TY - JOUR A1 - Hoesl, Christine A1 - Fröhlich, Thomas A1 - Posch, Christian A1 - Kneitz, Hermann A1 - Goebeler, Matthias A1 - Schneider, Marlon R. A1 - Dahlhoff, Maik T1 - The transmembrane protein LRIG1 triggers melanocytic tumor development following chemically induced skin carcinogenesis JF - Molecular Oncology N2 - The incidence of melanoma and nonmelanoma skin cancer has increased tremendously in recent years. Although novel treatment options have significantly improved patient outcomes, the prognosis for most patients with an advanced disease remains dismal. It is, thus, imperative to understand the molecular mechanisms involved in skin carcinogenesis in order to develop new targeted treatment strategies. Receptor tyrosine kinases (RTK) like the ERBB receptor family, including EGFR/ERBB1, ERBB2/NEU, ERBB3, and ERBB4, are important regulators of skin homeostasis and their dysregulation often results in cancer, which makes them attractive therapeutic targets. Members of the leucine‐rich repeats and immunoglobulin‐like domains protein family (LRIG1‐3) are ERBB regulators and thus potential therapeutic targets to manipulate ERBB receptors. Here, we analyzed the function of LRIG1 during chemically induced skin carcinogenesis in transgenic mice expressing LRIG1 in the skin under the control of the keratin 5 promoter (LRIG1‐TG mice). We observed a significant induction of melanocytic tumor formation in LRIG1‐TG mice and no difference in papilloma incidence between LRIG1‐TG and control mice. Our findings also revealed that LRIG1 affects ERBB signaling via decreased phosphorylation of EGFR and increased activation of the oncoprotein ERBB2 during skin carcinogenesis. The epidermal proliferation rate was significantly decreased during epidermal tumorigenesis under LRIG1 overexpression, and the apoptosis marker cleaved caspase 3 was significantly activated in the epidermis of transgenic LRIG1 mice. Additionally, we detected LRIG1 expression in human cutaneous squamous cell carcinoma and melanoma samples. Therefore, we depleted LRIG1 in human melanoma cells (A375) by CRISPR/Cas9 technology and found that this caused EGFR and ERBB3 downregulation in A375 LRIG1 knockout cells 6 h following stimulation with EGF. In conclusion, our study demonstrated that LRIG1‐TG mice develop melanocytic skin tumors during chemical skin carcinogenesis and a deletion of LRIG1 in human melanoma cells reduces EGFR and ERBB3 expression after EGF stimulation. KW - ERBB receptors KW - LRIG1 KW - melanoma KW - mouse model KW - skin carcinogenesis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-238925 VL - 15 IS - 8 SP - 2140 EP - 2155 ER - TY - THES A1 - Meinhardt, Julia T1 - Asthmatherapie im Mausmodell : Allergen spezifische Immuntherapie in Kombination mit einer Immunmodulation durch einen IL-4/IL-13 Antagonisten T1 - Inhibition of IL-4/IL-13 does not enhance efficacy of allergen immunotherapy in murine allergic airway inflammation N2 - Die allergenspezifische Immuntherapie ist derzeit die einzige kausale Behandlungsmöglichkeit von Soforttypallergien. Trotzdem ist weiterhin unklar, welcher Parameter für den Behandlungserfolg einer spezifischen Immuntherapie (SIT) pathogenetisch bedeutsam ist. Zusammenfassend zeigte sich, dass für eine pulmonale Soforttypallergie in einem Asthmamodell in der Maus erfolgreich eine SIT etabliert werden konnte, die in einer Reihe von Parametern mit einer SIT im Menschen vergleichbar ist. Dies ist das erste Modell einer pulmonalen Soforttypallergie in der Maus, an dem neben den Wirkprinzipien der SIT auch neue Therapiestrategien untersucht werden können. Eine Behandlung mit SIT in Kombination mit einem immunmodulatorisch wirksamen IL-4/IL-13 Antagonisten zeigte jedoch keinen zusätzlichen therapeutischen Nutzen, welches die scheinbar untergeordnete Rolle der Zytokine IL-4 und IL-13 bei etablierten Allergien untermauert. N2 - Successful allergen specific immunotherapy (SIT) is associated with a reduced Th2 cytokine produktion and the induction of IL-10 producing regulatory T-cells. In order to improve treatment efficacy we investigateed the impact of an IL-4/IL-13 inhibitor during SIT.. BALB/c mice were sensitized intranasally with Ovalbumin for 4 weeks. Subsequently, they were subjected to intranasal SIT, where Ovalbumin was supplied with increasing doses from 1µg - 1mg over 3 weeks together or without an IL-4/IL-13 inhibitor. Bronchoalveolar lavages (BAL) were performed and checked for airway eosinophilia. Cytokines were detected in BAL luids and in mediastinal lymphnodes suspensions. Furthermore OVA specific antibodies were measured. Intranasal OVA sensitization resulted in persisting IgE synthesis and an eosinophil rich airway inflammation. This was combined with increased IL-4 and IL-5 levels. Intranasal SIT could efficiently reverse the allergic phenotype by reducing OVA specific IgE synthesis and airway eosinophilia singnificantly in comparison to untreated OVA sensitized animals. This was associated with decreased IL-4 and IL-5 levels and an increased IFN-y and IL-10 production. Mice treated with the IL-4/IL-13 inhibitor during SIT, however, did not show any significant differences in all measured parameters, when compared to mice treated with SIT alone. The use of an IL-4/IL-13 inhibitor as adjuvant for SIT did not enhance anti allergic effects. Thus, the observed shift from Th2 to Th1 cytokines by allergen specific immunotherapy may not be the key event in successful SIT rather than other factors such as IL-10 producing regulatory T-cells. KW - Asthma KW - Allergie KW - Mausmodell KW - Immunmodulation KW - SIT KW - allergy KW - asthma KW - mouse model KW - cytokine inhibitor KW - SIT Y1 - 2005 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-20789 ER -