Isolation of circulating tumors cells from genetically engineered mouse models of lung adenocarcinoma

The major cause of cancer-associated mortality is tumor metastasis, but our understanding of this process is far from complete. During successful dissemination, tumor cells invade the surrounding tissue of the primary tumor, intravasate into blood and lymphatic vessels, translocate to distant tissues, extravasate, adapt to the new microenvironment, and eventually seed, proliferate, and colonize to form metastases. Because dissemination mostly occurs through the blood, circulating tumor cells (CTCs) that have been shed into the vasculature and may be on their way to potential metastatic sites are of obvious interest (1). KRAS mutations are the most frequent oncogenic drivers of non-small cell lung cancer and when associated with co-mutations lead to a decrease in overall survival. We have previously established a lenti-Cre-induced Kras and Lkb1 mutant and Kras and p53 mutant genetically engineered mouse modes (KLLenti) and (KPLenti) that develop 100% lung adenocarcinoma to conduct the first study to isolate and maintain primary, CTC and metastatic cells that are KLLenti or KPLenti. We are able to isolate TTF-1+ and pan-cytokeratin+ CTCs from the KLlenti and KPlenti mice and validated their mutational status by genotyping, western blot, and immunofluorescence. Moreover, lkb1-mutant or p53-mutant primary tumor cells have different 3-D invasive properties and patterns, as well as the respective CTCs and metastatic cells when compared across different genetic sub-types. To further study gene expression patterns between primary, CTC, and metastatic sites RNAseq will be employed to identify pathways that drive metastasis within the genetic sub-types. Citation Format: Liza J. Burton, Junghui Koo, Carol Tucker-Burden, Wei Zhou, Melissa Gilbert-Ross, Chunzi Huang, Gabriel Sica, Adam Marcus. Isolation of circulating tumors cells from genetically engineered mouse models of lung adenocarcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 865.