received vaccine therapy. Four patients developed cellular immunity specific for autologous tumor cells as measured by DTH responses; two had received no IL-2 and two had received high-dose IL-2. There were two partial responses (PR) noted, both in patients who received high-dose IL-2. One responding patient was DTH(+) and one was negative. A third patient who was DTH(+) after vaccination with no IL-2 had a dramatic PR after receiving IL-2 subcutaneously in a subsequent protocol. Prospective testing of response to recall antigens indicated that only 5 of 12 tested patients were positive, including both clinical responders. These data suggest that subcutaneously administered adjuvant IL-2 does not dramatically augment the immunologic response to autologous renal cell vaccines as determined by the development of tumor-specific DTH response.

Adjuvants, Immunologic↗
PubMed1996

Use of the polymerase chain reaction technique to determine c-myc expression in follicular center cell lymphoma.

We determined, in a semiquantitative fashion, the level of expression of c-myc in 18 follicular center cell lymphomas and five non-neoplastic lymph nodes using reverse transcription and the polymerase chain reaction technique (RT-PCR). With this method, RNA is extracted from lymph node specimens and reverse-transcribed to produce cDNA, which is then amplified using primers specific for c-myc sequences that span introns, thus precluding amplification of genomic DNA. Amplified products are compared with beta2-microglobulin sequences co-amplified in each case as a control for the quality of RNA extracted, RT, and PCR amplification. Using cell lines derived from Burkitt's lymphomas, the RT-PCR method yielded results equivalent to standard Northern blot analysis yet required smaller quantities of tissue. The c-myc transcripts were detected in all lymphoma cases studied (seven high, 11 low expression) and in all non-neoplastic lymph nodes. High or low c-myc expression was based on comparison with non-neoplastic lymph nodes. We conclude that the RT-PCR method is a sensitive, reliable method for measuring gene expression in lymphoma tissues and may be useful for studying the role of c-myc in follicular lymphomas.

Adult↗
PubMed1996

JAK2 is constitutively associated with c-Kit and is phosphorylated in response to stem cell factor.

Stem cell factor (SCF) interacts with the receptor tyrosine kinase c-Kit and has potent effects on hematopoiesis. We have examined the role of JAK2 in the SCF signal transduction pathway. JAK2 and c-Kit were constitutively associated, and treatment with SCF resulted in rapid and transient tyrosine phosphorylation of JAK2. Incubation of cells with JAK2 antisense oligonucleotides resulted in significant decreases in SCF-induced proliferation. These data suggest that JAK2 plays a role in SCF-induced proliferation.

Animals↗
PubMed1996

Phase I study of subcutaneously administered interleukin-2 in combination with interferon alfa-2a in patients with advanced cancer.

PURPOSE: Although high-dose interleukin-2 (IL-2) can produce durable remissions in a subset of responding patients with renal cell carcinoma (RCC), this occurs in the setting of significant toxicity. The purpose of this study is to define the maximum-tolerated dosage (MTD) of IL-2 and interferon alfa-2a (IFN alpha-2a) that can be administered chronically on an outpatient basis. PATIENTS AND METHODS: Fifty-three patients with advanced cancer of variable histology with good prognostic features were treated in six cohorts. Patients in cohorts one through five received IL-2 (1.5 or 3.0 x 10(6) million units (mU)/m2) Monday through Friday and IFN alpha-2a (1.5 or 3 x 10(6) mU/m2) daily for a 4-week cycle. In cohort six, IFN alpha-2a was given three times a week. Immunologic monitoring, including serum levels of soluble IL-2 receptor (sIL-2R) and neopterin, flow cytometry, and natural killer cell (NK) activity, were measured. Patients were evaluated for toxicity, response, and survival. RESULTS: Almost all patients developed grade I/II toxicities commonly associated with cytokine therapy. Symptoms were most severe with the first treatment of each week. Dose-limiting toxicities included grade III fatigue, hypotension, and creatinine elevations. The MTD was 1.5 mU/m2 daily x 5 given subcutaneously repeated weekly for IL-2 and 1.5 mU/m2 daily subcutaneously (dose level 3) for IFN. Six of 25 assessable patients with RCC (24%) achieved a partial response (PR), including four of eight patients who were previously untreated. There were no objective responses in patients with other tumors, including 12 melanoma patients. CONCLUSION: IL-2 and IFN alpha-2a can be given with tolerable toxicities on an outpatient basis and shows significant activity in patients with metastatic RCC.

Adult↗
PubMed1996

Lymphomas.

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Antineoplastic Agents↗
PubMed1996

Induction of interleukin 1 receptor antagonist after interleukin 1 therapy in patients with cancer.

The interleukin 1 receptor antagonist (IL-1ra) is a naturally occurring molecule that shares homology with IL-1alpha and IL-1beta and binds competitively to IL-1 receptors. Serum concentrations of IL-1ra were measured by ELISA in patients enrolled in Phase I clinical trials of IL-1alpha and IL-1beta given by 15-min infusion. Pretreatment levels of IL-1ra were <1500 (mean, 453 +/- 57) pg/ml. IL-1ra levels were increased in some patients within 1 h of completing the IL-1 infusion. By 2 h after infusion, serum levels of IL-1ra had increased dramatically, and they remained stable 4 h after infusion. There was evidence that peak IL-1ra levels were IL-1 dose dependent. Seven patients treated with IL-1alpha had IL-1ra levels that exceeded 1 microgram/ml. In contrast, serum levels of IL-1 declined rapidly and were undetectable 1 h after completing IL-1 infusion in most patients receiving <1.0 microgram/kg. IL-1ra levels remained slightly elevated over pretreatment values in serum obtained 18-24 h after IL-1 infusion, but there was no evidence for progressive accumulation over repeated days of therapy. A similar pattern of IL-1ra elevation was observed after the last IL-1 infusion on day 6. This study shows that cancer patients produce 2 to >6 log incremental increases in IL-1ra rapidly following treatment with IL-1, a response that has implications for the design of future clinical trials with IL-1 and with agents thought to induce IL-1 production.

Humans↗
PubMed1995

In vivo antitumor effects of unconjugated CD30 monoclonal antibodies on human anaplastic large-cell lymphoma xenografts.

CD30 is a M(r) 120,000 surface antigen identified originally by the Ki-1 monoclonal antibody (moAb) against primary and cultured Reed-Sternberg cells present in Hodgkin's disease and anaplastic large-cell lymphomas (ALCLs). Examination of two ALCL cell lines (Karpas 299 and Michel) demonstrated cell surface expression of CD30. Incubation of these lymphomas with two anti-CD30 moAbs that recognize the ligand-binding site (M44 or HeFi-1) resulted in significant growth inhibition in vitro, with significant decreases in cell viability. Another anti-CD30 moAb, Ber-H2, which recognizes a determinant not involved in ligand binding, had no effect on ALCL growth in vitro. When these human ALCL lines were transferred i.v. into mice with severe combined immune deficiency, the mice developed extensive metastasis in the s.c., brain, or eye tissues. The treatment of mice with either M44 or HeFi-1 anti-CD30 moAbs resulted in significant increases in survival, with some mice remaining disease free for more than 100 days. Thus, anti-CD30 treatment is efficacious for CD30+ ALCL cell lines in vivo, and unconjugated anti-CD30 moAbs may be of potential clinical use.

Adult↗