Abstract 5073: Novel fusion molecule with high dual antiangiogenic and anticancer potential.

Abstract

Abstract One of the most important mechanisms of tumorgenesis is formation of new blood vessels and tissue remodeling. Vascular endothelial growth factor (VEGF) is one of the most important and widely studied proangiogenic factors, that has an important role in many physiological and pathological processes. Blockade of VEGF pathway has been shown to inhibit both pathological angiogenesis and tumor growth. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo2L) was considered as a promising anticancer agent due its remarkable ability to induce apoptosis in cancer cells without harming normal cells. However, in clinical practice TRAIL efficacy was too low to made it an effective single therapy agent. Here we present a novel fusion protein based on TRAIL/Apo2L, equipped with an antiangiogenic, effector peptide, fused to its N- terminus. The effector role plays a 7-amino acid-long peptide that binds to natural VEGF receptors and competes with their natural ligand. The proposed fusion protein AD-O51.4 consists of extracellular soluble portion of TRAIL linked to two tandemly arranged copies of the effector peptide separated by a sequence containing the motif recognized by tumor-specific proteases (MMP's, uPa). The TRAIL-targeted peptide is able to bind and sequester the VEGF receptors on malignant (cancer) and endothelial cells. As a consequence, the peptide blocks the binding of VEGF ligand, preventing formation of new vessels. In addition, a lot of literature data confirm expression of the VEGF receptors on the surfaces of various cancer cell lines. Due to the presence of VEGF receptors, those cell lines can be also targeted by our VEGF receptor-blocking peptide making them susceptible for TRAIL-induced apoptosis. In vitro, AD-O51.4 showed cytotoxic effect on various cancer cell lines at IC50 below 0.1 ng/mL and no toxic effects on normal cells. Cytotoxic activity of TRAIL alone was significantly lower in comparison to AD-O51.4. We demonstrated that TRAIL/Apo2L-VEGF-antagonist is a strong activator of caspase 3 and Bid processing. Additionally, its direct antiangiogenic activity was confirmed with the ring aortic assay and HUVEC spheroid assay. Strong antitumor activity of novel fusion molecule was also confirmed in xenograft model of multidrug resistant human uterine sarcoma MES-SA/Dx5 where our protein caused complete tumor remission and showed much higher efficacy than TRAIL alone. The similar effect was observed using human colorectal adenocarcinoma Colo205 and human pancreatic carcinoma MIA PaCa-2 xenografts, as well as an orthotropic model of human lung carcinoma NCI-H460-luc2. Citation Format: Jerzy S. Pieczykolan, Piotr Rozga, Anna Pieczykolan, Bartlomiej Zerek, Sebastian D. Pawlak, Michal Szymanik, Albert Jaworski, Marlena Galazka, Katarzyna Wiciejowska, Wojciech Strozek, Malgorzata Teska - Kaminska, Lukasz Kutner, Anna Grochot - Przeczek, Neli Kahmakowa - Trojanowska. Novel fusion molecule with high dual antiangiogenic and anticancer potential. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5073. doi:10.1158/1538-7445.AM2013-5073