Background: PSMA expression varies among prostate cell lines. We examined the role of CpG methylation and histone deacetylation in PSMA transcriptional repression in prostate cell lines.
Materials and methods: The methylation status of a PSMA CpG island was investigated in LNCaP, DU145 and PC3 prostate cell lines. Cells were treated with a demethylating agent and a histone deacetylase inhibitor to determine if PSMA transcription could be activated in nonexpressing cells. A transfection assay with methylated and unmethylated PSMA promoter/enhancer-driven luciferase expression constructs was performed to examine the effect of methylation on transcription.
Results: The PSMA CpG island was only methylated in DU145 cells but transcription could not be activated by demethylation or histone deacetylase inhibition. Methylation repressed PSMA transcription in LNCaP cells.
Conclusion: Although promoter methylation represses PSMA transcription in LNCaP cells, another method inhibits PSMA expression in DU145 and PC3 cells.