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 carbohydrate moieties present on laminin play a crucial role in the multiple biological activities of this basement membrane glycoprotein. We report the identification of a human laminin binding protein with an apparent molecular mass of 14 kDa on sodium dodecyl sulfate-polyacrylamide gels that was found, after purification and amino acid microsequencing, to be identical to the previously described 14-kDa galactoside binding soluble L-14 lectin. We have designated this human laminin binding protein as HLBP14. HLBP14 was purified from human melanoma cells in culture by laminin affinity chromatography and gel electroelution. We demonstrate that HLBP14 binds specifically to the poly-N-acetyllactosamine residues of murine laminin and does not bind to other glycoproteins that do not contain such structures, such as fibronectin. HLBP14 was eluted from a murine laminin column by lactose, N-acetyllactosamine, and galactose but not by other control saccharides, including glucose, fucose, mannose, and melibiose. It did not bind to laminin treated with endo-beta-galactosidase. Lactose also eluted HLBP14 off a human laminin affinity column, implying that human laminin also contains poly-N-acetyllactosamine residues. On immunoblots, polyclonal antibodies raised against HLBP14 recognized HLBP14 as well as 31- and 67-kDa molecules that are also laminin binding proteins, indicating that these proteins share common epitopes. L-14, a dimeric lactose binding lectin, is expressed in a wide variety of tissues. Although the expression of this molecule has been linked to a variety of biological events, the elucidation of its specific functions has been elusive. The observation that HLBP14, a human cancer cell laminin binding protein, is identical to L-14 strongly suggests that the functions attributed to this lectin could be mediated, at least in part, through its ability to interact with the poly-N-acetyllactosamine residues of laminin. HLBP14 could potentially play a role during tumor invasion and metastasis by modulating the interactions between cancer cells and laminin.
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PMID:Identification of a 14-kDa laminin binding protein (HLBP14) in human melanoma cells that is identical to the 14-kDa galactoside binding lectin. 138 13

An inactive cathepsin B-like enzyme with a molecular mass of 40 kD was found in a human melanoma culture medium. The inactive form of this enzyme was converted into an active form with a molecular mass of 28 kD by pepsin treatment. This activated cathepsin B-like enzyme had almost the same characteristics regarding molecular size, substrate specificity, dependence on chemical reagents, and Km values as intracellular cathepsin B. Sodium dodecylsulphate polyacrylamide gel electrophoresis followed by electroblotting with an antiserum against cathepsin B yielded inactive cathepsin B-like enzyme fractions which showed two immunoreactive bands with molecular masses of 40 and 28 kD, respectively. On the other hand, alkali treatment of the inactive cathepsin B-like enzyme fractions released a cysteine proteinase inhibitor with a molecular mass of 12 kD. These data suggest that these inactive cathepsin B-like enzymes in melanoma culture medium are present not only in the precursor form, but that they are also present as enzyme-inhibitor complexes, both of which can be activated enzymatically in vitro.
Melanoma Res
PMID:Inactive cathepsin B-like enzyme in human melanoma culture medium. 142 90

Here we demonstrate a nonradioactive immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) technique which replaces the standard practice of isotopic protein labeling by iodination or metabolic tagging in the analysis of membrane proteins. The technique has proved extremely valuable in the biochemical analysis of small quantities of frozen, pathological tissue. Membranes were prepared from Dx3 (a human melanoma cell line), C6 (a rat glial cell line), and osteoclastoma (a human giant cell tumor of bone). The membranes were labeled with biotin and immunoprecipitated with a variety of antibodies to the vitronectin receptor (VNR). The VNR proteins were resolved by SDS-PAGE and immunoblotted onto nitrocellulose paper. The biotinylated protein was visualized using streptavidin horseradish peroxidase and enhanced chemiluminescence (ECL). Film exposures ranged from 15 min to 16 h. Good visualization of the VNR, yielding the typical heterodimeric receptor of 90 and 150 kDa, was given. Signals generated were high and background noise low with a 30-min film exposure. An overnight exposure increased the detection of weaker bands. In conclusion, biotinylation of membrane proteins proved a satisfactory label for immunoprecipitation and SDS-PAGE analysis. The ECL development stage was extremely flexible with visualization of strong and weak signals. The method has several advantages over a conventional radioactive immunoprecipitation in that it is relatively inexpensive, simple, quick and nonhazardous.
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PMID:A nonradioactive biochemical characterization of membrane proteins using enhanced chemiluminescence. 144 97

Toxins may be specifically directed to tumor cells and the toxins' potency greatly increased by covalent conjugation to monoclonal antibodies recognizing tumor-associated antigens. Antibody 15A8, an immunoglobulin G1 (IgG1) subclass anti-human breast carcinoma murine monoclonal antibody and gelonin, a plant toxin, were covalently modified with N-succimindyl 3-(2-pyridyldithio) proprionate and iminothiolane, respectively, and allowed to cross-link. 15A8-gelonin conjugates were purified from unreacted antibody and free gelonin by gel filtration and blue sepharose chromatography. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed that the final product contained two bands corresponding to antibody:gelonin conjugates of 1:1 (predominant) and 1:2. There were no contaminating amounts of free antibody or free toxin in the preparation. The yield of the final purified 15A8-gelonin conjugate was approximately 20% based on the amount of starting antibody. The protein synthesis inhibitory activity of the immunoconjugate was assessed by in vitro rabbit reticulocyte translation assay. This functional activity was normalized to that of unmodified gelonin for use in in vitro antiproliferative assays against antigen-negative (Hs294t human melanoma) and antigen-positive (ME-180 human cervical carcinoma) cell lines. Antigen-negative Hs294t cells incubated for 72 hours with 15A8-gelonin immunotoxin showed no increased cytotoxicity compared with HS294t cells exposed to free gelonin alone. However, the immunotoxin was preferentially toxic to antigen-positive ME-180 cells; over 5 logs greater cell kill was observed after 72 hours exposure to 15A8-gelonin than after the same exposure to gelonin alone. Various lysosomotropic agents augmented 15A8-gelonin cytotoxicity; the most effective potentiating agent appeared to be monensin. In addition, the chemotherapeutic agents L-phenylalanine mustard (L-PAM), 5-fluorouracil, vincristine, and bleomycin, and the biological response modifiers interferon-alpha and tumor necrosis factor-alpha were shown to augment 15A8-gelonin cytotoxicity. Should in vivo pharmacology and therapeutic studies confirm these in vitro findings, 15A8-gelonin conjugate may be a potent agent for therapy of cancer in man.
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PMID:A gelonin-containing immunotoxin directed against human breast carcinoma. 144 65

Seventeen patients with advanced melanoma and no prior exposure to chemotherapy were treated with brequinar sodium as first-line chemotherapy. Brequinar was given at a median weekly dose of 1200 mg/m2 intravenously. In 14 patients evaluable for efficacy, there were no objective responses. The toxicity was moderate. We conclude that, at this dose and schedule, brequinar has no activity in advanced melanoma.
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PMID:Multicenter phase II trial of brequinar sodium in patients with advanced melanoma. 145 49

The antifungal reagent Fungizone (amphotericin B and deoxycholate) caused an activation in dopachrome tautomerase and dopa oxidase activities of B16/F10 melanoma cells at the routine concentration (2.5 micrograms/ml) used for preventing molds and yeast growth in cultures of animal cells. However, higher amphotericin B concentrations caused a significant cell death and the inhibition of enzymatic activities. At the optimal concentration of Fungizone, the enzymatic activities and melanin content were augmented as incubation time increased. The detergent sodium deoxycholate alone exerted no effect on these melanogenic parameters, eliminating the possibility that this detergent was partially responsible for melanogenic modifications produced by Fungizone. After withdrawal of Fungizone from the reaction medium, the recovery of melanogenic parameters to normal values was slower for DCT than for tyrosinase. The behavior of dopa oxidase was very similar to that reported by Johnson and Bagnara (Pigment Cell Res. 3, 173-175) for tyrosine hydroxylase.
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PMID:Effect of amphotericin B on dopachrome tautomerase activity and other melanogenic parameters in cultured B16/F10 melanoma cells. 149 75

Tumor autocrine motility factor (AMF) is a cytokine which stimulates both random and directed cell migration by self-producing cells. AMF has been detected in and purified from serum-free conditioned medium of murine B16-F1 melanoma cells. Under nonreducing conditions AMF migrates in sodium dodecyl sulfate-polyacrylamide gel electrophoresis as a single band of Mr 55,000, whereas under reducing conditions it migrates as a single polypeptide of Mr 64,000. Two-dimensional polyacrylamide gel electrophoresis of the purified AMF resolved two polypeptides with isoelectric points of 6.35 (major) and 6.4 (minor). No carbohydrate side chains were detected in the B16-F1 AMF. Purified AMF stimulated B16-F1 cell migration in a dose-dependent fashion and bound directly in a protein-protein-binding assay to the AMF receptor, a cell surface glycoprotein of Mr 78,000 [glycoprotein (gp) 78]. The involvement of gp78 in AMF-stimulated function was demonstrated by motility assays. These results suggest that AMF is the natural ligand for the gp78-AMF receptor.
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PMID:Purification of B16-F1 melanoma autocrine motility factor and its receptor. 164 68

Retinoic acid, hexamethylene bisacetamide, sodium butyrate, and dimethylsulfoxide, four compounds which modulate phenotypic expression in a variety of neoplastic cell lines, all inhibited the induction of tyrosinase activity and melanogenesis by the combination of melanocyte-stimulating hormone and isobutylmethyxanthine in Cloudman S91 melanoma cells. Results were the same in assays of whole cells or in extracts made from them. Only retinoic acid, however, was effective at inhibiting the activation of dopachrome isomerase, another regulatory enzyme in melanogenesis. Despite inhibiting the effects of melanocyte-stimulating hormone (MSH) and isobutylmethylxanthine on tyrosinase activity, all of the agents tested increased the binding of MSH to intact cells. Ultrastructural analysis of treated cells following DOPA cytochemistry revealed that both retinoic acid and hexamethylene bisacetamide arrested melanosomal maturation at stage I-II. Retinoic acid resulted in a derangement of melanosomal structure. The specificity of these agents for preventing the induction of melanogenesis makes them powerful tools for the dissection of this complex cellular process.
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PMID:Inhibition of induced melanogenesis in Cloudman melanoma cells by four phenotypic modifiers. 170 21

Using allogeneic antibody, we previously described a tumor-associated antigen (TAA) in the urine of 68% of melanoma patients. The TAA was purified from urine of a melanoma patient and used as immunogen to develop a murine monoclonal antibody (AD1-40F4) and xenopolyclonal antibodies in a baboon. Sera from melanoma patients treated with whole melanoma cell vaccine were used as the source of human antibody to the glycoprotein antigen. Treatment with 2-mercaptoethanol and separation by sodium dodecyl sulfate/polyacrylamide gel electrophoresis resolved the high-molecular-mass glycoprotein TAA into smaller subunits. Immunoblot analysis indicates that the murine monoclonal antibody (AD1-40F4) recognized a 90-100-kDa subunit of the antigen while human anti-TAA antibodies primarily recognized a 65-kDa subunit in addition to the 90-100-kDa subunit. Baboon polyclonal antibodies recognized the same subunits plus a 120-kDa subunit. Blocking studies indicated that the murine monoclonal and baboon polyclonal antibodies recognized the closely related epitopes on the 90-100-kDa subunit, while human antibodies recognized an epitope entirely distinct from that recognized by the mouse antibody. These results demonstrate the epitope complexity associated with the high-molecular-mass glycoprotein TAA.
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PMID:Association between allo-immunoreactive and xeno-immunoreactive subunits of a glycoprotein tumor-associated antigen. 170 32

Since the human high-molecular-weight melanoma-associated antigen (HMW-MAA) represents a useful target to implement active specific immunotherapy with mouse antiidiotypic monoclonal antibody (mAb), the present study is aimed at developing and characterizing mouse antiidiotypic mAbs which bear the mirror image of the determinant defined by the anti-HMW-MAA mAb TP61.5. To this end, a BALB/c mouse was immunized with the syngeneic mAb TP61.5. Screening of the 703 generated hybridomas showed that 13 of them secrete antiidiotypic mAbs which inhibit the binding of the immunizing mAb TP61.5 to melanoma cells by at least 75%. The dose of antiidiotypic mAb required to inhibit by 50% the binding of mAb TP61.5 to melanoma cells ranged between 4 and 200 ng. The 13 antiidiotypic mAbs recognize conformational idiotypes, since they did not react in Western blotting with the heavy and light chain of mAb TP61.5 isolated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions. Furthermore, the 13 antiidiotypic mAbs did not react with 23 mAbs which recognize 13 determinants of the HMW-MAA distinct from that defined by mAb TP61.5. Analysis of the 13 antiidiotypic mAbs for their ability to elicit cellular and humoral anti-HMW-MAA immunity showed that only mAb TK7-371 elicited a delayed-type hypersensitivity reaction to HMW-MAA-bearing cells in syngeneic hosts and anti-HMW-MAA antibodies in BALB/c mice and in rabbits. Since rabbits express the HMW-MAA, the present results indicate that the antiidiotypic mAb TK7-371 can induce humoral immunity to self HMW-MAA. Therefore, the antiidiotypic mAb TK7-371 may be an efficacious immunogen to implement active specific immunotherapy in patients with melanoma.
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PMID:Human high-molecular-weight melanoma-associated antigen mimicry by mouse antiidiotypic monoclonal antibody TK7-371. 171 13


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