In vitro activity: CCG-1423 selectively inhibits SRF-mediated transcription activated by Rho pathway signaling, and specifically inhibits LPA-stimulated DNA synthesis. CCG-1423 also selectively inhibits the proliferation of RhoC-overexpressing melanoma cells (A375M2 and SK-Mel-147), and strongly suppresses the Rho-dependent invasion by PC-3 cells. CCG-1423 in combination with LY294002 enhances differentiation of mouse embryonic stem cells into intermediate mesoderm through BMP7-positive cells. In H9c2 cells, CCG-1423 inhibits MRTF nuclear localization, and completely blocks STARS proximal reporter activity. CCG-1423, as a Rho/MRTF/SRF pathway inhibitor, also represses both matrix-stiffness and TGF-beta-induced fibrogenesis in human colonic myofibroblasts.

Kinase Assay: CCG-1423 has nanomolar to low micromolar potency as well as selectivity toward Rho-overexpressing and invasive cancer cell lines for inhibition of DNA synthesis, cell growth, and/or invasion. Caspase-3 activation in the highly metastatic RhoC-overexpressing A375M2 melanoma cell line was enhanced by CCG-1423 whereas a smaller increase was seen with the parental A375 cell line, whereas just the opposite pattern was seen with daunorubicin.

Cell Assay: Cells in normal culture medium are plated (2,000 per well) in a 96-well plate coated with laminin. After attachment, the medium is replaced with serum-free medium (0% FBS) with 30 μmol/L LPA with or without 300 nM CCG-1423. Fresh LPA with or without CCG-1423 is added at day 5 to ensure that LPA and compound are present throughout the experiment. On day 8, WST-1 reagent is added to the wells for 1 h and absorbance at 450 nm is read using a Victor plate reader.