1. Effective use of PI3K and MEK inhibitors to treat mutant Kras G12D and PIK3CA H1047R murine lung cancers
- Author
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Kate McNamara, Robert F. Padera, Angela Lightbown, S. Michel Maira, Samanthi A. Perera, Lucian R. Chirieac, Ramneet Kaur, Ralph Weissleder, Liang Chen, Katherine Crosby, Lewis C. Cantley, Alexander R. Guimaraes, Umar Mahmood, Jessica Simendinger, Jeffrey A. Engelman, Xiaohong Tan, Youngchul Song, Kwok-Kin Wong, Rabi Upadhyay, Carlos Garcia-Echeverria, and Timothy Q. Li
- Subjects
Lung Neoplasms ,Class I Phosphatidylinositol 3-Kinases ,MAP Kinase Signaling System ,Down-Regulation ,Mice, Transgenic ,Biology ,Mitogen-activated protein kinase kinase ,medicine.disease_cause ,Article ,General Biochemistry, Genetics and Molecular Biology ,Proto-Oncogene Proteins p21(ras) ,Mice ,Phosphatidylinositol 3-Kinases ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Animals ,c-Raf ,Enzyme Inhibitors ,Protein kinase A ,Protein Kinase Inhibitors ,PI3K/AKT/mTOR pathway ,Phosphoinositide-3 Kinase Inhibitors ,030304 developmental biology ,Mitogen-Activated Protein Kinase Kinases ,0303 health sciences ,Kinase ,General Medicine ,Molecular biology ,3. Good health ,Gene Expression Regulation, Neoplastic ,Protein kinase domain ,030220 oncology & carcinogenesis ,Genetically Engineered Mouse ,Mutation ,ras Proteins ,Cancer research ,KRAS - Abstract
Somatic mutations that activate phosphoinositide 3-kinase (PI3K) have been identified in the p110-alpha catalytic subunit (encoded by PIK3CA). They are most frequently observed in two hotspots: the helical domain (E545K and E542K) and the kinase domain (H1047R). Although the p110-alpha mutants are transforming in vitro, their oncogenic potential has not been assessed in genetically engineered mouse models. Furthermore, clinical trials with PI3K inhibitors have recently been initiated, and it is unknown if their efficacy will be restricted to specific, genetically defined malignancies. In this study, we engineered a mouse model of lung adenocarcinomas initiated and maintained by expression of p110-alpha H1047R. Treatment of these tumors with NVP-BEZ235, a dual pan-PI3K and mammalian target of rapamycin (mTOR) inhibitor in clinical development, led to marked tumor regression as shown by positron emission tomography-computed tomography, magnetic resonance imaging and microscopic examination. In contrast, mouse lung cancers driven by mutant Kras did not substantially respond to single-agent NVP-BEZ235. However, when NVP-BEZ235 was combined with a mitogen-activated protein kinase kinase (MEK) inhibitor, ARRY-142886, there was marked synergy in shrinking these Kras-mutant cancers. These in vivo studies suggest that inhibitors of the PI3K-mTOR pathway may be active in cancers with PIK3CA mutations and, when combined with MEK inhibitors, may effectively treat KRAS mutated lung cancers.
- Published
- 2008