Preclinical lung cancer studies in the intramural program Phillip Dennis, M.D., Ph.D. Senior Investigator, Medical Oncology Branch Value of preclinical lung cancer studies • Evaluation of new drugs, new combinations in relevant model systems • Elucidation of mechanisms of lung carcinogenesis • Validation of genes or patterns of gene expression as predictive or prognostic factors for patients with lung cancer Tools • Cell lines – Primary human bronchial/alveolar epithelial cells – Human immortalized bronchial epithelial cells • BEAS-2B et al., HBEC et al. – Human lung cancer cell lines • SCLC, NSCLC – Syngeneic murine lung adenocarcinoma cell lines from tobacco carcinogen-driven model • Mouse models – Xenograft – Tobacco carcinogen-driven – Genetically engineered • Rat model – Radon +/- smoking Advantages of carcinogen-driven and genetically engineered mouse models of lung cancer • Prevention and treatment studies possible • Physiologic analysis of tumor microenvironment (immunocompetent models) • Preclinical PK, PD, toxicology- compare to human • Imaging- longitudinal assessment of lung tumor growth/regression Relevance of models to human lung cancer subsets • Current/former smokers – Tobacco carcinogen-driven • NNK (mutant Kras-dependent) • urethane – GEM • Mutant K-Ras • Mutant LKB1 • nAchR subunits • Never smokers – EGFR-driven (L858R/T790M) – XPC (DNA damage) Bench to bedside examples • Current/former smokers – Rapamycin to prevent tobacco carcinogen-induced lung tumors • Never smokers – Triciribine (Akt inhibitor) to overcome resistance to EGFR TKIs. A common pathway for different lung cancer subsets Smokers Never smokers Etiology? nAChR Kras mut EGFR mut/amp PI3K X X T LKB1 PTEN T AMPK Akt triciribine TSC2 T mTOR rapamycin Tumor suppressor genes Bench to bedside example- A lung cancer prevention model for current or former smokers (K-Ras driven) Study Schema NNK or saline rapamycin I. Tx of established tumors 50% tumor size II. Short term treatment Ø size, multiplicity III. Continuous treatment 90% tumor size, multiplicity Week of study 0 7 16 26 32 Clin Cancer Res. 2007 Apr 1;13(7):2281-9 A working model for prevention of tobacco carcinogen- induced lung tumors by rapamycin Anti-CD25 ab Genetic ablation Exposure to tobacco carcinogens X Permissive environment Foxp3 cytotoxic T cell response X Foxp3 Kras G12D genetic/epigenetic changes proliferation X Kras G12D X X Rapamycin Rapamycin PLoS ONE. 2009;4(3):e5061 Bench to bedside example- A model for never smokers whose lung cancers become resistant to an EGFR TKI Hypothesis- Akt inhibition will resensitize cells to an EGFR TKI In vitro model H1975 cells (resistant to EGFR TKI) (L858R/T790M mutation) Triciribine (Akt inhibitor) Gefitinib/erlotinib (EGFR TKI) Total Death Assay Gefitinib Triciribine 25 Combined DMSO 20 TCN 120 Erlot 100 2.5M Gefitinib % Death 15 TCN + Erlot % Growth 80 60 10 40 Synergism 20 5 0 0.0001 0.001 0.01 0.1 1 10 100 0 -20 48 Hr H1975 M Triciribine DMSO Gef TCN Combo P-EGFR (Y1068) EGFR T Gefitinib/erlotinib EGFR P-ERK Akt ERK T triciribine (Y202/204) P-AKT (S473) Pras40 P-Pras40 (T246) Bench to bedside example- A model for never smokers whose lung cancers become resistant to an EGFR TKI H1975 xenografts 1600 vehicle 1400 50 mg/kg erlotinib 0.3 mg/kg TCN-P Median tumor volume (mm3) 1200 50 mg/kg erlotinib + 0.3 mg/kg TCN-P 1000 800 600 400 200 0 0 5 10 15 Day Bench to bedside example- A model for never smokers whose lung cancers become resistant to an EGFR TKI- An inducible L858R/T790M transgenic model of lung cancer P-EGFR Total EGFR Specific induction of L858R/T790M mutations in Clara cells after 12 wk of doxycycline Before triciribine QuickTime™ and a Motion JPEG OpenDML d ecompressor are neede d to see this picture. QuickTime™ and a Motion JPEG OpenDML d ecompressor are neede d to see this picture. Day 9 triciribine QuickTime™ and a Motion JPEG OpenDML d ecompressor QuickTime™ and a Motion JPEG OpenDML d ecompressor are neede d to see this picture. are neede d to see this picture. Conclusions • Preclinical lung cancer expertise within the intramural program is extensive. • Mouse models with relevance to many molecular subsets of human lung cancer improve our understanding of lung cancer and aid targeted drug development. • The barriers between preclinical and clinical lung cancer research are minimized in the intramural program • A lung cancer prevention trial with rapamycin and a lung cancer treatment trial combining triciribine with erlotinib (Tarceva) are in the approval process. • The development of new mouse models based on results from human lung cancer GWAS is ongoing.