Abstract 3230: Immortalization of human small airway epithelial cells as a model for studying lung tumor transformation

Abstract

Abstract Normal human lung epithelial cells that can be genetically manipulated to study the various steps in lung cancer pathogenesis and stem cell biology would be of great utility and also provide isogenic strains to develop and test new diagnostic (biomarkers), preventative and therapeutic strategies for lung cancer. Previously we immortalized normal proximal human lung bronchial epithelial cells (HBECs) for studying lung tumors arising in the central compartment of the lung and now have over 40 of these strains (growing in defined KSFM media) including many isogenic derivatives with various oncogenic changes (Can Res 2004, Can Res 2006). We have extended this by immortalizing normal distal (small airway) epithelial cells that serve as models for studying tumors arising in the peripheral compartment of the lung. Using Cdk4 and hTERT exogenous expression vectors (as used for HBECs) and SAGM defined media routinely immortalized (N= 15) human small airway epithelial cells (HSAECs) from peripheral lung. These HSAEC strains are highly enriched (>50%) for cells with stem like properties (e.g. Aldehyde dehydrogenase positivity), express basal cell markers but not Clara cell, type 1 or type 2 differentiation markers., However, HSAECs can be induced to express Clara cell, type 1 or type 2 cell markers when they are grown in matrigel (where they form cyst like structures which express such differentiation markers) and under other conditions favoring differentiation (such as insulin depletion, Ca2+ addition). HSAECs show anchorage dependent growth, do not form colonies in soft agar, and are non-tumorigenic in NOD/SCID mice. However, HSAECs can be genetically manipulated by introducing oncogenes (such as KRASV12, missense p53 and other oncogene combinations) which now allow HSAECs to progress towards a transformed phenotype (e.g. formation of soft agar colonies), and selection of a subset of HSAEC(KRAS, p53) large soft agar colonies identifies sublines that can now form poorly differentiated carcinomas. Thus, we have developed conditions to routinely immortalize lung epithelial cells derived from distal small airways (HSAECs) which grow in defined media, exhibit stem cell like characteristics, and can be genetically manipulated to give rise to poorly differentiated cancers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3230.