Abstract 2037: A 3D model for lung cancer based on decellularized lung scaffolds allows for in vitro testing of viral oncolysis

Introduction: Viral oncolysis has been proposed as an adjuvant therapy for the treatment of advanced lung cancer. A more complex model would allow for improved in vitro testing of this therapy prior to moving towards clinical application. Methods: Lung blocks were harvested from Sprague Dawley rats and subjected to perfusion-decellularization via the pulmonary artery with 0.1% sodium dodecyl sulfate and 1% Triton X-100 to obtain decellularized whole-lung scaffolds. Decellularized lung scaffolds were placed in a bioreactor to allow perfusion of cell-specific media through the pulmonary artery. Human lung cancer cells were seeded into the scaffolds by tracheal delivery of cell suspensions containing 20-30 million cells. After 7-10 days of culture in the bioreactor, lung scaffolds harboring tumor nodules were treated with a replication-conditional Herpes Simplex Virus type-1 (hrR3) at a dose of 1x108 Plaque Forming Units delivered through the pulmonary artery. In parallel, scaffolds with tumors treated with cisplatin served as positive controls while delivery of phosphate-buffered saline served as a negative control. Tissue was collected 48 hours after treatment delivery and was analyzed by histology, immunostaining for Lac Z to allow the visualization and localization of replicating virus, and by assessment of cytotoxicity with a formazan-based assay. Results: There were no residual cellular elements after the decellularization process as demonstrated by histologic analysis, and the scaffolds showed preserved microarchitecture of the alveolar spaces and vasculature. Human lung cancer cell lines H358 and SW1573 showed engraftment and tumor nodule formation and growth inside the decellularized lung scaffolds. The custom-designed bioreactor system allowed for delivery of treatments including hrR3 through the pulmonary artery, in an easy and convenient way while maintaining sterility. Treatment with hrR3 decreased the total tumor burden per mg of tissue to 92% of that seen in negative controls in SW1573-seeded scaffolds and to 52% in H358-seeded scaffolds. Both SW1573- and H358-seeded scaffolds treated with cisplatin showed an overall >99% decrease in tumor burden. Tumors treated with hrR3 showed different morphology when compared to negative controls. Conclusions: Decellularized lung scaffolds can serve as a more realistic three-dimensional model for the in vitro study of viral oncolysis of human lung cancer, as they account for anatomical variations and provide natural micro-architectural barriers to oncolytic virus such as basement membranes. Differences in the efficacy of viral oncolysis according to epithelial vs. mesenchymal tumor phenotypes should be further investigated. Citation Format: Luis F. Tapias, Sarah E. Gilpin, Justin Elliott, Roshini Zachariah, Haiyu Zhou, Bryan C. Fuchs, Lan Wei, Danielle K. Deperalta, Kumudu D. Kuruppu, Kenneth K. Tanabe, Harald C. Ott, Michael Lanuti. A 3D model for lung cancer based on decellularized lung scaffolds allows for in vitro testing of viral oncolysis. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2037. doi:10.1158/1538-7445.AM2014-2037