Design, synthesis and antitumor evaluations of nucleoside base hydroxamic acid derivatives as DNMT and HDAC dual inhibitors

Herein we designed and synthesized a series of hydroxamic acid derivatives of nucleoside bases as dual DNMT and HDAC inhibitors. Further evaluations indicated representative compound 204 remarkably inhibited DNMT and HDAC in vitro and at cellular levels, leading to G0/G1 cell cycle arrest and proliferation inhibition in U937 cells. [Display omitted] DNA methyltransferase (DNMT) and histone deacetylase (HDAC) are well recognized epigenetic targets for discovery of antitumor agents. In this study, we designed and synthesized a series of nucleoside base hydroxamic acid derivatives as DNMT and HDAC dual inhibitors. MTT assays and enzymatic inhibitory activity tests indicated that compound 204 exhibited potent DNMT1 and HDAC1/6 inhibitory potency simultaneously in enzymatic levels and at cellular levels, inducing hypomethylation of p16 and hyperacetylation of histones H3K9 and H4K8. Besides, 204 remarkably inhibited proliferation against cancer cells U937 by prompting G0/G1 cell cycle arrest. Molecular docking models explained the functional mechanism of 204 inhibiting DNMT1 and HDAC. Preliminary studies on metabolic profiles revealed that 204 showed desirable stability in liver microsomes. Our study suggested that 204 inhibiting DNMT and HDAC concurrently can be a potential lead compound for epigenetic cancer therapy.