Background:

PD-0332991 is selective and oral inhibitor of cyclin-dependent kinase 4/6 with IC50 values of 11nM and 16nM, respectively for CDK4 and CDK6 [1].

PD-0332991 is a highly specific inhibitor of CDK4/6. It is a potent anti-proliferative agent against Rb-positive tumor cells in vitro, subsequently inducing an exclusive G1 arrest. It has been reported to prevent tumor growth in disseminated human myeloma xenografts and induce G1 arrest in primary bone marrow cells [2].

PD-0332991 is also studied in breast cancer. It causes growth inhibition of ER-positive cell lines and 10/16 HER2-amplified cell lines. 100nM PD-0332991 can inhibit the phosphorylation of Rb in three more sensitive cell lines, resulting in prevention of cell cycle progression [2].

参考文献:
[1] Ivan Diaz-Padilla, Lillian L. Siu and Ignacio Duran. Cyclin-dependent kinase inhibitors as potential targeted anticancer agents. Invest New Drugs. 2009, 27: 586–594.
[2] Richard S Finn, Judy Dering, Dylan Conklin, Ondrej Kalous, David J Cohen, Amrita J Desai, Charles Ginther, Mohammad Atefi, Isan Chen, Camilla Fowst, Gerret Los and Dennis J Slamon. PD 0332991, a selective cyclin D kinase 4/6 inhibitor, preferentially inhibits proliferation of luminal estrogen receptor-positive human breast cancer cell lines in vitro. Breast Cancer Research. 2009, 11: R77.