Abstract D133: Development of a racially/ethnically diverse collection of immortalized lung epithelial cell lines to model lung adenocarcinoma development and drug resistance across population groups
Authors: Tran Evelyn , Shi Tuo , Li Xiuwen , Firth Amy , Zhou Beiyun , Borok Zea , Offringa Ite A 
Published: September 2020

Abstract
Introduction: The most common type of lung cancer is lung adenocarcinoma, arising in the alveolar epithelium (air sacs). Drugs that specifically target certain known driver mutations are available. Unfortunately, resistance usually develops, and the cancer returns. In some cases, second and even third line targeted therapies have been established. The availability of such therapies is dependent on being able to screen for drugs that can treat resistant cells and elucidating the molecular basis of resistance. Importantly, the susceptibility of cancer cells to different therapies may be affected by the genetic background and thus the race/ethnicity of the patient. In order to ensure that effective therapies are available for all population groups, we propose to develop a collection of immortalized alveolar epithelial cell lines that represent a diversity of racial/ethnic groups. These cell lines can be used to study driver mutations and development of drug resistance, and to screen for new therapies to combat resistance. Results: Human alveolar epithelial cells are difficult to immortalize; they become senescent or undergo epithelial to mesenchymal transition, turning into fibroblasts. By using Y27632 dihydrochloride, a highly potent ATP-competitive inhibitor of Rho– associated coiled-coil forming protein serine/threonine kinase pathway, in combination with a viral oncogene, we have developed a method to culture and immortalize alveolar epithelial cells from remnant human transplant lung. The cells maintain their epithelial phenotype and can form spheres expressing lung epithelial markers in three dimensional culture. We are now in the process of inserting known driver mutations into these cells through targeted genome editing using CRISPR/Cas9. We intend to derive 10 similar cell lines each, from white, Latino, black and Asian subjects. Future directions: We will introduce driver mutations into cell lines of different backgrounds and resulting cell lines will be treated with targeted therapies in vitro to derive resistant cells. The parental, mutated, and resistant cell lines will be characterized by exome/transcriptome sequencing, and copy number variation analysis to determine the consequences of driver mutations and the basis for acquired resistance. We will use high throughput screening to identify drugs that can target resistant cells, using USC’s advanced drug screening facility, focusing on drugs that are approved by the Food and Drug Administration to ensure the greatest and fastest benefit to people suffering from lung cancer. Numerous existing drugs may have failed in trials due to differences between patients, and their therapeutic effect may be underestimated. Conclusion: Our ability to immortalize alveolar epithelial cells allows us to establish a large collection of alveolar epithelial cell lines that represent the diverse genetic background of the population of the United States. This will ensure that any developed therapies will be effective on a diversity of patients.
Citation Format: Evelyn Tran, Tuo Shi, Xiuwen Li, Amy Firth, Beiyun Zhou, Zea Borok, Ite A Offringa. Development of a racially/ethnically diverse collection of immortalized lung epithelial cell lines to model lung adenocarcinoma development and drug resistance across population groups [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr D133.