A series of 3-(1,2-disubstituted-1H-benzimidazol-5-yl)-N-hydroxyacrylamides (1) were designed and synthesized as HDAC inhibitors. Extensive SARs have been established for in vitro potency (HDAC1 enzyme and COLO 205 cellular IC(50)), liver microsomal stability (t(1/2)), cytochrome P450 inhibitory (3A4 IC(50)), and clogP, among others. These parameters were fine-tuned by carefully adjusting the substituents at positions 1 and 2 of the benzimidazole ring. After comprehensive in vitro and in vivo profiling of the selected compounds, SB939 (3) was identified as a preclinical development candidate. 3 is a potent pan-HDAC inhibitor with excellent druglike properties, is highly efficacious in in vivo tumor models (HCT-116, PC-3, A2780, MV4-11, Ramos), and has high and dose-proportional oral exposures and very good ADME, safety, and pharmaceutical properties. When orally dosed to tumor-bearing mice, 3 is enriched in tumor tissue which may contribute to its potent antitumor activity and prolonged duration of action. 3 is currently being tested in phase I and phase II clinical trials.

No abstract

No abstract

No abstract

Background and Purpose There are only a few cognitive screening tests for the Chinese-speaking population, and so this study aimed to validate the Chinese version of Addenbrooke's Cognitive Examination III (ACE-III) for detecting mild cognitive impairment (MCI) and mild dementia. Its diagnostic accuracy was compared with the Chinese versions of the Mini Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA). Methods The 176 included individuals were divided into 3 groups: mild dementia group, MCI group, and normal control group. MMSE, MoCA, and ACE-III were administered to all participants by researchers who were blinded to the clinical grouping. The receiver operating characteristic (ROC) curves were analyzed. Results ACE-III exhibited good internal consistency and convergent validity. Age and education level significantly influenced the total ACE-III scores. When screening MCI, the area under the ROC curve (AUC) was significantly larger for ACE-III than for MMSE (0.88 vs. 0.72, p <0.05) and MoCA (0.88 vs. 0.76, p <0.05). ACE-III showed higher sensitivity (0.75) and specificity (0.89) than MMSE (0.64 and 0.63, respectively) and MoCA (0.67 and 0.77) at the optimal cutoff score of 88/89. For detecting mild dementia, ACE-III yielded satisfactory sensitivity (0.94) and specificity (0.83) at the optimal cutoff score of 74/75. The AUC of ACE-III was 0.95, which was comparable to those of MMSE (0.95) and MoCA (0.91). In participants with ≥12 years of education, the AUC was significantly larger for ACE-III than for MMSE when detecting MCI (0.90 vs. 0.68, p <0.05) and mild dementia (0.97 vs. 0.90, p <0.05). Conclusions The present study has verified that ACE-III is a reliable and accurate tool for screening MCI and mild dementia in the Chinese-speaking population, and is significantly superior to MMSE and MoCA for detecting MCI.

DNA methyltransferases (DNMTs) are important regulators of gene transcription and their roles in carcinogenesis have been a topic of considerable interest in the last few years. Diverse classes of chemical compounds including nucleotide analogues, adenosine analogues, aminobenzoic derivatives, polyphenols, hydrazines, phthalides, disulfides and antisenses are being discovered and evaluated as DNMT inhibitors targeting DNA hypermethylation. Among them, 5-Azacytidine 5 and Decitabine 6 were launched recently. Several other compounds are under clinical trials. Some of these compounds were discovered from structure-based drug design. These compounds exert their DNA methylation inhibitory by different mechanisms. This review will present a brief account of various DNA methyltransferases and their biological functions, with focus on actuality of design and synthesis of various inhibitors of DNA hypermethylation as anticancer drugs.

SIRT1 is an NAD(+)-dependent deacetylase, whose activators have potential therapeutic applications in age-related diseases. Here we report a new class of SIRT1 activators. The activation is dependent on the fluorophore labeled to the substrate. To elucidate the activation mechanism, we solved the crystal structure of SIRT3/ac-RHKK(ac)-AMC complex. The structure revealed that the fluorophore blocked the H-bond formation and created a cavity between the substrate and the Rossmann fold. We built the SIRT1/ac-RHKK(ac)-AMC complex model based on the crystal structure. K(m) and K(d) determinations demonstrated that the fluorophore decreased the peptide binding affinity. The binding modes of SIRT1 activators indicated that a portion of the activators interacts with the fluorophore through π-stacking, while the other portion inserts into the cavity or interacts with the Rossmann fold, thus increasing the substrate affinity. Our study provides new insights into the mechanism of SIRT1 activation and may aid the design of novel SIRT1 activators.

No abstract