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)

The lipid pattern of thirteen human melanoma tumors from various tissues were investigated. In seven of the tumors, an estimate was given about the proportion of malignant melanocytes to the total cell population, and a reverse correlation was determined between the proportion of malignant cells in these tumors and their neutral lipid content. The phospholipids did not show any modification, nor did the cholesterol in the cancerous tissues. The ganglioside pattern was found to be similar in all analyzed samples, with GM3, GM2 and GD3 as major components, although no correlation was found between the malignant level and the ganglioside content of the tumors.
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PMID:Lipid composition of human malignant melanoma tumors at various levels of malignant growth. 43 39

R24 is a mouse IgG3 monoclonal antibody that reacts with the ganglioside GD3 expressed by melanoma cells and other cells of neuroectodermal origin (e.g. adrenal medulla). Antitumour activity of R24 was demonstrated in initial phase I and pilot trials, but treatment was limited by urticaria at cumulative doses of 400 mg/m2. A trial exploring intensification of the dose of R24 was conducted in eight patients. Planned doses of R24 antibody were 800 and 1200 mg/m2 over 6-8 days by continuous i.v. infusion. All patients received concomitant therapy with hydroxyzine hydrochloride and cimetidine to minimize urticaria. One patient developed anaphylaxis, after which no further therapy was given. All patients developed peripheral blood lymphopenia and marked decreases in serum complement values during treatment, suggesting depletion of two possible effector mechanisms of the antitumour effects of R24. A vascular leak syndrome, manifested by weight gain, oedema and hypotension, was evident in seven patients during the initial 24-36 h of treatment. Serum sickness syndrome was observed in six of seven evaluable patients between days 5 and 8, coincident with the onset of the human anti-globulin response to R24. One patient given 1200 mg/m2 had a minor response (38% reduction in pelvic nodes) lasting 12 months. There was no detectable increase (by immunohistochemical staining) in deposition of R24 within tumour sites at doses used in this trial compared to that observed at doses of 240 and 400 mg/m2. The maximum tolerated dose was 800 mg/m2. Dose-limiting toxicity was manifest as reversible hypertension with end-organ symptoms (chest pain or visual field defects) in patients treated with a dose of 1200 mg/m2.(ABSTRACT TRUNCATED AT 250 WORDS)
Melanoma Res 1992 Dec
PMID:Treatment with high dose mouse monoclonal (anti-GD3) antibody R24 in patients with metastatic melanoma. 129 83

There is increasing evidence that cell-surface gangliosides play a role in tumor growth, progression and metastases. In order to determine the frequency of ganglioside GD3 in patients with metastatic malignant melanoma for further therapeutic trials, GD3 ganglioside expression was determined in 119 tissue samples. Of these melanomas, 93% (111/119) were R-24-positive, which indicates the value of this diagnostic marker for melanoma. To study the structural epitopes of gangliosides, 10 ganglioside antibodies with defined specificities and affinities were tested on over 100 fresh-frozen tissue specimens of human normal and melanoma tissues. All the antibodies tested recognize the ganglioside GD3, but vary in their cross-reactivity with other gangliosides. According to their epitope specificity, they can be divided into 5 groups. For example, the antibodies Z-21 and A-4 react like the previously established MAb R-24 with gangliosides GD3 and GQlb, and one MAb (Q-4) detects all gangliosides containing 2 connected sialic acids (GD3, GD2, GDlb, GTlb, GQlb). Specificity on TLC does not always correlate with specificity to melanoma tissues and vice-versa. For example, MAb A-4, which recognizes only GD3 and GQlb on TLC, shows no specific reactivity on tissues. Furthermore, antibodies with the same ganglioside specificity do not have the same staining pattern on human tissues. For example, MAb Z-21, which is directed against the same gangliosides as MAb R-24 on TLC, does not cross-react with as many neuroectodermal tissues as MAb R-24. Because of their distinct properties, some of these antibodies may be even more useful for immunodiagnosis and immunotherapy of malignant melanoma than MAb R-24.
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PMID:Immunorecognition of different ganglioside epitopes on human normal and melanoma tissues. 137 99

Cell-surface gangliosides have immunomodulatory effects that are presumed to play a role in tumour growth, progression, metastasis and therapy. To study the epitopes of gangliosides on human malignant melanomas and to search for monoclonal antibodies (Mabs) with superior immunological effector functions, 19 ganglioside antibodies were established. Specificity and affinity of nine antibodies of IgG3 isotype were evaluated by enzyme linked immunosorbent assay and thin layer chromatography with a panel of purified gangliosides. All antibodies recognised the ganglioside GD3, but their epitope specificity divided them into five groups. Their affinity constants for ganglioside GD3 ranged from 4.7 x 10(6) to 2.3 x 10(8), with 2 x 10(7) for Mab R-24. Two antibodies possessed a higher affinity for GD2 than for GD3. The functional properties of the antibodies were investigated in vitro. Differences in the degree of tumour lysis by complement fixation correlated with the affinity constants. Every ganglioside antibody differed in epitope recognition, affinity and cytotoxicity. Therefore some of these antibodies might even be more useful in the immunotherapy of malignant melanoma than Mab R-24.
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PMID:Immunorecognition of ganglioside epitopes: correlation between affinity and cytotoxicity of ganglioside antibodies. 138 91

GM2 is usually significantly elevated in human melanoma cells. The lysosomal hydrolase beta-hexosaminidase A (Hex A), is an isoenzyme required for terminal GalNAc hydrolysis from intact GM2 to GM3. The objective of the present studies is to determine if the elevated levels of gangliosides, particularly GM2, correlate with the activity of Hex A in cultured melanoma cells. The Hex A activity in 13 melanoma cell lines ranged from 26%-88.3% There was a inverse correlation between GM2 nmole/g and Hex A activity (r = -0.48; p less than 0.003). An inverse correlation (p less than 0.03) occurred between GD2 nmole/g and Hex A activity. There was an inverse correlation (r = -0.53; p less than 0.05 and r = -0.51; p less than 0.05, respectively) between the ratio of substrate/product (GM2/GM3) and (GD2/GD3) and Hex A activity. These results indicate that the level of GM2 in melanoma is inversely correlated with the level of activity of Hex A.
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PMID:Ganglioside GM2 levels in human melanoma cells: inverse correlation with lysosomal beta-hexosaminidase A activity. 138 84

In order to elucidate some of the factors that determine the characteristic expression of gangliosides in malignant melanoma and neuroblastoma the levels of ganglioside synthases (glycosyltransferases) were determined in a panel of cell lines from those tumors that exhibited a wide range of ganglioside composition. Sialyltransferases (GM3, GD3, GD1a, and GT1b synthases), N-acetylgalactosaminyltransferases (GM2 and GD2 synthases), and galactosyltransferase (GM1 and GD1b synthases) were analyzed in crude membrane preparations from these cells. The results confirmed the importance of GM3 and GD3 synthases in determining the prominence of the a (GM3 to GT1a) or b (GD3 to GQ1b) biosynthetic pathways. The overall ganglioside composition in cells was found to be dependent on the relative levels of specific enzymes acting sequentially or in competing pathways. In general, the pattern and levels of transferases correlated with the actual ganglioside content of the cell line, although several important discrepancies were noted. For example, in cell lines containing high amounts of GD2 ganglioside, the level of the preceding enzyme in the pathway (GD3 synthase) was unexpectedly low. Thus, the high GD2:GD3 ratios characteristic of most neuroblastomas result from low levels of GD3 synthase as well as high levels of GD2 synthase. In other cell lines, GD3 synthase was completely absent, resulting in the synthesis of GM2, but not GD2, by N-acetylgalactosaminyltransferase I, as would be expected. It was concluded that different glycosyltransferases play key roles in determining glycolipid expression in different cell types.
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PMID:Glycosylation pathways in the biosynthesis of gangliosides in melanoma and neuroblastoma cells: relative glycosyltransferase levels determine ganglioside patterns. 139 96

Gangliosides may play an important role in the proliferation and spread of human malignant melanoma. Because the frequency of metastases in uveal and cutaneous melanoma differs, it is possible that they may express different gangliosides. We analyzed the ganglioside profiles of primary uveal melanoma in 14 cases and of cutaneous melanoma metastasis in 19 cases. In cutaneous melanoma, GM3 ranged from 4.2% to 74.6% and GD3 from 22.1% to 91.8% of total lipid-bound sialic acid. GM2 (found in 13 of 19 cases, ranging from 0.5% to 11.7%), GD2 (11/19, 0.5%-22.0%) and 9-O-acetyl-GD3 (13/19, 0.5%-12.6%) were also frequently observed. By contrast, in 11 cases of uveal melanoma, GM3 was > 90%, GD3 was < 10%, GM2 was < 1.1%; neither GD2 nor 9-O-acetyl-GD3 were detected. The ganglioside profiles of these uveal melanomas were virtually identical to those of normal melanocytes obtained from foreskins. Histological examination of these 11 biopsies showed a monomorphous cell composition, but neither infiltration of lymphocytes or melanophages nor cell necrosis was observed. In 3 other cases, GD3 was increased to 19.5%-46.0%. Histological examination of these 3 biopsy specimens showed at least 2 populations of tumor cells that were separable based on morphological grounds, and mononuclear inflammatory cells interspersed among the tumor cells. An increase in GD3 appears to be related to tumor polyclonality and infiltration of the tumor by lymphocytes and macrophages. These results suggest that ganglioside expression of uveal melanoma is associated with host immune responses to the tumor. Furthermore, the low metastatic capacity of uveal melanoma, in contrast to the high metastatic rate of cutaneous melanoma, may be a result of its differentiated ganglioside expression, which is strikingly similar to that of normal melanocytes.
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PMID:Variations in the ganglioside profile of uveal melanoma correlate with cytologic heterogeneity. 142 27

Human melanoma provides a model to study malignant transformation and tumor progression. Expression of ras oncogenes in cultured normal human diploid melanocytes has induced a subset of phenotypic traits that are characteristic of malignant melanoma cells, including altered morphology, anchorage independence, induction of class II MHC antigens, up-regulation of the ganglioside GD3, and chromosomal abnormalities. However, other characteristics of melanoma, such as loss of expression of adenosine deaminase-binding protein and tumorigenicity, were not observed. We report here that melanocytes infected with a retrovirus containing the viral Ha-ras oncogene underwent complete transformation, acquiring all phenotypic characteristics of malignant melanomas observed in vivo. Transformation occurred in a sequential manner and was associated with spontaneous chromosomal instability. Cytogenetic analysis of transformed melanocytes indicated that the earliest structural chromosomal abnormalities were isochromosomes 6p and 9q followed by complete loss of chromosome 1p, all common karyotypic abnormalities described in human melanomas. The findings suggest that these chromosome regions which are deleted or relatively deficient may contain genes that are critical for the initiation and progression of the melanoma phenotype.
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PMID:Malignant transformation of human melanocytes: induction of a complete melanoma phenotype and genotype. 143 53

The expression of gangliosides in non-malignant tissues (epidermis and pigmented nevus) and neoplastic lesions (melanoma, squamous cell carcinoma [SCC] and basal cell carcinoma [BCS]) of the human skin was analyzed immunohistochemically and biochemically to characterize the features associated with malignancy. Immunohistochemical staining with an anti-II3NeuAc-LacCer (GM3) monoclonal antibody (M2590 mAb) and an anti-II3(NeuAc)2-LacCer (GD3) mAb (R24) showed the expression of the gangliosides GM3 and GD3 to vary among the different tissues. M2590 clearly stained epidermal keratinocytes and the tumor cells of BCC and SCC, and strongly stained melanocytes and melanoma cells. In contrast, R24 did not stain epidermal keratinocytes and only faintly stained SCC cells, while it clearly stained BCC cells, and intensely stained melanocytes and melanoma cells. GM3 showed a similar level of staining among the tissue specimens, while the level of GD3 staining was quite variable among the tumor specimens. Biochemical analysis by thin-layer chromatography (TLC) with resorcinol staining and TLC immunostaining with either M2590 or R24 showed both GM3 and GD3 to be commonly expressed by both the normal and malignant skin tissues, including SCC. There was no close correlation between the intensity of immunohistochemical staining and the biochemically detected amounts of these gangliosides. This may have been partly due to the so-called cryptic expression of cell membrane gangliosides. Our results thus suggest that analysis of the tumor-associated expression of gangliosides requires several methods, since the sensitivity of the methods used may have a considerable effect on the diagnostic value of gangliosides as skin cancer markers.
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PMID:Common phenotypic expression of gangliosides GM3 and GD3 in normal human tissues and neoplastic skin lesions. 146 93

We developed a sensitive method for detection of glycosphingolipid (GSL) antigen(s) on the cell surface. As a model of GSL antigen, ganglioside GD3 was used. An IgM monoclonal antibody (DSG-1) specific for ganglioside GD3 was preincubated with standard inhibitor liposomes containing ganglioside GD3. Then carboxyfluorescein-entrapped indicator liposomes containing ganglioside GD3 and complement were added. Release of the marker from the indicator liposomes was specifically inhibited by inhibitor liposomes. The assay system was simple, sensitive, reproducible, and semiquantitative. Pg to ng of ganglioside GD3 could be detected. Furthermore, ganglioside GD3 on the cells was investigated with SK-MEL-28 human melanoma cell line and human red blood cells (HRBC). When SK-MEL-28 melanoma with ganglioside GD3 was used as an inhibitor, specific inhibition was observed. However, HRBC without ganglioside GD3 showed no significant inhibition. The marker release was 50% inhibited by 1.4 x 10(6)SK-MEL-28 melanoma cells/ml. The amount of ganglioside GD3/melanoma cell was estimated to be at least 1.1 x 10(-14) g from the standard curve made with the liposomes containing 10% epitope density of ganglioside GD3. This assay system may be useful for detection of GSL antigen on the cell.
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PMID:Sensitive detection of ganglioside GD3 on the cell surface using liposome immune lysis assay. 148 37


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