Flavopiridol is an orally bioavailable inhibitor of cyclin dependent kinases (IC
50s = ~100, ~100, ~100, and 300 nM for Cdk1, Cdk2, Cdk4, and Cdk7, respectively).
1 It also inhibits TEFb, a complex composed of Cdk9 and cyclin T1, with a K
i value of 3 nM.
2 Flavopiridol inhibits transcription of a CMV promoter in HeLa nuclear extract (IC
50 = 34 nM), Tat-stimulated transcription of an HIV-1 promotor (IC
50 = 7 nM), and HIV-1 replication in HEK239T cells (IC
50 = <10 nM).
In vivo, flavopiridol (5 mg/kg, i.p.) induces apoptosis and cyclin D1 depletion and delays tumor growth in an HN-12 head and neck carcinoma mouse xenograft model.
1 It also suppresses synovial hyperplasia and joint destruction in a mouse model of collagen-induced arthritis.
3