Abstract 823: Anti-melanoma effects of novel Cripto-1 CFC small peptide mimetics

The diagnosis of melanoma is increasing and current therapies for advanced disease remain unsuccessful. Thus, research aimed at developing novel targeting approaches is needed. Cripto-1 (CR-1), an epidermal growth factor (EGF)-like developmental morphogen, functions as a co-receptor for the tumor growth factor (TGF)-beta related molecule, Nodal. CR-1/Nodal signaling pathways can induce cell survival, proliferation and migration of cancer cells. Studies have shown that Nodal is expressed at high levels in advanced melanoma. CR-1 has also been shown to be expressed in melanoma but limited to a small subpopulation of melanoma cells with more stem cell-like characteristics. Recent work has demonstrated that targeting Nodal in melanoma is associated with reduction of a significant population of melanoma cells. However, a residual population continues to persist. We hypothesize that interference with CR-1/Nodal receptor binding dynamics will negatively affect downstream Nodal-dependent signaling events important for cancer growth and further reduce the number of surviving melanoma cells. To test this hypothesis, we have developed small peptides that mimic CR-1 CFC binding domain and prevent CR-1 from binding to the ALK4 receptor necessary for proper CR-1 co-receptor function for Nodal. We show that in vitro treatment of human melanoma cells with our prototype CFC mimetic B3 reduced melanoma cell viability and negatively affected melanoma cell cycle progression. We also show that treatment with B3 resulted in reduction of active Smad2/3 and ERK1/2, known to be involved in downstream Nodal signaling, as a result of B3 interference with CR-1 co-receptor function. These preliminary data provide the scientific rationale for the development of anti-CR-1 and Nodal therapeutics that can synergize with or complement current treatment approaches in melanoma. Citation Format: Emanuela Iaccarino, Gustavo Untiveros, Annamaria Sandomenico, Andrea Caporale, Luisa Calvanese, Lucia Falcigno, Gabriella D'Auria, Menotti Ruvo, Luigi Strizzi. Anti-melanoma effects of novel Cripto-1 CFC small peptide mimetics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 823.