acy-1215 and Neoplasms

Alzheimer's disease (AD) as the most prevalent dementia type has become one of the greatest threats to the health and life of the elder people worldwide. Although there has been a great effort in the discovery of anti-AD drugs, those approval drugs only demonstrated the temporarily relieving the symptoms without completely stopping the progression of the neuropathology. It is very urgent and reasonable to develop more effective agents against other therapeutic targets. In the last two decades, zinc-dependent deacetylases (HDACs) have attracted much attention as an important group of epigenetic targets in drug discovery, because five HDAC inhibitors have been approved for clinically treating cancers. This review is to summarize the possible roles of HDACs in AD pathophysiology and their inhibitors used in AD studies. And the future perspectives related to HDACs as epigenetic targets for treating AD by their selective inhibitors, multi-target inhibitors or PROTACs are also discussed.

Topics: Aged; Alzheimer Disease; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Neoplasms; Zinc

Myeloid-derived suppressor cells (MDSCs) are widely implicated in negative regulation of immune responses in cancer. Inhibition of class I histone deacetylases (HDAC) with entinostat has anti-MDSC activity. However, as single agent, it did not delay tumor growth in EL4 and LLC tumor models. Here, we found that entinostat reduced immune suppressive activity of only one type of MDSC-polymorphonuclear, PMN-MDSC, whereas it had no effect on monocytic M-MDSC or macrophages. M-MDSC had high amount of class II HDAC-HDAC6, which was further increased after the treatment of mice with entinostat. Inhibition of HDAC6 with ricolinostat reduced suppressive activity of M-MDSC, but did not affect PMN-MDSC or delayed tumor growth. However, combination of entinostat and ricolinostat abrogated suppressive activity of both populations of MDSC and substantially delayed tumor progression. Thus, inactivation of MDSC required targeting of both major subsets of these cells via inhibitors of class I and class II HDAC.

Topics: Animals; Benzamides; Cell Line, Tumor; Female; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Hydroxamic Acids; Mice; Mice, Inbred C57BL; Monocytes; Myeloid Cells; Myeloid-Derived Suppressor Cells; Neoplasms; Pyridines; Pyrimidines

Novel selective histone deacetylase 6 (HDAC6) inhibitors using the quinazoline as the cap were designed, synthesized, and evaluated for HDAC enzymatic assays. N-Hydroxy-4-(2-methoxy-5-(methyl(2-methylquinazolin-4-yl)amino)phenoxy)butanamide, 23bb, was the most potent selective inhibitor for HDAC6 with an IC50 of 17 nM and showed 25-fold and 200-fold selectivity relative to HDAC1 and HDAC8, respectively. In vitro, 23bb presented low nanomolar antiproliferative effects against panel of cancer cell lines. Western blot analysis further confirmed that 23bb increased acetylation level of α-tubulin in vitro. 23bb has a good pharmacokinetic profile with oral bioavailability of 47.0% in rats. In in vivo efficacy evaluations of colorectal HCT116, acute myelocytic leukemia MV4-11, and B cell lymphoma Romas xenografts, 23bb more effectively inhibited the tumor growth than SAHA even at a 4-fold reduced dose or ACY-1215 at the same dose. Our results indicated that 23bb is a potent oral anticancer candidate for selective HDAC6 inhibitor and deserves further investigation.

Topics: Acetylation; Animals; Antineoplastic Agents; Cell Line, Tumor; Female; Histone Deacetylase 6; Histone Deacetylase Inhibitors; Histone Deacetylases; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Mice, SCID; Molecular Docking Simulation; Neoplasms; Quinazolines; Rats; Tubulin; Xenograft Model Antitumor Assays