Abstract 3269: Enhancing chemotherapy response with sustained EphA2 silencing using multistage vector delivery .

Abstract

Abstract RNA interference has the potential to specifically knock down the expression of target genes, and thereby transform cancer therapy. However, lack of effective delivery of small inhibitory RNA (siRNA) has dramatically limited its in vivo applications. We have developed a multistage vector (MSV) system, composed of discoidal porous silicon particles loaded with siRNA oligos packaged in dioleoyl phosphatidylcholine (DOPC) nanoliposomes, that directs effective delivery and sustained release of siRNA in tumor tissues. Tumor accumulation of siRNA was observed after i.v. administration of MSV/siRNA, and sustained release of siRNA from DMSV maintained high levels of siRNA in tumor for over one week after a single dose of DMSV/siRNA. Treatment of SKOV3ip2 tumor mice with DMSV carrying siRNA oligos specific for the human EphA2 gene (MSV/EphA2) biweekly for 6 weeks resulted in dose-dependent (5, 10 and 15 μg/mice) reduction of tumor weight (36%, 64%, and 83%) and number of tumor nodules compared with the control groups. In addition, tumor growth was completely inhibited when mice were treated with MSV/EphA2 in combination with paclitaxel. Furthermore, combination treatment with MSV/EphA2 and docetaxel inhibited growth of HeyA8-MDR tumors, which were otherwise resistant to docetaxel treatment. Taken together, MSV/EphA2 merits further development as a therapeutic approach for ovarian cancer. Citation Format: Cristian Rodriguez-Aguayo, Haifa Shen, Vianey Gonzalez-Villasana, Guodong Zhang, Xiaoyong Deng, Burcu Aslan, Xuewu Liu, Jason Sakamoto, Arturo Chavez-Reyes, Hee-Dong Han, Anil K. Sood, Mauro Ferrari1, Gabriel Lopez-Berestein. Enhancing chemotherapy response with sustained EphA2 silencing using multistage vector delivery . [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 3269. doi:10.1158/1538-7445.AM2013-3269