Biology subjects

Zhao, O.

Publications and source records attributed to Zhao, O..

2 recordsLinked to original sources

bioRxiv2025

Prioritizing Combinational Drug Screening: A Ranking System for In Vitro Drug Combinations in Neurofibromatosis Type 1

Neurofibromatosis type 1 (NF1) is a genetic disorder characterized by benign tumors, including plexiform neurofibromas, which can be difficult to treat. Currently, only two FDA-approved therapies exist: selumetinib, approved for pediatric patients with inoperable tumors, and mirdametinib, approved for patients aged two and older with symptomatic peripheral neuropathy where surgical resection is not possible. These limited options highlight the urgent need for novel therapeutic strategies, including combination therapies and therapies applicable to adult populations. In this study, we introduce the Composite Matrix Reduction Score (CMRS), a novel algorithm designed to evaluate the in vitro efficacy of drug combinations for NF1-related plexiform neurofibromas. Using a high-throughput 6x6 combinatorial matrix, we screened three cell lines: ipnNF95.11c (NF1+/-, non-tumor reference), and two NF1-/- tumor lines: ipNF05.5mc and ipNF95.6. Cell viability responses to drug combinations were normalized to vehicle controls, and combination effects were compared to single-agent responses. Tumor-to-non-tumor response ratios were aggregated to generate a composite ranking for each drug pair. Our results show that certain drug combinations outperformed single agents in reducing tumor cell viability, consistent with findings in other cancers. A focused analysis on selumetinib combinations supported the CMRS algorithm and identified potential synergistic partners that may surpass a single-agent therapy, highlighting candidates for continued investigation. CMRS provides a scalable, standardized framework for prioritizing drug combinations in NF1 and potentially other cancers. By integrating multi-cell line analysis, this approach enhances the identification of promising therapeutic candidates and mechanisms of action for further preclinical development.

cancer biology↗

bioRxiv2024

Single-Platelet Mapping of Jugular, Puncture-Wound Thrombi Reveals the Spatial Evolution of Platelet Activation

BackgroundThe contributions of platelet activation to thrombus formation during hemostatic bleeding cessation likely involve multiple activation states. However, the spatial and temporal distribution of platelets in these states has not been defined in a clot. ObjectivesTo use single-platelet mapping of activation states within jugular vein puncture thrombi to determine how the spatial distribution of platelet state evolves during hemostasis. MethodsMontaged, wide-area electron micrographs (EM) were taken at various time points, post-puncture, and annotated for platelet activation state. These classifications were mapped onto the images to identify regions of platelet activation and calculate neighbor associations. The importance of -granule secretion was tested using VAMP8-/- mice. Resultsmapping of platelet activation states at 1 min post-puncture showed extensive spatial intermixing of most platelet activation classes. No high-activation-state, platelet-rich core was observed in 5-min post-puncture thrombi, rather such platelets tended to be localized on the interior surfaces of thrombus vaults open to the circulation. Only at a later stage, 20 min post-puncture, was distinct clustering of high activation, degranulated, cytosol-rich platelets observed. These clusters localized to the central portion of the intravascular platelet-rich crown, and they were now inaccessible to the circulation. Counterintuitively, deletion of the primary platelet v-SNARE, VAMP8, increased the frequency and spatial clustering of highly activated, degranulated platelets in association with intra-thrombus vault surfaces at 5 min post puncture. ConclusionsWe conclude recent multi-activation state models can provide a realistic thrombus formation framework if linked together to encompass the dynamics of puncture wound formation.

systems biology↗