FIGURE 3.

TLP promotes UV-mediated cell death and senescence. A, shTLP-expressing HCT116 cells were exposed to UV light, and viable cells were counted at the indicated times. B, shTLP-expressing HCT116 cells were exposed to UV light, and the cells were re-plated in a 6-well plate. After 7 days, colonies were stained with crystal violet. NT, no treatment. C, top, shTLP-expressing HCT116 cells were exposed to UV light and cultured for 5 days, and then senescence-associated β-galactosidase (SA-β-gal) activity was measured using a SA-β-gal staining method. A single cell is enclosed by a dotted line. Scale bar, 100 μm. Bottom, The SA-β-gal-positive cells were quantified, and results are shown as ratios (mean ± S.D.). **, p < 0.01 (Welch's t test).