Figure 2

HDAC inhibition induces the senescence-associated-β-glacatosidase (SA-β-gal) activity in proliferating WI-38 cells. Proliferating WI-38 cells were propagated for 14 days in 0.5 mM butyrate (Proliferating WI-38; Butyrate) or 9 days in 0.5 μM TSA (Proliferating WI-38; TSA) and stained for SA-β-gal activity. The level of SA-β-gal staining was also determined in untreated young WI-38 cells propagated in parallel (Proliferating WI-38; Control), as well as WI-38 cells propagated to replicative senescence (Senescent WI-38; Control). Phase contrast images are shown in duplicate at 100 × magnification.