Background:

OSI-027 is a potent and selective inhibitor of mTORC1 and mTORC2 with IC50 values of 22nM and 65nM, respectively [1].

OSI-027 is developed as a potent anticancer agent through inhibiting mTORC1 and mTORC2. It shows more than 100-fold selectivity against mTOR over other PI3K-related kinases in biochemical assays. In cellular assays, OSI-027 inhibits the phosphorylation of mTORC1 and mTORC2 substrates including AKT, PRAS40 and S6K1, results in the blockade of downstream signaling. It shows equipotent cellular inhibition of both mTORC1 and mTORC2. It is demonstrated that OSI-027 is more potent in inhibiting cell proliferation and inducing cell death than rapamycin in a lot of tumor cell lines. Besides that, OSI-027 is also found to cause apoptosis via inducing sub-G1 fraction significantly. Furthermore, OSI-027 shows potent antitumor activity in MDA-MB-231 breast cancer xenograft model and human ovarian cancer xenograft models. The antitumor spectrum of OSI-027 is found to be quite broad including breast, colon, lung, prostate, lymphoma, and head and neck cancer [1].

参考文献:
[1] Bhagwat S V, Gokhale P C, Crew A P, et al. Preclinical characterization of OSI-027, a potent and selective inhibitor of mTORC1 and mTORC2: distinct from rapamycin. Molecular cancer therapeutics, 2011, 10(8): 1394-1406.