Fig. 4.

Induction of HTATIP2 or depletion of MPG reduce MMS‐induced SSB and AP sites. The formation of single‐strand breaks (SSBs) and abasic or apurinic/apyrimidinic (AP) sites were evaluated upon induction of HTATIP2 or depletion of MPG using the alkaline comet assay after 48 h of methylmethansulfonate (MMS) treatment. (A) Visualization of the comet tail moment under the four indicated experimental conditions using the Dox‐inducible cell line LN‐229‐C25 for HTATIP2 expression (image scale bar, 50 μm), and (B) the LN‐229‐C25 cell line with IPTG‐inducible anti‐MPG shRNA5^IPTG (image scale bar, 50 μm). SSBs and AP sites were quantified as comet tail moment, defined by the distance from the center of the comet head to the center of the comet tail. (C) Analysis was performed on 478 cells (imagej, fiji, adding opencomet analysis tool). Treatment conditions: Untreated, gray; Dox (250 ng·mL⁻¹), green; MMS (200 nm), red; and combination, blue. (D) Analysis was performed on a total of 208 images, comprising 713 cells. Treatment conditions: Untreated, gray; IPTG (500 ng·mL⁻¹), black; MMS 200 nm, red; and the combination, green (C, D, ****P < 0.0001, t‐test, mean ± SD). The experiments were performed in triplicate. Control experiment for anti‐MPG shRNA with not‐targeting shRNA, see Fig. S9.