The effect of TG2 inhibitors on R37 and KP1 viability.

<p>(<b>A</b>) <b>The effect of TG inhibitors on R37 and KP1 cells using the XTT assay.</b> R37 and KP1 cells in DMEM medium containing 1.5% serum were seeded into 96-well plates at the density of 3,000 cells/well in the presence or absence of TG2 inhibitors, R281, R283 and R294. The XTT assay was performed after a 16 h incubation time point as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057017#s2" target="_blank">Materials and Methods</a>. Data represent the mean ± S.D. from 3 separate experiments. (<b>B</b>) <b>Caspase staining for apoptosis.</b> The presence of active caspase-3 in the R37 and KP1 cells treated with TG2 inhibitor R294 was detected using fluorescent staining (red) and visualized under a fluorescence microscope as described in the <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0057017#s2" target="_blank">Materials and Methods</a>, while DAPI was used for the nuclei staining (blue). Bar, 25 µm. (<b>C</b>) <b>Effect of TG2 inhibitors on R37 and KP1 cell viability after 72 h.</b> The TG2 inhibitors were introduced to R37 and KP1 cells at the concentrations described above and incubated upto 72 h. The XTT assays were performed to detect cell viability as introduced in (<b>A</b>).