... NSC-741909's antitumor cellactivity of several LOX inhibitors, including aesculetin (anonselective LOX inhibitor), MK886 (an inhibitor of the5-LOX-activating protein), zileuton (a 5-LOX inhibitor),baicalein ... leads to inactivation of MKPs and activation of MAPKs [7-9]. ROS-mediatedinhibition of MKPs is critical for TNFα-induced sus-tained activation of JNK and subsequent apoptosis [7].Interestingly, ... (O2-), and hydroxyl radical (OH·), are generated in cells byFigure 1 NSC-741909-induced MKP1 and MKP7 clustering, and ROS production in sensitive cell lines. (A, B), Clustering of MKP1 (A) and...