201. Differential Requirement of mTOR in Postmitotic Tissues and Tumorigenesis
- Author
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Robin M. Hobbs, Ainara Egia, George Thomas, Arkaitz Carracedo, Michelangelo Fiorentino, Sara C. Kozma, Pier Paolo Pandolfi, Alessandro Fornari, John G. Clohessy, Carlos Cordon-Cardo, Massimo Loda, Andrea Alimonti, Zhenbang Chen, Caterina Nardella, Nardella C, Carracedo A, Alimonti A, Hobbs RM, Clohessy JG, Chen Z, Egia A, Fornari A, Fiorentino M, Loda M, Kozma SC, Thomas G, Cordon-Cardo C, and Pandolfi PP
- Subjects
mTOR, PTEN, cancer ,Mitosis ,mTORC1 ,Mechanistic Target of Rapamycin Complex 1 ,medicine.disease_cause ,Models, Biological ,Biochemistry ,mTORC2 ,Article ,Mice ,medicine ,Animals ,Humans ,PTEN ,Tensin ,Molecular Biology ,Protein kinase B ,PI3K/AKT/mTOR pathway ,Cell Line, Transformed ,Cell Proliferation ,biology ,TOR Serine-Threonine Kinases ,RPTOR ,PTEN Phosphohydrolase ,Proteins ,Cell Biology ,Cell biology ,Gene Expression Regulation, Neoplastic ,Phosphotransferases (Alcohol Group Acceptor) ,Cell Transformation, Neoplastic ,Multiprotein Complexes ,biology.protein ,Cancer research ,Carrier Proteins ,Carcinogenesis ,Proto-Oncogene Proteins c-akt ,Signal Transduction - Abstract
The mammalian target of rapamycin (mTOR) is a crucial effector in a complex signaling network commonly disrupted in cancer. mTOR exerts its multiple functions in the context of two different multiprotein complexes: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). Loss of the tumor suppressor PTEN (phosphatase and tensin homolog deleted from chromosome 10) can hyperactivate mTOR through AKT and represents one of the most frequent events in human prostate cancer. We show here that conditional inactivation of mTor in the adult mouse prostate is seemingly inconsequential for this post-mitotic tissue. Conversely, inactivation of mTor leads to a marked suppression of Pten-loss-induced tumor initiation and progression in the prostate. This suppression is more pronounced than that elicited by the sole pharmacological abrogation of mTORC1. Acute inactivation of mTor in vitro also highlights the differential requirement of mTor function in proliferating and transformed cells. Collectively, our data constitute a strong rationale for developing specific mTOR kinase inhibitors targeting both mTORC1 and mTORC2 for the treatment of tumors triggered by PTEN deficiency and aberrant mTOR signaling.
- Published
- 2009