PP242

The mammalian target of rapamycin (mTOR) is a serine-threonine kinase that is central to two protein complexes, mTORC1 and mTORC2. These complexes are differentially regulated (e.g., only mTORC1 is sensitive to rapamycin) and regulate different pathways. PP242 is an inhibitor of the active site of mTOR kinase in both mTORC1 and mTORC2 (IC₅₀ = 8 nM). It less effectively inhibits PKCα, PI3-kinase subunit p110γ, JAK2, PKCβI, and PKCβII (IC₅₀ = 49, 102, 110, 198, and 185, respectively). PP242 has been shown to cause the death of certain human and murine leukemia cells more potently than rapamycin and, in vivo, delays leukemia onset and augments the effects of tyrosine kinase inhibitors in suppressing leukemic expansion and extending survival.

PP 242 is used in leukemia therapy suppressing mTOR signaling. Dual mTORC1/C2 inhibitor.

ChEBI: A member of the class of pyrazolopyrimidines that is 1H-pyrazolo[3,4-d]pyrimidine substituted by isopropyl, 5-hydroxyindol-2-yl and amino groups at positions 1, 3 and 4 respectively. It is a potent inhibitor of mTOR and exhi its anti-cancer properties.

This ATP-competitive mTORC1/mTORC2 inhibitor (FW = 308.34 g/mol; CAS 1092351-67-1; Solubility: 25 mM in DMSO), also named 2-[4-amino- 1-(1-methylethyl)-1H-pyrazolo[3,4-d]pyrimidin-3-yl]-1H-indol-5-ol, has a IC50 = 8 nM for both isoforms of mammalian target of rapamycin (mTOR), also known as FK506-binding protein 12-rapamycin-associated protein 1, or FRAP1, a serine/threonine protein kinase that regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, autophagy, and transcription. PP-242 shows considerable selectivity for mTOR versus PI3K family kinases. In models of acute leukemia harboring the Philadelphia chromosome (Ph) translocation, PP242, but not rapamycin, causes death of mouse and human leukemia cells. Indeed, PP242 completely inhibits TORC1 and TORC2 signaling in BCR-ABL+ cells, whereas rapamycin partially suppresses TORC1 and drives a PI3K/AKT surge. Moreover, PP242 augments TNF-related apoptosis-inducing ligand- (TRAIL-) induced apoptosis in NSCLC cells, indicating that mTORC2 regulates Cbl-dependent FLIPS degradation and TRAIL-induced apoptosis Other Targets: p110γ (IC50 = 0.102 μM); DNA-PK ((IC50 = 0.408 μM); p110δ ((IC50 = 1.27 μM); p110α ((IC50 = 1.96 μM), and p110β ((IC50 = 2.2 μM), with much weaker inhibition of 215 other kinases.