A labelled pyrazolopyrimidines derivative that is a potent and ATP-competitive mTOR inhibitor with much reduced activity against PI 3-Kα or PI 3-Kγ. WYE-354 is equally potent against mTORC1 and mTORC2 activities in HEK293 immune complex kinase assays using S6K and Akt as the respective substrate (IC50 <200 nM; [ATP] = 100 μM) and effectively blocks cellular phosphorylation of S6K on T389 and Akt on S473 both in cultures and in a murine xenograft model, resulting in a significant suppression of PC3MM2-derived tumor growth (by 86% on day 7; 50 mg/kg, i.p twice per day) in vivo.
