Trichostatin A (
TSA), originally developed as an
antifungal agent, is one of potent
histone deacetylase (
HDAC) inhibitors, which are known to cause growth arrest and apoptosis induction of transformed cells, including urinary bladder, breast, prostate, ovary, and
colon cancers. However, the effect of
HDAC inhibitors on human
non-small cell lung cancer cells is not clearly known yet. Herein, we demonstrated that treatment of
TSA resulted in a significant decrease of the viability of H157 cells in a dose-dependent manner, which was revealed as apoptosis accompanying with nuclear fragmentation and an increase in sub-G0/G1 fraction. In addition, it induced the expression of Fas/FasL, which further triggered the activation of
caspase-8. Catalytic activation of
caspase-9 and decreased expression of anti-apoptotic Bcl-2 and Bcl-XL
proteins were observed in
TSA-treated cells. Catalytic activation of
caspase-3 by
TSA was further confirmed by cleavage of
pro-caspase-3 and intracellular substrates, including
poly (ADP-ribose) polymerase (PARP) and inhibitor of
caspase-activated deoxyribonuclease (ICAD). In addition, a characteristic phenomenon of
mitochondrial dysfunction, including mitochondrial membrane potential transition and release of mitochondrial
cytochrome c into the cytosol was apparent in
TSA-treated cells. Taken together, our data indicate that inhibition of HDAC by
TSA induces the apoptosis of H157 cells through signaling cascade of Fas/FasL-mediated extrinsic and mitochondria-mediated intrinsic
caspases pathway.