Thieno[3,2-c]pyridine-4,6(5H,7H)-dione, 7-imino-2-phenyl-

JMS-053 is a potent inhibitor of the dual specificity phosphatase PTP4A3 that is potentially suitable for cancer therapy. JMS-053 markedly enhanced microvascular barrier function after exposure of endothelial cells to vascular endothelial growth factor or lipopolysaccharide. JMS-053 also blocked the concomitant increase in RhoA activation and loss of Rac1. In human ovarian cancer cells, JMS-053 impeded migration, disrupted spheroid growth, and decreased RhoA activity. Importantly, JMS-053 displayed anticancer activity in a murine xenograft model of drug resistant human ovarian cancer.