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  • CANCER  (17)
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  • 1
    Keywords: APOPTOSIS ; CANCER ; CELLS ; EXPRESSION ; INHIBITION ; DISTINCT ; GENE ; PROTEIN ; LINES ; DNA ; CELL-CYCLE ; IDENTIFICATION ; REPAIR ; MELANOMA ; MALIGNANT-MELANOMA ; CISPLATIN ; drug resistance ; ABCC2 ; MRP2 ; ANTICANCER DRUGS ; ACQUIRED DRUG-RESISTANCE ; cMOAT ; ETOPOSIDE ; FOTEMUSTINE ; MeWo
    Abstract: Resistance to various anti-neoplastic agents is a common observation in clinical management of melanoma. The biologic mechanisms conferring these different drug-resistant phenotypes, including resistance against the commonly used anti-cancer drug cisplatin, are unclear. In order to elucidate the role of the membrane adenosine triphosphate binding cassette-transporter cMOAT (canalicular multispecific anion transporter) (MRP2/ABCC2) in cisplatin resistance of melanoma, the expression of this protein was analyzed in the platinum drug-resistant cell line MeWo CIS 1. Cisplatinresistant melanoma cells showed a distinct overexpression of cMOAT on mRNA and protein level. This observation was accompanied by a reduced formation of platinum-induced intrastrand cross-links in the nuclear DNA measured by an immunocytologic assay. This decrease in DNA platination was accompanied by an accelerated re-entry into the cell cycle after the typical cisplatin- induced G(2) arrest, and a resistance to undergo apoptosis. Kinetics of formation and elimination of platinum-DNA adducts suggest that the DNA repair capacity for Pt-d(GpG) adducts was not elevated in platinum drug-resistant melanoma cells. The decrease in platinum-DNA adduct formation in cisplatin- resistant melanoma cells was rather a reflection of the protecting activity of the transporter cMOAT. In conclusion, the functional inhibition of cMOAT might be a promising strategy in the reversal of resistance to platinum-based anti- cancer drugs in human melanoma
    Type of Publication: Journal article published
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  • 2
    Keywords: ANGIOGENESIS ; CANCER ; EXPRESSION ; INVASION ; proliferation ; SURVIVAL ; tumor ; CELL-PROLIFERATION ; MICROVESSEL DENSITY ; DENSITY ; GENE ; GENES ; TUMORS ; PATIENT ; ACTIVATION ; FAMILY ; prognosis ; PROGRESSION ; MUTATION ; metastases ; MELANOMA ; MUTATIONS ; ONCOGENE ; CHILDREN ; CUTANEOUS MELANOMA ; INITIATION ; BRAF ; N-RAS ; Ras ; neuroblastoma ; RE ; PATIENT SURVIVAL ; cell proliferation ; CODON ; CUTANEOUS MELANOMAS ; Ki-67 ; NEVI ; RAS MUTATIONS ; VERTICAL GROWTH-PHASE
    Abstract: Previous studies have shown frequent mutations in the BRAF (V-raf murine sarcoma viral oncogene homolog B1) or NRAS ( neuroblastoma RAS viral [V-ras] oncogene homolog) genes in cutaneous melanoma, but the relationship between these alterations and tumor cell proliferation has not been examined in human melanoma. In our study of 51 primary nodular melanomas and 18 paired metastases, we found mutations in BRAF ( codon 600, previously denoted 599) in 15 primary tumors (29%) and eight metastases (44%). The figures for NRAS mutations were 27% and 22%, respectively. Mutations in BRAF and NRAS genes were mutually exclusive in all but one case, and were maintained from primary tumors through their metastases. Mutations, however, were not associated with tumor cell proliferation by Ki-67 expression, tumor thickness, microvessel density, or vascular invasion, and there were no differences in patient survival. Although BRAF and NRAS mutations are likely to be important for the initiation and maintenance of some melanomas, other factors might be more significant for proliferation and prognosis in subgroups of aggressive melanoma
    Type of Publication: Journal article published
    PubMed ID: 16098042
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  • 3
    Keywords: CANCER ; carcinoma ; INHIBITION ; POPULATION ; DIFFERENTIATION ; DENDRITIC CELLS ; TOLERANCE ; antigen presentation ; IMMUNITY ; SUBSETS ; PD-1
    Abstract: Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of cells, and they promote an immunosuppressive environment in tumor-bearing hosts. To characterize MDSCs in melanoma, we examined the expression of inhibitory B7 molecules by CD11b(+)Gr1(+) cells isolated from mice with transplantable ret tumors. B7 molecules were expressed on CD11b(+)Gr1(+) cells, which also expressed CD124 and inducible nitric oxide synthase, thus verifying their relation to MDSCs. In developing melanomas, CD11b(+)Gr1(+) cells express only low levels of B7-H1. In contrast, B7-H1 is upregulated in large tumors, and functional analysis demonstrates that CD11b(+)Gr-1(+) cells suppress the proliferation of CD4(+) T cells through B7-H1. Depletion of regulatory T cells (Tregs) significantly downregulated the expression of B7-H1, B7-H3, and B7-H4 on MDSCs and reduced tumor growth, indicating a concerted immunosuppressive activity of Tregs and MDSCs. No differences in the suppressive function of MDSCs between CD25-depleted and non-depleted mice were recorded. Instead, tumor-derived MDSCs from Treg-depleted hosts produced less IL-10 and more IFN-gamma as compared with Treg-harboring mice. These studies indicate that Tregs in tumors not only suppress effector T cells directly, but also modify the phenotype of tumor-infiltrating CD11b(+) cells to express inhibitory B7-H molecules and to produce IL-10.
    Type of Publication: Journal article published
    PubMed ID: 22189788
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  • 4
    Keywords: CANCER ; ACTIVATION ; SKIN ; INDUCED APOPTOSIS ; chemotherapy ; MUTATIONS ; MUTANT P53 ; SIMIAN-VIRUS-40 ; DNA-DAMAGE RESPONSE ; nutlin-3
    Abstract: Merkel cell carcinoma (MCC) is a rare and very aggressive skin cancer with viral etiology. The tumor-associated Merkel cell polyoma virus (MCV) belongs to a group of viruses encoding T antigens (TAs) that can induce tumorigenesis by interfering with cellular tumor-suppressor proteins like p53. To explore possible modes of p53 inactivation in MCC p53 sequencing, expression analysis and reporter gene assays for functional analyses were performed in a set of MCC lines. In one MCV-negative and one MCV-positive cell line, p53 inactivating mutations were found. In the majority of MCC lines, however, wild-type p53 is expressed and displays some transcriptional activity, which is yet not sufficient to effectively restrict cellular survival or growth in these cell cultures. Interestingly, the MCV TAs are not responsible for this critical lack in p53 activity, as TA knockdown in MCV-positive MCC cells does not induce p53 activity. In contrast, inhibition of the ubiquitin ligase HDM-2 (human double minute 2) by Nutlin-3a leads to p53 activation and p53-dependent apoptosis or cell cycle arrest in five out of seven p53 wild-type MCC lines, highlighting p53 as a potential target for future therapies of this aggressive tumor.
    Type of Publication: Journal article published
    PubMed ID: 23563200
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  • 5
    Keywords: CANCER ; EXPRESSION ; IN-VIVO ; ANTIGEN ; REPLICATION ; GENE-THERAPY ; SUICIDE GENE ; VIROTHERAPY ; VACCINIA VIRUS ; YEAST CYTOSINE DEAMINASE
    Abstract: Effective treatment modalities for advanced melanoma are desperately needed. An innovative approach is virotherapy, in which viruses are engineered to infect cancer cells, resulting in tumor cell lysis and an amplification effect by viral replication and spread. Ideally, tumor selectivity of these oncolytic viruses is already determined during viral cell binding and entry, which has not been reported for melanoma. We engineered an oncolytic measles virus entering melanoma cells through the high molecular weight melanoma-associated antigen (HMWMAA) and proved highly specific infection and spread in melanoma cells. We further enhanced this oncolytic virus by inserting the FCU1 gene encoding the yeast-derived prodrug convertases cytosine deaminase and uracil phosphoribosyltransferase. Combination treatment with armed and retargeted MV-FCU1-alphaHMWMAA and the prodrug 5-fluorocytosine (5-FC) led to effective prodrug conversion to 5-fluorouracil, extensive cytotoxicity to melanoma cells, and excessive bystander killing of noninfected cells. Importantly, HMWMAA-retargeted MV showed antitumor activity in a human xenograft mouse model, which was further increased by the FCU1/5-FC prodrug activation system. Finally, we demonstrated susceptibility of melanoma skin metastasis biopsies to HMWMAA-retargeted MV. The highly selective, entry-targeted and armed oncolytic virus MV-FCU1-alphaHMWMAA may become a potent building block of future melanoma therapies.Journal of Investigative Dermatology advance online publication, 6 December 2012; doi:10.1038/jid.2012.459.
    Type of Publication: Journal article published
    PubMed ID: 23223133
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  • 6
    Keywords: CANCER ; CELLS ; EXPRESSION ; INVASION ; tumor ; TUMOR-CELLS ; CELL ; human ; DISEASE ; cell line ; TISSUE ; INFECTION ; DOMAIN ; INDUCTION ; TISSUES ; KERATINOCYTES ; ASSOCIATION ; culture ; STAGE ; ACQUISITION ; PROGRESSION ; DISRUPTION ; MEMBRANE ; SIGNAL-TRANSDUCTION ; LINE ; ADHESION ; CELL-ADHESION ; TRANSFORMATION ; NEOPLASTIC PROGRESSION ; DEGRADATION ; INTEGRIN ; CARCINOMAS ; beta-catenin ; ORGANIZATION ; ADENOVIRUS ; ARCHITECTURE ; organotypic culture ; adherens junctions,basement membrane,E-cadherin,organotypic culture,tumor cell invasion ; CATENIN ; HUMAN BREAST ; MELANOMA DEVELOPMENT
    Abstract: The role of cell-cell adhesion in the transition from premalignancy to invasive cancer is not well understood. The purpose of this study was to determine how abrogation of E-cadherin-mediated adhesion influenced early neoplastic progression in tissues that mimic human, premalignant disease. To accomplish this, E-cadherin function was abrogated in a human cell line representing an early stage in the transformation process (HaCaT-II-4 cells) that was grown in three-dimensional, organotypic cultures with intact basement membrane. Before modification, this cell line showed a paucity of cell adhesion structures by ultrastructural and immunohistochemical analysis, whereas immunoblot studies demonstrated that expression and association of E-cadherin and catenins were not diminished when compared with normal keratinocytes. To further reduce functional E-cadherin, II-4 cells were infected with a dominant-negative, recombinant adenovirus, expressing E-cadherin lacking an extracellular domain (AdECadEC). AdECadEC infection resulted in loss of endogenous E-cadherin and completely disrupted II-4 cell adhesion, as seen by loss of beta-catenin from II-4 cell junctions in monolayer culture. In three-dimensional cultures, AdECadEC-infected cells demonstrated disruption of tissue architecture, loss of cell-cell adhesion, and the invasion of individual tumor cells into the stroma. The induction of this invasive phenotype was associated with loss of basement membrane integrity, as seen by degradation of type IV collagen and laminin 5. These studies showed that loss of E-cadherin-mediated adhesion enabled acquisition of an invasive phenotype, suggesting that maintenance of intercellular adhesion and tissue organization plays a crucial part in suppressing the incipient stages of squamous cell cancer progression
    Type of Publication: Journal article published
    PubMed ID: 14708624
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  • 7
    Keywords: APOPTOSIS ; CANCER ; CELLS ; GROWTH ; IRRADIATION ; proliferation ; tumor ; TUMOR-CELLS ; MODEL ; CARCINOGENESIS ; KERATINOCYTES ; MOUSE ; EQUIVALENT ; PROGRESSION ; MUTATION ; MUTATIONS ; NEOPLASTIC PROGRESSION ; intraepithelial neoplasia ; organotypic culture ; HA-RAS ; HACAT-RAS ; HUMAN SKIN ; MALIGNANT KERATINOCYTES ; RECONSTRUCTED IN-VITRO ; SUNLIGHT ; UVB irradiation
    Abstract: Ultraviolet B irradiation is thought to enable skin cancer progression as clones of genetically damaged keratinocytes escape apoptosis and expand at the expense of adjacent normal cells. Mechanisms through which potentially malignant cells in human skin undergo clonal expansion, however, are not well understood. The goal of this study was to characterize the role of ultraviolet B irradiation on the intraepithelial expansion of early stage human tumor cells in organotypic skin cultures. To accomplish this, we have studied the effect of ultraviolet B irradiation on organotypic cultures that were fabricated by mixing normal human keratinocytes with beta-galactosidase- marked, intraepithelial tumor cells (HaCaT-ras , clone II-4), which bear mutations in both p53 alleles and harbor an activated H-ras oncogene. We found that when organotypic mixtures were exposed to an ultraviolet B dose of 50 mJ per cm(2) , intraepithelial tumor cells underwent a significant degree of proliferative expansion compared to nonirradiated cultures. To understand this response, organotypic cultures of nor-mal keratinocytes were exposed to ultraviolet B and showed a dose-dependent increase in numbers of sunburn cells and TUNEL-positive cells although their proliferation was suppressed. In contrast, neither the apoptotic nor the proliferative response of II-4 cells was altered by ultraviolet B in organotypic cultures. The differential response of these cell types suggested that II-4 cells were resistant to ultraviolet-B-induced alterations, which allowed these intraepithelial tumor cells to gain a selective growth and survival advantage relative to neighboring normal cells. These findings demonstrate that ultraviolet B exposure can induce the intraepithelial expansion of apoptosis-resistant, p53-mutant, and ras -activated keratinocytes, suggesting that this agent can act to promote the early stages of epithelial carcinogenesis
    Type of Publication: Journal article published
    PubMed ID: 12839581
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  • 8
    Keywords: RECEPTOR ; CANCER ; EXPRESSION ; tumor ; carcinoma ; GENE ; PROTEIN ; transcription ; LINES ; PATIENT ; DNA ; SERA ; colon ; DENDRITIC CELLS ; BREAST ; IDENTIFICATION ; AMPLIFICATION ; MELANOMA ; POLYMERASE-CHAIN-REACTION ; IMMUNE-RESPONSE ; IMMUNOTHERAPY ; vaccination ; CTCL ; sero-reactivity ; head and neck ; cancer-testis antigens ; MYCOSIS-FUNGOIDES ; PSEUDOGENES ; tumor immunology
    Abstract: cTAGE-1 is a cutaneous-T-cell-lymphoma-specific tumor antigen recently identified by serologic identification of antigens by recombinant expression cloning. This study was aimed at identifying and characterizing related genes. Rapid amplification of cDNA ends and DNA screening led to five new members of the cTAGE gene family belonging to four different genes, two of which were differentially spliced (cTAGE-1/2 and cTAGE-5). Expression analysis using reverse transcription polymerase chain reaction revealed that cTAGE-1, cTAGE-1B, and cTAGE-5A expression was restricted to testis and tumor tissues, whereas the other cTAGE members were found in two to eight other normal tissues (of 27 tissues tested). Tumor-specific protein expression of cTAGE-5 was confirmed by Western blotting. Sero-reactivity against cTAGE-1, cTAGE-4, cTAGE-5A, and cTAGE-5B was found only in tumor patients (cutaneous T cell lymphoma and melanoma). The immunogenic epitope of cTAGE-1 was determined by using epitope mapping and sera of two cutaneous T cell lymphoma patients. Moreover, cTAGE-1, cTAGE-4, cTAGE-5A, and cTAGE-5B could be detected in most types of tumor tissues and cell lines at variable frequencies, including those of cutaneous T cell lymphoma, melanoma, head and neck squamous cell carcinoma, breast carcinoma, and colon carcinoma. We conclude that cTAGE-1 and cTAGE-5 are new cancer germline antigens and that tumor-specific splicing of cTAGE genes may lead to further candidate proteins for specific immunotherapy of cutaneous T cell lymphoma and other malignancies
    Type of Publication: Journal article published
    PubMed ID: 12839582
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  • 9
    Keywords: RECEPTOR ; CANCER ; CELLS ; EXPRESSION ; carcinoma ; CELL ; Germany ; LUNG ; lung cancer ; LUNG-CANCER ; SITE ; SITES ; cell line ; DIFFERENTIATION ; LINES ; LIGAND ; CELL-LINES ; BREAST ; METASTASIS ; metastases ; CELL-LINE ; LINE ; MELANOMA ; SURFACE ; adenocarcinoma ; GASTROINTESTINAL-TRACT ; chemokine ; THYMOCYTES ; CHEMOKINE RECEPTOR ; thymus ; homing ; MELANOMA-CELLS ; LYMPH-NODE METASTASIS ; SDF-1 ; small bowel ; small intestine ; SMALL-BOWEL ; TECK
    Abstract: In general, metastases to the small intestine are rare, and mostly occur in melanoma. CCR9 has been shown to be the principal chemokine receptor for the thymus expressed chemokine (TECK), a chemokine selectively expressed in the small intestine and thymus. Here we show that CCR9 is highly expressed on melanoma cells and all melanoma cell lines isolated from small intestinal metastases, and on a proportion of cell lines from other sites. Only melanoma cells and cell lines from small intestinal metastases, however, were responsive to the CCR9 ligand TECK, as assessed by receptor downregulation and by actin polymerization. CCR9 expression was also found on the adenocarcinoma cell line CaCo-2 expressing characteristics of enterocytic differentiation, but not on any other cell line isolated from colorectal, breast, and lung cancer. Our data provide evidence that the aberrant functional cell surface expression of an organ-specific chemokine receptor is associated with metastasis to this site. The regulation of receptor function seems to be a critical step in the metastatic process
    Type of Publication: Journal article published
    PubMed ID: 15086554
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  • 10
    Keywords: CANCER ; CELLS ; EXPRESSION ; INVASION ; tumor ; TUMOR-CELLS ; carcinoma ; CELL ; human ; MODEL ; DISEASE ; NEW-YORK ; TISSUE ; ACTIVATION ; INDUCTION ; TISSUES ; KERATINOCYTES ; SKIN ; SUPPRESSION ; culture ; STAGE ; PROGRESSION ; MEMBRANE ; RAS ONCOGENE ; skin cancer ; CELL-LINE ; EXTRACELLULAR-MATRIX ; CARCINOMA-CELLS ; BETA ; ADHESION ; CELL-ADHESION ; MIGRATION ; squamous cell carcinoma ; BEHAVIOR ; ORGANIZATION ; CELL-MIGRATION ; SKIN-CANCER ; E-cadherin ; CELL CARCINOMA ; FEATURES ; BETA-ACTIN ; cell adhesion ; cell migration ; 3D ; USA ; LOSSES ; MOTILITY ; SQUAMOUS-CELL ; ACTIN ; CELL MOTILITY
    Abstract: The link between loss of cell-cell adhesion, the activation of cell migration, and the behavior of intraepithelial (IE) tumor cells during the early stages of skin cancer progression is not well understood. The current study characterized the migratory behavior of a squamous cell carcinoma cell line (HaCaT-II-4) upon E-cadherin suppression in both 2D, monolayer cultures and within human skin equivalents that mimic premalignant disease. The migratory behavior of tumor cells was first analyzed in 3D tissue context by developing a model that mimics transepithelial tumor cell migration. We show that loss of cell adhesion enabled migration of single, IE tumor cells between normal keratinocytes as a prerequisite for stromal invasion. To further understand this migratory behavior, E-cadherin-deficient cells were analyzed in 2D, monolayer cultures and displayed altered cytoarchitecture and enhanced membrane protrusive activity that was associated with circumferential actin organization and induction of the nonmuscle, beta actin isoform. These features were associated with increased motility and random, individual cell migration in response to scrape-wounding. Thus, loss of E-cadherin-mediated adhesion led to the acquisition of phenotypic properties that augmented cell motility and directed the transition from the precancer to cancer in skin-like tissues
    Type of Publication: Journal article published
    PubMed ID: 18528437
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