Antitumor activity of SK-7041, a novel histone deacetylase inhibitor, in human lung and breast cancer cells

Background: A class of synthetic histone deacetylase (HDAC) inhibitors, which are hybrids of trichostatin A and MS-275 were previously developed. In this study, the antitumor effects of SK-7041, one of those novel HDAC inhibitors, was evaluated on lung and breast cancer cell lines. Materials and Methods: Human lung and breast cancer cells, as well as normal human bronchial epithelial (NHBE) cells were treated with SK-7041, and results were compared with those of cells treated with suberoylanilide hydroxamic acid (SAHA). Results: SK-7041 induced time-dependent histone hyperacetylation and showed more potent cytotoxicity than SAHA in cancer cells. These antiproliferative effects of SK-7041 were due to apoptotic cell death caused by G21M-phase arrest and to a lesser extent to G1 arrest. Moreover, SK-7041 inhibited cancer cell proliferation more selectively than NHBE cell proliferation. Conclusion: These results suggest that SK-7041 may have potential anticancer activity.