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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been proposed that benign nevi that fail to differentiate normally may undergo stepwise growth and morphologic changes resulting in progression toward dysplastic nevi, which in some cases progress into malignant melanoma. In this study, we sought to determine the relationship between production of endogenous growth factors and the appearance of chromosomal abnormalities in cultured nevi and melanomas. Newly established cultures from 8 nevi with benign histology and 6 malignant melanomas, and 2 malignant melanoma cell lines were studied. Assays for mitogenic growth factors were based on stimulation of [3H]thymidine incorporation into DNA in Hs0294 malignant melanoma cells, produced by serum-free conditioned medium from nevus or melanoma cultures. Karyotypes were examined in cultures of an equivalent passage. Three of the 8 nevus cultures were mitogen-negative and displayed normal karyotypes; one nevus culture was mitogen-positive and had a normal karyotype, although the biopsied tissue demonstrated histologic evidence of benign melanocytic proliferation; one was mitogen-negative initially, but had an extra chromosome 8 in 2 of 50 cells; 3 were mitogen-positive and chromosomally abnormal. Each of the cultures in this latter group exhibited reciprocal translocation (rcpt) as the only identifiable abnormality [rcpt(6;15), rcpt(10;15), rcpt(15;20)], or a constitutional rcpt(4;5). Thus, there was direct correlation between growth factor production and chromosome abnormality in 6 of 8 benign nevus cultures. In the newly established melanoma cultures there was also concordance between growth factor and chromosomal status; conditioned media from 4 of 6 were mitogen-positive by at least one assay, and all 4 of the mitogen-positive cultures had chromosomally abnormal cell populations. Of the 2 melanoma cultures negative for growth factors, one was also negative for chromosome abnormality; the other had chromosomal change consisting of increased polyploidy. Both melanoma cell lines had abnormal karyotypes and were mitogen-positive. Though numerous chromosome changes were noted in the karyotypically abnormal melanoma cells, 6 of the 8 cultures exhibited abnormalities in chromosomes 1, 6, and/or 7. These data suggest that steps in the progression from benign nevi toward dysplastic nevi or malignant melanoma include: proliferation resulting from altered production of endogenous mitogenic growth factors; and development of specific chromosomal abnormalities.
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PMID:Growth factor and cytogenetic abnormalities in cultured nevi and malignant melanomas. 374 55

A monoclonal antibody, Leo Mel 3, raised against a melanoma cell line (LiBr), binds to a carbohydrate determinant of cell surface gangliosides, the simplest of which is GD3. This monoclonal antibody was screened for by its capacity to block the recognition and lysis of the melanoma cells by cytotoxic T-lymphocytes with anomalous killer cell function, illustrating a novel approach for identifying monoclonal antibody to biologically relevant tumor-associated antigens. Leo Mel 3 reacted selectively with melanoma cells by indirect immunofluorescent and immunoperoxidase staining; it reacted with tissue from all primary and metastatic melanoma tested, and it bound to cells from all but one of six cultured melanoma cell lines. Leo Mel 3 did not react with a variety of carcinomas, lymphomas, leukemias, and other neuroectodermal tumors, nor with adult or fetal tissues, except fetal liver. Very weak staining of cutaneous basal melanocytes was noted in a minority of skin sections, and 50 to 80% of melanocytes in four of seven benign nevi showed weak to moderate reactivity. The antibody was relatively specific for human adherent melanoma cells, since it did not bind to the adherent murine B16 melanoma line nor to a nonadherent human melanoma cell line (PMC-22). Expression of the Leo Mel 3-defined antigen was unrelated to changes in cell cycle. When cells from an adherent melanoma cell line were detached and maintained briefly in suspension culture, the cells became markedly less reactive with Leo Mel 3 and, after readherence to plastic, they rapidly reexpressed higher levels of the ganglioside antigen; since Leo Mel 3 prevented attachment and growth of melanoma cells in vitro, a functional role for the ganglioside is suggested in cell adhesion and metastasis. Differentiation of melanoma cells with dimethyl sulfoxide, retinoic acid, and theophylline resulted in a marked and selective increase in the amount of Leo Mel 3-defined antigen, together with an increase in the target cell binding ability of these cells, assessed by cold target competition assays using anomalous killer cells.
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PMID:Fluctuations in the expression of a glycolipid antigen associated with differentiation of melanoma cells monitored by a monoclonal antibody, Leo Mel 3. 379 Dec 9

Malignant melanoma developed in an apparently benign nevus four months after therapy with levodopa in a patient with Parkinson's disease. This case is reported, and previous reports of this possible causal relationship are reviewed. Although this and previously reported cases are not inconsistent with the unpredictable and variable natural history of malignant melanoma, it seems prudent to clinically monitor pigmentary lesions in patients receiving levodopa therapy. Biopsy specimens of suspicious lesions in these patients should be examined histologically, and if malignancy is found, alternate therapies for treatment of parkinsonism should be considered.
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PMID:Development of malignant melanoma after levodopa therapy for Parkinson's disease. Report of a case and review of the literature. 401 96

Estrogen and progesterone binding studies in a series of 22 melanocytic lesions from 14 patients with the dysplastic nevus syndrome were done using a fluorescent estrogen and progesterone binding technique. Melanocytic lesions from these patients, including primary cutaneous melanomas, dysplastic nevi, and benign nevi, contained large numbers of estrogen and progesterone binding cells. Comparison is made to a series of control intradermal nevi that had little or no detectable estrogen or progesterone binding. Increased hormonal binding, and possibly responsiveness, is seen in melanomas, melanoma precursor lesions such as dysplastic nevi and congenital nevi, as well as benign nevi from patients with the dysplastic nevus syndrome.
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PMID:Estrogen and progesterone receptors in melanocytic lesions. Occurrence in patients with dysplastic nevus syndrome. 403 21

The classification proposed by Clark et al. of cutaneous malignant melanoma into 3 groups: lentigo maligna melanoma (LMM), superficial spreading melanoma (SSM) and nodular melanoma (NM) was based on a correlation between histology and biological behaviour. Many studies have shown different growth rates, prognosis and incidence of antecedent benign nevi for each of these groups, confirming that each is a separate entity with its own biological behaviour. The recent proposal that acral lentiginous melanoma (ALM) is a distinct clinico-histological entity, however, is more difficult to accept. Many melanomas on acral locations are histologically intermediate between SSM and ALM and the epidemiological value of classifying ALM as an entity separate from SSM is doubtful.
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PMID:Biological behaviour of cutaneous malignant melanomas. 404 27

Monoclonal antibodies, directed against functionally different lymphocyte subsets, were applied on frozen sections of primary malignant melanomas and benign nevi. Positive reaction was identified by means of an immunoperoxidase method. It was found that lymphocytic infiltrate underneath and in between malignant melanoma is composed of approximately equal numbers of OKT4 positive helper and OKT8 positive suppressor/cytotoxic T cells. The majority of these lymphocytes also expressed HLA-Dr antigen, indicating an activated state. In addition HLA-Dr, OKT6 positive dendritic cells were present in the infiltrate and between the melanoma cells. Finally, melanoma cells expressed demonstrable amounts of HLA A, B, C antigens, whereas benign nevi did not. It is concluded that all ingredients for a successful immune reaction against primary malignant melanoma are on hand. This finding is in agreement with the relatively frequent occurrence of partial or even complete regression of primary malignant melanoma of the skin.
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PMID:In situ analysis of the mononuclear cell infiltrate in primary malignant melanoma of the skin. 621 41

We have used immunoprecipitation to test tumor biopsies and normal adult and fetal human tissues for p97, a tumor-associated protein. Five of nine melanoma biopsies contained p97 in low to very high levels. Three of seven non-melanoma tumors contained p97, but in smaller amounts. No p97 was detected in any of the normal adult tissues examined. The protein was, however, observed in samples of fetal colon and umbilical cord, and in one sample of fetal lung. One of two benign nevi contained high levels of p97, whole on benign angiofibroma was negative. We conclude that the presence of p97, in levels detectable by our method, appears to be characteristic of certain neoplastic and fetal tissues.
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PMID:Analysis of normal neoplastic human tissues for the tumor-associated protein p97. 627 10

An immunohistochemical investigation regarding the presence of S-100 protein in benign and malignant, primary and metastatic melanocytic tumors is reported. The studied series consisted of 15 benign nevi, 3 blue nevi, 4 juvenile melanomas, 1 balloon cell nevus, 30 primary malignant melanomas of skin, mucous membranes and conjunctiva and 30 metastatic malignant melanomas. The immunohistochemical analysis showed positive staining for S-100 protein within the majority of the tumor cells in all benign tumors examined, except the balloon cell nevus, as well as in all the primary and metastatic malignant melanomas, including low-differentiated epitheloid or spindle-cell types without demonstrable melanin pigment. The results indicate that S-100 protein is a valuable marker for melanocytic tumors, especially in the fairly frequent dilemma of malignant melanoma presenting as a solitary non-pigmented metastasis of uncharacteristic light-microscopic appearance, and without known primary tumor. A characterization and quantification of the S-100 protein immunoreactivity in 5 metastatic malignant melanomas is presented. Using immuno-electrophoresis, the presence of 3 antigenic S-100 determinants was demonstrated within homogenates from the malignant melanomas, including the previously characterized S-100 A (alpha/beta) and S-100 B (beta/beta), and suggesting the presence of a hitherto undescribed variant of S-100 protein, possibly consisting of 2 alpha-subunits. Using rocket immuno-electrophoresis, the amount of S-100 protein was estimated.
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PMID:S-100 protein in melanocytic tumors. An immunohistochemical investigation of benign and malignant melanocytic tumors and metastases of malignant melanoma and a characterization of the antigen in comparison to human brain. 649 75

The roles of constitutional factors and benign nevi in causation of malignant melanoma were examined in a case-control study of 511 patients and 511 matched controls in Western Australia. The strongest risk factor was the number of palpable benign nevi on a subject's arms. Compared to the risk of melanomas for persons having no palpable nevi on the arms, the relative risk of melanoma was 2.0 for persons with 1-4 nevi, 4.0 for persons with 5-9 nevi, and 11.3 for persons with 10 or more nevi (P less than .0001). Of the several pigmentary traits known to have associations with melanoma, inability to tan was the most important. Susceptibility to sunburn and hair color also had significant effects that were independent of tanning ability; however, after these traits were controlled, measured skin color and eye color had no additional effects. A reduced risk of melanoma was observed in persons having two or more Southern European grandparents [odds ratio (OR) = 0.39; P = .025]. Persons of Celtic origin did not have a significantly increased risk (OR = 1.18). Possession of one or more affected blood relatives was related to an increased risk of melanoma (OR = 2.69; P less than .0001). The effects of pigmentary traits, benign nevi, ethnic origin, and family history as risk factors were largely independent of one another.
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PMID:Pigmentary traits, ethnic origin, benign nevi, and family history as risk factors for cutaneous malignant melanoma. 658 14

Human melanoma cells have unexpectedly been found to express Ia-like antigens, histocompatibility type antigens which are believed to be the gene products of the immune response region. Melanoma derived Ia-like antigens are immunologically functional. Monoclonal antibodies have been produced to these antigens. The level of Ia-like antigens on melanoma cells is significantly lower than on B lymphoid cells, and this is more likely to reflect a reduced synthesis than an increased shedding. We have employed radioimmunometric and immunofluorescent procedures in this investigation, Melanoma cell-derived Ia-like antigens have a structure similar to that of B lymphoid cell-derived Ia-like antigens. The antigens are composed of two non covalently associated glycoproteins. One chain, referred to as the alpha chain, has an approximate molecular weight of 34,000 and the other one, referred to as the beta chain, has an approximate molecular weight of 29,000. The expression of Ia-like antigens is restricted to malignant melanoma and not on benign nevi.
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PMID:A radioimmunoassay and biological profile of Ia-like antigens on human melanoma cells. 697 2


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