Patients with
lung cancer with activating mutations in the
EGF receptor (EGFR)
kinase, who are treated long-term with
tyrosine kinase inhibitors (TKI), often develop secondary mutations in EGFR associated with resistance. Mice engineered to develop
lung adenocarcinomas driven by the human EGFR T790M resistance mutation are similarly resistant to the EGFR TKI
erlotinib. By
tumor volume endpoint analysis, these mouse
tumors respond to
BIBW 2992 (an irreversible EGFR/HER2 TKI) and
rapamycin combination
therapy. To correlate EGFR-driven changes in the lung with response to drug treatment, we conducted an integrative analysis of global transcriptome and metabolite profiling compared with quantitative imaging and histopathology at several time points during
tumor progression and treatment. Responses to single-drug treatments were temporary, whereas combination
therapy elicited a sustained response. During
tumor development, metabolomic signatures indicated a shift to high anabolic activity and suppression of antitumor programs with 11 metabolites consistently present in both lung tissue and blood.
Combination drug treatment reversed many of the molecular changes found in tumored lung. Data integration linking
cancer signaling networks with metabolic activity identified key pathways such as
glutamine and
glutathione metabolism that signified response to single or dual treatments. Results from
combination drug treatment suggest that metabolic transcriptional control through C-MYC and SREBP, as well as ELK1, NRF1, and NRF2, depends on both EGFR and
mTORC1 signaling. Our findings establish the importance of kinetic therapeutic studies in preclinical assessment and provide in vivo evidence that TKI-mediated antiproliferative effects also manifest in specific metabolic regulation.