Abstract 3392: Generation and characterization of transgenic oncopig model for lung cancer
Authors: Joshi Kirtan , Sirpu Nagabhishek , Schmelzle Amanda , Poonooru Ravikanth , Nelson Benjamin , Subramanyam Pradeep , Garrett Colleen , Sponchiado Mariana , Schlink Sarah , Gerb Samantha , Porter Jesse , Kim Dae , Kunin Jeffrey , Bryan Jeffrey , Hoffman Timothy , Telugu Bhanu , Kaifi Jussuf , Rachagani Satyanarayana 
Published: March 2024

Lung cancer (LC) is the leading cause of cancer-associated death in the United States. Preclinical findings in small animal models do not translate into human clinics. There is an urgent need to develop relevant preclinical large animal models for LC. We describe a novel method to induce LC in transgenic pigs carrying Cre-inducible KrasG12D and TrP53R167H mutations (Oncopigs).

The Oncopigs (n=12; 9 females, and 3 males) at 9 weeks of age were anesthetized and adenovirus (1 × 1011 PFU) carrying Cre recombinase gene (Ad-Cre) ± polybrene (1:100) ± IL-8 (5 ng/ml) was injected via flexible bronchoscopy with two techniques: (1) Bronchial lavage (n=6) and (2) Transbronchial needle injection (n=6) into different lung lobes. As controls, a combination of polybrene ± IL-8 was injected without AdCre into the contralateral lobes in the same pigs (n=8). Oncopigs were monitored via clinical monitoring, blood counts, basic metabolic panel, and contrast-enhanced computed tomography (CT) imaging for LC progression and metastasis at 3-, 4-, 7-, 10-, 16-, and 26 weeks post-intervention.

All animals tolerated the injections with expected weight gains. Blood counts and metabolic panels remained normal during LC progression. At the site of injection/lavage, lung masses were detected on CT imaging at 3 weeks post-injections. However, a decrease in masses was observed on CT at 7 weeks post-intervention. The decrease in size of the lung masses coincided with increasing attenuation. No distant metastases were observed on CT imaging. Lavage-based lesions appeared to be more heterogeneous with surrounding inflammatory changes. Transbronchial-injection-based lesions appeared more consolidated and coin-shaped without surrounding inflammatory changes. Control injection sites did not show any mass growth on CT imaging.

Immunohistochemistry analysis on lung tumors revealed increased pancytokeratin, trichrome, E-cad, Ki-67, IBA, and CD3 expression. Further, immunofluorescence revealed decreased E-Cad, CK-19, and Zo-1 expression, whereas increased expression of N-Cad, FN1, snail, CD44, α-SMA, and γ-catenin, was observed in the LC and metastatic tissue compared to normal.

We successfully generated and characterized a novel transgenic Oncopig LC model. There is robust tumor production status post AdCre delivery. One of four Oncopigs had carcinomatous metastatic skin growth. The remaining 7 Oncopigs are monitored longitudinally for tumor growth and development of metastasis.

Citation Format: Kirtan Joshi, Nagabhishek Sirpu, Amanda Schmelzle, Ravikanth Poonooru, Benjamin Nelson, Pradeep Subramanyam, Colleen Garrett, Mariana Sponchiado, Sarah Schlink, Samantha Gerb, Jesse Porter, Dae Kim, Jeffrey Kunin, Jeffrey Bryan, Timothy Hoffman, Bhanu Telugu, Jussuf Kaifi, Satyanarayana Rachagani. Generation and characterization of transgenic oncopig model for lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3392.