Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

A murine monoclonal antibody (mAb), designated mAb 202, was generated using a human melanoma cell line, UCLASO-M14 as the immunogen. mAb 202 reacted with two (GM2 and GM3) of the four (GM2, GM3, GD2, and GD3) gangliosides expressed by M14. Several authentic monosialogangliosides, including GM4, GM3, GM2, GM1, GM1b, and sialylparagloboside were then tested for their binding to 202 mAb by the immune adherence inhibition assay, TLC-enzyme immunostaining, and enzyme-linked immunosorbent assay. All showed positive binding but in varying degrees. GM4 showed the strongest affinity. No significant differences of reactivity were observed between the sialic acid derivatives, N-acetyl and N-glycolyl, in these gangliosides. Disialogangliosides such as GD3, GD2, GD1a, and GD1b, trisialoganglioside GT1b, and neutral glycolipids including GlcCer, GalCer, LacCer, GbOs3Cer, GbOs4Cer, GgOs3Cer, GgOs4Cer, and nLcOs4Cer were all negative. These results indicate that the 202 mAb detects sialyl alpha 2----3Gal residue in the monosialoganglioside, irrespective of the internal structure. Since GM4 is not expressed by M14 cells, the terminal disaccharide (sialyl alpha 2----3Gal) in GM3 and/or GM2 must have been the epitope responsible for the generation of the antibody.
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PMID:Monoclonal antibody detects monosialogangliosides having a sialic acid alpha 2----3-galactosyl residue. 357 Dec 88

Theophylline-treated cells of the human melanoma line showed an increase in NK-sensitivity in vitro and a concomitant decrease in tumorigenicity and spontaneous metastasis in Balb/c nude mice. The MeWo cells were heterogeneous and contained related subpopulations which were cloned to produce two cell lines, one hypodiploid (Cd-16) and one hypotetraploid (Ct-1). Prolonged (3 months) or short-term (4 days) treatment of these cell lines with 1 mM theophylline markedly reduced the incidence and size of tumors in Balb/c nude mice early after s.c. injection and their ability to metastasize spontaneously to the lung was also reduced. The effect was much more pronounced with Cd-16 cells, which contain amplified DNA compared to Ct-1 cells which lack DNA amplification. Part of the tumor inhibition caused by theophylline was due to natural killer (NK) cells. Thus, in vivo treatment of nude mice with anti-asialo GM1, a procedure known to remove NK cells, partially reversed the inhibitory effects of theophylline on tumor formation and generation of metastasis by Cd-16 cells. Consistent with this observation theophylline treatment enhanced the in vitro NK sensitivity of Cd-16 cells four-fold whereas Ct-1 was enhanced only slightly. The data suggest that theophylline can act preferentially on certain tumor cell subpopulations to enhance their NK-sensitive phenotype and thereby inhibit their capacity to form tumors and to metastasize in nude mice.
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PMID:NK-mediated reduction of malignancy in human melanoma cells treated with theophylline. 366 24

Recombinant human interferon alpha A/D (alpha A/D) restored or augmented host defense systems against tumors in immunosuppressed mice. In normal C57BL/6 mice, inoculation of B16 melanoma F1 cells caused few pulmonary metastasis, whereas in mice pretreated with cyclophosphamide (CY) it caused a high incidence of pulmonary metastasis, leading to earlier death than in the normal mice inoculated with the same dose of the tumor. alpha A/D given after the CY treatment counteracted the deleterious effects of the CY treatment. Since such restorative activity was seen even against the subline of B16 F1 which had been made resistant to its direct antiproliferative effect, alpha A/D seems to exert its effect indirectly through host defense systems. However, this activity of alpha A/D in the mice pretreated with CY was abrogated by inoculation of anti-asialo GM1 serum but not by i-carrageenan. The CY treatment reduced NK activity, while alpha A/D given after the CY treatment restored or augmented the NK cell activity in lung cells and peripheral blood mononuclear cells, but not in spleen cells. These findings suggest that the restoration or augmentation of NK activity in the lung and/or peripheral blood might be the major factor leading to the antimetastatic activity of alpha A/D in the mice treated with CY.
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PMID:Restoration by recombinant interferon alpha A/D of host defense systems against tumor in immunosuppressed mice. 369 67

H-2+ and H-2- cells of B16 melanoma were established by repeated fluorescence-activated cell sorting. The H-2- line formed no metastasis in untreated C57BL/6 mice, whereas the H-2+ cells showed evidence of metastatic development. This difference was ascribed mainly to the increased susceptibility of H-2- cells to attack by natural effector mechanisms, particularly asialo GM1+ NK cells. After treatment with both anti-asialo GM1 serum and whole body irradiation (400 rad), numerous colonies of H-2- cells formed in the lung, whereas the metastasis was only marginally enhanced by irradiation and moderately by treatment with anti-asialo GM1 serum. With the H-2+ cells, treatment with each modality significantly increased the number of metastatic colonies. Therefore collaboration of asialo GM1+ NK cells and radiosensitive natural effectors seems to be the main mechanism involved in the synergistic effects on defense against H-2- cell metastasis, and to a lesser extent against H-2+ cell metastasis. Irradiation (1000 rad) to the right lung to abrogate the organ-associated defense increased the colonies, particularly in the H-2+ cells. On the other hand, treatment with anti-asialo GM1 serum increased colonization in the early phase of metastasis with H-2- cells and may have abolished asialo GM1+ NK cells capable of recognizing the reduced expression of H-2 antigens and eliminating H-2- cells in the blood-born phase. Natural defense mechanisms probably exert suppressive effects on the metastasis of H-2+ cells, mainly in the organ-associated phase after extravasation.
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PMID:Synergistic defense system by cooperative natural effectors against metastasis of B16 melanoma cells in H-2-associated control: different behavior of H-2+ and H-2- cells in metastatic processes. 371 64

Murine peritoneal macrophages harvested 3-4 days after IP injection of vaccinia virus lysed S91-melanoma tumor cells in vitro; enhanced tumoricidal activity was measured with effector macrophages prepared 5-6 days after vaccinia virus infection. Treatment of virus-elicited macrophages prepared from DBA/2 mice with anti-asialo-GM1 antiserum, anti-Thy 1.2 antiserum or anti-Iad antiserum in the presence of complement so that cells sensitized with antibodies were lysed, did not reduce the measured level of tumoricidal activity indicating that macrophages [Ia(-); asialo GM1(-)] and not natural killer cells [asialo GM1(+); Thy 1.2(+/-)] or T-cells [Thy 1.2(+)] were responsible for mediating the lysis of S91-melanoma tumor cells. When incubated with virus-elicited macrophages but not thioglycollate-elicited macrophages, the ability of S91-melanoma tumor cells. to synthesize DNA was completely blocked. The results of these experiments support the view that one aspect of antitumor immunity enhanced during immunotherapy with vaccinia virus is the activation of macrophages which have cytolytic as well as cytostatic effects on melanoma tumor cells.
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PMID:Infection of DBA/2 or C3H/HeJ mice by intraperitoneal injection of vaccinia virus elicits activated macrophages, cytolytic and cytostatic for S91-melanoma tumor cells. 373 Dec 5

The effect of anticoagulant drugs on formation of experimental tumor metastases after i.v. inoculation of BL6 melanoma or Lewis lung carcinoma (3LL) cells was studied in mice with stimulated or depressed natural killer (NK) cell activity. When mice were treated with anticoagulants (warfarin or heparin) or when NK cell activity was stimulated by polyinosinic-polycytidylic acid, significant antimetastatic effects were observed; these effects were substantially augmented when the treatments were combined. However, when NK reactivity of mice was suppressed by anti-asialo GM1 serum or cyclophosphamide, the antimetastatic effects of warfarin and heparin were diminished or completely abrogated. In some experiments, the anticoagulants had a partial effect in mice treated with cyclophosphamide or anti-asialo GM1 serum and reduced at least to control levels the number of metastases in these mice. This limited antimetastatic effect of the anticoagulants was mostly due to the action of residual NK cells, since it was completely abrogated in mice whose NK cell activity was more completely suppressed by two injections of anti-asialo GM1 serum. In addition, the low NK reactivity of 3-week-old C57BL/6 or beige mice was sufficient to support the antimetastatic effects of the anticoagulants, effects that completely disappeared after these mice were treated with anti-asialo GM1 serum. Augmentation or abrogation of the antimetastatic effects of heparin after polyinosinic-polycytidylic acid or anti-asialo GM1 treatments, respectively, was observed in athymic nude and allogeneic BALB/c mice that received i.v. injections of B16F1 melanoma cells, indicating that the antimetastatic effects of anticoagulants depend on the presence of active NK rather than T-cells. Furthermore, adoptive transfer of NK-competent but not NK-depleted syngeneic spleen cells restored the antimetastatic effect of heparin in cyclophosphamide-treated mice. Warfarin treatment increased the elimination of radiolabeled BL6 melanoma cells from the lungs of normal mice, and the rate of tumor cell elimination was further potentiated when NK cell activity was stimulated by polyinosinic-polycytidylic acid. In contrast, after anti-asialo GM1 treatment, warfarin had no effect on the survival of i.v. administered tumor cells. Covering of YAC-1 or 3LL tumor cells with fibrin after in vitro exposure with fibrinogen and thrombin substantially protected them from the in vitro cytotoxic action of NK or lymphokine-activated killer cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Augmentation of the antimetastatic effect of anticoagulant drugs by immunostimulation in mice. 380 83

The structures involved in the recognition of melanoma cells by nonspecific cytotoxic T lymphocytes (CTL) activated in mixed lymphocyte culture were investigated with monoclonal antibodies (MAb) which blocked this anomalous killer (AK) function. Of over 2000 MAb raised against melanoma cells, only three inhibited killing; one of these, an IgMk termed Leo Me13, was investigated in detail. In antibody-binding studies using a large range of cultured tumor cells, it was shown that Leo Me13 was relatively specific for melanoma cells. Of more importance, Leo Me13 inhibited conjugate formation between AK cells and melanoma target cells by 60 to 80% and caused an eight- to 10-fold reduction in killing. The MAb did not immunoprecipitate protein from melanoma cells surface-labeled with 125I, and thin-layer chromatography followed by immunoblotting of the separated glycolipids from melanoma cells indicated that the epitope was on acidic glycolipids migrating between GM1 and GD1a; moreover, treatment of melanoma cells with neuraminidase resulted in complete loss of binding of Leo Me13 but not of other anti-melanoma antibodies which did not inhibit AK cell-mediated lysis. Other melanoma-reactive MAb of the same isotype as Leo Me13 did not block killing of melanoma cells, but one documented antibody, R24, an IgG3 with specificity for the ganglioside GD3, was found to inhibit this function. These data suggest that the AK cells recognize and bind to melanoma cells by a secondary "lectin-type" receptor for a carbohydrate moiety.
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PMID:Identification of a structure on human melanoma cells recognized by CTL exhibiting anomalous killer cell function. 387 98

Ten human melanoma cell lines (HMCL) were tested for their ability to grow subcutaneously in nude mice. Using a standard inoculum, the HMCL could be characterized by their highly, fairly or poorly xenografting phenotype. These phenotypes were stable and the phenotype of one HMCL was recovered within cell clones derived from it. The role of nude mice natural defences in the expression of HMCL xenografting phenotypes was studied. Sublethal whole body irradiation and silica pretreatment of recipients enabled poorly tumourigenic HMCL to grow in most animals without affecting their splenic NK activity. Admixture of BCG or MDP encapsulated in liposomes with highly tumourigenic HMCL resulted in the abrogation of tumour growth in naive nude mice. The long lasting abrogating of NK activity in vivo by treatment with anti-asialo-GM1 anti-serum did not enhance the growth of a poorly tumourigenic HMCL. The HMCL were found to be resistant to in vitro murine NK activity. These results showed that the expression of the HMCL xenografting phenotypes could be controlled by the nude mice natural defences. NK cells did not seem to be largely involved whereas macrophages might be good candidates as anti-xenograft effectors.
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PMID:Tumourigenic phenotypes of human melanoma cell lines in nude mice determined by an active antitumour mechanism. 388 12

The authors studied the role of natural killer (NK) cells in spontaneous metastasis of murine intraocular melanoma by transplanting murine B16 melanoma cells into the anterior chamber of the eye in syngeneic C57BL/6 mice and determining the number of metastatic lung tumor colonies after 40 days. Depletion of NK activity by anti-asialo GM1 serum dramatically enhanced metastasis and augmentation of NK activity by interferon inhibited it. The strong correlation between host NK activity and intraocular melanoma metastasis indicated that NK cells have an important role in spontaneous metastasis of intraocular melanoma.
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PMID:Role of natural killer cells in intraocular melanoma metastasis. 395 68

Mice treated with anti-asialo GM1 (asGM1) serum exhibited increased formation of experimental metastases in lung and liver after i.v. challenge with B16 melanoma or Lewis lung carcinoma. This increased metastasis formation coincided with decreased splenic NK activity and increased survival of i.v. injected radiolabeled tumor cells. In contrast, the injection of mice with the pyran copolymer maleic anhydride divinyl ether (MVE-2) augmented NK activity in the spleen and significantly depressed the formation of experimental metastases in the lungs and liver. However, a single or double administration of anti-asGM1 antiserum to MVE-2-pretreated mice failed to inhibit the immunoprophylaxis associated with MVE-2 administration, although it did decrease splenic NK activity and also increased the survival of i.v.-injected radiolabeled tumor cells. To address the mechanism for this dichotomy, we examined NK activity not only in the spleen but also in the blood, lungs, and livers of MVE-2-treated mice. Levels of NK activity in the lungs and liver were several-fold higher than those observed in spleen and blood. However, MVE-2-augmented NK activity in lung and liver was more resistant to depletion by the standard regimen of anti-asGM1 treatment than was NK activity in blood and spleen, and required two high-dose administrations of a higher titered antiserum for depletion of the augmented response. This high-dose regimen removed all detectable NK activity from the lung and liver, and concomitantly eliminated the metastasis-inhibiting effect of MVE-2. These data are consistent with a role for organ-associated NK cells in inhibiting metastasis formation during the extravasation and/or early postextravasation phases of the metastatic process. The results also suggest that biologic effects of NK activity in spleen and blood can be dissociated from those mediated by NK activity in other organs by use of different treatment regimens with anti-asGM1 serum. Finally, because NK activity in target organs can be augmented to an even greater extent than in the blood and spleen by at least some biologic response modifiers (BRMs), organ-associated NK activity should be considered as a possible mechanism for the therapeutic effects of BRM treatment.
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PMID:Role of organ-associated NK cells in decreased formation of experimental metastases in lung and liver. 398 7


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