Investigation of flexibility of neuraminidase 150-loop using tamiflu derivatives in influenza A viruses H1N1 and H5N1.

This study focuses on design, synthesis and in vitro evaluation of inhibitory potency of two series of sialylmimetic that target an exosite ("150-cavity") adjacent to the active site of influenza neuraminidases from A/California/07/2009 (H1N1) pandemic strain and A/chicken/Nakorn-Patom/Thailand/CU-K2-2004 (H5N1). The structure-activity analysis as well as 3-D structure of the complex of parental compound with the pandemic neuraminidase p09N1 revealed high flexibility of the 150-cavity towards various modification of the neuraminidase inhibitors. Furthermore, our comparison of two methods for inhibition constant determination performed at slightly different pH values suggest that the experimental conditions of the measurement could dramatically influence the outcome of the analysis in the compound-dependent manner. Therefore, previously reported Ki values determined at non-physiological pH should be carefully scrutinized.

Developing PRISM: A Pragmatic Institutional Survey and Bench Marking Tool to Measure Digital Research Maturity of Cancer Centers.

BACKGROUND: Multicenter precision oncology real-world evidence requires a substantial long-term investment by hospitals to prepare their data and align on common Clinical Research processes and medical definitions. Our team has developed a self-assessment framework to support hospitals and hospital networks to measure their digital maturity and better plan and coordinate those investments. From that framework, we developed PRISM for Cancer Outcomes: PR: agmatic I: nstitutional S: urvey and benchM: arking. OBJECTIVES: The primary objective was to develop PRISM as a tool for self-assessment of digital maturity in oncology hospitals and research networks; a secondary objective was to create an initial benchmarking cohort of >25 hospitals using the tool as input for future development. METHODS: PRISM is a 25-question semiquantitative self-assessment survey developed iteratively from expert knowledge in oncology real-world study delivery. It covers four digital maturity dimensions: (1) Precision oncology, (2) Clinical digital data, (3) Routine outcomes, and (4) Information governance and delivery. These reflect the four main data types and critical enablers for precision oncology research from routine electronic health records. RESULTS: During piloting with 26 hospitals from 19 European countries, PRISM was found to be easy to use and its semiquantitative questions to be understood in a wide diversity of hospitals. Results within the initial benchmarking cohort aligned well with internal perspectives. We found statistically significant differences in digital maturity, with Precision oncology being the most mature dimension, and Information governance and delivery the least mature. CONCLUSION: PRISM is a light footprint benchmarking tool to support the planning of large-scale real-world research networks. It can be used to (i) help an individual hospital identify areas most in need of investment and improvement, (ii) help a network of hospitals identify sources of best practice and expertise, and (iii) help research networks plan research. With further testing, policymakers could use PRISM to better plan digital investments around the Cancer Mission and European Digital Health Space.

Unraveling the anti-influenza effect of flavonoids: Experimental validation of luteolin and its congeners as potent influenza endonuclease inhibitors.

The biological effects of flavonoids on mammal cells are diverse, ranging from scavenging free radicals and anti-cancer activity to anti-influenza activity. Despite appreciable effort to understand the anti-influenza activity of flavonoids, there is no clear consensus about their precise mode-of-action at a cellular level. Here, we report the development and validation of a screening assay based on AlphaScreen technology and illustrate its application for determination of the inhibitory potency of a large set of polyols against PA N-terminal domain (PA-Nter) of influenza RNA-dependent RNA polymerase featuring endonuclease activity. The most potent inhibitors we identified were luteolin with an IC50 of 72 ± 2 nM and its 8-C-glucoside orientin with an IC50 of 43 ± 2 nM. Submicromolar inhibitors were also evaluated by an in vitro endonuclease activity assay using single-stranded DNA, and the results were in full agreement with data from the competitive AlphaScreen assay. Using X-ray crystallography, we analyzed structures of the PA-Nter in complex with luteolin at 2.0 Å resolution and quambalarine B at 2.5 Å resolution, which clearly revealed the binding pose of these polyols coordinated to two manganese ions in the endonuclease active site. Using two distinct assays along with the structural work, we have presumably identified and characterized the molecular mode-of-action of flavonoids in influenza-infected cells.

Kinetic, thermodynamic and structural analysis of tamiphosphor binding to neuraminidase of H1N1 (2009) pandemic influenza.

Influenza virus causes severe respiratory infections that are responsible for up to half a million deaths worldwide each year. Two inhibitors targeting viral neuraminidase have been approved to date (oseltamivir, zanamivir). However, the rapid development of antiviral drug resistance and the efficient transmission of resistant viruses among humans represent serious threats to public health. The approved influenza neuraminidase inhibitors have (oxa)cyclohexene scaffolds designed to mimic the oxonium transition state during enzymatic cleavage of sialic acid. Their active forms contain a carboxylate that interacts with three arginine residues in the enzyme active site. Recently, the phosphonate group was successfully used as an isostere of the carboxylate in oseltamivir, and the resulting compound, tamiphosphor, was identified as a highly active neuraminidase inhibitor. However, the structure of the complex of this promising inhibitor with neuraminidase has not yet been reported. Here, we analyzed the interaction of a set of oseltamivir and tamiphosphor derivatives with neuraminidase from the A/California/07/2009 (H1N1) influenza virus. We thermodynamically characterized the binding of oseltamivir carboxylate or tamiphosphor to the neuraminidase catalytic domain by protein microcalorimetry, and we determined crystal structure of the catalytic domain in complex with tamiphosphor at 1.8 Å resolution. This structural information should aid rational design of the next generation of neuraminidase inhibitors.