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

Melanocyte stimulating hormone (alpha-MSH, alpha-melanotropin),Ac-Ser-Tyr-Ser-Met-Glu-His-Phe-Arg-Trp-Gly-Ly-Pro-Va l-NH2, regulates melanogenesis within epidermal melanocytes of many animals. An MSH analogue ([Nle4,D-Phe7]alpha-MSH) that exhibits superpotency and prolonged biological activity has been synthesized, biologically characterized, and is presently in clinical trials to determine its possible clinical use in tanning of the skin. It also has potential for the diagnosis, localization, and chemotherapy of melanoma. The effects of this analogue on the growth, metastatic behavior, and invasive potential of a melanotic variant of Cloudman S-91 murine melanoma are reported here. In an intracutaneous murine model of melanoma cell tumor growth, the analogue did not increase primary tumor growth (size) after the period of administration of the peptide hormone analogue and did not affect spontaneous lung metastases. Survival times for the control and melanotropin-treated groups were similar, suggesting that overall tumor burden was not affected by treatment with the hormone analogue. Last, melanoma cell invasion through a human amniotic basement membrane in vitro was not enhanced compared to untreated cells.
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PMID:Effects of a melanotropic peptide on melanoma cell growth, metastasis, and invasion. 133 2

Gamma-interferon (gamma IFN) was found to induce expression of the 150,000 M(r) cell surface and the 35,000 M(r) chromatin receptors for nerve growth factor (NGF) in the SW1116 colorectal carcinoma cell line that does not express NGF receptors. In the SW707 colorectal carcinoma cell line that expresses a low level of NGF receptors, gamma IFN stimulated expression of the cell surface and the nuclear receptors. Induction of NGF receptors in SW1116 cells resulted in internalization and nuclear translocation of 125I-NGF. When NGF bound to the chromatin, ribosomal RNA synthesis was inhibited. Two-dimensional gel electrophoresis of [35S]methionine-labeled chromatin proteins indicated significant changes in chromatin protein composition in cells treated and not-treated with gamma IFN. gamma IFN effectively stimulated the expression of NGF receptors in two colorectal carcinoma cell lines, but inhibited the expression in melanoma and breast carcinoma cells. It is suggested that gamma IFN, by modulating the expression of NGF receptors may affect the NGF-dependent growth of some tumor cell lines.
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PMID:Gamma-interferon-induced nerve growth factor receptors in colorectal carcinoma cell lines. 134 Feb 11

Normal human melanocyte proliferation and differentiation is dependent on stimulation of one of three growth factor/receptor systems. They are fibroblast growth factor (FGF), hepatocyte growth factor (HGF), and mast cell growth factor (MGF), which activate the FGF receptor, c-Met, and c-Kit, respectively, known to be receptor tyrosine kinases. In contrast, human melanoma cells from primary nodular and metastatic lesions grow autonomously partially because of inappropriate production of basic FGF (bFGF) and continuous activation of the bFGF-receptor kinase. Activation of transmembrane receptor tyrosine kinases in melanocytes stimulates not only proliferation but also the expression of pigmentation. Melanoma cells constitutively express several tyrosyl-phosphorylated proteins that in normal melanocytes are stimulated in response to growth factors. This high level of phosphorylation was not due to either the presence of constitutively active Kit kinase and Met kinase nor to the absence of any of several known protein tyrosine phosphatases. Because bFGF by itself does not transform melanocytes to melanomas, there must be additional cooperating factors that confer the malignant phenotype to pigment cells.
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PMID:Growth factors, receptor kinases, and protein tyrosine phosphatases in normal and malignant melanocytes. 144 4

The potential of 4-borono-2-[18F]fluoro-D,L-phenylalanine ([18F]FBPA), a flurodinated derivative of a target compound for boron neutron capture therapy, for melanoma imaging by positron emission tomography (PET) was studied using animal models. A high uptake of [18F]FBPA was found in murine B16 melanoma or in Greene's melanoma No. 179, a melanotic cell line in hamsters, for the first 6 h after injection. Whole body autoradiography using [18F]FBPA gave a clear image of the B16 tumor. The acid-insoluble 18F in the B16 increased to 27% by 6 h, and most of the free 18F was detected as [18F]FBPA in both B16 and plasma. In the hamster models, No. 179 showed a 1.7 times higher uptake than amelanotic Greene's melanoma No. 178 at 6 h post-injection, although both melanomas indicated similar metabolic activities when examined by a tracer uptake study using L-[14C]methionine, 2-deoxy-D-[14C]glucose and [3H]thymidine. [18F]FBPA may be a very promising PET tracer for melanoma imaging.
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PMID:4-Borono-2-[18F]fluoro-D,L-phenylalanine: a possible tracer for melanoma diagnosis with PET. 162 21

Employing as immunogen a short-term passaged, highly pigmented human melanoma cell line, we have produced the murine MoAb 2G10 of the IgG1 isotype. The antibody immunoprecipitated from 35S-methionine and 3H-glucosamine metabolically labeled human melanoma cells with a single-chain glycoprotein of 75 kD molecular weight. No such molecule could be precipitated from murine melanomas. To further investigate the fine specificity of the MoAb, immunochemical and immunohistochemical studies were performed. These studies demonstrated that MoAb 2G10 binds a significant fraction of tyrosinase activity from cell lysates, completely immunodepletes soluble cell extract of T4-tyrosinase molecules, and produces immunostaining patterns superimposable on those obtained with anti-T4-tyrosinase antibodies. Thus, MoAb 2G10 appears to recognize a human-specific determinant carried by either T4-tyrosinase or a closely related molecule. The functional relevance of this epitope remains to be evaluated.
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PMID:Production and characterization of the murine monoclonal antibody 2G10 to a human T4-tyrosinase epitope. 170 43

Our aim was to identify the biochemical defect responsible for the inability of highly growth autonomous human tumor cells to proliferate in culture medium devoid of methionine, but containing homocysteine and 5-methyletrahydrofolic acid. We have adopted the terms "homocysteine-responsive" and "homocysteine-nonresponsive" to describe cells which can or cannot proliferate in methionine-free homocysteine-supplemented medium. Using a panel of genetically related homocysteine-responsive and -nonresponsive human melanoma cell lines, the results from a number of experiments indicate that acquisition of the "homocysteine-nonresponsive phenotype" is associated with the reduced intracellular accumulation of methyl-cobalamin, a critical cofactor of the methionine synthase enzyme. When in vitro methionine synthase assays were performed in the presence of exogenously added methyl-cobalamin, specific methionine synthase activity in extracts obtained from homocysteine-responsive cells was only twofold greater than that observed with extracts prepared from homocysteine-nonresponsive cells. However, when exogenous methyl-cobalamin was omitted from the enzyme assays, methionine synthase activity in extracts derived from homocysteine-nonresponsive cells was dramatically reduced, compared with the small decrease observed with homocysteine-responsive cell extracts. Compared with their homocysteine-responsive counterparts, homocysteine-nonresponsive cells exhibited increased levels of cobalamin efflux and decreased intracellular accumulation of methyl-cobalamin. There was a clear relationship between the abilities of these related melanoma cell lines to proliferate in methionine-free homocysteine-supplemented medium, and the extent of cobalamin loss and capacity of exogenously added methyl-cobalamin to stimulate in vitro methionine synthase activity. These results indicate a link between alterations in the intracellular trafficking and/or metabolism of cobalamin and the increased growth autonomy of human melanoma cells.
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PMID:Changes in cobalamin metabolism are associated with the altered methionine auxotrophy of highly growth autonomous human melanoma cells. 174 23

A new immunomodifier, [omega-(hypoxanthin-9-yl) pentoxy-carbonyl-leucyl-methionine] (RM06), was synthesized and its effect was evaluated on the activity of Natural Killer (NK) cells. Results indicate that RM06 is able to boost the NK activity of normal mice as well as to augment the regeneration of NK activity of lethally irradiated mice transplanted with syngeneic bone marrow (BM). This later effect also correlated with a significant increase in anti-tumor activity as evaluated by the resistance to metastasis in mice injected with syngeneic melanoma cells. These data indicate that RM06 is able to modulate the NK cell activity as well as the antitumor resistance.
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PMID:Effect of a new peptidyl-hypoxanthine derivative on natural killer cells and antitumor activity. 179 38

Metastatic colonization of a secondary organ site is initiated by the attachment of blood-borne tumor cells to organ-specific adhesion molecules expressed on the surface of microvascular endothelial cells. Using digital video imaging microscopy and fluorescence activated cell sorting techniques, we show here that highly metastatic cells (B16-F10 murine melanoma and R3230AC-MET rat mammary adenocarcinoma cells) previously labeled with the fluorescent dye BCECF begin to transfer dye to endothelial cell monolayers shortly after adhesion is established. The extent of BCECF transfer to endothelial cell monolayers is dependent upon the number of BCECF-labeled tumor cells seeded onto the endothelial cell monolayer and the time of coculture of the two cell types, as visualized by an increase in the number of BCECF-positive cells among cells stained with an endothelial cell-specific mAb. Dye transfer to BAEC monolayers proceeds with a progressive loss of fluorescence intensity in the BCECF-labeled tumor cell population with time of coculture. The transfer of dye is bidirectional and sensitive to inhibition by 1-heptanol. In contrast, poorly metastatic B16-F0 melanoma cells and non-metastatic R3230AC-LR mammary adenocarcinoma cells do not efficiently couple with vascular endothelial cells. It is inferred from these experiments and from the amounts of connexin43 mRNA expressed by tumor cells that tumor cell/endothelial cell communication is mediated by gap junctional channels and that this interaction may play a critical role in tumor cell extravasation at secondary sites.
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PMID:Cytoplasmic dye transfer between metastatic tumor cells and vascular endothelium. 195 78

Alanine aminopeptidase was partially purified from cultured human melanoma cells (Bowes) by gel filtration on Sephadex G-200 and DEAE Sepharose column chromatography. The molecular weight of the enzyme was about 52,000 as determined by gel filtration on Sephadex G-100. The enzyme hydrolyzed L-alanine beta-naphthylamide (NA), but not or slightly L-methionine-NA, L-leucine-NA, and L-arginine-NA. The Km value for L-alanine-NA was 0.17 mmol/l, pH optimum was 7.4. The enzyme was stable at 50 degrees C for 20 min, but lost about 50% of its activity at 60 degrees C within 20 min. It was markedly stimulated by chloride ions, and was inhibited by sulfhydryl blocking agents and EDTA. The activity was restored by the addition of Co2+ or Zn2+ after EDTA treatment. The enzyme is a metallo- and thiol-dependent and chloride-activated, low-molecular weight aminopeptidase.
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PMID:A chloride activated alanine aminopeptidase from a melanoma cell line. 197 56

With the advent of a new generation of PET scanners that have introduced whole-body PET to the clinical setting, there is now more interest in developing protocols for the evaluation of both intracranial and somatic cancers. The value of PET in clinical oncology has been demonstrated with studies in a variety of cancers including colorectal carcinomas, lung tumors, head and neck tumors, primary and metastatic brain tumors, breast carcinoma, lymphoma, melanoma, bone cancers, and other soft-tissue cancers. A summary of current clinical applications of PET in oncology is presented with special attention to colorectal, lung, and intracranial neoplasms since the majority of clinical trials have focused on these cancers. A variety of radiopharmaceuticals are described that are currently included in clinical tumor-imaging protocols, including metabolic substrates such as fluorine-18-fluorodeoxyglucose and carbon-11-methionine, and analogs of chemotherapeutic agents such as fluorine-18-fluorouracil and fluoroestradiol. An attempt is also made to include examples of clinical trials that demonstrate response to therapeutic intervention. The increasing number of oncologic PET studies reflects the growing interest in functional imaging in oncology.
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PMID:The applications of PET in clinical oncology. 201 3


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