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)

Two melanotic human melanoma cell lines, IRE 1 and IRE 2, and the lymphoma- and leukaemia-derived cell lines Raji and K 562, were exposed to different concentrations (from 5 X 10(-3) M to 10(-5) M) of phenols, both substrates (s) and non-substrates (ns) of tyrosinase, in the presence or absence of the oxygen-radical-scavenger enzymes superoxide dismutase, catalase and peroxidase. Monophenols were tyrosine (s), 4-hydroxyanisole (s) and butylated hydroxyanisole (ns); diphenols were L-3,4-dihydroxyphenylalanine (s), dopamine (3,4-dihydroxyphenethylamine) (s), terbutylcatechol (s), hydroquinone (s) and resorcinol (ns); triphenols were 6-hydroxydopa (3,4,6-trihydroxyphenylalanine) (s) and methyl gallate (s). Triphenols and o- and p-diphenols underwent complete oxidation in culture medium within 24 h of incubation and were significantly more toxic than monophenols and the m-diphenol resorcinol, which, under the same cultural conditions, were much more stable. No significant differences in percentage survival were found among the different cell lines for each drug tested. The major component of toxicity up to 24 h of di- and tri-phenols is due to toxic oxygen species acting outside the cells and not to cellular uptake of these phenols as such. In fact the addition of oxygen-radical-scavenger enzymes significantly (P less than 0.01) decreased the adverse effect of these drugs on all cell lines. The lower toxicity of monophenols and resorcinol as compared with that of di- and tri-phenols is due, in our opinion, to the fact that they are less oxidized under the conditions existing in the culture medium, and therefore do not produce sufficient levels of oxygen radicals. For these compounds, a primary intracellular action has to be taken into account to explain their cytotoxicity.
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PMID:Comparative cytotoxicity of phenols in vitro. 282 25

alpha MSH is known to act on several nonmelanocyte cell types, which has led to recent interest in its regulatory roles in fever, inflammation, immunity, and behavior. To determine its possible sites of action, we examined the distribution of alpha MSH receptors in a variety of tissues in mice and rats. The superpotent and enzymatically resistant alpha MSH analog, Nle4,D-Phe7-alpha MSH (NDP-MSH), was radioiodinated using lactoperoxidase (Enzymobeads) and purified by reverse phase chromatography for use as a tracer. [125I]NDP-MSH exhibited consistent and specific binding to cultured B16 and Cloudman S91 murine melanoma cells, which are highly responsive to alpha MSH. The tracer had full biological activity, as determined by its potency in stimulating melanogenesis in B16 cells. To study receptor distribution in vivo, [125I]NDP-MSH was administered iv to C3H/HeJ (pigmented) mice and Sprague-Dawley (albino) rats. To determine the specificity of tracer uptake by tissues, some animals received a large molar excess of alpha MSH together with [125I]NDP-MSH. Data were expressed as tissue to plasma radioactivity concentration ratios. In mice, specific (i.e. alpha MSH-inhibitable) binding of [125I]NDP-MSH was found in a number of glandular organs, including lacrimal, Harderian, preputial, submandibular, and adrenal glands and pancreas, as well as in brown and white adipose tissues, bladder, duodenum, skin, spleen, and hypothalamus. In rats, results were generally similar; specific tracer uptake was observed in lacrimal, Harderian, preputial, and thyroid glands; pancreas, duodenum, spleen, hypothalamus; and white adipose tissue. These results show that specific receptors for alpha MSH are widely distributed, suggesting that alpha MSH may affect the functions of a number of organs.
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PMID:Specific receptors for alpha-melanocyte-stimulating hormone are widely distributed in tissues of rodents. 282 78

S-100 protein, originally isolated from neural tissues, has also been identified in various normal and neoplastic cells, including malignant melanomas. A systematic immunohistochemical investigation of this antigen was performed on formalin-fixed paraffin-embedded samples of benign and malignant breast tissues with use of the avidin-biotin-peroxidase complex immunoperoxidase technique and a polyclonal antiserum that recognizes both the alpha and beta subunits of S-100 protein. In benign breast tissue, S-100 protein was present in both epithelial and myoepithelial cells of terminal ducts and lobules; the staining was cytoplasmic and sometimes nuclear. Of 100 randomly selected invasive breast carcinomas, 48 per cent contained S-100 protein-positive tumor cells. Lobular and medullary carcinomas (60 per cent and 80 per cent, respectively) were more frequently positive than ductal carcinomas (45 per cent). Dendritic cells, most likely Langerhans' cells, were present in some carcinomas and were also positive for S-100. There was no relationship of S-100 positivity to histologic differentiation, recurrence interval, or the expression of various tumor markers. The presence of S-100 protein positivity in metastatic breast carcinomas may lead to the erroneous diagnosis of malignant melanoma. Our observations underscore the importance of testing for a broad panel of tumor markers rather than relying on single antigens in evaluating metastatic malignancies of undetermined origin.
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PMID:S-100 protein positivity in breast carcinomas: a potential pitfall in diagnostic immunohistochemistry. 282 23

Papanicolaou-destained imprint smears from 24 brain tumors were investigated by means of avidin-biotin-peroxidase complex method (ABC) with the use of monoclonal antibodies against glial fibrillary acidic protein (GFAP). Positive staining reaction to GFAP antibody has been demonstrated in cells from the following tumors: astrocytoma, anaplastic astrocytoma, glioblastoma multiforme, mixed glioma, and ependymoma. The reaction for GFAP was negative for the following tumors: medulloblastoma, neurilemmoma, melanoma, hemangioblastoma, and metastatic tumors. In astrocytoma, the cell bodies and processes were positive with delicate fibrillary patterns; in anaplastic astrocytoma, cytoplasm and the processes were intensively stained. In glioblastoma multiforme, the staining patterns were also mixed, and the short, thickened processes were characteristic. Use of both a smear preparation and the immunoperoxidase staining technique is of great value in diagnosis of tumors of the central nervous system.
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PMID:Immunocytochemical demonstration of glial fibrillary acidic protein in imprint smears of human brain tumors. 283 75

As some tumors metastasize frequently to marrow we modified the clonogenic assay for human tumor cell growth by culturing tumor cells in the presence of human bone marrow stromal cells. In a bilayer soft agar assay, human tumor cells which had been passaged in nude mice were plated in the agar overlayer on an underlayer containing a suspension of trypsinized human bone marrow stromal cells. These marrow stromal cells stimulated the growth of tumor cells in a dose-dependent fashion, with a growth peak at a stromal cell density of 5-10 x 10(5)/ml. The maximal stimulation of tumour cell growth was 13-fold. We evaluated clonal growth of six separate tumors of five different histological types (small and large cell bronchogenic carcinoma; mammary carcinoma; malignant melanoma; pleural mesothelioma) and demonstrated that in 9 of 11 experiments tumor cell colonies formed in the absence of stromal cells, but colony growth was markedly stimulated by stromal cells in every case. Stromal stimulation persisted after irradiation of the stromal cells with 10 Gy. Growth of five fresh human tumor samples was similarly stimulated by the presence of human bone marrow stromal cells. Tumor cell colonies were characterized morphologically by Pappenheim stain and immunologically for surface antigens by peroxidase-antiperoxidase immunostaining utilizing monoclonal antibodies (carcinoembryonic antigen 26/3/13 and 26/5/1, EMA, HEA125, Sam 2 and Sam 10) which detected epithelial cell antigens. Colonies consisted of cytologically malignant cells which expressed epithelial cell antigens. Thus, the tumor cell origin of colonies from mammary carcinoma and bronchogenic small cell, large cell, and adenocarcinoma was proven. This tumor stem cell assay permits further analyses of human tumor cell biology and may be useful for testing drug sensitivity.
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PMID:Effects of human bone marrow stroma on the growth of human tumor cells. 291 45

The antigen recognized by a newly produced monoclonal antibody (bra55; IgG1) elicited by the non-T, non-B acute lymphoblastic leukemia cell line REH 6, was expressed on all examined hemopoietic neoplastic cell lines (including non-T, non-B, T, B and myeloid leukemia cell lines), but not on examined nonhemopoietic human tumor cell lines (such as carcinoma, sarcoma, melanoma and neuroblastoma cell lines), as demonstrated by indirect immunofluorescence and enzyme-linked immunoassay. Specific immunoprecipitation of 125I-lacto-peroxidase radioiodinated cell surface proteins and sodium metaperiodate/tritiated sodium borohydride 3H-radiolabeled cell surface sialoglycoproteins followed by electrophoretic analysis (SDS-PAGE) demonstrated that the immunoprecipitated antigen is a cell surface 200 kDa sialoglycoprotein (on the non-T, non-B ALL cell line REH 6), with variation in its electrophoretic mobility (in the Mr range of 170,000-210,000) on different examined cell lines. These properties are characteristic for the leukocyte common antigen (LCA, T200). Immunoperoxidase staining of several normal and malignant tissues, as well as some nonhemopoietic tumor tissues confirmed the type of antigen tissue distribution pattern characteristic for LCA.
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PMID:Human neoplastic cell line distribution, immunoprecipitation and immunohistopathological study of a gp200 cell surface glycoprotein (LCA) detected by a monoclonal antibody elicited with an ALL cell line. 296 36

By the peroxidase-antiperoxidase technique, the authors studied 7 malignant choroidal melanomas, 7 conjunctival nevi and 1 malignant conjunctival melanoma with the aim to detect the presence of vasoactive intestinal polypeptide (VIP), adrenocorticotropic hormone (ACTH), gastrin, estradiol and testosterone. Positive staining reaction for VIP, estradiol and testosterone was observed in both malignant melanomas of the choroid and conjunctival nevi. The case of conjunctival melanoma was positive for VIP and ACTH but not for estradiol and gastrin.
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PMID:Steroids and neuroendocrine hormones detected by the immunoperoxidase technique from malignant melanomas and nevi of the choroid and conjunctiva. 301 Feb 9

We examined 2,227 lymph nodes from 100 patients with clinical Stage I cutaneous melanoma for the presence of microscopic deposits of tumor. On examination of hematoxylin-and-eosin-stained sections, none had melanoma. Sixteen nodes from 14 patients had melanoma detectable by an antiserum to S-100 protein in a peroxidase-antiperoxidase (PAP) assay. The melanomatous nature of these cells was confirmed by their reaction with the melanoma-directed monoclonal antibody NKl/C3. The incidence of occult nodal metastases was highest in patients with deeply invasive and micrometrically thick primary tumors. The incidence of occult melanoma was not increased where additional serial sections were cut and semiserial sections examined. Pitfalls in the identification of occult melanoma cells (OMC) include S-100 protein-positive interdigitating dendritic cells, capsular nevus cells, a minority of sinus "macrophages," and the Schwann cells of node-associated nerves. Thus, we conclude that the incidence of early melanoma metastases in the regional lymph nodes of patients with clinical Stage I melanoma is greater than has previously been appreciated on the basis of assessment of routine hematoxylin-and-eosin-stained sections. Six of the 14 patients with OMC died of melanoma (41%), as compared to only 18 of 86 patients without OMC (21%; 0.10 greater than P greater than 0.05).
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PMID:Occult tumor cells in the lymph nodes of patients with pathological stage I malignant melanoma. An immunohistological study. 271 94

Antibodies to S-100 protein have been used widely as markers of malignant melanoma, despite abundant evidence that they are non-specific for this neoplasm. Hence, alternatives to these reagents are desirable in diagnostic dermatopathology. We evaluated the characteristics of a new monoclonal antibody (HMB-45) which does have putative specificity for melanoma, and compared it with a polyclonal anti-S-100 reagent in immunohistochemical staining of 67 melanomas of the skin and 133 non-melanomatous cutaneous neoplasms. All specimens were formalin-fixed and paraffin-embedded, and were studied with the avidin-biotin-peroxidase complex technique. HMB-45 labelled 62 of 67 melanomas, while anti-S-100 recognized all tumors of this type. On the other hand, S-100 also was expressed by 15 of the non-melanocytic neoplasms, all 133 of which were HMB-45-negative. The only cases of melanoma that were missed by the latter reagent were of the spindle-cell type. Hence, HMB-45 was 100% specific and 93% sensitive, relative to a diagnosis of malignant melanoma in paraffin sections. Epithelioid and small-cell neoplasms are reliably recognized by this antibody, but it would appear that spindle-cell melanomas must be detected by other immunohistochemical means.
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PMID:Recognition of malignant melanoma by monoclonal antibody HMB-45. An immunohistochemical study of 200 paraffin-embedded cutaneous tumors. 305 11

A sensitive, specific, competitive enzyme-linked immunosorbent assay (ELISA) was developed for quantitative analysis of tyrosinase. Binding sites of anti-tyrosinase antibodies were competed for by purified tyrosinase adsorbed onto microtiter plates and a known (standard) or unknown (sample) amount of tyrosinase in solution. Adsorbed antibodies were detected by goat anti-rabbit IgG F(ab')2 labeled with peroxidase. A sensitivity range of 2.1 to 14 ng (30-200 fmol)/well was obtained. SDS was found to be the most suitable detergent for solubilizing the enzyme. Tyrosinase was extracted from B16 mouse melanoma and assayed by the ELISA. The tyrosinase content per mg melanoma protein was 505 +/- 106 (S.D.) ng. This assay is not only useful for measuring the content of normal tyrosinase in crude extracts but also is possibly applicable to detecting the unprocessed tyrosinases.
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PMID:Quantitative analysis of mouse tyrosinase by enzyme-linked immunosorbent assay. 308 1


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