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 high-molecular-weight RNA encapsulated with an RNA-instructed DNA polymerase in particles possessing the density characteristic of the RNA tumor viruses has been detected in 13 out of 14 human malignant melanomas. The [3H]DNA synthesized by these particles in an endogenous reaction hybridizes to RNA extracted from the human melanoma particulate structures, but not to RNA from normal skin. Similar particles containing RNA and enzyme have been found in basal cell and squamous cell carcinomas of the skin. The RNA of the melanoma particles is easily distinguishable by hybridization from the RNAs found in the particles of the basal and squamous cell carcinomas.
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PMID:Oncornavirus-like particles in human skin cancers. 5 74

High-performance steric exclusion chromatography on a 1250-A pore size polyethylene glycol-treated glass bead column was used to purify avian myeloblastosis virus and hamster melanoma virus from plasma protein and tissue culture media. The purified hamster melanoma virus was still infectious and the avian myeloblastosis virus-associated RNA-directed DNA polymerase showed a 1100-fold purification of the virus from one column treatment. Electron microscopy of the purified virus showed intact particles, with surface projections evident. The time required for column purification of the virus was 5 min.
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PMID:Rapid purification of an RNA tumor virus and proteins by high-performance steric exclusion chromatography on porous glass bead columns. 6 20

The mouse melanoma B16 contains particles encapsulating high molecular weight RNA of 60--70S size associated with a reverse transcriptase. The [3H]DNA synthesized by these particles possesses homology with RNA isolated from a hamster melanoma and from three human malignant melanomas.
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PMID:Particles from mouse melanoma B16 containing reverse transcriptase and 70S RNA related to human melanoma cytoplasmic RNA. 8 Jan 58

The mouse melanoma B16 contains particles encapsulating a high molecular weight RNA of 60--70S size associated with a reverse transcriptase. The particles possess a density of 1.14--1.18 g/cm3. The RNA shares sequences with the 70S RNAs of several mammalian C-type RNA tumor viruses. The nuclear DNA of the mouse melanoma B16 possesses particle-related sequences not present in the genome of normal C57BL mice.
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PMID:Biochemical studies on RNA tumor virus information and its transmission in B16 murine melanoma. 8 43

An RNA-direct DNA polymerase was purified from human melanoma tissue by successive column chromatography on DEAE-cellulose (DE-23 and DE-52) and phosphocellulose. The purified reverse transcriptase has a mol. wt. of 68,000, a pH optimum of 8.0, a Mn2+ optimum of 0.6 mM, and a KCl optimum of 60 mM. The purified enzyme transcribes (rA)n - (dT)12, (rC)n - (dG)18, (Ome-rC)n - (dG)18 and a 70s RNA from Rauscher leukemia virus (RLV), but failed to transcribe (dA)n - (dT)12. This enzyme has no terminal deoxynucleotidyl transferase activity. Serological studies have shown that the reverse transcriptase from human melanoma tissue is antigenically not related to DNA polymerases from Simian sarcoma virus (SiSV), Avian myeloblastosis virus (AMV), RLV, and human spleen of a patient with myelofibrosis. The purified enzyme showed a close antigenic resemblance to DNA polymerases from baboon endogenous virus (BEV) and rhabdomyosarcoma virus (RD-114), the endogenous virus of the cat.
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PMID:Biochemical and immunological characterization of a reverse transcriptase from human melanoma tissue. 8 88

The continuous culture of a hamster melanoma cell line has led to the spontaneous appearance of a retrovirus (HaRV) with typical type-C characteristics. The virus differs from all other known hamster viruses in its ability to transform murine as well as rat and hamster cells with apparent one-hit kinetics. Guinea pig, human and feline cells were not transformed although reverse transcriptase activity was detected in the supernatant from infected human cells. HaRV-transformed hamster embryo cells produced solid tumours (all non-pigmented) in 4 out of 35 animals when injected into hamsters while HaRV-transformed murine cells produced no tumours in mice. Injection of HaRV alone in hamsters, mice and rabbits did not induce tumours. HaRV possesses a 70S RNA which dissociates to 35S in DMSO and has a reverse transcriptase which utilizes the 70S virus RNA as a template. The size, morphology and density (1.15 g/ml) are similar to other known type-C viruses. Polyacrylamide gel electrophoresis indicates the presence of polypeptides analogous to those found in other type-C viruses.
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PMID:Characteristics of a retrovirus associated with a hamster melanoma. 9 Jan 12

Tests for the presence of oncornavirus-like particles in human biopsies were made by the Spiegelman simultaneous assay for 70S RNA and RNA-dependent DNA polymerase and by detection of 600-900S particles, incorporating 3H-uridine, produced by cultured biopsy cells. Thirty-one malignant melanoma biopsies from 29 patients were studied. Using the simultaneous assay, evidence of virus-like particles was found in 15/26 (58%) of melanoma biopsies, 0/3 naevi pools, 1/4 samples of skin adjacent to melanoma, 0/3 samples of normal adult skin and 0/3 prepuces. The velocity sedimentation technique was shown to be a useful screening test for oncornaviruses in studies of two virus-producing mouse cell lines (TKL-5 and WEHI-22), and was positive with 7/9 melanoma biopsies. Overall, these results are compatible with the earlier findings of similar virus-like particles in malignant melanoma cell lines, but the exact nature of the particles remains to be defined.
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PMID:Oncornavirus-like particles in malignant melanoma and control biopsies. 99 6

Expression of the endothelial adhesion molecule VCAM-1 was studied in human malignant melanoma lines by flow cytometry. Clones 2/4 and 2/14 (derived from the same lesion) had appreciable levels of VCAM-1 expression, whereas clone 2/21 and the lines A2058, Mel24, and A375 were negative. Clone 2/14 was selected for further analysis. Exposure to tumor necrosis factor (TNF) markedly augmented VCAM-1 on melanoma cells. Surface VCAM-1 was associated with expression of specific transcripts that were augmented by TNF. Analysis by reverse transcriptase and polymerase chain reaction using appropriate primers revealed that TNF-stimulated melanoma cells expressed both 7 and 6 immunoglobulin domain transcripts with predominance of the longer species. Tumor necrosis factor--stimulated melanoma cells bound more VLA-4-expressing cells (melanoma and monocytes) than resting tumor cells and anti-VCAM-1 monoclonal antibodies significantly inhibited binding, thus suggesting that surface VCAM-1 on melanoma is functional. Analysis of melanoma tissue sections demonstrated that VCAM-1 is not a marker of transformation of melanocytes because it can be detected in benign nevi. Although, unlike ICAM-1, VCAM-1 is not correlated with tumor progression, its expression in a fraction of primary melanomas indicates that it may play a role in regulating host immune response and homotypic interactions in some malignant melanomas.
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PMID:Regulated expression of vascular cell adhesion molecule-1 in human malignant melanoma. 128 17

As a preliminary to transducing human melanoma cells with lymphokine genes, we sought for constitutive gene expression and production of eight interleukins, tumour necrosis factors and granulocyte-colony stimulating factor in 19 human melanoma cell lines. Conversion of RNA into cDNA by reverse transcriptase and polymerase chain reaction (RT-PCR) were employed to evaluate gene expression while enzyme-linked immunosorbent assays (ELISA) or biological assays were used to assess the presence of proteins. No expression of interleukins (IL) 3, 4, and 5 or interferon-gamma RNA was found, while the other cytokines were variably expressed in melanoma lines, with IL-1 alpha, IL-1 beta, IL-6, IL-8, being detectable in most of the lines. At protein level, 10 melanoma cells were tested with ELISA and all were found to produce IL-8, five produced IL-6, two tumour necrosis factor (TNF)-alpha, one IL-1 alpha and two TNF beta. The levels of TNF beta were at the limit of test sensitivity. The amount of various cytokines released by the different lines varied widely. Biological assay with the D10-G4 clone confirmed the presence of IL-1 alpha in the supernatant of melanoma (ME) 10221 and revealed an IL-1 activity in the supernatant of Me 4024/1. The proliferating activity of melanoma supernatants on D10-G4 was inhibited by treatment with polyclonal antibodies against IL-1 alpha but not with antibodies against IL-1 beta. TNF biological activity was tested against the TNF-susceptible fibrosarcoma WEHI 164 clone 13.(ABSTRACT TRUNCATED AT 250 WORDS)
Melanoma Res 1992 Sep
PMID:Expression of cytokine genes, including IL-6, in human malignant melanoma cell lines. 145 Jun 72

Mutations in ras genes have been found in the DNA of numerous cancer types including melanomas, but the expression of these mutations in melanomas has not yet been addressed. We have used the polymerase chain reaction (PCR) and allele-specific restriction analysis (ASRA) to determine the frequency of expressed N-ras mutations on 25 short-term melanoma tissue culture samples. N-ras cDNA generated using reverse transcriptase from whole cells was used as the PCR template. 14 secondary melanoma cultures that varied in differentiation patterns were analysed. Only 2 were found to express N-ras mutations; in both, the mutation was localised to one of the first two positions of the 61st codon of N-ras. These tumour lines, KMI-M8412a and KMI-M8412b, were established from separate tumour deposits in the same patient. Codons 12 and 13 were found to be free of mutations in all of the lines studied. 8 primary melanomas and 3 unclassified skin lesions were also analysed and found free of N-ras mutations. These results suggest that N-ras may not play such an important role in melanoma tumorigenesis as is speculated by others.
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PMID:Analysis of expressed N-ras mutations in human melanoma short-term cell lines with allele specific restriction analysis induced by the polymerase chain reaction. 156 99


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