雷帕霉素Rapamycin (Sirolimus)是一种特定的 mTOR 抑制剂，在 HEK293细胞中，IC50 为 ~0.1 nM。
Rapamycin inhibits endogenous mTOR activity in HEK293 cells with IC50 of 0.1 nM, more potently than iRap and AP21967 with IC50 of 5 nM and 10 nM, respectively[1]. Rapamycin exerts its antitumor effect on malignant glioma cells by inducing autophagy and suggest that in malignant glioma cells a disruption of the PI3K/Akt signaling pathway could greatly enhance the effectiveness of mTOR inhibitors. Rapamycin inhibits cell viability in all three cell lines in a dose-dependent manner, but their sensitivities varied. The IC50 levels of T98G, U87-MG, and U373-MG cells are 2 nM, 1 μM, and >25 μM, respectively[3].Treatment with Rapamycin (i.p, 1.5 mg/kg) almost completely prevents the hypertrophic increases in plantaris muscle weight and fibre size at 7 and 14 days[4]. WT or LS/+ mice are treated daily Rapamycin (2 mg/kg body weight i.p.) for 4 weeks, follows by an additional 4 weeks of weekly injections of the same dose. There is significant reversal of the abnormal fetal gene expression profile of hearts from Rapamycin-treated LS/+ mice[5].