Objective: Histone deacetylase inhibitors (HDACIs) can inhibit cell proliferation, induce cell cycle arrest, and stimulate apoptosis of cancer cells.
Methods: We investigated the effects of a novel synthesized HDACI, M344, on Ishikawa endometrial cancer cell line, SK-OV-3 ovarian cancer cell line, and normal human endometrial epithelial cells. Endometrial and ovarian cancer cells were treated with various concentrations of M344, and its effect on cell growth, cell cycle, apoptosis, and related measurements was investigated.
Results: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays showed that all endometrial and ovarian cancer cell lines were sensitive to the growth inhibitory effect of M344, although normal endometrial epithelial cells were viable after the treatment with the same doses of M344 that induced growth inhibition of endometrial and ovarian cancer cells. Cell cycle analysis indicated that their exposure to M344 decreased the proportion of cells in the S-phase and increased the proportion in the G0/G1 phases of the cell cycle. Induction of apoptosis was confirmed by annexin V staining of externalized phosphatidylserine and loss of the transmembrane potential of mitochondria. This induction occurred in concert with altered expression of genes related to cell growth, malignant phenotype, and apoptosis. Furthermore, M344 treatment of these cell lines increased acetylation of H3 and H4 histone tails.
Conclusions: These results raise the possibility that M344 may prove particularly effective in the treatment of endometrial cancers and ovarian cancers.