Background:

P276-00 is a novel inhibitor for CDK-1, CDK4 and CDK9 with IC50 of 79 nM, 63 nM and 20 nM, respectively [1].
CDK (cyclin-dependent kinase) plays an important role in cell cycle progression via promoting the G1/S cell cycle transition. Many studies have shown that more CDKs are overexpressed in cancer cells than in normal cells, which explain the reason of cancer cells divide uncontrollably[2]. The overexpression of CDK1/4/6 contributes to the phosphorylation of retinoblastoma protein (RB) via binding to CCND1 and results in the release of E2F transcription of genes required for cell cycle progression [3].
P276-00 is a novel inhibitor of CDK (cyclin-dependent kinase) with the ability of arresting the cells in G1/S phase transcription. When tested with NSCLC cell lines, P276-00 showed high ability of inhibiting cell proliferate thus decreased the colony forming potential via blocking cell cycle [4]. In head and neck squamous carcinoma cell line (FaDu, Detroits-562, SCC-25), treated with P276-00 for 12 hours could significantly inhibit cell ability with IC50 value ranging from 0.8 to 1.7 uM for different cell lines via decreasing the expression of CCND1[2].
In SCID mice model with H460 xenograft, treatment of P276-00 could down regulate the expression of CDK1 thus induced tumor regression [4]. When tested with HNSCC tumor xenograft mouse model, P276-00 treatment showed anti-cancer ability with a 48% tumor growth inhibition [2].
参考文献:
1.Manohar, S.M., et al., Cyclin-dependent kinase inhibitor, P276-00 induces apoptosis in multiple myeloma cells by inhibition of Cdk9-T1 and RNA polymerase II-dependent transcription. Leuk Res, 2011. 35(6): p. 821-30.
2.Mishra, P.B., et al., Molecular mechanisms of anti-tumor properties of P276-00 in head and neck squamous cell carcinoma. J Transl Med, 2013. 11(42): p. 1479-5876.
3.Raje, N., et al., Preclinical activity of P276-00, a novel small-molecule cyclin-dependent kinase inhibitor in the therapy of multiple myeloma. Leukemia, 2009. 23(5): p. 961-70.
4.Shirsath, N., et al., Potentiation of anticancer effect of valproic acid, an antiepileptic agent with histone deacetylase inhibitory activity, by the cyclin-dependent kinase inhibitor P276-00 in human non-small-cell lung cancer cell lines. Lung Cancer, 2013. 82(2): p. 214-21.