Human lung epithelial cells progressed to malignancy through specific oncogenic manipulations

We have developed cdk4/hTERT-immortalized normal human bronchial epithelial cells (HBECs) to study lung cancer pathogenesis. By studying the oncogenic effect of common lung cancer alterations (p53, KRAS, and c-MYC) we demonstrate the ability of this model to characterize the stepwise transformation of bronchial epithelial cells to full malignancy. Using HBECs derived from multiple individuals we found: 1) the combination of five genetic alterations (p53, KRASV12, c-MYC, CDK4 and hTERT) is sufficient for full tumorigenic conversion of HBECs; 2) high levels of KRASV12 are required for full malignant transformation of HBECs, however these levels also stimulate oncogene-induced senescence; 3) RAS-induced senescence is largely bypassed with loss of p53 function; 4) over-expression of c-MYC greatly enhances malignancy but only in the context of sh-p53+KRASV12; 5) HBECs from different individuals vary in their sensitivity to transformation by these oncogenic manipulations; 6) serum-induced epithelial-to-mesenchymal transition (EMT) increases in vivo tumorigenicity; 7) genetically-identical clones of transformed HBECs exhibit pronounced differences in tumor growth, histology, and differentiation as well as sensitivity to standard platinum-based chemotherapies; and 8) an mRNA signature derived from tumorigenic and non-tumorigenic clones is predictive of outcome in lung cancer patients. Collectively, we demonstrate this HBEC model system can be used to study the effect of oncogenic mutations on malignant progression, oncogene-induced senescence, and EMT along with clinically translatable applications such as development of prognostic signatures and drug response phenotypes.

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Sato M, Larsen JE, Lee W, Sun H, Shames DS, Dalvi MP, Ramirez RD, Tang H, DiMaio JM, Gao B, Xie Y, Wistuba II, Gazdar AF, Shay JW, Minna JD