arXiv subjects

Olga Tsoy

Publications and source records attributed to Olga Tsoy.

3 recordsLinked to original sources

arXiv2026

Biomedical systems biology workflow orchestration and execution with PoSyMed

The rapid growth of scientific software has created practical barriers for bioinformatics research. Although powerful statistical, artificial intelligence (AI)-based methods are now widely available, their effective use is often hindered by fragmented distribution, inconsistent documentation, complex dependencies, and difficult-to-reproduce execution environments. As a result, reusing published tools and workflow adaptation to own date remains technically demanding and time-intensive, even for experienced users. Here, we present PoSyMed, an open and modular platform for the controlled integration, composition, and execution of bioinformatics tools and workflows. PoSyMed combines a backend-centered platform architecture with formal tool descriptions, controlled container-based build and execution processes, persistent workflow state, and a dialogue-based user interface. Large language models (LLM) are integrated not as autonomous decision-makers, but as human-computer interface with bounded semantic assistants that help identify tools, propose workflow steps, and support parameterization within a typed, validated, and human-supervised execution environment. PoSyMed is designed to improve reproducibility, traceability, and transparency in practical biomedical analysis within one platform. We describe the system architecture and evaluate its behavior across representative biological software scenarios with respect to workflow support, interaction design, and platform extensibility. PoSyMed is publicly available at https://apps.cosy.bio/posymed.

cs.SE↗

arXiv2025

Transcriptome signature for the identification of bevacizumab responders in ovarian cancer

The standard of care for ovarian cancer comprises cytoreductive surgery, followed by adjuvant platinum-based chemotherapy plus taxane therapy and maintenance therapy with the antiangiogenic compound bevacizumab and/or a PARP inhibitor. Nevertheless, there is currently no clear clinical indication for the use of bevacizumab, highlighting the urgent need for biomarkers to assess the response to bevacizumab. In the present study, based on a novel RNA-seq dataset (n=181) and a previously published microarray-based dataset (n=377), we have identified an expression signature potentially associated with benefit from bevacizumab addition and assumed to reflect cancer stemness acquisition driven by activation of CTCFL. Patients with this signature demonstrated improved overall survival when bevacizumab was added to standard chemotherapy in both novel (HR=0.41(0.23-0.74), adj.p-value=7.70e-03) and previously published cohorts (HR=0.51(0.34-0.75), adj.p-value=3.25e-03), while no significant differences in survival explained by treatment were observed in patients negative for this signature. In addition to the CTCFL signature, we found several other reproducible expression signatures which may also represent biomarker candidates not related to established molecular subtypes of ovarian cancer and require further validation studies based on additional RNA-seq data.

q-bio.GN↗

arXiv2024

UnPaSt: unsupervised patient stratification by biclustering of omics data

Unsupervised patient stratification is essential for disease subtype discovery, yet, despite growing evidence of molecular heterogeneity of non-oncological diseases, popular methods are benchmarked primarily using cancers with mutually exclusive molecular subtypes well-differentiated by numerous biomarkers. Evaluating 22 unsupervised methods, including clustering and biclustering, using simulated and real transcriptomics data revealed their inefficiency in scenarios with non-mutually exclusive subtypes or subtypes discriminated only by few biomarkers. To address these limitations and advance precision medicine, we developed UnPaSt, a novel biclustering algorithm for unsupervised patient stratification based on differentially expressed biclusters. UnPaSt outperformed widely used patient stratification approaches in the de novo identification of known subtypes of breast cancer and asthma. In addition, it detected many biologically insightful patterns across bulk transcriptomics, proteomics, single-cell, spatial transcriptomics, and multi-omics datasets, enabling a more nuanced and interpretable view of high-throughput data heterogeneity than traditionally used methods.

cs.LG↗