M344 is a potent HDAC inhibitor, which can also induced expression of the pro-apoptotic genes, Puma and Bax, together with the morphological features of apoptosis, in MCF-7 cells.

In contrast to the significant induction of p21(waf1/cip1) mRNA expression following treatment with M344 (10μM) for 1 or 3 days, there was a significant decrease in p53 mRNA expression, although p53 protein levels were unchanged. Similar treatment with M344 also induced expression of the pro-apoptotic genes, Puma and Bax, together with the morphological features of apoptosis, in MCF-7 cells. With the addition of M344, the platinum-sensitive breast and ovarian cancer cell lines that displayed relatively high BRCA1 protein levels demonstrated significant potentiation of cisplatin cytotoxicity in association with a reduction of BRCA1 protein.  M344 up-regulates SMN2 protein expression in fibroblast cells derived from SMA patients up to 7-fold after 64 h of treatment.

M344 was a highly effective inhibitors of histone deacetylases as potential therapeutic tools for high-risk embryonal tumors of the nervous system of childhood.