Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

IFN-alpha and IFN-gamma were found to enhance monocyte-mediated activity by acting on both tumor cells and monocytes. The addition of IFN-alpha or IFN-gamma enhanced the monocyte-mediated cytotoxicity of the human melanoma cell line, A375, as well as the human colon carcinoma cell line, HT-29. However, IFN-alpha generally induced more monocyte-mediated lysis of the A375 cells, whereas IFN-gamma induced more monocyte-mediated lysis of the HT-29 cells. These differences are, in part, due to the direct effects of the IFN on the tumor cells. Pretreatment of A375 cells with either IFN-alpha or IFN-gamma significantly enhanced their susceptibility to lysis by untreated monocytes. However, only IFN-gamma pretreatment of HT-29 cells enhanced the lysis of these cells by untreated monocytes. Differences were also observed in the activation of monocytes by IFN-alpha vs IFN-gamma with respect to their ability to induce soluble cytotoxic factors. We found that the addition of IFN-gamma and tumor cells (either the A375 or HT-29 cells) to monocytes induced TNF release, whereas IFN-alpha or IFN-gamma alone or IFN-alpha and tumor cells had no effect. Despite its presence, TNF did not appear to play a major role in the killing of either tumor cell line. However, inhibitors of H2O2-myeloperoxidase system suppressed both IFN-alpha- and IFN-gamma-induced cytotoxicity of the HT-29 cells. Thus IFN-alpha and IFN-gamma can induce both similar and distinct mechanisms of cytotoxicity in monocytes. In addition, both IFN types can increase the susceptibility of tumor cells to lysis by untreated monocytes, although sensitivity to IFN-alpha vs IFN-gamma may vary with different tumor cell lines. These differences observed between IFN-alpha and IFN-gamma on monocytes and tumor cells could have important implications for the clinical use of these cytokines.
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PMID:IFN-alpha and IFN-gamma can affect both monocytes and tumor cells to modulate monocyte-mediated cytotoxicity. 215 15

Intratumoral heterogeneity has been proposed as a possible basis for immunotherapeutic failure when tumor-specific agents such as tumor infiltrating lymphocytes (TIL) are employed for cancer therapy. To examine this issue, highly specific oligoclonal MHC class I-restricted cytolytic TIL grown in bulk culture from patient 397 were used to immunoselect a TIL-resistant variant tumor from the autologous cultured melanoma line 397-mel. Four cycles of immunoselection produced tumor 397-R4, a variant completely resistant to 397 TIL but not to allogeneic LAK cell lysis in 4-h 51Cr release assays. By flow microfluorometry analysis, this tumor variant had not lost MHC molecules, adhesion molecules, or a variety of tumor-associated Ag expressed by the parent tumor but showed decreased expression of many Ag examined. Failure of 397-R4 to cold target inhibit TIL lysis of 397-mel suggested that cell-surface modification was at least one mechanism causing TIL resistance. The inherent lysability of 397-R4 was equal to 397-mel, as confirmed by lectin-dependent cellular cytotoxicity, lysis by non-MHC restricted allogeneic TIL, and lysis by a second line of 397 TIL grown independently from tumor 397. Treatment of 397-R4 with IFN-alpha or IFN-gamma, +/- TNF-alpha for 72 h before cytolytic assays enhanced TIL lysis of this target slightly, and enhanced surface expression of MHC class I and II molecules and the adhesion molecule ICAM-1. The resistant phenotype of 397-R4 was evident in all clones of 397-R4 examined and has been maintained in serial culture for over 13 mo and through passage in nude mice, suggesting that such stable tumor variants may provide an in vivo escape mechanism from specific immune reagents such as TIL. Evolving patterns of TIL culture clonality over time, as well as the spontaneous emergence of different clones in two long term TIL cultures grown under identical conditions from the same source of cryopreserved tumor, were documented by analyzing TCR gene rearrangements and suggest that TIL from different culture passages or lines may be used to overcome resistant tumor subpopulations.
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PMID:Immunoselection of a human melanoma resistant to specific lysis by autologous tumor-infiltrating lymphocytes. Possible mechanisms for immunotherapeutic failures. 216 May 3

Anti-tumour effector cells were generated through 4 days culture of normal C57BL/6 splenocytes in a medium containing concanavalin A supernatant and then fractionated with Dolichos biflorus lectin (DBA) into DBA+ (agglutinable with DBA) and DBA- (non-agglutinable with DBA) cells. The DBA- cells, infused intravenously into mice together with B16 melanoma cells, or adoptively transferred into mice 3 days after the injection of B16 cells, caused a marked decrease in the number of lung nodules, while the DBA+ cells exerted no effect. On the other hand, the DBA+ cells exhibited higher cytolytic activity in vitro than the DBA- cells in short-term 51Cr-release assays. Then, we analysed the mechanism of the strong anti-tumour activity of DBA- cells in vivo. We found that DBA- cells showed higher response to recombinant interleukin-2 (rIL-2) than DBA+ cells and proliferated very well with a small amount of IL-2. In addition, DBA- cells adhered more strongly to lung endothelial cells than DBA+ cells in response to rIL-1 or rTNF. Furthermore, DBA- cells produced larger amounts of macrophage activating factor (MAF) including IFN-gamma when cultured with B16 melanoma. Taken together, our results show that DBA- cells are effective in reducing experimental pulmonary metastases not only by the direct lytic activity but also by the indirect killing activity through the activated macrophage.
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PMID:Anti-tumour efficacy of mouse spleen cells separated with Dolichos biflorus lectin (DBA) in experimental pulmonary metastasis of B16 melanoma cells. 217 66

Highly purified interleukin 1 (IL 1) obtained from stimulated human monocytes appeared to be growth inhibitory and cytocidal for a human melanoma cell line, A375. Although IL 1 did not have an immediate cytolytic effect, with time in culture the growth of the target cells was irreversibly inhibited. The cells eventually lysed and decreased markedly in number; the IL 1 effect can therefore be said to be cytocidal. IL 1 activity could not be separated from the cytocidal activity by a variety of chromatography procedures by using conventional and high-performance liquid chromatography (HPLC). The A375 melanoma cell line was also sensitive to another human cytokine alpha-lymphotoxin (alpha-LT) derived from a human B cell line. IL 1 also appeared to be partially growth inhibitory and cytocidal for a LT-sensitive mouse fibroblast cell line, L929; but not for LT-resistant cells, including a subline of L929; a human epithelial carcinoma cell line, HeLa; a human osteosarcoma cell line, HOS; and a mouse SV40-transformed kidney cell line, TU5. However, the LT-sensitive mouse fibroblast cell line, L-M, was resistant to IL 1. Therefore, the cytocidal activity of IL 1 only partially overlapped the target cell selectivity of alpha-LT. Although natural IFN-alpha and recombinant IFN-beta were appreciably growth inhibitory for the A375 cell line, natural and recombinant IFN-alpha and recombinant IFN-beta and IFN-gamma exhibited little cytocidal activity. Purified IL 1 did not have any antiviral activity, and conversely, IFN and alpha-LT were not co-mitogenic for thymocytes. Furthermore, by ELISA and radioimmunoassays, antibodies against human alpha-LT, tumor necrosis factor, and IFN-gamma did not react with IL 1, indicating that IL 1 is antigenically distinct from these other cytokines. These in vitro results suggest that IL 1 may play a role in host defense against some tumors as a cytocidal factor.
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PMID:Human interleukin 1 is a cytocidal factor for several tumor cell lines. 241 93

Corynebacterium parvum-activated macrophages (M phi), purified by adherence, were cytotoxic for B16 melanoma cells maintained in vitro. Pretreatment of the melanoma cells for 18 hr with interferon-alpha/beta or -gamma (IFN-alpha/beta or -gamma) caused a reduced susceptibility of the B16 cells to M phi-mediated cytotoxicity. The IFN-induced protective effect of B16 cells from cytotoxic M phi was found to be dose dependent. In addition, IFN-gamma was more protective than IFN-alpha/beta. The protective effect observed with partially purified IFN was reproduced by using highly purified IFN-alpha/beta or recombinant IFN-gamma. Monoclonal antibodies to IFN-gamma neutralized the protective effect provided by IFN-gamma. These results show that the susceptibility of a tumor cell line to killing by activated M phi can be altered by IFN pretreatment.
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PMID:Interferon-mediated protection of B16 melanoma cells from cytotoxicity by activated macrophages. 242 5

The ability of interferons to modulate the antigenic phenotype of tumor cells may involve alterations in the transcription, translation, membrane expression and shedding of Major Histocompatibility Complex (MHC) and Tumor Associated Antigens (TAAs). In the present study we have investigated possible mechanisms by which recombinant human interferons, IFN-alpha, -beta and -gamma, alter the antigenic profile of long- and short-term human melanoma cultures. IFN-alpha and -beta induced similar changes in the synthesis, expression and shedding of two TAAs, a HMW-MAA and a Cyt-MAA, in the established melanoma cell line Colo 38, whereas IFN-gamma exerted a differential effect on these melanoma associated antigens. Moreover, IFN-gamma was relatively more effective than IFN-alpha or -beta in upregulating the synthesis, expression and shedding of class I MHC antigens. At the same time a dramatic differential effect of the interferons was observed with class II MHC antigens. IFN-alpha or -beta induced a modest increase in the synthesis and expression of these antigens, whereas IFN-gamma was greater than 3-fold more active in inducing the synthesis and expression of DR/DP antigens and greater than 4- and greater than 10-fold more effective in increasing the synthesis and expression, respectively, of DQ antigens. Analysis of the levels of cytoplasmic mRNA for the DR-alpha and DQ-beta genes indicated no significant difference between IFN-alpha, beta or -gamma treated cells suggesting that IFN-gamma enhancement of the synthesis of DR and DQ antigens may occur at a posttranscriptional level. In the case of a newly established human melanoma cell line (MG-3) IFN-gamma enhanced the synthesis but not the expression of DR antigens and did not alter either the synthesis or expression of DQ antigens. Our studies indicate that the effects of interferons on the antigenic phenotype of melanoma cells will vary depending on the type of interferon employed, the antigen monitored and the target cell studied. In addition, it is also apparent that some of the biosynthetic steps involved in regulating the synthesis, expression and shedding of antigens may be coordinately regulated in some melanoma cells, whereas these processes may be under independent control in other melanoma populations.
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PMID:Regulation of the antigenic phenotype of human melanoma cells by recombinant interferons. 243 32

In this study, murine interferons (IFNs) were employed separately and in combination at subeffective and effective antitumor concentrations in a mouse B-16 melanoma system. Murine IFN-gamma (MuIFN-gamma) was demonstrated to be approximately 20 times more potent than MuIFN-alpha and MuIFN-beta in this system. Potentiation was observed with combinations of both subeffective and effective concentrations of MuIFN-gamma with MuIFN-alpha or MuIFN-beta. The level of potentiation was observed to increase from undetectable to two-fold to fourfold with three increasing IFN concentrations. Thirty percent of the mice treated for 14 days with 332 U/day MuIFN-gamma plus 7,500 U/day MuIFN-alpha survived apparently tumor-free for 100 days. Forty percent of the mice treated for 14 days with 332 U/day MuIFN-gamma plus 7,500 U/day MuIFN-beta survived apparently tumor-free for 100 days. All control mice died by day 41. The results are consistent with the suggestion that combination IFN therapy may have some use in the control of at least some tumors in humans.
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PMID:Quantitation of in vivo potentiation resulting from combined interferon therapy: antitumor effect against B-16 melanoma in mice. 243 61

Herpes simplex virus (HSV) infections can enhance the progression of neoplastic diseases. Since macrophages can be activated to become tumorilytic and may figure prominently in host defense against cancer, the ability of HSV to modify macrophage-mediated tumoricidal functions was evaluated. Murine peritoneal macrophages treated with HSV could not be activated to a tumoricidal state by mouse recombinant gamma-interferon (IFN-gamma). Addition of HSV 4 h after treatment with IFN-gamma, at a time when the macrophages are fully committed to developing the cytotoxic phenotype, blocked macrophage-mediated lysis of syngeneic melanoma target cells. This inhibition of activation and cytotoxicity was not due simply to uptake of virus particles, because treatment with heat-inactivated HSV at 4-h posttreatment with IFN-gamma had no effect. In addition, HSV did not undergo a productive infection within macrophages, suggesting that the observed inhibitory activity might be due to a virus-induced product. In this regard, treatment of macrophages with recombinant alpha-interferon suppressed the activation of these cells by IFN-gamma, suggesting that virus-induced alpha-interferon may be mediating all or part of the suppressive activity. These studies suggest that enhancement of tumor progression following HSV infection may be related to the virus-induced suppression of macrophage-mediated tumoricidal activity.
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PMID:Herpes simplex virus-induced suppression of macrophage-mediated tumoricidal activity in murine macrophages. 243 19

The requirements for interferon (IFN)-induced priming of murine peritoneal macrophages for cytolysis of tumor cell lines of distinct histological origin were investigated. Lysis of B16 melanoma targets required exposure of elicited macrophages to recombinant murine gamma interferon plus lipopolysaccharide (LPS) together, while sequential treatment of macrophages with IFN-gamma then LPS resulted in lysis of P815 mastocytoma targets. The kinetics of macrophage activation by IFN-gamma and LPS for lysis of P815 and B16 melanoma targets varied considerably, 8 h being sufficient for P815 targets but 24 h being required for B16 targets. Pretreatment of the macrophages with the antibiotic polymyxin B was able to inhibit completely the induction of tumor lysis of B16 targets but not of P815 targets. In addition, IFN-alpha/beta was able to prime macrophages for lysis of P815 targets but not of B16. Finally, the kinetics of priming macrophages with IFN-gamma for lysis of B16 targets had a profound effect on the subsequent exposure time requirement for LPS. The results indicate that the induction of murine macrophage-mediated tumor cytotoxicity can vary considerably depending on the amount and type of interferon used, the presence of a second signal, and the type of tumor target used.
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PMID:Differential expression of murine macrophage-mediated tumor cytotoxicity induced by interferons. 243 58

The control of expression of human class II MHC genes has been studied in lymphoid and melanoma cells. Specific unmethylation of all restriction sites nearby the promoter regions has been detected in all cell lines and tissues studied, irrespective of their ability to express class II MHC products. The main functional role of DNA methylation appears, on the contrary, to be the regulation of a fraction of the nucleotide polymorphism of class II MHC genes. Constitutive expression of these genes can be modified by recombinant IFN-gamma and by the demethylating agent 5-azacytidine. Both the modifiers differentially regulate the levels of class II MHC and invariant chain products. In melanoma cells IFN-gamma derepresses transcription of a 1.2-Kb HLA-DR alpha mRNA, but does not affect the levels of a 0.8-Kb HLA-DR alpha specific mRNA. These molecular changes are triggered by IFN-gamma through a protein-synthesis-dependent pathway.
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PMID:Regulation of the expression of class II genes of the human major histocompatibility complex in tumor cells. 244 40


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