Targeting the FOXO1/KLF6 axis regulates EGFR signaling and treatment response.
EGFR activation is both a key molecular driver of disease progression and the target of a broad class of molecular agents designed to treat advanced cancer. Nevertheless, resistance develops through several mechanisms, including activation of AKT signaling. Though much is known about the specific molecular lesions conferring resistance to anti-EGFR-based therapies, additional molecular characterization of the downstream mediators of EGFR signaling may lead to the development of new classes of targeted molecular therapies to treat resistant disease. We identified a transcriptional network involving the tumor suppressors Krüppel-like factor 6 (KLF6) and forkhead box O1 (FOXO1) that negatively regulates activated EGFR signaling in both cell culture and in vivo models. Furthermore, the use of the FDA-approved drug trifluoperazine hydrochloride (TFP), which has been shown to inhibit FOXO1 nuclear export, restored sensitivity to AKT-driven erlotinib resistance through modulation of the KLF6/FOXO1 signaling cascade in both cell culture and xenograft models of lung adenocarcinoma. Combined, these findings define a novel transcriptional network regulating oncogenic EGFR signaling and identify a class of FDA-approved drugs as capable of restoring chemosensitivity to anti-EGFR-based therapy for the treatment of metastatic lung adenocarcinoma.
Pubmed ID: 22653055 RIS Download
Active Transport, Cell Nucleus | Adenocarcinoma | Animals | Antineoplastic Agents | Cell Line, Tumor | Drug Resistance, Neoplasm | Drug Synergism | Enzyme Activation | Erlotinib Hydrochloride | Female | Forkhead Box Protein O1 | Forkhead Transcription Factors | Gene Expression Regulation, Neoplastic | Humans | Kruppel-Like Transcription Factors | Lung Neoplasms | Mice | Mice, Inbred BALB C | Mice, Nude | Mutation | Proto-Oncogene Proteins | Proto-Oncogene Proteins c-akt | Quinazolines | Real-Time Polymerase Chain Reaction | Receptor, Epidermal Growth Factor | Signal Transduction | Transcription, Genetic | Trifluoperazine | Tumor Burden | Xenograft Model Antitumor Assays