1. mTOR Inhibition Specifically Sensitizes Colorectal Cancers with KRAS or BRAF Mutations to BCL-2/BCL-XL Inhibition by Suppressing MCL-1
- Author
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Kenneth E. Hung, Sridhar Ramaswamy, Erin M. Coffee, Cyril H. Benes, Carlotta Costa, Aaron N. Hata, Youngchul Song, Miguel Rivera, Hiromichi Ebi, Rakesh K. Jain, Anthony C. Faber, Ah Ting Tam, Randy J. Milano, Ryan B. Corcoran, Anahita Dastur, Jessica L. Boisvert, Alan T. Yeo, David P. Kodack, Elena J. Edelman, Jatin Roper, and Jeffrey A. Engelman
- Subjects
Proto-Oncogene Proteins B-raf ,Colorectal cancer ,Morpholines ,medicine.medical_treatment ,bcl-X Protein ,Mice, Nude ,Antineoplastic Agents ,Mechanistic Target of Rapamycin Complex 2 ,mTORC1 ,Mechanistic Target of Rapamycin Complex 1 ,Biology ,medicine.disease_cause ,Article ,Targeted therapy ,Proto-Oncogene Proteins p21(ras) ,Mice ,chemistry.chemical_compound ,Cell Line, Tumor ,Proto-Oncogene Proteins ,medicine ,Animals ,Humans ,Protein Kinase Inhibitors ,neoplasms ,PI3K/AKT/mTOR pathway ,Sulfonamides ,Mutation ,Aniline Compounds ,Navitoclax ,TOR Serine-Threonine Kinases ,medicine.disease ,Mice, Mutant Strains ,digestive system diseases ,Proto-Oncogene Proteins c-bcl-2 ,Oncology ,chemistry ,Apoptosis ,Multiprotein Complexes ,ras Proteins ,Cancer research ,Myeloid Cell Leukemia Sequence 1 Protein ,KRAS ,Colorectal Neoplasms - Abstract
Colorectal cancers harboring KRAS or BRAF mutations are refractory to current targeted therapies. Using data from a high-throughput drug screen, we have developed a novel therapeutic strategy that targets the apoptotic machinery using the BCL-2 family inhibitor ABT-263 (navitoclax) in combination with a TORC1/2 inhibitor, AZD8055. This combination leads to efficient apoptosis specifically in KRAS- and BRAF-mutant but not wild-type (WT) colorectal cancer cells. This specific susceptibility results from TORC1/2 inhibition leading to suppression of MCL-1 expression in mutant, but not WT, colorectal cancers, leading to abrogation of BIM/MCL-1 complexes. This combination strategy leads to tumor regressions in both KRAS-mutant colorectal cancer xenograft and genetically engineered mouse models of colorectal cancer, but not in the corresponding KRAS-WT colorectal cancer models. These data suggest that the combination of BCL-2/BCL-XL inhibitors with TORC1/2 inhibitors constitutes a promising targeted therapy strategy to treat these recalcitrant cancers. Significance: Effective targeted therapies directed against colorectal cancer with activating mutations in KRAS remain elusive. We have leveraged drug-screen data from a large panel of human colorectal cancers to uncover an effective, rational targeted therapy strategy that has preferential activity in colorectal cancers with KRAS or BRAF mutations. This combination may be developed for clinical testing. Cancer Discov; 4(1); 42–52. ©2013 AACR. See related commentary by Russo et al., p. 19 This article is highlighted in the In This Issue feature, p. 1
- Published
- 2014