Discovery of Potent Multikinase Type-II Inhibitors Targeting CDK5 in the DFG-out Inactive State with Promising Potential against Glioblastoma.

Kinases have proven valuable targets in successful cancer drug discovery projects, but not yet for malignant brain tumors where type-II inhibition of cyclin-dependent kinase 5 (CDK5) stabilizing the DFG-out inactive state has potential for design of selective and clinically efficient drug candidates. In the absence of crystallographic evidence for a CDK5 DFG-out inactive state protein-ligand complex, for the first time, a model was designed using metadynamics/molecular dynamics simulations. Glide docking of the ZINC15 biogenic database identified [pyrimidin-2-yl]amino-furo[3,2-b]-furyl-urea/amide hit chemical scaffolds. For four selected analogues (4, 27, 36, and 42), potent effects on glioblastoma cell viability in U87-MG, T98G, and U251-MG cell lines and patient-derived cultures were generally observed (IC50s ∼ 10-40 µM at 72 h). Selectivity profiling against 11 homologous kinases revealed multikinase inhibition (CDK2, CDK5, CDK9, and GSK-3α/ß), most potent for GSK-3α in the nanomolar range (IC50s ∼ 0.23-0.98 µM). These compounds may therefore have diverse anticancer mechanisms of action and are of considerable interest for lead optimization.

ChatGPT.

An algorithm is a process or set of rules to be followed, especially by a computer.

Multidisciplinary docking, kinetics and X-ray crystallography studies of baicalein acting as a glycogen phosphorylase inhibitor and determination of its' potential against glioblastoma in cellular models.

Glycogen phosphorylase (GP) is the rate-determining enzyme in the glycogenolysis pathway. Glioblastoma (GBM) is amongst the most aggressive cancers of the central nervous system. The role of GP and glycogen metabolism in the context of cancer cell metabolic reprogramming is recognised, so that GP inhibitors may have potential treatment benefits. Here, baicalein (5,6,7-trihydroxyflavone) is studied as a GP inhibitor, and for its effects on glycogenolysis and GBM at the cellular level. The compound is revealed as a potent GP inhibitor against human brain GPa (Ki = 32.54 µM), human liver GPa (Ki = 8.77 µM) and rabbit muscle GPb (Ki = 5.66 µM) isoforms. It is also an effective inhibitor of glycogenolysis (IC50 = 119.6 µM), measured in HepG2 cells. Most significantly, baicalein demonstrated anti-cancer potential through concentration- and time-dependent decrease in cell viability for three GBM cell-lines (U-251 MG, U-87 MG, T98-G) with IC50 values of ∼20-55 µM (48- and 72-h). Its effectiveness against T98-G suggests potential against GBM with resistance to temozolomide (the first-line therapy) due to a positive O6-methylguanine-DNA methyltransferase (MGMT) status. The solved X-ray structure of rabbit muscle GP-baicalein complex will facilitate structure-based design of GP inhibitors. Further exploration of baicalein and other GP inhibitors with different isoform specificities against GBM is suggested.

Surveys are not simple: beware of the pitfalls.

Surveys are quick and easy to produce. This paper outlines some of the many problems that should be anticipated.

Surveys are not simple: beware of the pitfalls.

Surveys are quick and easy to produce. This paper outlines some of the many problems that should be anticipated.

The Effect of Cryoprotectants and Storage Conditions on the Transfection Efficiency, Stability, and Safety of Lipid-Based Nanoparticles for mRNA and DNA Delivery.

Lipid-based nanoparticles have recently shown great promise, establishing themselves as the gold standard in delivering novel RNA therapeutics. However, research on the effects of storage on their efficacy, safety, and stability is still lacking. Herein, the impact of storage temperature on two types of lipid-based nanocarriers, lipid nanoparticles (LNPs) and receptor-targeted nanoparticles (RTNs), loaded with either DNA or messenger RNA (mRNA), is explored and the effects of different cryoprotectants on the stability and efficacy of the formulations are investigated. The medium-term stability of the nanoparticles was evaluated by monitoring their physicochemical characteristics, entrapment and transfection efficiency, every two weeks over one month. It is demonstrated, that the use of cryoprotectants protects nanoparticles against loss of function and degradation in all storage conditions. Moreover, it is shown that the addition of sucrose enables all nanoparticles to remain stable and maintain their efficacy for up to a month when stored at -80 °C, regardless of cargo or type of nanoparticle. DNA-loaded nanoparticles also remain stable in a wider variety of storage conditions than mRNA-loaded ones. Importantly, these novel LNPs show increased GFP expression that can signify their future use in gene therapies, beyond the established role of LNPs in RNA therapeutics.

Statistics: an introduction to basic principles.

The essential principles of statistics as applied to surveys, studies, sampling, epidemiology, screening, and trials are described and explained.

Structure-Based Design of Potent Selective Nanomolar Type-II Inhibitors of Glycogen Synthase Kinase-3ß.

For the first time, the in silico design, screening, and in vitro validation of potent GSK-3ß type-II inhibitors are presented. In the absence of crystallographic evidence for a DFG-out GSK-3ß activation loop conformation, computational models were designed using an adapted DOLPHIN approach and a method consisting of Prime loop refinement, induced-fit docking, and molecular dynamics. Virtual screening of the Biogenics subset from the ZINC database led to an initial selection of 20 Phase I compounds revealing two low micromolar inhibitors in an isolated enzyme assay. Twenty more analogues (Phase II compounds) related to the hit [pyrimidin-2-yl]amino-furo[3,2-b]furyl-urea scaffold were selected for structure-activity relationship analysis. The Phase II studies led to five highly potent nanomolar inhibitors, with compound 23 (IC50 =0.087 µM) > 100 times more potent than the best Phase I inhibitor, and selectivity for GSK-3ß inhibition compared to homologous kinases was observed. Ex vivo experiments (SH-SY5Y cell lines) for tau hyperphosphorylation revealed promising neuroprotective effects at low micromolar concentrations. The type-II inhibitor design has been unraveled as a potential route toward more clinically effective GSK-3ß inhibitors.

Personal historical perspective of HIV: part 11.

All animal life on earth is thought to have a common origin and have common genetic mechanisms. Evolution has enabled differentiation of species. Pathogens likewise have evolved within various species and mostly come to a settled dynamic equilibrium such that co-existence results (pathogens ideally should not kill their hosts). Problems arise when pathogens jump species because the new host had not developed any resistance. These infections from related species are known as zoonoses. COVID-19 is the latest example of a virus entering another species but HIV (and various strains of influenza) were previous examples. HIV entered the human population from monkeys in Africa. These two papers outline the underlying principle of HIV and the differing epidemiologies in Africa, the USA and in Edinburgh. The underlying immunosuppression of HIV in Africa was initially hidden behind common infections and HIV first came to world awareness in focal areas of the USA as a disease seemingly limited to gay males. The epidemic of intravenous drug abuse in Edinburgh was associated with overlapping epidemics of bloodborne viruses like hepatitis B, hepatitis C and HIV.

A personal historical perspective of HIV.

All animal life on earth is thought to have a common origin and have common genetic mechanisms. Evolution has enabled differentiation of species. Pathogens likewise have evolved within various species and mostly come to a settled dynamic equilibrium such that co-existence results (pathogens ideally should not kill their hosts). Problems arise when pathogens jump species because the new host had not developed any resistance. These infections from related species are known as zoonoses. COVID-19 is the latest example of a virus entering another species but HIV (and various strains of influenza) were previous examples.