Fig. 8.

MIT induces ERK-dependent DNA damage. Four hours after a 10 min exposure to 100 μm MIT, cultures were stained for TUNEL and counterstained with thionin. Using this procedure, nuclei with damaged DNA are stained darkbrown (arrowheads in B), and cells are stained purple. A, Control.B, MIT-treated cultures. C, MIT-treated cultures in the presence of the MEK inhibitor U0126 (10 μm). D, MIT-treated cultures in the presence of the antioxidant trolox (100 μm). Note the absence of TUNEL staining in A, C, andD.