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Biomedical subjects

Cornelia Mauch

Publications and source records attributed to Cornelia Mauch.

At least 19 recordsLinked to original sources
PubMed2006

Phase II trial of a toll-like receptor 9-activating oligonucleotide in patients with metastatic melanoma.

PURPOSE: The recent identification of toll-like receptors (TLRs) and respective ligands allows the evaluation of novel dendritic cell (DC) -activating strategies. Stimulation of TLR9 directly activates human plasmacytoid DCs (PDCs) and indirectly induces potent innate immune responses in preclinical tumor models. We performed an open-label, multicenter, single-arm, phase II pilot trial with a TLR9-stimulating oligodeoxynucleotide in melanoma patients. PATIENTS AND METHODS: Patients with unresectable stage IIIb/c or stage IV melanoma received 6 mg PF-3512676 weekly by subcutaneous injection for 24 weeks or until disease progression to evaluate safety as well as clinical and immunologic activity. Clinical and laboratory safety assessments were performed weekly; blood samples for immunological measurements were taken every 8 weeks. Tumor measurements were performed according to Response Evaluation Criteria in Solid Tumors. RESULTS: Twenty patients received PF-3512676 for a mean of 10.9 weeks with a mean of 10.7 injections. Laboratory and nonlaboratory adverse events were limited, transient, and did not result in any withdrawals. Two patients experienced a confirmed partial response; one response is ongoing for 140+ weeks. Three patients experienced stable disease. Immunologic measurements revealed induction of an activated phenotype of PDC, elevation of serum levels of 2',5'-oligoadenylate, a surrogate marker of type I interferon production, and significant stimulation of natural killer cell cytotoxicity (the latter was associated with clinical benefit). CONCLUSION: These results indicate that TLR9-targeted therapy can stimulate innate immune responses in cancer patients, identify biomarkers that may be associated with TLR9-induced tumor regression, and encourage the design of follow-up studies to evaluate the ability of this therapeutic approach to target human cancer.

Adult↗
PubMed2006

Melanoma cell-derived vascular endothelial growth factor induces endothelial tubulogenesis within fibrin gels by a metalloproteinase-mediated mechanism.

Angiogenesis is a process required not only for embryonal development but is encountered in wound healing and in pathological situations such as tumour growth. In vitro, formation of capillary-like structures can be induced by seeding human microvascular endothelial cells (HDMECs) on top of a fibrin matrix in the presence of phorbol 12-myristate 13-acetate (PMA) as a stimulating agent. In this study, we show that supernatants collected from high-invasive melanoma cells (BLM) induce the formation of tubular structures similar to PMA treatment whereas supernatants from low-invasive cells (WM164) did not. Analysis of proteins secreted into the supernatant of both melanoma cell lines identified differential expression of several pro-angiogenic proteins in high- and low-invasive melanoma cells. Vascular endothelial growth factor (VEGF) was strongly expressed by high- but not by low-invasive melanoma cells. Neutralisation of VEGF as well as inhibition of matrix metalloproteases (MMPs) using the broad spectrum MMP inhibitor 1,10-phenanthroline, both strongly reduced the melanoma-induced tube formation. PMA treatment of HDMECs on a fibrin matrix stimulated MT1-MMP synthesis, indicating that this protease is involved in PMA-induced angiogenesis. In addition, stimulation of HDMECs by supernatants of BLM melanoma cells resulted in a strong induction of ADAM-15, which is known to act as a metalloproteinase. In conclusion, these results show that VEGF released by melanoma cells is an important mediator of neo-vascularisation and that this process depends on the presence of metalloproteinases.

Endothelium, Vascular↗
PubMed2006

Enhanced expression levels of IL-31 correlate with IL-4 and IL-13 in atopic and allergic contact dermatitis.

BACKGROUND: IL-31 is produced by activated T lymphocytes, preferentially by TH2 cells. Transgenic mice overexpressing IL-31 have a phenotype resembling allergic dermatitis in human subjects. OBJECTIVE: We sought to evaluate the potential importance of IL-31 in the pathogenesis of human T cell-mediated skin diseases. METHODS: We analyzed total RNA taken from 149 skin biopsy specimens from patients with atopic dermatitis (AD), allergic contact dermatitis (ACD), or psoriasis in comparison with specimens taken from patients with healthy skin (n = 13) by using quantitative real-time PCR for the expression of TH1/TH2 cytokines. RESULTS: We found statistically increased mRNA levels of IL-31 in biopsy specimens taken from patients with AD, irrespective of the severity of the disease and serum IgE levels. Moreover, IL-31 mRNA levels were strongly increased in many biopsy specimens taken from patients with ACD. However, no increased transcription of IL-31 could be detected in biopsy specimens taken from psoriatic plaques. A comparison of mRNA levels of IL-31 with TH1 or TH2 cytokines demonstrates a correlation of the expression of IL-31 with IL-4 and IL-13 but not with IFN-gamma. No significant increase of IL-31 receptor mRNA could be detected in any disease, whereas the second receptor subunit of IL-31, the oncostatin M receptor, seems to be enhanced transcribed in patients with psoriasis. CONCLUSION: IL-31 expression is not only increased in patients with AD but also in those with ACD, 2 pruritic skin disorders. In both types of eczema, expression of IL-31 is associated with the expression of the TH2 cytokines IL-4 and IL-13. CLINICAL IMPLICATIONS: IL-31 might contribute not only to the development of AD but also to ACD-provoked skin inflammation.

Dermatitis, Allergic Contact↗
PubMed2006

Contact of high-invasive, but not low-invasive, melanoma cells to native collagen I induces the release of mature cathepsin B.

Metastasis of malignant tumor cells involves cell-cell and cell-matrix interactions, which regulate the expression and localization of proteolytic enzymes. In the present study, we investigated the expression and localization of the lysosomal cysteine proteinase cathepsin B and its natural inhibitors cystatin A, B and C in high- (MV3), intermediate- (SKmel28) and low-invasive (SKmel23, WM164) human melanoma cell lines grown on plastic or in contact with monomeric or fibrillar collagen type I. Neither the transcript levels of cathepsin B nor those of the natural inhibitors, cystatin B and C, were altered by the interaction of melanoma cells with collagen type I. However, protein expression and cellular localization of cathepsin B and its inhibitors were markedly affected. In contrast to low-invasive cells, high-invasive cells constitutively released procathepsin B when cultured on plastic. In addition, contact of invasive cells with fibrillar collagen type I resulted in the release of both mature forms of the protease. Perturbation studies using inhibitory antibodies against the beta1 subunit of the integrin receptor indicated a role for the beta1 integrin receptor family in the regulation of cathepsin B release. Cystatin B protein expression was much lower in high-invasive cells in both culture conditions, when compared to low-invasive cells. Cystatin C expression was comparable in all cells, but cell contact to fibrillar collagen type I induced its expression. These results strongly implicate a pivotal role of cell-matrix interactions for the regulation of cathepsin B localization and activity in melanoma cells.

Cathepsin B↗
PubMed2006

Dissociation of the complex between CD151 and laminin-binding integrins permits migration of epithelial cells.

Laminin-binding integrins form a complex with CD151, a member of the tetraspanin family suggested to be involved in the regulation of cell migration. In the epidermis, CD151 is localized with alpha3beta1 and alpha6beta4 integrins at cell-cell and cell-matrix contacts, respectively, characteristic structures of non-migrating cells. Taking advantage of a monoclonal antibody against CD151, TS151r, which epitope overlaps with the tetraspanin integrin-binding site, we have investigated the role of CD151 in epithelial cell migration. Under standard culture conditions, the migratory capacity of epithelial HaCaT cells on laminins is low, apparently due to endogenous laminin 5. However, challenging HaCaT cells with TS151r allows a re-arrangement of the actin cytoskeleton, dismantling of cell-cell and beta4 integrin-mediated cell-matrix contacts and cell migration. In vivo, free CD151 is absent in resting epithelial cells of interfollicular epidermis, and all CD151 is bound to integrins in intercellular and cell-matrix contacts. By contrast, free CD151 is present at intercellular contacts in the epithelial sheet lining the deeper region of anagen hair follicles, which is considered to contain migrating cells. Together, these results strongly suggest that dissociation of the CD151-integrin complex permits remodeling of epithelial cell interactions with the extracellular matrix and cell migration.

Antigens, CD↗
PubMed2006

Identification and discrimination of extracellularly active cathepsins B and L in high-invasive melanoma cells.

We established a novel protocol for lithium dodecyl sulfate (LDS) gelatin zymography, which operates under reducing conditions and at a slightly acidic pH value (6.5). This zymographic assay is based on polyacrylamide gel electrophoresis and facilitates the electrophoretic separation of human cathepsins in an active state. By this technique, activity of purified human liver cathepsin B was detected at a concentration as low as 50 ng and was blocked only in the presence of the cysteine protease inhibitor E-64 and the specific cathepsin B inhibitor CA-074 but not by aspartate, serine, or matrix metalloprotease inhibitors. The method was applied to analyze cathepsin activities in cell culture supernatants of the high-invasive melanoma cell line MV3. Interestingly, LDS zymography of MV3 cell supernatants in combination with specific inhibitors of cathepsins B and L identified three forms of extracellularly active cathepsin B and two forms of proteolytically active cathepsin L. We herein describe the generation and biochemical significance of acidic LDS zymography. This novel method permits not only the enzymatic analysis of purified cysteine proteases but also the identification and discrimination of different cathepsin activities in biological fluids, cell lysates, or supernatants, especially of cathepsins B and L, which are closely linked to major inflammatory and malignant processes.

Cathepsin B↗
PubMed2006

Delayed wound healing and epidermal hyperproliferation in mice lacking JunB in the skin.

The cutaneous response to injury and stress comprises a temporary change in the balance between epidermal proliferation and differentiation as well as an activation of the immune system. Soluble factors play an important role in the regulation of these complex processes by coordinating the intercellular communication between keratinocytes, fibroblasts, and inflammatory cells. In this study, we demonstrate that JunB, a member of the activator protein-1 transcription factor family, is an important regulator of cytokine expression and thus critically involved in the cutaneous response to injury and stress. Mice lacking JunB in the skin develop normally, indicating that JunB is neither required for cutaneous organogenesis, nor homeostasis. However, upon wounding and treatment with the phorbol ester 12-O-decanoyl-phorbol-13-acetate, JunB-deficiency in the skin likewise resulted in pronounced epidermal hyperproliferation, disturbed differentiation, and prolonged inflammation. Furthermore, delayed tissue remodelling was observed during wound healing. These phenotypic skin abnormalities were associated with JunB-dependent alterations in expression levels and kinetics of important mediators of wound repair, such as granulocyte macrophage colony-stimulating factor, growth-regulated protein-1, macrophage inflammatory protein-2, and lipocalin-2 in both the dermal and epidermal compartment of the skin, and a reduced ability of wound contraction of mutant dermal fibroblasts in vitro.

Animals↗
PubMed2006

Mechanical tension and integrin alpha 2 beta 1 regulate fibroblast functions.

The extracellular matrix (ECM) environment in connective tissues provides fibroblasts with a structural scaffold and modulates cell shape, but it also profoundly influences the fibroblast phenotype. Here we studied fibroblasts cultured in a three-dimensional network of native collagen, which was either mechanically stressed or relaxed. Mechanical load induces fibroblasts that synthesize abundant ECM and a characteristic array of cytokines/chemokines. This phenotype is reminiscent of late granulation tissue or scleroderma fibroblasts. By contrast, relaxed fibroblasts are characterized by induction of proteases and a subset of cytokines that does not overlap with that of mechanically stimulated cells. Thus, the biochemical composition and physical nature of the ECM exert powerful control over the phenotypes of fibroblasts, ranging from "synthetic" to "inflammatory" phenotypes. Interactions between fibroblasts and collagen fibrils are mostly mediated by a subset of beta 1 integrin receptors. Fibroblasts utilize alpha 1 beta 1, alpha 2 beta 1, and alpha 11 beta 1 integrins for establishing collagen contacts and transducing signals. In vitro assays and mouse genetics have demonstrated individual tasks served by each receptor, but also functional redundancy. Unraveling the integrated functions of fibroblasts, collagen integrin receptors, collagen fibrils, and mechanical tension will be important to understand the molecular mechanisms underlying tissue repair and fibrosis.

Animals↗
PubMed2006

Expression of matrix metalloproteinase (MMP)-2, MMP-9, MMP-13, and MT1-MMP in skin tumors of human papillomavirus type 8 transgenic mice.

Human papillomaviruses (HPV) are small DNA viruses that induce a wide variety of hyperproliferative lesions in cutaneous and mucosal epithelia. It is proposed that HPV is involved in non-melanoma skin cancer development. We have previously shown that HPV8 transgenic mice spontaneously develop papillomatous skin tumors. Histology revealed epidermal hyperplasia, acanthosis and hypergranulosis and in some cases squamous cell carcinomas (SCC). Zymographic and immunoblot analysis of normal skin extracts identified increased amounts of matrix metalloproteinase (MMP)-9, MMP-13 and MT1-MMP in HPV8-positive mice compared with HPV8-negative animals. In situ gelatin zymography of tumor specimens displayed a strong proteolytic activity in papillomas, and SCC putatively attributed to the increased amounts of activated MMP-9 found in tissue extracts. In addition, immunoblot analysis revealed increased amounts of active MMP-13 and MT1-MMP in tumor extracts as compared with control extracts. Immunohistochemical stainings of SCC specimens depicted MMP-13 to be specifically expressed in stromal fibroblasts neighboring the tumor islands, whereas MT1-MMP was detected both in tumor cells and in stromal cells. Taken together, these results implicate a role for MMPs in the development of HPV8-induced cutaneous tumors.

Animals↗
PubMed2006

A novel aspartic proteinase-like gene expressed in stratified epithelia and squamous cell carcinoma of the skin.

Homeostasis of stratified epithelia, such as the epidermis of the skin, is a sophisticated process that represents a tightly controlled balance between proliferation and differentiation. Alterations of this balance are associated with common human diseases including cancer. Here, we report the cloning of a novel cDNA sequence, from mouse back skin, that is induced by the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) and codes for a hitherto unknown aspartic proteinase-like protein (Taps). Taps represents a potential AP-1 target gene because TPA-induced expression in epidermal keratinocytes critically depends on c-Fos, and co-treatment with dexamethasone, a potent inhibitor of AP-1-mediated gene regulation, resulted in impaired activation of Taps expression. Taps mRNA and protein are restricted to stratified epithelia in mouse embryos and adult tissues, implicating a crucial role for this aspartic proteinase-like gene in differentiation and homeostasis of multilayered epithelia. During chemically induced carcinogenesis, transient elevation of Taps mRNA and protein levels was detected in benign skin tumors. However, its expression is negatively associated with dedifferentiation and malignant progression in squamous cell carcinomas of the skin. Similar expression was observed in squamous skin tumors of patients, suggesting that detection of Taps levels represents a novel strategy to discriminate the progression state of squamous skin cancers.

Amino Acid Sequence↗
PubMed2005

Temozolomide in combination with interferon-alfa versus temozolomide alone in patients with advanced metastatic melanoma: a randomized, phase III, multicenter study from the Dermatologic Cooperative Oncology Group.

PURPOSE: Temozolomide (TMZ) has shown efficacy in metastatic melanoma equal to that of dacarbazine (DTIC), the standard chemotherapeutic agent for melanoma. As the combination with interferon-alfa (IFN-alpha) appears superior to single-agent DTIC regarding response rates, the purpose of this study was to compare TMZ alone and TMZ plus IFN-alpha in terms of objective response (OR), overall survival, and safety in a prospective, randomized, multicenter trial. PATIENTS AND METHODS: Two hundred ninety-four patients with untreated stage IV metastatic melanoma (American Joint Committee on Cancer staging system) were randomly assigned to receive either oral TMZ alone (200 mg/m2/day; days 1 through 5 every 28 days) or in combination with subcutaneous IFN-alpha (5 MU/m2; days 1, 3, and 5 every week). RESULTS: Two hundred eighty-two patients were eligible for an intent-to-treat analysis, 271 patients were treated per protocol. In the TMZ + IFN-alpha arm, 33 (24.1%) of 137 patients responded to therapy (partial or complete remission) whereas in the monotherapy arm, in 18 (13.4%) of 134 patients, a response was evident. Thus, the response rate was significantly higher in the combination arm (P = .036). Median survival time was 8.4 months for patients treated with TMZ (95% CI, 7.07 to 9.27) and 9.7 months for those treated with the combination (95% CI, 8.26 to 11.18; P = .16). Dose modifications and interval prolongations due to hematologic toxicity were significantly more frequent in the TMZ + IFN-alpha arm (P < .001). CONCLUSION: In metastatic melanoma treatment with TMZ + IFN-alpha leads to a significantly superior OR rate compared to treatment with TMZ alone, which did not translate into prolonged survival in our study population.

Adult↗
PubMed2005

Adam-9 expression and regulation in human skin melanoma and melanoma cell lines.

ADAM-9 belongs to a family of transmembrane disintegrin-containing metalloproteinases (ADAMs) involved in protein ectodomain shedding and cell-cell and cell-matrix interactions. However, the specific biological functions of ADAM-9 are still unclear. The aim of this study was to analyze the expression of ADAM-9 in melanoma in vivo and in melanoma cell lines in vitro. In melanoma ADAM-9 protein expression appeared to be restricted to the melanoma cells within the invading front. Interestingly, ADAM-9 protein was detected in the melanoma cells and in peritumoral stromal fibroblasts, while it was absent in fibroblasts distal to the tumor site. RNA analysis of melanoma cell lines with different invasive abilities showed ADAM-9 expression in varying amounts in all cell lines, independent of their invasive and metastatic capacities. In MV3 melanoma cells, ADAM-9 expression did not depend on homotypic cell-cell contact and on cell-matrix interaction when the cells were cultured on planar extracellular matrix components. However, we observed downregulation of ADAM-9 mRNA expression upon culture of melanoma cells within 3-dimensional lattices composed of fibrillar type I collagen, whereas culture within gels consisting of the polysaccharide alginate did not alter transcript levels. These results identified fibrillar collagen type I as a key factor in ADAM-9 regulation by cell-matrix interactions. Interestingly, we also observed a 3-fold downregulation of ADAM-9 transcript levels upon treatment with interleukin (IL)-1alpha, a proinflammatory cytokine known to induce expression of other ADAM and matrix metalloproteinase (MMP) family members. In summary, our data suggest a novel role of fibrillar collagen and of soluble factors for the regulation of ADAM-9 expression in vitro.

ADAM Proteins↗
PubMed2005

Role of the snake venom toxin jararhagin in proinflammatory pathogenesis: in vitro and in vivo gene expression analysis of the effects of the toxin.

To assess the indirect effects of snake venom metalloproteinases (SVMP) on host tissue local necrosis, we investigated the effect of the SVMP jararhagin on the gene expression profiles of human fibroblasts in vitro and mouse tissue in vivo. Two functional classes of up-regulated proteins, cell death and inflammatory disease were identified as being significantly populated. The changes in gene expression observed by qRT-PCR on laser microdissected mouse muscle tissue treated with jararhagin were similar with significant up-regulation of proinflammatory transcripts such as IL-1 beta, IL-6, CXCL1, CXCL2, IL-8, and apoptosis, inflammation responsive transcripts such as TNF-alpha induced protein 6. Proteolytically inactive jararhagin had no effect on the gene expression profile of fibroblasts, indicating proteolysis as the primary mechanism affecting gene expression of cells and tissues resulting in a proinflammatory, pro-apoptotic host response which likely exacerbates the local necrosis frequently observed at the site of envenoming.

Animals↗
PubMed2005

Human scalp dermal papilla and fibrous sheath cells have a different expression profile of matrix metalloproteinases in vitro when compared to scalp dermal fibroblasts.

The dermal papilla is a cluster of specialised mesenchymal cells at the bottom of the mammalian hair follicle, embedded in a loose extracellular matrix. These cells have the capability to induce and support hair growth via close epithelial-mesenchymal interactions with the keratinocytes surrounding the hair matrix. The extracellular matrix of the dermal papilla differs markedly from the interfollicular matrix and plays a key role in the maintenance of hair growth. In this study we investigated the expression pattern and activity of matrix metalloproteinases (MMP) and their tissue inhibitor in in vitro cultures of cells derived from scalp dermal papilla and fibrous sheath. Expression and activity of MMP-1, MMP-2, MMP-3, MMP-9, TIMP-1, TIMP-2 and MT1-MMP were analysed in those cells cultured in contact with one of the relevant protein component of the dermal matrix, collagen type I as well as in monolayer. Zymographic analysis showed activation of MMP-2 in all cells grown in three-dimensional collagen lattices whereas MMP-9 was activated only in three-dimensional collagen cultures of dermal fibroblasts and weakly in follicular cells. Expression of MMP-1, TIMP-1, TIMP-2 and MT1-MMP was similar in all cells, in both culture conditions, whereas expression of MMP-3 was absent in dermal papilla cells. In addition to a series of reported morphological and functional differences between dermal fibroblasts and the dermal mesenchyme-derived cells of the hair follicle, we reported differences in MMP expression in dermal papilla and fibrous sheath cells within the mesenchymal population of the hair follicle.

Cells, Cultured↗
PubMed2005

Gene expression profiling reveals cross-talk between melanoma and fibroblasts: implications for host-tumor interactions in metastasis.

Host-tumor interaction is considered critical in carcinogenesis, tumor invasion, and metastasis. To explore the reciprocal effects of host-tumor interaction, we developed a system to assess the gene expression patterns of A2058 human melanoma cells cocultured in fibrillar collagen with HS-68 primary human fibroblasts. The gene expression pattern of the cocultured A2058 cells was only modestly affected, whereas the HS-68 fibroblast gene expression pattern was significantly altered. Interleukin-11 and inhibitor of DNA-binding domain-1 gene expression in the cocultured A2058 cells was down-regulated, indicative of a proinflammatory response and resistance to apoptosis, respectively. The overall pattern of up-regulated genes indicated triggering of the proinflammatory process. In addition, the melanoma growth and migration stimulatory chemokines CXCL1 and CXCL2 were significantly up-regulated in the cocultured fibroblasts. These results were corroborated by additional coculture experiments with the melanoma cell lines WM-164, BLM, and SK-Mel-28 and immunohistochemistry on invasive human melanoma sections. Taken together, these results indicate that tumor cells cause a proinflammatory and melanoma growth-promoting response in stromal fibroblasts. The role of inflammation in carcinogenesis, tumor promotion, invasion, and metastasis is viewed as being increasingly important and the results of these studies underscore this as well as identify certain key proteins that are expressed as a result of the complex interactive processes in the host-tumor microenvironment.

Cell Communication↗
PubMed2005

c-Fos-dependent induction of the small ras-related GTPase Rab11a in skin carcinogenesis.

Malignant transformation of mouse skin by tumor promoters and chemical carcinogens, such as the phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA), is a multistage process leading to the formation of squamous cell carcinomas. It has been shown that mice lacking the AP-1 family member c-Fos exhibit an impaired transition from benign to malignant skin tumors. Here, we demonstrate enhanced expression of the small Ras-related GTPase Rab11a after short-term TPA treatment of mouse back skin. Expression of Rab11a in vivo and in vitro critically depended on c-Fos, because TPA application to the back skin of c-Fos-deficient mice and to mouse embryonic fibroblasts did not induce Rab11a mRNA or protein expression. Moreover, dexamethasone, which is a potent inhibitor of AP-1-mediated transactivation that exhibits anti-inflammatory and anti-tumor promoting activities, inhibited TPA-induced expression of Rab11a. Within the Rab11a gene promoter, we identified a functional AP-1 binding element that exhibited elevated c-Fos binding activity after TPA treatment of keratinocytes. Enhanced expression was not restricted to chemically induced mouse skin tumors but was also found in tumor specimens derived from patients with epithelial skin tumors. These data identify Rab11a as a novel, tumor-associated c-Fos/AP-1 target and may point to an as yet unrecognized function of Rab11a in the development of skin cancer.

Animals↗