Nox4 inhibitory activity of new synthesized oxindole derivatives

Recently, the Nox4 inhibitory activity shown by some oxindole derivatives has been described. in This study, a panel of new synthesized derivatives against different leukemia cell lines in the NCI assays were tested for the ability to inhibit Nox4 in B1647 cells, a human acute myeloid leukemia cell line. Nox4 is known to be costitutively active and to play the major role in the generation of ROS requird for sustaining cellular growth and proliferation of B1647 cells. MTT assay confirmes the anti-proliferative activity of alla the tested molecules in a dose dependent manner at a concentration of 5 and 10 microM. ROS production was measured in B1647 cells after an acute treatment (30 min) with the selected compounds. Results indicate that two compounds (C5 and C7) are able to inhibit ROS generation in a dose-dependent manner. As B1647 cells express Nox2 and Nox4, in order to rule out the role of Nox2-derived ROS, the acute inhibition of ROS production was measured following RNA silencing of Nox2. Data show that the two selected compounds were able to inhibit ROS production at the same extent either in Nox2 silenced cells or in the control. Finally, Wester blotting analysis was performed to investigate Nox4 expression inB1647 cells after 24 h-incubation with the compounds. Data show that treatments with C5 and C7 were able to downregulate Nox4. In conclusion, results here reported indicate that Nox4 could be a target for two of the new synthesized oxindole derivatives and the Nox4 inhibition seems to contribute to the anti-proliferative effect of the compounds in acute leukemia B1647 cells and to be a promising strategy for a novel antileukemic therapy.