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 periodate-thiocarbohydrazide silver proteinate (PA-TCH-SP) method was used to study the envelopment process in varicella-zoster virus-infected human melanoma cells. Viral envelopment could be seen at two sites, the nuclear membrane and at virus-induced intracytoplasmic vacuoles. Virus-associated glycoconjugates were detected by the PA-TCH-SP method at the plasmalemma and on the inner membrane of the intracytoplasmic vacuoles. Virion envelopes acquired at the nuclear membrane were PA-TCH-SP negative, whereas those acquired at intracytoplasmic vacuoles were PA-TCH-SP positive. All virions found inside these vacuoles contained periodate-reactive envelopes. Release of virions into the extracellular space, where virtually all virions were PA-TCH-SP positive, appeared to be via exocytosis. Thus, the PA-TCH-SP method identifies glycoprotein incorporation at specific cytoplasmic vacuoles distinct from nuclear envelope, endoplasmic reticulum, and Golgi lamellae. These results suggest that envelopment within the cytoplasm is a stage in the assembly of the varicella-zoster virion.
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PMID:Varicella-zoster viral glycoprotein envelopment: ultrastructural cytochemical localization. 300 84

The effect of LiCl on melanoma cell growth and differentiation was studied in mouse and human melanoma cell lines. LiCl markedly inhibited B16 and HT-144 melanoma cell growth in vitro. Clonogenicity in soft agar of the melanoma cells was also markedly inhibited by LiCl. Pretreatment of B16 mouse melanoma cells with LiCl delayed the appearance of melanoma tumours in syngeneic mice. Growth inhibition of cells was accompanied by morphological and biochemical alterations. LiCl induced cell enlargement and formation of dendrite-like structures. The activity of NADPH cytochrome c reductase, an enzymatic marker of endoplasmic reticulum was significantly (2-3 fold) increased. Addition of myo-inositol to cell cultures partially reversed the anti-proliferative and morphological effects of LiCl on melanoma cells. This finding may suggest that the anti-proliferative effect of LiCl is related to its effect on phosphatidylinositol metabolism.
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PMID:The anti-proliferative effect of lithium chloride on melanoma cells and its reversion by myo-inositol. 302 60

A spontaneous, hypomelanotic variant (MI) of the highly melanotic transplantable hamster melanoma of Bomirski (Ma) is the subject of this report. Tyrosinase activity is 2-3 times higher, but melanin content significantly lower than in the parental Ma melanotic melanoma. Acid phosphatase activity is similar in both, but beta-glucuronidase and aryl-sulfatase A are 2-3 times higher in the hypomelanotic variant. Transplanted MI melanomas grow more slowly than the parental tumor, but metastasize with similar incidence and localization. Hypomelanotic variant melanoma cells, even those in grossly nonnecrotic parts of the transplants, show signs of low viability like swelling of the cytoplasm or cellular condensation, and disintegration. Autophagic vacuoles are numerous. They appear to be formed by enclosure of a portion of cytoplasm by cisternae of smooth endoplasmic reticulum or trans-Golgi network. These limiting cisternae contain tyrosinase as evidenced by deposition of electron dense reaction product on incubation with tyrosine or DOPA. Other sites of ultrastructural tyrosinase reaction are melanosomes and the smooth-surfaced cisternae and vesicles of the trans-Golgi network. We postulate the low cell viability, associated with autophagosome formation, is the cause for the growth retardation of the MI variant, and that the lower melanin content of these tyrosinase-rich cells is due to sequestration of a substantial portion of newly synthesized enzyme into autophagic vacuoles before it has the chance of being incorporated into melanosomes.
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PMID:Pathology and ultrastructural characteristics of a hypomelanotic variant of transplantable hamster melanoma with elevated tyrosinase activity. 311 4

Previously, we have developed a mouse monoclonal antibody (MoAb) HMSA-1 (human melanosome-associated antigen-1) against the melanosome fraction of human malignant melanoma, and demonstrated the selective distribution of the HMSA-1 in neoplastic melanocytes on routine paraffin sections. This study examined, by using enzyme linked immunosorbent assay (ELISA) and immunoelectron microscopy, the subcellular distribution of the HMSA-1 in malignant melanocytes. Fractionation of cell organelles and ELISA assay indicated that the HMSA-1 is rich in fractions of large granule, melanosome and endoplasmic reticulum (ER) in melanoma cells. Immunoelectron microscopic study showed that the HMSA-1 is localized in the melanosomes of various developmental stages and vacuolar structures, which appeared to be the stage I melanosomes and which contained the matrix protein. Dopa cytochemistry revealed that the distribution of MoAb HMSA-1 reaction product is localized in the area different from that of tyrosinase, indicating that the synthetic processes of melanosomal matrix protein and tyrosinase are different. Furthermore, the reaction product with MoAb HMSA-1 was seen in the rough ER, indicating that the melanosomal matrix protein is synthesized by membrane-bound ribosomes and processed through the channel of ER.
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PMID:Immunoelectron microscopic demonstration of human melanosome associated antigens (HMSA) on melanoma cells: comparison with tyrosinase distribution. 312 59

Cultured human melanoma M21 cells were treated with diethylcarbamazine (DEC), an inhibitor of proteoglycan biosynthesis in rat chondrosarcoma cells, to examine the assembly and transport of a chondroitin sulfate proteoglycan to the plasma membrane. Pretreatment of melanoma cells at 37 degrees C for 15 min with increasing doses of DEC followed by a 60-min pulse with [35S]sulfate in the presence of DEC resulted in a dose-related inhibition of incorporation of [35S]sulfate into macromolecules. In cells incubated for 75 min with both 1 mM beta-D-xyloside and 15 mM DEC, synthesis and secretion of beta-D-xyloside-bound 35S-glycosaminoglycans were inhibited by more than 80% as compared to cells treated with beta-D-xyloside alone; this inhibition was reversible. As assessed by [3H]serine incorporation into protein, overall protein synthesis was not substantially inhibited by DEC treatment. Detergent lysates from [35S]methionine-labeled melanoma cells were incubated with a monoclonal antibody (9.2.27) that specifically recognizes the peptide core of the melanoma proteoglycan. As assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the immunoprecipitate, a 240,000 Mr endoglycosidase H (Endo-H)-sensitive intermediate was the only form of the proteoglycan present inside the cells when the cultures were treated for 60-120 min with 10-15 mM DEC. When the melanoma cells were incubated for 10 min with 15 mM DEC and 100 mu Ci/ml of [35S]methionine, washed, and then chased for 15 min to 4 h in radioactive-free medium, the 240,000 Mr Endo-H-sensitive intermediate was slowly converted to a 250,000 Endo-H-resistant intermediate but not to a mature proteoglycan molecule that possessed chondroitin sulfate glycosaminoglycans. SDS-PAGE analysis of cell surface immunoprecipitates revealed that only a small amount of the 250,000 Mr intermediate was transported to the plasma membrane within 5 h of incubation in the presence of DEC. Proteoglycan synthesis was also inhibited when the melanoma cells were incubated for 60-120 min with ammonium chloride, but unlike DEC-treated cells the majority of the synthesized peptide core was converted to a 245,000 Mr Endo-H-resistant intermediate that was detected on the cell surface. Light and electron microscopic analysis of DEC-treated melanoma cells revealed large vacuoles and a distended Golgi and endoplasmic reticulum. Ammonium chloride-treated cells contained fewer vacuoles than DEC-treated cells but more vacuoles than normal cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Inhibition of post-translational modification and surface expression of a melanoma-associated chondroitin sulfate proteoglycan by diethylcarbamazine or ammonium chloride. 351 9

To characterize the biological property unique to melanocytes and to utilize this property to establish laboratory diagnostic tools for malignant melanoma, monoclonal antibody (MoAb) human melanosome-associated antigen-1 (HMSA-1), a mouse monoclonal antibody, was developed against purified melanosomal fractions of human melanoma. MoAb HMSA-1 belongs to an IgG1 (kappa) subclass. Fractionation of cell organelles combined with enzyme linked immunosorbent assay analysis indicated that the antigen(s) reactive with MoAb HMSA-1 is localized in melanosome and endoplasmic reticulum fractions and that it is related to melanosomal protein and its precursor forms. The localization of the antigen in the melanosome and endoplasmic reticulum was also confirmed by immunoelectron microscopy. Characteristically, MoAb HMSA-1 reacted with formalin-fixed and paraffin-processed tissues of melanocytic nevi and malignant melanoma, including amelanotic lesions. It did not react with normal melanocytes, normal tissues and organs from fetuses and adults, or most non-melanocytic tumors. Thus MoAb HMSA-1 identifies the differentiation antigen for the melanosome-associated property in neoplastic melanocytes and is a useful adjunct for immunohistological diagnosis of melanocytic lesions on routine paraffin sections.
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PMID:Development and characterization of a mouse monoclonal antibody, MoAb HMSA-1, against a melanosomal fraction of human malignant melanoma. 351 87

Antimelanosome-associated monoclonal antibody has recognized the common antigenic determinant of melanosomes and cell surface of pigment cells, and it is suggested that melanosomes play a significant role as an antigen in progressive depigmentary disorders, in which melanocytes are selectively altered and disappear presumably by auto-antibodies in vivo. Mouse myeloma cells were fused with spleen cells from BALB/c mice immunized with a melanosomal fraction separated from human melanotic melanoma cells (Mm-1-JCK). The monoclonal antibody (MoAb) A4F11 has been found to react with premelanosomes, melanosomes, and probably with Golgi-associated endoplasmic reticulum lysosomes, but not with mitochondria, nuclei, and cytosol from human melanoma cells, by immunoelectron microscopy using the saponin permeation method, which was carried out together with indirect radioimmunoassay and quantitative absorption assay. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting using melanosome preparations have revealed the antigen(s) reactive with the MoAb A4F11 in 3 bands corresponding to Mr 50,000, 18,000, and 17,000. Cell binding assay has shown the reactivity of the MoAb A4F11 with the cell surface of human normal melanocytes and melanoma cells, but not with other mammalian melanoma cells or with human nonpigment cells examined. Indirect immunofluorescence on cultured cells and frozen sections has revealed distinct granular reactivity not only with human melanotic melanoma, but also with junctional and intradermal nevi, cultured malignant blue nevus cells, as well as normal melanocytes. The above evidence has indicated the presence of an antigenic determinant common to the intracellular melanogenic compartments and to the cell surface of human pigment cells, regardless of their oncogenic differentiation status.
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PMID:Melanosomal antigenic expression on the cell surface and intracellular subunits within melanogenic compartments of pigment cells: analysis by antimelanosome-associated monoclonal antibody. 352 55

Pigmentation-associated antigen (PAA) or gp75 is a glycoprotein localized to the melanosomes of human melanomas and melanocytes to which a mouse monoclonal antibody (AbTA99) has been produced (T. M. Thomson et al. (1985) J. Invest. Dermatol. 85, 169). Treatment of 3H-labeled immunoprecipitated melanoma PAA with alkaline-borohydride, hydrazinolysis, or N-glycanase released three families of carbohydrate chains (I, II, and III). Peak I consists of a major component (Ia) of sialylated triantennary N-linked chains which are partially substituted with fucose on terminal positions as well as on the chitobiose core and a minor component (Ib) which is a sialylated biantennary N-linked species. Peak II was not well characterized but may be a monoantennary complex chain species. Peak III consists of typical N-linked high mannose units with six to seven mannose residues. Melanocyte PAA carbohydrate chains have the same general features as melanoma PAA except that the biantennary complex chain predominates; this difference resembles that observed between the cell surface glycopeptides of transformed animal cells and their nontransformed counterparts. The glycosylation characteristics of this melanosomal glycoprotein are compared with those of glycoproteins from endoplasmic reticulum, Golgi, and lysosomes, and with tyrosinase. It is suggested that the glycosylation pattern is a reflection of the biosynthetic origin and cellular destination of a particular organelle and its constituents.
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PMID:Glycosylation characteristics of pigmentation-associated antigen (GP75): an intracellular glycoprotein of human melanocytes and malignant melanomas. 353 23

This case presentation illustrates peculiar tubular aggregates in rough endoplasmic reticulum (RER) of human melanoma cells, a location in which they have been reported in a small percentage of malignant melanomas.
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PMID:Straight intracisternal tubules in rough endoplasmic reticulum of human melanoma cells. 368 13

Specific inhibition of core carbohydrate synthesis has been found to induce selective aberration and melanin loss in melanosomes, accompanied by alteration of the carbohydrate moiety in functioning glycoproteins, tyrosinases. In order to further clarify the biologic significance of glycoproteins in the initiation of melanization, initial melanogenesis which occurs during the recovery period following interrupted melanogenesis induced by glycosylation inhibitors, has been electron microscopically investigated. Changes in the tyrosinase activity of the corresponding melanogenic subcellular compartments have also been studied electron cytochemically. Removal of glycosylation inhibition was carried out after exposure of B-16 melanotic melanoma cells to the inhibitors for 10-20 culture days resulting in the loss of their melanization. Recovery of melanization begins visibly 48 h later, thereafter almost attaining the previous normal level by 72 h. At the electron microscopic level, re-formation of melanosomal matrix with periodicity is observed within premelanosomes 48 h after removal of glucosamine, soon followed by deposition of apparent melanin particles along their periodicity by 72 h. In tunicamycin experiments, melanization within premelanosomes starts after the concentration of the fine threadlike interior becomes less distinct followed by a prominence of multiple accumulation of microvesicles within the interior. Electron microscopic dopa reaction shows that the deposition of dopa melanin is prominent in Golgi-associated endoplasmic reticulum of lysosome and coated vesicles up to 24 h after the removal. Thereafter, predominant localization of dopa melanin in premelanosomes gradually increases and finally becomes almost uniform. These observations suggest 2 possible mechanisms for the involvement of glycosylation in melanogenesis: first, the translocation of tyrosinases may be regulated by the presence of specific carbohydrate moieties; second, melanosomal matrix proteins contain carbohydrates which may contribute to the tyrosinase-accepting function or in vivo melanizing function of tyrosinases after forming particle-bound T3 tyrosinase.
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PMID:Importance of glycoproteins in the initiation of melanogenesis: an electron microscopic study of B-16 melanoma cells after release from inhibition of glycosylation. 373 83


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