Fig. 4.

The OGG1-specific small molecule inhibitor, SU0268, is less effective in shMTH1-transduced cells vs. control shGFP-transduced cells.

A. Published chemical structure of SU0268. B. Immunoblot showing MTH1 and GAPDH (loading control) protein expression levels in A549 shGFP and shMTH1 cultures, to establish levels of MTH1 protein knockdown. C. Change in cell density under shMTH1, SU0268 or the combined treatment conditions. A549 shMTH1 or shGFP cells were dosed with the indicated concentrations of SU0268 in triplicate. Cell density across the treatment conditions was assessed at 24 and 48 h

post-treatment via the luminescence signal from CellTiter-Glo®. Error bars represent ± SD. D. Relative change in shMTH1 vs. shGFP cell density under treatment conditions. Cell densities for shMTH1 normalized to the corresponding shGFP values in (C) are shown at 24 and 48 h. The increase in normalized shMTH1 values over time and increasing SU0268 doses indicate an enhanced survival advantage of shMTH1 cells with OGG1 inhibition vs. shGFP cells with OGG1 inhibition.