Molecular mechanisms involved in activity of h7C10, a humanized monoclonal antibody, to IGF-1 receptor
2009
Broussas, - | Dupont, Joëlle | González, A. | Blaecke, A. | Fournier, M. | Corvaia, N. | Goetsch, L. | Centre de Recherche Pierre Fabre (Centre de R&D Pierre Fabre) ; PIERRE FABRE | Physiologie de la reproduction et des comportements [Nouzilly] (PRC) ; Institut National de la Recherche Agronomique (INRA)-Institut Français du Cheval et de l'Equitation [Saumur] (IFCE)-Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS)
International audience
显示更多 [+] 显示较少 [-]英语. IGF-1 receptor (IGF-1R) plays a key role in the development of numerous tumors. Blockade of IGF-1R axis using monoclonal antibodies constitutes an interesting approach to inhibit tumor growth. We have previously shown that VC 10, a humanized anti-IGF-1R Mali, exhibited potent antitumor activity in vivo. However, mechanisms of action of h7C10 are still unknown. Here, we showed that h7C10 inhibited IGF-1-induced IGF-1R phosphorylation in a dose-dependent manner. Also, h7C10 abolished IGF-1-induced activation of PI3K/AKT and MAPK pathways. Cell cycle progression and colony formation were affected in the presence of h7C10 probably because of the inhibition of IGF-1-induced cyclin D1 and E expression. In addition, we demonstrated that h7C10 induced a rapid IGF-1R internalization leading to an accumulation into cytoplasm resulting in receptor degradation. Using lysosome and proteasome inhibitors, we observed that the IGF-1R alpha-and beta-chains could follow different degradation routes. Thus, we demonstrated that antitumoral properties of h7C10 are the result of IGF-1-induced cell signaling inhibition and down-regulation of IGF-1R level suggesting that VC 10 could be a candidate for therapeutic applications.
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