Trichostatin A induces apoptosis in oral squamous cell carcinoma cell lines independent of hyperacetylation of histones

Aim of Study: To investigate the apoptotic event of trichostatin A (TSA) and its associated mechanism in oral squamous cell carcinoma (OSCC) lines. Materials and Methods: HSC-3 and Ca9.22 cell lines were evaluated using a trypan blue exclusion assay, histone isolation, soft agar assay, live/dead assay, 4%,6-diamidino-2-phenylindole staining, JC-1 mitochondrial membrane potential (MMP) assay, and Western blot analysis to demonstrate the anticancer activity of TSA. Results: TSA decreased OSCC cell viability and proliferation without affecting the histone acetylation. TSA-induced caspase-dependent or -independent apoptosis according to cell types, TSA enhanced the expression levels of Bim protein by dephosphorylating ERK1/2 pathway in HSC-3 cells. TSA also damaged MMP and increased cytosolic apoptosis-inducing factor (AIF) in Ca9.22 cells. Conclusion: The present study suggests that TSA may be a potential anticancer drug candidate for the treatment of OSCC through the induction of apoptosis.