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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We investigated the correlations between the biological effects of interferon-alpha (IFN-alpha) and clinical responsiveness in low-grade non-Hodgkin's lymphomas (NHL). In this disease, 40-50% of cases respond to IFN-alpha therapy. Patients with nodular NHL were selected for a phase II trial in which they were treated daily with 9 x 10(6) U of IFN-alpha 2a. Binding experiments with [125I]IFN-alpha 2a showed the presence of IFN-alpha receptors on tumor B-cells isolated from lymph nodes before therapy in 9 out of 10 patients. Receptor levels were not related to the subsequent clinical responses. However, no specific binding was detected in one patient who turned out to be unresponsive to IFN-alpha treatment. Single injections of IFN-alpha 2a before beginning the therapeutic protocol resulted in down-regulation of IFN-alpha receptors without change in their affinity in peripheral blood leukocytes from only patients who subsequently responded to therapy (4/10). In 4/5 non-responders and one patient displaying a minor response, receptor numbers did not decrease but Kd values rose markedly in all six cases. These results indicate that lack of in vivo IFN-alpha receptor down-regulation and reduced receptor affinity, as detected before therapy, may be correlated with failure of IFN-alpha therapy in nodular NHL.
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PMID:Correlation between the biological and therapeutic effects of interferon-alpha in low-grade nodular non-Hodgkin's lymphoma: lack of in vivo down-regulation and reduced affinity of IFN-alpha receptors in unresponsive patients. 182 51

We previously showed that the in vivo invasion of a squamous cell carcinoma induced by the intradermal injection of tumor cells was significantly delayed after the IFN-gamma-producing gene transfer to tumor cells. With respect to the mechanism of the delayed invasion, it was suggested that the IFN-gamma might inhibit the adhesion of the cells to extracellular matrices (ECM) and the subsequent locomotion. Thus, we examined the effect of IFN-gamma on the adhesion of Pam-T cells to ECM. The attachment of Pam-T cells to fibronectin (FN) was significantly higher than that to laminin (LN), collagen type I (COL I) or collagen type IV (COL IV) substrata. The attachment to FN was significantly enhanced specifically by the IFN-gamma-treatment of the cells, although the attachment to LN, COL I or COL IV was not altered by IFN-gamma. Neither IFN-alpha nor IFN-beta had any effect on the attachment of Pam-T cells to FN. When Pam-T cells were treated with IFN-gamma together with a neutralizable anti-IFN-gamma antibody, this enhancement was completely abolished. Moreover, the attachment of IFN-gamma-treated Pam-T cells as well as non-treated cells to FN was blocked by the synthetic peptide Arg-Gly-Asp-Ser (RGDS), but not by the control peptide Arg-Gly-Glu-Ser. Based on these results, we conclude that IFN-gamma specifically enhances the adhesiveness of Pam-T cells to FN substrata by the modulation of integrin activity.
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PMID:Modulatory effects of interferon-gamma on the fibronectin receptor function of squamous cell carcinoma cells in vitro. 183 57

Cells of the monocytic leukemia line, THP-1, mimic several of the functional characteristics of activated monocytes and macrophages following incubation in the tumor promoting agent, mezerein. The current paper explores the nature of the factors in medium conditioned by THP-1 cells which inhibit cell growth and the effects of interferon-gamma (IFN gamma) on their synthesis. Activity inhibiting the growth of the MDA-MB-415 mammary carcinoma line migrated in a pH range of 6.5 to 7.5 and could be resolved into 2 peaks, one corresponding to interleukin-1 beta (IL-1 beta) and the other with an apparent average molecular weight of 43 Kd. Antisera against tumor necrosis factor alpha and beta (TNF alpha and beta) and monocyte colony stimulating factor (M-CSF) had no effect on the 43 Kd inhibitor. IFN gamma enhanced the secretion of IL-1, but decreased the production of the 43 Kd inhibitor. The L-929 cell cytotoxicity assay and an ELISA were used to show that the amount of TNF alpha present was less in medium from IFN gamma treated cells. THP-1 cells also produced an IFN gamma repressed activity separating at pH 4.8 to 6.1 which inhibited the response of T cells to IL-1 in a thymocyte co-mitogenic assay. The inhibitors expressed by THP-1 cells may be comparable to the cytotoxic and cytostatic activities expressed by activated human monocytes and macrophages.
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PMID:Characterization of inhibitory activities secreted by THP-1 leukemia cells and regulation by interferon-gamma. 184 67

Interferon-alpha (IFN-alpha) production was investigated in whole-blood cultures of 66 bladder cancer patients and 65 control subjects. IFN synthesis was induced with Sendai virus, and IFN activity was assayed in FL cells challenged with vesicular stomatitis virus (VSV). The mean levels of the IFN-alpha produced were 5,724 +/- 2,288 IU/ml in the control subjects and 4,800 +/- 2,353 IU/ml in the bladder cancer patients. IFN-alpha production was significantly suppressed in the bladder cancer patients compared with that in the control subjects (P less than 0.05). The impairment in IFN-alpha production correlated with the tumor grade, and it was shown that the tendency toward decreased IFN-alpha production was closely associated with the advancement of the tumor stage. Our results suggested that the decreased IFN-alpha production may contribute to the disordered immunoregulation in bladder cancer patients.
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PMID:Impaired interferon-alpha production in whole-blood cultures from bladder cancer patients. 185 48

Adoptive immunotherapy in cancer has been essentially restricted to the use of lymphoid effector cells (NK, TIL, LAK) stimulated with IL-2. Differentiated macrophages represent another key effector population even more important for the immune control of cancer. We have shown that activated murine macrophages reduced primary tumors and experimental metastases. Human macrophages differentiated from circulating monocytes and activated with IFN gamma (MAK) were cytotoxic in vitro for a variety of tumor cell and caused regression of human tumors implanted in nude mice. A large scale technology has been developed for the generation of antitumor macrophages. These MAK cells (10(8) to 10(9] were injected in cancer patients in pilot clinical trials and were well tolerated. MAK treatment is technically feasible, clinically safe and presents several advantages compared to other immunotherapies.
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PMID:Adoptive immunotherapy of solid tumors with activated macrophages: experimental and clinical results. 188 50

We recently demonstrated that GH and interferon-gamma (IFN gamma) act in a similar manner to prime macrophages in vitro and in vivo for enhanced superoxide anion release. In this report we investigated the physiological role of the pituitary gland and GH in in vivo priming of resident peritoneal macrophages for the synthesis of tumor necrosis factor-alpha (TNF alpha) in vitro. Compared to normal rats, hypophysectomized animals had an 83% reduction in macrophage production of TNF alpha after in vitro stimulation with lipopolysaccharide. Sham operation had no significant effect on the ability of macrophages to secrete TNF alpha in response to lipopolysaccharide. Both native pituitary-derived porcine GH (48 micrograms/rat.9 days) and native pituitary-derived rat GH (96 micrograms/rat.9 days) more than tripled the in vitro production of TNF alpha by macrophages from hypophysectomized rats (342 and 358 vs. 112 U/mg protein for placebo-treated rats, respectively). Each of these preparations of GH also increased growth more than 6-fold in hypophysectomized rats (32 and 30 g vs. 5 g in placebo controls). Heat inactivation of native pituitary-derived porcine GH significantly reduced its in vivo ability to augment both TNF alpha synthesis by macrophages and body growth. Recombinant rat IFN gamma (2000 U/rat.9 days) more than tripled the production of TNF alpha by macrophages from hypophysectomized rats (343 vs. 112 U/mg protein). In contrast to its in vivo effects, addition of GH in vitro to macrophages from hypophysectomized rats did not prime these cells for the synthesis of TNF alpha, indicating an indirect mechanism of action for GH. To further test the biological relevancy of GH with respect to synthesis of TNF alpha, hemorrhagic necrosis of TNF alpha-sensitive murine methyl-cholanthrene-induced tumors was assessed in pituitary-intact mice. Native porcine GH (133 micrograms/mouse.7 days) significantly augmented both the necrosis to tumor ratio and the hemorrhage to tumor ratio. These findings establish the physiological relevance of the pituitary gland and GH in the priming of macrophages for TNF alpha synthesis.
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PMID:Hypophysectomy inhibits the synthesis of tumor necrosis factor alpha by rat macrophages: partial restoration by exogenous growth hormone or interferon gamma. 189 24

A panel of 12 squamous cell carcinoma of the head and neck (SCCHN) cell lines has been used to determine sensitivity of tumor cells to cytokines, tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), and interferon alfa (IFN-alpha) in vitro. Antiproliferative activity of these cytokines on squamous cell carcinoma of the head and neck monolayers was measured in a colorimetric MTT [3-(4,5-dimethylthiazol-2yl)-2,5-diphenyl tetrazolium bromide]-based assay. All 12 cell lines tested were sensitive to IFN-gamma, with the 50% inhibitory dose (ID50) ranging from 0.07 +/- 0.001 to 104 +/- 4.6 U/mL. The TNF-alpha showed antiproliferative activity on three cell lines at relatively high doses (ID50 from 55 +/- 4.1 to 847.10 +/- 10 U/mL), and IFN-alpha was growth inhibitory in only one line (ID50 = 1211 +/- 46.2 U/mL). The combination of IFN-gamma and TNF-alpha had a synergistic antiproliferative effect on eight cell lines and an additive effect on two cell lines. In two cell lines, the effect of the combination was equal to that of IFN-gamma alone. A combination of IFN-alpha and TNF-alpha resulted in cell growth inhibition in six of the seven lines tested, and this effect was synergistic. These in vitro studies indicate that combinations of IFN-gamma and TNF-alpha or IFN-alpha and TNF-alpha may be more growth inhibitory against squamous cell carcinoma of the head and neck and at lower doses than each of these cytokines used singly.
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PMID:Antiproliferative effects of cytokines on squamous cell carcinoma. 190 Jan 61

In vivo stimulation of pulmonary alveolar macrophages (PAMs) may enhance tumor cell cytotoxicity. A model using aerosolized gamma-interferon (gamma-IFN) and lipopolysaccharide (LPS) was developed to induce enhanced PAM activation in vivo in C57BL/6 mice. Mice received four doses of aerosol (2 doses/day) consisting of gamma-IFN (10(4) microU/mouse) and LPS (100 micrograms/mouse). Other groups received either gamma-IFN alone, LPS alone, or saline (control). Cells were harvested by bronchoalveolar lavage. Macrophage cell count demonstrated an increase in macrophage recruitment in the gamma-IFN and LPS group. PAMs were evaluated for in vitro cytotoxicity against B16-F10 melanoma cells. Treatment groups demonstrated enhanced cytotoxicity over controls, and the combination (gamma-IFN plus LPS) was significantly better in cell killing than either treatment modality alone (p less than or equal to 0.02). Activated PAMs selectively killed tumor cells, but did not kill the 3T3 fibroblast cell line. Peritoneal macrophages from mice treated by inhalational gamma-IFN + LPS were enhanced (indicating a systemic effect), but not to the same extent as PAMs. These studies suggest that inhalation of gamma-IFN + LPS can selectively enhance in vivo cytotoxicity of murine PAMs. This may potentially be applicable to human tumor management.
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PMID:Aerosolized gamma-interferon and lipopolysaccharide enhances cytotoxicity of murine pulmonary alveolar macrophages. 190 97

The host factors involved in the restriction of tumor growth were studied in nude mice transplanted with a cloned line of chronically human immunodeficiency virus (HIV)-infected U937 cells. HIV-infected and uninfected U937 cells exhibited the same growth patterns in culture. However, HIV-infected cells were not tumorigenic when injected subcutaneously in nude mice, whereas large solid tumors were observed in mice injected with uninfected U937 cells. Injection of nude mice with antibody to alpha/beta interferon (IFN-alpha/beta) enabled HIV-infected U937 cells to grow progressively in approximately 90 to 100% of mice. HIV-infected U937 cells formed solid tumors in the majority (60 to 90%) of either immunosuppressed (splenectomized, irradiated, and anti-asialo-GM1-treated) or genetically immunodeficient (bg/nu/xid) nude mice. In mice treated with antibodies to IFN-alpha/beta with established HIV-positive tumors, a direct correlation was found between p24 antigenemia and tumor size. Treatment of established HIV-positive U937 cell tumors with human IFN-alpha or mouse IFN-alpha/beta resulted in a clear-cut inhibition of both tumor growth and p24 HIV antigenemia. In contrast, treatment with tumor necrosis factor alpha markedly inhibited tumor growth but did not significantly decrease serum p24 levels. 3'-Azido-3'-deoxythymidine treatment did not affect either tumor growth or the levels of serum p24 antigen. These data indicate that endogenous IFN-alpha/beta is a crucial factor in the restriction of both tumor growth and p24 antigenemia in mice injected with HIV-infected tumor cells. Moreover, the results suggest that the development of HIV-1 p24 antigenemia in athymic immunosuppressed mice may represent an interesting in vivo model for anti-HIV therapy.
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PMID:Human immunodeficiency virus (HIV)-infected tumor xenografts as an in vivo model for antiviral therapy: role of alpha/beta interferon in restriction of tumor growth in nude mice injected with HIV-infected U937 tumor cells. 190 15

We have determined that interferon-alpha (IFN-alpha) and IFN-gamma inhibit the growth of a human breast tumor cell line, S4, in vitro. Cells were more sensitive to the antiproliferative effects of low-dose IFN-gamma than IFN-alpha. As the growth of the S4 cell line is enhanced by epidermal growth factor (EGF), we examined the effect of IFN on EGF-dependent growth of S4 cells. Cells plated in 2.5% serum alone failed to grow. EGF stimulated these cells to grow more than twofold. IFN substantially attenuated the EGF-stimulated growth of S4 cells. Binding of EGF to its receptor was unaffected by pretreatment of cells with IFN-alpha. However, a 24-h exposure of cells to IFN-gamma significantly increased the number of EGF receptors on S4 cells. Internalization of the EGF receptor was unaffected by IFN treatment. Binding remained elevated through 4 days of IFN-gamma exposure. Scatchard analysis of receptor binding data revealed that IFN-gamma increased the number of binding sites without changing the affinity of the receptor for its ligand. These results demonstrate that IFN inhibits EGF-stimulated growth of a breast tumor cell line and suggest that the antiproliferative effect of IFN may be due, in part, to its interaction with growth factor-initiated pathways.
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PMID:Interferon-induced modulation of epidermal growth factor-stimulated growth of a human breast tumor cell line. 190 41


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