Valproic acid induces p21 and topoisomerase-II (α/β) expression and synergistically enhances etoposide cytotoxicity in human glioblastoma cell lines

Object Etoposide, a topoisomerase-II inhibitor promotes DNA damage and apoptosis of cancer cells. In this study, we have examined the ability of the histone deacetylase inhibitor, valproic acid (VPA) to modulate gene expression and sensitize glioblastoma cell lines to the cytotoxic effects of etoposide in vitro.