We first examined whether simultaneous inhibition of GSK3B and HDACs is more effective than inhibition of HDAC alone in reducing the survival of ovarian cancer cells in vitro. We designed and synthesized four dual inhibitors (Metavert, APCS-540, APCS-643, APCS-644), which were tested in comparison to the HDAC inhibitor SAHA in human (KURAMOCHI, OVSAHO, OVCA420) and mouse (MOSE-HRas-Myc) cell lines at concentrations of 1.2 μM, 2.4 μM, and 4.8 μM vs. control. This evidence concerns the gene HDAC9 and ovarian carcinoma.