Cdk9 Inhibitor II

Cdk9 Inhibitor II is a potent and selective inhibitor of Cdk9 with an IC₅₀ value of 0.35 µM in vitro. It is also an inhibitor of Cdk2-cyclin E with respect to ATP, with Ki and IC₅₀ values of 13.3 µM and 20 µM respectively. It reduces the frequency of S-phase cells in the cancer cell line HT-29 and decreases the phosphorylation of the retinoblastoma protein and the C-terminal domain of RNA polymerase II. It inhibits mRNA synthesis and induces the tumor suppressor protein p53. It inhibits cell proliferation of cancer cell lines such as MCF-7, HOS, G361, and K562 cells with IC₅₀ values of 33 µM, 49 µM, 64 µM, and 62 µM respectively.