Qiming Chen

CNTO 95 is a fully human monoclonal antibody that recognizes αv integrins. Previous studies have shown that CNTO 95 exhibits both anti-tumor and anti-angiogenic activities (Trikha M et al., Int J Cancer 110:326–335, 2004). In this study we investigated the biological activities of CNTO 95 on breast tumor cells both in vitro and in vivo. In vitro treatment with CNTO 95 decreased the viability of breast tumor cells adhering to vitronectin. CNTO 95 inhibited tumor cell adhesion, migration, and invasion in vitro. CNTO 95 treatment also induced tyrosine dephosphorylation of focal adhesion kinase (FAK), and the docking protein paxillin that recruits both structural and signaling molecules to focal adhesions (Turner CE, Int J Biochem Cell Biol 30:955–959, 1998; O’Neil GM et al., Trends Cell Biol 10:111–119, 2000). These results suggest that CNTO 95 inhibits breast tumor cell growth, migration and invasion by interruption of αv integrin mediated focal adhesions and cell motility signals. In vivo studies of CNTO 95 were conducted in an orthotopic breast tumor xenograft model. Treatment with CNTO 95 resulted in significant inhibition of both tumor growth and spontaneous metastasis of MDA-MB-231 cells to the lungs. CNTO 95 also inhibited lung metastasis in a separate experimental (tail vein injection) model of metastasis. The results presented here demonstrate the anti-tumor and anti-metastatic activities of CNTO 95 in breast cancer models and provide insight into the cellular and molecular mechanisms mediating its inhibitory effects on metastasis.

Purpose: Targeted delivery of cytotoxic agents to solid tumors through cell surface antigens can potentially reduce systemic toxicity and increase the efficacy of the targeted compounds. The purpose of this study was to show the feasibility of treating solid tumors by targeting α_v integrins with antibody-maytansinoid conjugates and to test the relative in vivo activities of several linker-maytansinoid chemistries.