γ-Secretase is a protease complex that cleaves single-pass transmembrane proteins, such as Notch receptors and β-amyloid precursor protein (APP), within the transmembrane domain. MK-0752 is a potent, reversible inhibitor of γ-secretase, reducing the cleavage of APP to Aβ40 in human neuroblastoma SH-SY5Y cells with an IC50 value of 5 nM. It is orally bioavailable and crosses the blood-brain barrier, as orally administered MK-0752 dose-dependently reduces the generation of new amyloid β protein in the brain of rhesus monkeys. Through its effects on the Notch pathway, MK-0752 reduces the number of breast cancer stem cells in tumorgrafts, enhancing the efficacy of the chemotherapy drug docetaxel in mice with breast cancer tumors.[Cayman Chemical]
mk-0752 is a potent gamma secretase inhibitor in clinical development (ic50 ~50 nm). gamma secretase is an important component in the notch cleavage machinery that catalyzes the cleavage of receptor protein substrates within their transmembrane domain. inhibition of notch inhibits bc cell proliferation in vitro. notch signaling requires gamma secretase, which cleaves notch, releasing the notch intracellular domain (nicd) to activate transcription of target genes. notch signaling plays an important role in normal tissue development, cell fate determination, proliferation, and survival. notch signaling is activated following the binding of cognate ligands that include delta1, delta2, and delta3 and jagged1 and jagged2.i. e. krop, m. kosh, i. fearen, j. savoie, a. dallob, c. matthews, j. stone, e. winer, s. j. freedman and p. lorusso. phase i pharmacokinetic (pk), and pharmacodynamic (pd) trial of the novel oral notch inhibitor mk-0752 in patients (pts) with advanced breast cancer (bc) and other solid tumors. j clin oncol (meeting abstracts) june 2006 vol. 24 no. 18_suppl 10574.maryam fouladi, clinton f. stewart, james olson, lars m. wagner, arzu onar-thomas, mehmet kocak, roger j. packer, stewart goldman, sridharan gururangan, amar gajjar, tim demuth, larry e. kun, james m. boyett and richard j. gilbertson. phase i trial of mk-0752 in children with refractory cns malignancies: a pediatric brain tumor consortium study. jco september 10, 2011 vol. 29 no. 26 3529-3534