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)

Several studies have shown antitumor activities of the melanoma differentiation-associated gene 7 (mda-7) and the nonsteroidal anti-inflammatory drug sulindac when used as a monotherapies against a wide variety of human cancers. However, the combined effects of mda-7 and sulindac have not previously been tested. Therefore, we tested the antitumor activity of an adenoviral vector expressing mda-7 (Ad-mda7) in combination with sulindac against non-small cell lung cancer cells in vitro and in vivo. When treated with Ad-mda7 in combination with sulindac, human lung cancer cells (A549 and H1299) underwent growth suppression resulting in apoptosis. The growth inhibition induced by Ad-mda7 in combination with sulindac was significantly greater than that observed with Ad-mda7 or sulindac alone. Furthermore, the degree of growth inhibition induced using this combination was dose-dependent for sulindac. Treatment with Ad-mda7 in combination with sulindac had no growth inhibitory effects on human normal lung (CCD-16) fibroblasts. We then investigated the mechanism by which sulindac enhances Ad-mda7-mediated apoptosis. Sulindac increased expression of ectopic MDA-7 protein in tumor cells, thereby increasing the expression of downstream effectors RNA-dependent protein kinase, p38MAPK, caspase-9, and caspase-3 and enhancing apoptosis of non-small cell lung cancer cells. Pulse-chase experiments showed that the increased expression of MDA-7 protein in sulindac-treated cells was due to increased half-life of the MDA-7 protein. Finally, treatment of human lung tumor xenografts in nude mice with Ad-mda7 plus sulindac significantly suppressed growth (P = 0.001) compared with Ad-mda7 or sulindac alone. Our results show for the first time that combined treatment with Ad-mda7 plus sulindac enhances growth inhibition and apoptosis of human lung cancer cells. The increased antitumor activity observed with the combination treatment is a result of increased half-life of MDA-7 protein. Regulation of protein turnover is a heretofore-unrecognized mechanism of this nonsteroidal anti-inflammatory drug.
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PMID:Sulindac enhances adenoviral vector expressing mda-7/IL-24-mediated apoptosis in human lung cancer. 1571

In a previous study, we showed that G3139, an antisense phosphorothioate oligonucleotide that down-regulates the expression of Bcl-2 protein, did not cause chemosensitization of 518A2 melanoma cells. In this work, we show that G3139, and the 2-base mismatch, G4126, can initiate apoptosis in this and other melanoma cell lines as shown by increased cell surface Annexin V expression, typical nuclear phenotypic changes as assessed by 4',6-diamidino-2-phenylindole staining, activation of caspase-3 (but not caspase-8) and Bid, appearance of DEVDase (but not IETDase) activity, and cleavage of poly(ADP-ribose)-polymerase 1. Depolarization of the mitochondrial membrane occurs as a relatively late event. All of these processes seem to be substantially, but perhaps not totally, Bcl-2 independent as shown by experiments employing an anti-Bcl-2 small interfering RNA, which as shown previously down-regulated Bcl-2 protein expression but did not produce apoptosis or chemosensitization in melanoma cells. In fact, these G3139-induced molecular events were not dramatically altered in cells that forcibly overexpressed high levels of Bcl-2 protein. Addition of irreversible caspase inhibitors (e.g., the pan-caspase inhibitor zVAD-fmk) to G3139-treated cells almost completely blocked cytotoxicity. Examination of the time course of the appearance of caspase-3 and cleaved poly(ADP-ribose)-polymerase 1 showed that this could be correlated with the release of cytochrome c from the mitochondria, an event that begins only approximately 4 hours after the end of the oligonucleotide/LipofectAMINE 2000 5-hour transfection period. Thus, both G3139 and cytotoxic chemotherapy activate the intrinsic pathway of apoptosis in these cells, although Bcl-2 expression does not seem to contribute strongly to chemoresistance. These findings suggest that the attainment of G3139-induced chemosensitization in these cells will be difficult.
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PMID:Phosphorothioate oligodeoxynucleotides and G3139 induce apoptosis in 518A2 melanoma cells. 1571 1

Previous studies showed that long-wave ultraviolet (UVA) radiation induces severe skin damage through the generation of reactive oxygen species and the depletion of endogenous antioxidant systems. Recent results from our laboratory indicate a dramatic increase of both lipid peroxidation products (TBARS) and abnormal L-isoaspartyl residues, marker of protein damage, in UVA-irradiated human melanoma cells. In this study, the effects of hydroxytyrosol (DOPET), the major antioxidant compound present in olive oil, on UVA-induced cell damages, have been investigated, using a human melanoma cell line (M14) as a model system. In UVA-irradiated M14 cells, a protective effect of DOPET in preventing the uprise of typical markers of oxidative stress, such as TBARS and 2'7'-dichlorofluorescein (DCF) fluorescence intensity, was observed. In addition, DOPET prevents the increase of altered L-isoAsp residues induced by UVA irradiation. These protective effects are dose dependent, reaching the maximum at 400 microM DOPET. At higher concentrations, DOPET causes an arrest of M14 cell proliferation and acts as a proapoptotic stimulus by activating caspase-3 activity. In the investigated model system, DOPET is quantitatively converted into its methylated derivative, endowed with a radical scavenging ability comparable to that of its parent compound. These findings are in line with the hypothesis that the oxidative stress plays a major role in mediating the UVA-induced protein damage. Results suggest that DOPET may exerts differential effects on melanoma cells according to the dose employed and this must always be taken into account when olive oil-derived large consumer products, including cosmetics and functional foods, are employed.
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PMID:Hydroxytyrosol, a natural antioxidant from olive oil, prevents protein damage induced by long-wave ultraviolet radiation in melanoma cells. 1574 87

Protein kinase C (PKC) activation is believed to protect against apoptosis induced by death receptors. We have found however that the effect of activation of PKC on tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis of melanoma differs between cell lines. Pretreatment with phorbol 12-myristate 13-acetate (PMA) led to inhibition of apoptosis in the majority of the melanoma cell lines, but those with relatively low PKC epsilon expression were sensitized to TRAIL-induced apoptosis. Introduction of PKC epsilon into PKC epsilon-low cell lines reversed sensitization of the cells to TRAIL-induced apoptosis by PMA. In contrast, a dominant-negative form of PKC epsilon caused an increase in sensitivity. The changes in sensitivity to TRAIL-induced apoptosis were reflected in similar changes in conformation of Bax and its relocation from the cytosol to mitochondria. Similarly, there were concordant increases or decreases in mitochondrial release of second mitochondria-derived activator of caspase/DIABLO, activation of caspase-3, and processing of its substrates. Activation of PKC seemed to mediate its effects upstream of mitochondria but downstream of caspase-8 and Bid in that pretreatment with PMA did not cause significant changes in the expression levels of TRAIL death receptors, alterations in the levels of caspase-8 activation, or cleavage of Bid. PKC activated the anti-apoptotic extracellular signal-regulated kinase 1/2 pathway, but inhibitors of this pathway only partially reversed the protective effect of PKC against TRAIL-induced apoptosis. These results provide further insights into the variable responses of melanoma to TRAIL-induced apoptosis and may help define responsive phenotypes to treatment of melanoma with TRAIL.
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PMID:Variable expression of protein kinase C epsilon in human melanoma cells regulates sensitivity to TRAIL-induced apoptosis. 1582 41

We examined the anti-tumor activity and structure-activity requirements of omega-hydroxy fatty acids (omega-HFAs) on the human melanoma cell line G361. The omega-hydroxystearic acid (omega-HSA) had strong growth-inhibiting and cytotoxic activity. Although omega-hydroxypalmitic acid (omega-HPA) also had growth-inhibiting and cytotoxic activity, these effects were relatively low. The effects of both these acids were dose and time dependent. Further, DNA laddering, which is an index of apoptosis, was also observed in G361 cells on treatment with these compounds. On the other hand, the omega-HFAs tested in this study, omega-hydroxymyristic acid and omega-hydroxyeicosanoic acid, had no growth-inhibiting or cytotoxic activity. Treatment for 12 h with 100 microM of omega-HPA and omega-HSA resulted in the expression of caspase-3 activity, and then increased upon 24 h, suggesting that the cell death induced by omega-HPA and omega-HSA was apoptosis. Fatty acids and dicarboxylic acids, which are analogs of omega-HFAs, had no cytotoxicity. However, fatty alcohols and diols, which have a 16- to 18-carbon chain length had weak cytotoxicity. From these results, the most effective carbon chain length is 18. Furthermore, the hydroxyl group at one end of the carbon chain and the carboxyl group at the other end seem to be required for the cytotoxic effect. At least one end of the carbon chain must have a hydroxyl group. The carbon chain length of omega-HFAs appears to be closely related to the cytotoxicity. This study revealed the potent cytotoxic actions of omega-HFAs on the human melanoma cell line G361.
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PMID:Growth inhibition and apoptosis induction of human melanoma cells by omega-hydroxy fatty acids. 1584 20

The cholesterol-lowering medications, statins, inhibit cellular proliferation and induce apoptosis in an array of cancer cell lines, including melanoma. We investigated the apoptotic mechanism of lovastatin on human melanoma cell lines in vitro. The cytotoxicity of statins on multiple cell lines was examined by Cell Titer 96 Aqueous One solution cell proliferation assay (MTS assay). Apoptosis was assayed by ethidium bromide and acridine orange morphologic assays, an Annexin V apoptosis detection kit and active caspase 3 assays. Farnesyl pyrophosphate and geranylgeranyl pyrophosphate add-back experiments were performed to better define the molecular mechanisms mediating lovastatin cytotoxicity. Lovastatin caused cytotoxicity in human and murine melanoma cells, but did not induce toxicity in an epidermoid carcinoma cell line A431. For human melanoma cells, lovastatin precipitated cell rounding, increased the percentage of apoptotic cells detected by ethidium bromide and acridine orange staining and by the Annexin V apoptosis detection kit, and resulted in a 50-fold increase in active caspase 3, corroborating that lovastatin induced apoptosis. Adding back geranylgeranyl pyrophosphate, but not farnesyl pyrophosphate, reversed the effects of lovastatin in A375 cells. Of the five statins tested, pravastatin was least effective in killing melanoma cells. Lovastatin induced caspase-dependent apoptosis in multiple melanoma cell lines via a geranylation-specific mechanism. This study supports a possible role of lovastatin as a therapeutic, adjuvant or chemopreventive agent for melanoma.
Melanoma Res 2005 Apr
PMID:Lovastatin-induced apoptosis in human melanoma cell lines. 1584 40

CTLA-4 (CD152) is a cell surface receptor that behaves as a negative regulator of the proliferation and the effector function of T cells. We have previously shown that CTLA-4 is also expressed on neoplastic lymphoid and myeloid cells, and it can be targeted to induce apoptosis. In our study, we have extended our analysis and have discovered that surface expression of CTLA-4 is detectable by flow cytometry on 30 of 34 (88%) cell lines derived from a variety of human malignant solid tumors including carcinoma, melanoma, neuroblastoma, rhabdomyosarcoma and osteosarcoma (but not in primary osteoblast-like cultures). However, by reverse transcriptase-PCR, CTLA-4 expression was detected in all cell lines. We have also found, by immunohistochemistry, cytoplasmic and surface expression of CTLA-4 in the tumor cells of all 6 osteosarcoma specimens examined and in the tumour cells of all 5 cases (but only weakly or no positivity at all in neighbouring nontumor cells) of ductal breast carcinomas. Treatment of cells from CTLA-4-expressing tumor lines with recombinant forms of the CTLA-4-ligands CD80 and CD86 induced apoptosis associated with sequential activation of caspase-8 and caspase-3. The level of apoptosis was reduced by soluble CTLA-4 and by anti-CTLA-4 scFvs antibodies. The novel finding that CTLA-4 molecule is expressed and functional on human tumor cells opens up the possibility of antitumor therapeutic intervention based on targeting this molecule.
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PMID:CTLA-4 is constitutively expressed on tumor cells and can trigger apoptosis upon ligand interaction. 1591 38

Measles virus (MV) nucleoprotein (N) is a cytosolic protein that is released into the extracellular compartment after apoptosis and/or secondary necrosis of MV-infected cells in vitro. Thus, MV-N becomes accessible to inhibitory cell-surface receptors: FcgammaRIIB and an uncharacterized nucleoprotein receptor (NR). MV-N is composed of two domains: NCORE (aa 1-400) and NTAIL (aa 401-525). To assess the contribution of MV-N domains and of these two receptors in suppression of cell proliferation, a human melanoma HT144 cell line expressing (HT144IIB1) or lacking FcgammaRIIB1 was used as a model. Specific and exclusive NCORE-FcgammaRIIB1 and NTAIL-NR interactions were shown. Moreover, NTAIL binding to human NR predominantly led to suppression of cell proliferation by arresting cells in the G0/G1 phases of the cell cycle, rather than to apoptosis. NCORE binding to HT144IIB1 cells primarily triggered caspase-3 activation, in contrast to HT144IIB1/IC- cells lacking the FcgammaRIIB1 intra-cytoplasmic tail, thus demonstrating the specific inhibitory effect of the NCORE-FcgammaRIIB1 interaction. MV-N- and NCORE-mediated apoptosis through FcgammaRIIB1 was inhibited by the pan-caspase inhibitor zVAD-FMK, indicating that apoptosis was dependent on caspase activation. By using NTAIL deletion proteins, it was also shown that the region of NTAIL responsible for binding to human NR and for cell growth arrest maps to one of the three conserved boxes (Box1, aa 401-420) found in N of Morbilliviruses. This work unveils novel mechanisms by which distinct domains of MV-N may display different immunosuppressive activities, thus contributing to our comprehension of the immunosuppressive state associated with MV infection. Finally, MV-N domains may be good tools to target tumour cell proliferation and/or apoptosis.
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PMID:Measles virus nucleoprotein induces cell-proliferation arrest and apoptosis through NTAIL-NR and NCORE-FcgammaRIIB1 interactions, respectively. 1591 56

Advanced melanoma is difficult to treat, in part because of greater resistance to therapy compared with other cancer types. The mechanisms underlying this resistance are not well-understood. One factor that is reported to be involved in melanoma cell survival is PAX3, a transcription factor normally expressed during embryonic development, and which is critically required for development of neural crest-derivatives, including skin melanocytes. PAX3 expression is deregulated in primary melanomas and most melanoma cell lines. Here we have investigated whether targeting PAX3 expression in melanoma cell lines together with chemotherapeutic treatment increases susceptibility to therapeutic cell death. Using PAX3-specific antisense oligodeoxynucleotides (PAX3-AS) to treat melanoma cell lines in vitro, we showed dose-dependent reduction of proliferation of melanoma cells, and induction of apoptosis compared with control treatments. Induction of apoptosis was accompanied by the induction of active caspase-3 in UACC62 and M14 cells, and p53 protein in UACC62 cells. Treatment of melanoma cells with cisplatin induces DNA damage and cytotoxicity, which is thought to be via p53-dependent and -independent mechanisms. Treatment of either p53 mutant (M14) or wild-type (UACC62) melanoma cells with cisplatin, and varying doses of PAX3-AS, resulted in percentages of cells undergoing apoptosis equivalent to the sum of the individual treatments, irrespective of mutation status [e.g., UACC62, 43.8% (1 micromol/L PAX3-AS), 30.1% (20 micromol/L cisplatin), 69.6% (PAX3-AS + cisplatin); M14, 12.6% (1 micromol/L PAX3-AS), 41.5% (40 micromol/L cisplatin), 50.2% (PAX3-AS + cisplatin)]. These data suggest that treatment of melanoma cells with PAX3-AS complements cytotoxicity induced by cisplatin.
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PMID:Transfection of melanoma cells with antisense PAX3 oligonucleotides additively complements cisplatin-induced cytotoxicity. 1595 57

In cancer, spontaneous apoptosis of circulating peripheral blood lymphocytes (PBLs) is a general phenomenon. In this study we aimed to determine whether spontaneous apoptosis of circulating PBLs of patients with malignant melanoma occurs. Pathologically proven 45 patients with malignant melanoma and 19 healthy controls were included in this study. Samples were obtained both on first admission before treatment, either adjuvant or metastatic, and follow-up period of patients. Human active caspase-3 immunoassay (R&D Systems, Inc. MN, USA) employs the quantitative sandwich enzyme immunoassay technique. A monoclonal specific for caspase-3 has been used. The spontaneously apoptotic PBLs in melanoma patients were not significantly different from those obtained for normal controls (p=0.25). None of the clinical characteristics were significantly correlated with spontaneous apoptosis (p>0.05). Likewise, we found that apoptosis in PBLs was not a prognostic factor in melanoma patients (p=0.79). In conclusion, we did not observe accelerated apoptosis of PBLs in patients with melanoma. Further studies are necessary to determine the potential prognostic importance of this observation.
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PMID:Apoptosis of lymphocytes in peripheral blood of patients with melanoma. 1596 81


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