Figure 7.

Alkaline comet assay of CPT-treated TDP1-transduced MEF-TDP1^−/−cells.A, expression of TDP1-wt, TDP1_149–608, TDP1-S81E, or TDP1-S81A in extracts of MEF-TDP1^−/− cells after lentiviral transduction. Upper panel, immunoblotting with rabbit anti-TDP1-C-term (Abcam). Lower panel, immunoblotting with anti-histone H3 antibody (Cell Signaling Technology). B, alkaline comet assays of MEF-TDP1^−/− cells and the indicated derivatives treated with CPT for 1 h were performed as described in Experimental procedures. C, comparison of the percentage of DNA in the comet tail MEF-TDP1^−/− cells and the indicated derivatives. The results shown represent three independent experiments with at least 50 comet tail measurements for each sample. ∗∗ and ∗∗∗∗ represents p <0.0011 and <0.0001, respectively.