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)

Angiogenesis plays an essential role in the growth and dissemination of solid tumor cancers. The expression of endothelial cell integrin alpha(v)beta3 has been shown to increase during vascular proliferation associated with human tumors. Selective antagonists of alpha(v)beta3 can block angiogenesis and tumor growth by inducing programmed cell death in proliferating endothelial cells. Monoclonal antibody 7E3, an antagonist of the human, but not murine, integrins alpha(v)beta3 and alphaIIbbeta3 (GPIIb/IIIa), inhibits platelet aggregation. It is the parent antibody of a mouse/human chimeric antibody fragment approved for adjunctive therapy of patients undergoing percutaneous coronary interventions to prevent ischemic complications (c7E3Fab; abciximab; ReoPro). To evaluate the potential of 7E3 to inhibit human angiogenesis and tumor growth independent of its antiplatelet effects, we established integrin alpha(v)beta3-negative human melanoma tumors in full-thickness human skin grafted onto SCID mice. The resulting tumors induce a human angiogenic response as assessed by the immunoreactivity of vascular cells with monoclonal antibodies specific for human CD31. Administration of 7E3 prevented or significantly inhibited the growth of tumors, and this effect correlated with a significant reduction in the number of blood vessels supplying the tumors. These results support the previous findings that blockade of integrin alpha(v)beta3 inhibits angiogenesis and tumor growth and indicates that dual inhibitors of alpha(v)beta3 and alphaIIbbeta3 are effective in blocking tumor growth and angiogenesis.
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PMID:Inhibition of angiogenesis and tumor growth by murine 7E3, the parent antibody of c7E3 Fab (abciximab; ReoPro). 1451 44

Bruceantin was first isolated from Brucea antidysenterica, a tree used in Ethiopia for the treatment of cancer, and activity was observed against B16 melanoma, colon 38, and L1210 and P388 leukemia in mice. Phase I and II clinical trials were then initiated, but no objective tumor regressions were observed and clinical development was terminated. Recently, the activity of bruceantin has been studied with a number of leukemia, lymphoma, and myeloma cell lines. Cell differentiation was induced and c-MYC was down-regulated, suggesting a mechanistic correlation between c-MYC down-regulation and induction of cell differentiation or cell death. Treatment of HL-60 and RPMI 8226 cell lines induced apoptosis, and this involved the caspase and mitochondrial pathways. Moreover, an in vivo study using RPMI 8226 human-SCID xenografts demonstrated that bruceantin induced regression in early as well as advanced tumors, and these significant antitumor responses were facilitated in the absence of overt toxicity. Apoptosis was significantly elevated in tumors derived from animals treated with bruceantin. In sum, bruceantin interferes with the growth of leukemia, lymphoma, and myeloma cells in culture and xenograft models. Responses of this type suggest bruceantin should be reinvestigated for clinical efficacy against hematological malignancies.
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PMID:Antitumor activity of bruceantin: an old drug with new promise. 1498 68

Functional inactivation of genes critical to immunity may occur by mutation and/or by repression, the latter being potentially reversible with agents that modify chromatin. This study was constructed to determine whether reversal of gene silencing, by altering the acetylation status of chromatin, might lead to an effective tumor vaccine. We show that the expression of selected genes important to tumor immunity, including MHC class II, CD40, and B7-1/2 are altered by treating tumor cells in vitro with a histone deacetylase inhibitor, trichostatin A (TSA). Tumor cells treated in vitro with TSA showed delayed onset and rate of tumor growth in 70% of the J558 plasmacytoma and 100% of the B16 melanoma injected animals. Long-term tumor specific immunity was elicited to rechallenge with wild-type cells in approximately 30% in both tumor models. Splenic T cells from immune mice lysed untreated tumor cells, and SCID mice did not manifest immunity, suggesting that T cells may be involved in immunity. We hypothesize that repression of immune genes is involved in the evasion of immunity by tumors and suggest that epigenetically altered cancer cells should be further explored as a strategy for the induction of tumor immunity.
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PMID:An epigenetically altered tumor cell vaccine. 1499 46

For patients with advanced malignant melanoma, the 5 y survival rate with current treatment modalities is low. There is an urgent need for more effective therapeutic concepts. One approach with great potential is to stimulate the body's own immune defense to reject cancer cells using CpG oligonucleotides. Distinct oligonucleotides containing nonmethylated cytidine residues in cytidine-guanosine dinucleotides with particular flanking bases (CpG motifs) are capable of eliciting powerful immune stimulation by mimicking infectious disease. We evaluated the in vivo antitumoral effects of CpG oligonucleotides against human malignant melanoma xenografts in NOD/SCID mice. CpG oligonucleotides administered in single peritumoral subcutaneous injections three times per week resulted in elevated plasma levels of interleukin-12 and significant inhibition of the growth of established tumor xenografts by 60% (p<0.016) compared to the saline control. In addition to this a significant invasion of macrophages into tumor xenografts and increased numbers of Langerhans-cell-derived dendritic cells in draining lymph nodes could be observed. Our findings demonstrate the antitumor activity of oligonucleotides containing immune-stimulatory CpG motifs in a xenotransplantation model with absent B, T cells and a lack of natural killer cell function.
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PMID:CpG oligonucleotides elicit antitumor responses in a human melanoma NOD/SCID xenotransplantation model. 1500 20

Procoagulant activity on tumor cells can enhance their ability to spread via the circulation to colonize distant organs. Toward defining the relative importance of the main host responses to coagulation for hematogenous metastasis, we examined lung metastases after intravenous injection of melanoma cells in Nf-E2(-/-) mice, which have virtually no circulating platelets; Par4(-/-) mice, which have platelets that fail to respond to thrombin; Par1 and Par2(-/-) mice, which have markedly attenuated endothelial responses to coagulation proteases; and Fib(-/-) mice, which lack fibrinogen. In a severe combined immunodeficiency (SCID) background, median lung tumor count in Nf-E2(-/-), Par4(-/-), and Fib(-/-) mice was 6%, 14%, and 24% of wild type, respectively; total tumor burden was only 4%, 9%, and 3% of wild type, respectively. Similar results were seen in a syngeneic C57BL6 background. By contrast, deficiencies of protease-activated receptor 1 (PAR1) or PAR2 did not provide protection. These results provide strong genetic evidence that platelets play a key role in hematogenous metastasis and contribute to this process by both thrombin-dependent and -independent mechanisms. Importantly, PAR4 heterozygosity conferred some protection against metastasis in this model. Thus even partial attenuation of platelet function may be sufficient to provide benefit.
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PMID:Platelets, protease-activated receptors, and fibrinogen in hematogenous metastasis. 1503 Dec 12

NS1 protein of influenza virus is a virulence factor that counteracts Type I interferon (IFN)-mediated antiviral response by the host. A recombinant influenza A virus that lacks the NS1 protein only replicates efficiently in systems that contain defective IFN pathways. We demonstrate that the conditional replication properties of NS1-modified influenza A virus mutants can be exploited for the virus-mediated oncolysis of IFN-resistant tumor cells. IFN resistance in analyzed tumor cell lines correlated with a reduced expression of STAT1. Addition of exogenous IFNalpha or supernatant of virus-infected endothelial cells inhibited viral oncolysis in IFN-sensitive but not in IFN-resistant cell lines. The oncolytic potential of NS1-modified influenza A virus mutants could be exploited in vivo in a SCID mouse model of a subcutaneously-implanted human IFN-resistant melanoma. The data indicate that IFN-resistant tumors are a suitable target for oncolysis induced by NS1-modified influenza virus mutants. STAT1 might serve as a marker to identify these IFN-resistant tumors.
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PMID:Interferon resistance promotes oncolysis by influenza virus NS1-deletion mutants. 1505 64

The Immunotherapy and Gene Therapy meeting of the Academy of Medical Sciences reviewed the state-of-the-art and translational prospects for therapeutic interventions aimed at killing tumor cells, correcting genetic defects and developing vaccines for chronic infections. Crucial basic science concepts and information about dendritic cells, the structure and function of T-cell receptors, and manipulation of the immune response by cytokine antagonists and peptides were presented. This information underpins vaccine design and delivery, as well as attempts to immunomodulate autoimmune disease. Results from studies using anticancer DNA vaccines, which include appropriate signals for both the innate and adaptive immune response, were presented in several talks. The vaccines incorporated helper epitopes and cancer target epitopes such as immunoglobulin idiotypes (for lymphomas and myelomas), melanoma-associated antigens (for melanoma and other solid tumors) and minor histocompatibility antigens (for leukemia). The results of using vaccines employing similar principles and designed to reduce viral load in HIV/AIDS patients were also presented. The introduction of suicide genes incorporating the bacterial enzyme nitroreductase gene (ntr) targeted at tumor cells prior to administration of the prodrug CB-1954, converted by ntr into a toxic alkylating agent, was discussed against the background of clinical trials and improved suicide gene design. The introduction into hematopoietic stem cells of missing genes for the common gamma-chain, deficiency of which causes severe combined immunodeficiency (SCID), used similar retroviral transduction. The outcome of treating six SCID patients in the UK, and ten in France was successful immune reconstitution in the majority of patients, but in two of the French cases a complication of lymphoproliferative disease due to insertional mutagenesis was observed. The adoptive transfer of T-cells specific for minor histocompatibility antigens (for leukemia), cytomegalovirus (CMV; for CMV infection following stem cell transplantation) and selected Epstein-Barr virus-encoded antigens (for nasopharyngeal carcinoma) were discussed in relation to the source of specifically primed T-cells or the possibility of transducing recipient T-cells with high-affinity, antigen-specific T-cell receptor genes.
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PMID:Immunotherapy and gene therapy. 1505 48

Attempts to suppress a harmful genetic trait by antisense means, or to restore a normal phenotype by gene transfer, attract much publicity. This is especially the case where clinical trials incorporating such methodologies have been initiated, such as antisense oligonucleotide therapies for some types of leukaemia, antisense gene-transfer therapy for a form of lung cancer, and gene-transfer therapies for adenosine deaminase deficiency, severe combined immunodeficiency disease, and various forms of cancer including brain tumours and melanoma. However, translation of laboratory success into treatment or control of disease is unlikely to be straightforward. Here, Nick Miller and Richard Vile summarize the rationale, problems and potential of such techniques as applied to parasitic disease.
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PMID:Gene transfer and antisense nucleic acid techniques. 1527 88

The expression of integrin alphaV subunit on 4 melanoma-derived cell lines (A2058, SK-mel-5, WM-115 and WM-266-4) was analyzed. WM-115 cells, which originate from a primary tumor, were negative, whereas all 3 metastasis-derived lines had high levels of alphaV. To study alphaV integrins in the survival of melanoma cells, we developed a novel strategy that is exempt from extracellular inhibitors of ligand binding, which can activate integrin signaling and have integrin-independent effects on apoptosis. A recombinant adenovirus was used to transfer cDNA coding for a single-chain intracellular anti-alphaV integrin antibody into the melanoma cells. Anti-alphaV integrin adenovirus effectively inhibited the cell surface expression of alphaV integrins. In cell culture experiments, the depletion of alphaV integrins detached cells from extracellular matrix and induced apoptosis. Moreover, it prevented WM-266-4 cells from forming tumors in severe combined immunodeficiency mice but it could not prevent the growth of tumors that were formed by alphaV-negative WM-115 cells. Our results indicate that in primary melanomas there are cells that survive without alphaV integrins, whereas during the progression of disease cells can develop a dependency on these receptors. Furthermore, the data oppose the possibility that in melanoma cells apoptosis could occur due to direct activation of caspases by ligand-free alphaV integrins on the cell surface.
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PMID:alphaV integrin promotes in vitro and in vivo survival of cells in metastatic melanoma. 1530 76

Melanoma is the most fatal skin cancer, often highly resistant to chemotherapy. Here we show that treatment with an 11-base DNA oligonucleotide homologous to the telomere 3' overhang sequence (T-oligo) induces apoptosis of several established human melanoma cell lines, including the aggressive MM-AN line, whereas normal human melanocytes exposed to the same or higher T-oligo concentrations show only transient cell cycle arrest, implying that malignant cells are more sensitive to T-oligo effects. When MM-AN cells were briefly exposed to T-oligo in culture and injected into the flank or tail vein of SCID mice, eventual tumor volume and number of metastases were reduced 85-95% compared with control mice. Similarly, T-oligos administered intralesionally or systemically selectively inhibited the growth of previously established MM-AN tumor nodules in the flank and peritoneal cavity by 85 to 90% without detectable toxicity. We previously showed that T-oligos act through ATM, p95/Nbs1, E2F1, p16INK4A, p53, and the p53 homologue p73 to modulate downstream effectors and now additionally demonstrate striking down-regulation of the inhibitor of apoptosis protein livin/ML-IAP. We suggest that T-oligo mimics a physiologic DNA damage signal that is frequently masked in malignant cells and thereby activates innate cancer prevention responses. T-oligos may provide a novel therapeutic approach to melanoma.
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PMID:Telomere-based DNA damage responses: a new approach to melanoma. 1533 80


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