The Rho family of small GTPases play an important role in transduction of cell signaling events associated with several human cancers. CCG-1423 is a specific inhibitor of Rho pathway-mediated signaling and activation of serum response factor (SRF) transcription. The site of inhibition in the pathway is not precisely defined but CCG-1423 appears to act on some aspect of the interaction of SRF with its transcriptional cofactor megakaryoblastic leukemia 1 (MKL1) at a point upstream of DNA binding. CCG-100602 is a CCG-1423 analog developed for improved selectivity, potency, and attenuated cytotoxicity relative to its parent compound. CCG-100602 inhibits RhoA/C-mediated, SRF-driven luciferase expression in PC-3 prostate cancer cells with an IC50 value of 9.8 μM. At 100 μM, CCG-100602 demonstrates 72% inhibition of PC-3 cell invasion into a Matrigel model of metastasis, exhibiting an efficacy:toxicity profile superior to that of CCG-1423 at 10 μM.
