Comparative effects of viral-transport-medium heat inactivation upon downstream SARS-CoV-2 detection in patient samples.

Introduction. The COVID-19 pandemic, which began in 2020 is testing economic resilience and surge capacity of healthcare providers worldwide. At the time of writing, positive detection of the SARS-CoV-2 virus remains the only method for diagnosing COVID-19 infection. Rapid upscaling of national SARS-CoV-2 genome testing presented challenges: (1) Unpredictable supply chains of reagents and kits for virus inactivation, RNA extraction and PCR-detection of viral genomes. (2) Rapid time to result of <24 h is required in order to facilitate timely infection control measures.Hypothesis. Extraction-free sample processing would impact commercially available SARS-CoV-2 genome detection methods.Aim. We evaluated whether alternative commercially available kits provided sensitivity and accuracy of SARS-CoV-2 genome detection comparable to those used by regional National Healthcare Services (NHS).Methodology. We tested several detection methods and tested whether detection was altered by heat inactivation, an approach for rapid one-step viral inactivation and RNA extraction without chemicals or kits.Results. Using purified RNA, we found the CerTest VIASURE kit to be comparable to the Altona RealStar system currently in use, and further showed that both diagnostic kits performed similarly in the BioRad CFX96 and Roche LightCycler 480 II machines. Additionally, both kits were comparable to a third alternative using a combination of Quantabio qScript one-step Quantitative Reverse Transcription Polymerase Chain Reaction (qRT-PCR) mix and Centre for Disease Control and Prevention (CDC)-accredited N1 and N2 primer/probes when looking specifically at borderline samples. Importantly, when using the kits in an extraction-free protocol, following heat inactivation, we saw differing results, with the combined Quantabio-CDC assay showing superior accuracy and sensitivity. In particular, detection using the CDC N2 probe following the extraction-free protocol was highly correlated to results generated with the same probe following RNA extraction and reported clinically (n=127; R2=0.9259).Conclusion. Our results demonstrate that sample treatment can greatly affect the downstream performance of SARS-CoV-2 diagnostic kits, with varying impact depending on the kit. We also showed that one-step heat-inactivation methods could reduce time from swab receipt to outcome of test result. Combined, these findings present alternatives to the protocols in use and can serve to alleviate any arising supply-chain issues at different points in the workflow, whilst accelerating testing, and reducing cost and environmental impact.

The FLT3 internal tandem duplication mutation is a secondary target of the aurora B kinase inhibitor AZD1152-HQPA in acute myelogenous leukemia cells.

Aurora kinases play an essential role in orchestrating chromosome alignment, segregation, and cytokinesis during mitotic progression and both aurora-A and B are frequently overexpressed in a variety of human malignancies. In this study, we report the effects of AZD1152-HQPA, a highly selective inhibitor of aurora-B kinase, in acute myeloid leukemia (AML) cell lines and primary samples. We show that AZD1152-HQPA inhibits the phosphorylation of Histone H3 (pHH3) on serine 10 resulting in polyploid cells, apoptosis, and loss of viability in a panel of AML cell lines. We also show that AZD1152-HQPA sensitivity in our cell lines is irrespective of p53 status and the FLT3-ITD-expressing MOLM-13 and MV4-11 cell lines are particularly sensitive to AZD1152-HQPA. Internal tandem duplications (ITD) within the FLT3 tyrosine kinase receptor are found in approximately 25% of AML patients and are associated with a poor prognosis. Here, we report that AZD1152-HQPA directly targets phosphorylated FLT3 along with inhibiting its downstream target phospho-signal transducer and activator of transcription 5 (STAT5) in the FLT3-ITD cell lines. We show pHH3 expression in primary AML blasts and its inhibition by AZD1152-HQPA at low doses in all of our primary samples tested. AZD1152-HQPA inhibits the clonogenic potential of primary AML samples, with FLT3-ITD samples being the most sensitive (P = 0.029). FLT3-ITD primary samples are also more sensitive to pHH3 inhibition (P = 0.022) and are particularly sensitive to pSTAT5 downregulation after treatment with AZD1152-HQPA compared with FLT3 wild-type samples (P = 0.007). We conclude that mutant FLT3 is a secondary target of AZD1152-HQPA and that FLT3-ITD primary samples are particularly sensitive to the drug.