Nakayama, HironaoBruneau, SarahKochupurakkal, NoraComa, SilviaBriscoe, DavidKlagsbrun, Michael2015-08-032015Nakayama, Hironao, Sarah Bruneau, Nora Kochupurakkal, Silvia Coma, David M. Briscoe, and Michael Klagsbrun. 2015. “Regulation of mTOR Signaling by Semaphorin 3F-Neuropilin 2 Interactions In Vitro and In Vivo.” Scientific Reports 5 (1): 11789. doi:10.1038/srep11789. http://dx.doi.org/10.1038/srep11789.2045-2322http://nrs.harvard.edu/urn-3:HUL.InstRepos:17820800Semaphorin 3F (SEMA3F) provides neuronal guidance cues via its ability to bind neuropilin 2 (NRP2) and Plexin A family molecules. Recent studies indicate that SEMA3F has biological effects in other cell types, however its mechanism(s) of function is poorly understood. Here, we analyze SEMA3F-NRP2 signaling responses in human endothelial, T cell and tumor cells using phosphokinase arrays, immunoprecipitation and Western blot analyses. Consistently, SEMA3F inhibits PI-3K and Akt activity, and responses are associated with the disruption of mTOR/rictor assembly and mTOR-dependent activation of the RhoA GTPase. We also find that the expression of vascular endothelial growth factor, as well as mTOR-inducible cellular activation responses and cytoskeleton stability are inhibited by SEMA3F-NRP2 interactions in vitro. In vivo, local and systemic overproduction of SEMA3F reduces tumor growth in NRP2-expressing xenografts. Taken together, SEMA3F regulates mTOR signaling in diverse human cell types, suggesting that it has broad therapeutic implications.en-USJournal Article2015-08-0310.1038/srep11789