0000000000988120
AUTHOR
Christiane Amendt
IgG1 anti-epidermal growth factor receptor antibodies induce CD8-dependent antitumor activity
Anti-EGFR monoclonal antibodies (mAb) like Cetuximab are commonly used for treatment of EGFR+ solid tumors mainly by exerting their therapeutic effect through inhibition of signal transduction. Additionally, IgG1 is a potent mediator of antibody-dependent cytotoxicity (ADCC). In case of the IgG1, Cetuximab induction of ADCC in vivo is controversially discussed. In our study, we investigated the efficiency of Cetuximab-mediated ADCC in a humanized mouse tumor model in vivo and analyzed the contribution of immunologic processes toward antitumor activity. Therefore, we used immunodeficient NOD/Scid mice transgenic for human MHC class I molecule HLA-A2 and adoptively transferred human HLA-A2+ P…
Expression of a dominant negative type II TGF-β receptor in mouse skin results in an increase in carcinoma incidence and an acceleration of carcinoma development
The role of Transforming growth factor beta (TGF-beta) in carcinogenesis is complex. There are reports on both tumor inhibition and tumor promotion by TGF-beta. To elucidate the complex role of TGF-beta in epithelial carcinogenesis, we generated transgenic mice overexpressing a dominant negative type II TGF-beta receptor in the basal cell compartment and in follicular cells of the skin. Despite the reduced responsiveness of transgenic keratinocytes to TGF-beta, both proliferation and differentiation were normal in non-irritated epidermis of these transgenic mice. Thus, interruption of signaling of all three isoforms of TGF-beta in basal and follicular cells does not disturb tissue homeostas…
The Serum Protein α2-HS Glycoprotein/Fetuin Inhibits Apatite Formation in Vitro and in Mineralizing Calvaria Cells
We present data suggesting a function of alpha2-HS glycoproteins/fetuins in serum and in mineralization, namely interference with calcium salt precipitation. Fetuins occur in high serum concentration during fetal life. They accumulate in bones and teeth as a major fraction of noncollagenous bone proteins. The expression pattern in fetal mice confirms that fetuin is predominantly made in the liver and is accumulated in the mineralized matrix of bones. We arrived at a hypothesis on the molecular basis of fetuin function in bones using primary rat calvaria osteoblast cultures and salt precipitation assays. Our results indicate that fetuins inhibit apatite formation both in cell culture and in …
Resistance of keratinocytes to TGFbeta-mediated growth restriction and apoptosis induction accelerates re-epithelialization in skin wounds.
The pleiotropic growth factor TGFβ plays an important role in regulating responses to skin injury. TGFβ targets many different cell types and is involved in all aspects of wound healing entailing inflammation,re-epithelialization, matrix formation and remodeling. To elucidate the role of TGFβ signal transduction in keratinocytes during cutaneous wound healing, we have used transgenic mice expressing a dominant negative type II TGFβ receptor exclusively in keratinocytes. We could demonstrate that this loss of TGFβ signaling in keratinocytes led to an accelerated re-epithelialization of full thickness excisional wounds accompanied by an increased proliferation in keratinocytes at the wound ed…