The invention relates to the inhibition of histone deacetylase expression and enzymatic activity and, in particular, to the inhibition of a specific histone deacetylase. The invention also relates to compositions comprising antisense oligonucleotides and methods of using the same to inhibit a histone deacetylase. Also disclosed are methods for identifying a histone deacetylase involved in induction of cell proliferation, and methods for identifying compounds that interact with and reduce the enzymatic activity of such a histone deacetylase.