Abstract 3305: Sustained production of a soluble IGF-I receptor by gutless adenovirus - transduced host cells protects from tumor growth in the liver .

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC The IGF-I receptor (IGF-IR) plays an important role in malignant disease by increasing cancer cell survival and promoting metastasis. It is presently the target of several drugs in clinical trials. Gene therapy is currently being developed for cancer treatment using different nanoparticle vectors designed to deliver therapeutic genes that could induce cell death, increase sensitivity to chemotherapy, block angiogenesis or enhance the anti-cancer immunological response. Previously, we have shown that the implantation of autologous bone-marrow stromal cells producing a soluble form of IGF-IR (sIGFIR) inhibited experimental liver metastasis of several tumor types in mice. Here we evaluated the utility of adenovirus-based gene delivery for generating therapeutically effective plasma levels of this decoy. A third generation gutless adenovirus was selected to deliver the sIGFIR gene because of its reduced immunogenicity and preferential tropism for the liver, the main source of endocrine IGF-1. We found that HEK-293 cells transduced by this, but not by control adenoviruses, secreted soluble receptor protein that blocked IGF-I-induced tumor cell migration, proliferation and survival in vitro. Following virus injection in vivo, viral DNA was detectable by PCR in several host organs, particularly the liver, and this resulted in the production of measurable sIGFIR plasma levels for up to 21 days post injection. In mice producing virus-encoded sIGFIR, experimental liver metastasis was inhibited, indicating that sIGFIR levels were therapeutically effective. The results show that adenovirus-based delivery of inhibitory soluble proteins can provide an effective strategy for blockade of cancer cell growth. Citation Format: Ni Wang, Yifan Lu, Amelie Pilotte, Maxime Pinard, Renald Gilbert, Bernard Massie, Pnina Brodt. Sustained production of a soluble IGF-I receptor by gutless adenovirus - transduced host cells protects from tumor growth in the liver . [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 3305. doi:10.1158/1538-7445.AM2013-3305