Total anticholinergic burden and survival within a cohort of elderly Mexican Americans.

AIM: Studies examining the association between mortality and anticholinergic burden in the geriatric population are conflicting and are absent in the Mexican American population. The present study aimed to determine whether higher anticholinergic burden increases mortality in a cohort representative of community-based older Mexican Americans in the USA. METHODS: This retrospective cohort database study used the Hispanic Established Populations for the Epidemiologic Study of the Elderly cohort. The primary outcome, mortality, was assessed beginning at the second interview in 1995 until the fifth interview in 2005. Medications were classified for anticholinergic burden according to the modified-Anticholinergic Drug Scale and were summed across all reported medications creating a measure of total anticholinergic burden. Anticholinergic burden was tested for association with mortality using survival analysis. RESULTS: The 1497 older adults reporting medication usage were included. Survival analysis showed a statistically significant (P < 0.05) relationship between anticholinergic burden and increased mortality. CONCLUSIONS: Anticholinergic burden is associated with increased mortality in Southwestern Mexican American older adults who report taking prescription or non prescription medications. These findings suggest that anticholinergic burden might be a risk factor for mortality in this selected population, with additional studies required to further define the risk. Geriatr Gerontol Int 2017; 17: 1515-1521.

AZD5438, a potent oral inhibitor of cyclin-dependent kinases 1, 2, and 9, leads to pharmacodynamic changes and potent antitumor effects in human tumor xenografts.

Deregulation of the cell cycle has long been recognized as an essential driver of tumorigenesis, and agents that selectively target key cell cycle components continue to hold promise as potential therapeutics. We have developed AZD5438, a 4-(1-isopropyl-2-methylimidazol-5-yl)-2-(4-methylsulphonylanilino) pyrimidine, as a potent inhibitor of cyclin-dependent kinase (cdk) 1, 2, and 9 (IC(50), 16, 6, and 20 nmol/L, respectively). In vitro, AZD5438 showed significant antiproliferative activity in human tumor cell lines (IC(50) range, 0.2-1.7 micromol/L), causing inhibition of the phosphorylation of cdk substrates pRb, nucleolin, protein phosphatase 1a, and RNA polymerase II COOH-terminal domain and blocking cell cycling at G(2)-M, S, and G(1) phases. In vivo, when orally administered at either 50 mg/kg twice daily or 75 mg/kg once daily, AZD5438 inhibited human tumor xenograft growth (maximum percentage tumor growth inhibition, range, 38-153; P < 0.05). In vivo, AZD5438 reduced the proportion of actively cycling cells. Further pharmacodynamic analysis of AZD5438-treated SW620 xenografts showed that efficacious doses of AZD5438 (>40% tumor growth inhibition) maintained suppression of biomarkers, such as phospho-pRbSer(249)/Thr(252), for up to 16 hours following a single oral dose. A comparison of different schedules indicated that chronic daily oral dosing provided optimal cover to ensure antitumor efficacy. These data indicate that broad cdk inhibition may provide an effective method to impair the dysregulated cell cycle that drives tumorigenesis and AZD5438 has the pharmacologic profile that provides an ideal probe to test this premise.

Imidazoles: SAR and development of a potent class of cyclin-dependent kinase inhibitors.

An imidazole series of cyclin-dependent kinase (CDK) inhibitors has been developed. Protein inhibitor structure determination has provided an understanding of the emerging structure activity trends for the imidazole series. The introduction of a methyl sulfone at the aniline terminus led to a more orally bioavailable CDK inhibitor that was progressed into clinical development.

The cellular phenotype of AZ703, a novel selective imidazo[1,2-a]pyridine cyclin-dependent kinase inhibitor.

Because the majority of cancers exhibit direct or indirect deregulation of cyclin-dependent kinase (CDK) function, members of the CDK family are attractive targets for the development of anticancer agents. As part of an ongoing program, novel imidazopyridines were identified and developed as potent and selective CDK inhibitors. Here, we describe data on the in vitro biological activities of one of these compounds, AZ703. The selectivity profile of AZ703 was investigated in kinase assays against a range of CDK enzymes as well as a panel of protein kinases in vitro. IC50s were assessed against different tumor cell lines in vitro. The mechanism of action of AZ703 was determined by observing changes in phosphorylation of CDK substrates and cell cycle effects on tumor and normal cells. In vitro studies revealed that AZ703 is a selective inhibitor of CDK1 and CDK2 and displays a mode of action consistent with the induction of G1-, S-, and G2-M-phase arrest. AZ703 also showed potent antiproliferative activity across a wide range of tumor cell lines in vitro. Moreover, AZ703 induced reversible blockade of normal cells while causing tumor cells to undergo apoptosis. We have identified AZ703 as a novel selective imidazo[1,2-a]pyridine CDK inhibitor that shows promising antitumor properties in vitro.

Imidazo[1,2-a]pyridines. Part 2: SAR and optimisation of a potent and selective class of cyclin-dependent kinase inhibitors.

Exploration of SAR and optimisation of the imidazo[1,2-a]pyridine CDK inhibitors has lead to the discovery of novel, potent and selective inhibitors of the cyclin-dependent kinase CDK2. Understanding of SAR has identified positions of substitution, which allow modification of physical properties and offer the potential for in vivo optimisation.

Imidazo[1,2-b]pyridazines: a potent and selective class of cyclin-dependent kinase inhibitors.

Modification of imidazo[1,2-a]pyridine CDK inhibitors lead to identification of less lipophilic imidazo[1,2-b]pyridazine series of CDK inhibitors. Although several equivalent compounds from these two series have similar structure and show similar CDK activity, the SAR of the two series differs significantly. Protein inhibitor structure determination has confirmed differences in binding mode and given some understanding of these differences in SAR. Potent and selective imidazo[1,2-b]pyridazine inhibitors of CDK2 have been identified, which show >1 microM plasma levels following a 2mg/kg oral dose to mice.