Biology subjects

Stokowy, T.

Publications and source records attributed to Stokowy, T..

6 recordsLinked to original sources

bioRxiv2021

eXNVerify: coverage analysis for long and short-read sequencing data in clinical context

Accurate identification of genetic variants to a large extent is based on type of experimental technology, quality of the material and coverage of obtained sequencing data. Our motivation was to create a tool that will evaluate genome coverage and accelerate the introduction of long-read sequencing to medical diagnostics and clinical practice. Here we present eXNVerify: a tool for inspection of clinical data in the context of pathogenic variants. The tool calculates Clinical Depth Coverage - a measure of coverage which we introduce to evaluate loci with pathogenic germline and somatic variants reported in ClinVar. The tool additionally provides visualization options for user-defined genes of interest. Finally, we present an examples of BRCA1, TP53, CFTR application and results of a test conducted in the Extensive Sequence Dataset of Gold-Standard Samples for Benchmarking and Development. eXNVerify is available at https://github.com/porebskis/eXNVerify and can be directly pulled from the DockerHub repository: docker pull porebskis/exnverify:1.0.

genomics↗

bioRxiv2021

Phosphatidylserine Receptors Enhance SARS-CoV-2 Infection: AXL as a Therapeutic Target for COVID-19

AUTHOR SUMMARYPhosphatidylserine (PS) receptors are PS binding proteins that mediate uptake of apoptotic bodies. Many enveloped viruses utilize this PS/PS receptor mechanism to adhere to and internalize into the endosomal compartment of cells and this is termed apoptotic mimicry. For viruses that have a mechanism(s) of endosomal escape, apoptotic mimicry is a productive route of virus entry. We evaluated if PS receptors serve as cell surface receptors for SARS-CoV-2 and found that the PS receptors, AXL, TIM-1 and TIM-4, facilitated virus infection when low concentrations of the SARS-CoV-2 cognate receptor, ACE2, was present. Consistent with the established mechanism of PS receptor utilization by other viruses, PS liposomes competed with SARS-CoV-2 for binding and entry. We demonstrated that this PS receptor enhances SARS-CoV-2 binding to and infection of an array of human lung cell lines and is an under-appreciated but potentially important host factor facilitating SARS-CoV-2 entry.

microbiology↗

bioRxiv2021

Heat Shock Factor 1 (HSF1) as a new tethering factor for ESR1 supporting its action in breast cancer.

Heat shock factor 1 (HSF1), a key regulator of transcriptional responses to proteotoxic stress, was recently linked to estrogen (E2) signaling through ESR1. We found that an HSF1 deficiency could lead to the inhibition of the mitogenic action of E2 in breast cancer cells. The stimulatory effect of E2 on the transcriptome is weaker in HSF1-deficient cells, in part due to the higher basal expression of E2-dependent genes, which correlates with the enhanced binding of unliganded ESR1 to chromatin. HSF1 and ESR1 can cooperate directly in E2-stimulated regulation of transcription, and HSF1 potentiates the action of ESR1 through a mechanism involving chromatin reorganization. Analyses of data from the TCGA database indicate that HSF1 increases the transcriptome diversity in ER-positive breast cancer and can enhance the genomic action of ESR1. Moreover, ESR1 and HSF1 are only prognostic when analyzed together (the worst prognosis for ER-/HSF1high cancers).

cancer biology↗

bioRxiv2020

Accuracy and efficiency of germline variant calling pipelines for human genome data

Advances in next-generation sequencing technology has enabled whole genome sequencing (WGS) to be widely used for identification of causal variants in a spectrum of genetic-related disorders, and provided new insight into how genetic polymorphisms affect disease phenotypes. The development of different bioinformatics pipelines has continuously improved the variant analysis of WGS data, however there is a necessity for a systematic performance comparison of these pipelines to provide guidance on the application of WGS-based scientific and clinical genomics. In this study, we evaluated the performance of three variant calling pipelines (GATK, DRAGEN and DeepVariant) using Genome in a Bottle Consortium, "synthetic-diploid" and simulated WGS datasets. DRAGEN and DeepVariant show a better accuracy in SNPs and indels calling, with no significant differences in their F1-score. DRAGEN platform offers accuracy, flexibility and a highly-efficient running speed, and therefore superior advantage in the analysis of WGS data on a large scale. The combination of DRAGEN and DeepVariant also provides a good balance of accuracy and efficiency as an alternative solution for germline variant detection in further applications. Our results facilitate the standardization of benchmarking analysis of bioinformatics pipelines for reliable variant detection, which is critical in genetics-based medical research and clinical application.

bioinformatics↗

bioRxiv2019

Proteome and phosphoproteome changes associated with prognosis in acute myeloid leukemia

Acute myeloid leukemia (AML) is a hematological cancer that mainly affects the elderly. Although complete remission (CR) is achieved for majority of the patients after induction and consolidation therapies, nearly two-thirds relapse within a short interval. Understanding biological factors that determine relapse has therefore become of major clinical interest in AML. We utilized liquid chromatography tandem mass spectrometry (LC-MS/MS) to identify protein changes and protein phosphorylation events associated with AML relapse in primary cells from 41 AML patients at time of diagnosis. Patients were defined as relapse-free if they had not relapsed within a 5-year clinical follow-up after AML diagnosis. Relapse was associated with increased expression of RNA processing proteins and decreased expression of V-ATPase proteins. We also observed an increase in phosphorylation events catalyzed by cyclin-dependent kinases (CDKs) and casein kinase 2 (CSK2). The biological relevance of the proteome findings was supported by cell proliferation assays using inhibitors of V-ATPase (bafilomycin), CSK2 (CX-4945), CDK4/6 (abemaciclib) and CDK2/7/9 (SNS-032). While bafilomycin preferentially inhibited the cells from relapse patients, the kinase inhibitors were less efficient in these cells. This suggests that therapy against the upregulated kinases also could target the factors inducing their upregulation rather than their activity. In conclusion, our study presents markers that could help predict AML relapse and direct therapeutic strategies.

cancer biology↗

bioRxiv2018

Comparison of three variant callers for human whole genome sequencing

Testing of patients with genetics-related disorders is in progress of shifting from single gene assays to gene panel sequencing, whole-exome sequencing (WES) and whole-genome sequencing (WGS). Since WGS is unquestionably becoming a new foundation for molecular analyses, we decided to compare three currently used tools for variant calling of human whole genome sequencing data. We tested DeepVariant, a new TensorFlow machine learning-based variant caller, and compared this tool to GATK 4.0 and SpeedSeq, using 30x, 15x and 10x WGS data of the well-known NA12878 DNA reference sample.\n\nAccording to our comparison, the performance on SNV calling was almost similar in 30x data, with all three variant callers reaching F-Scores (i.e. harmonic mean of recall and precision) equal to 0.98. In contrast, DeepVariant was more precise in indel calling than GATK and SpeedSeq, as demonstrated by F-Scores of 0.94, 0.90 and 0.84, respectively.\n\nWe conclude that the DeepVariant tool has great potential and usefulness for analysis of WGS data in medical genetics.

genomics↗