The Theranostic Role of Small Extracellular Vesicle Mediated microRNA in Medulloblastoma

Amusan, Oyindamola

Abstract

Small extracellular vesicles (sEVs) cargo can potentially alter response to chemotherapy, indicating specific cargo as a potential theranostic biomarker. In this study, we explored miRNAs mediated sEVs for chemotherapy associated biomarkers. We took an unbiased genome approach with the investigation of miRNAs using small RNA sequencing and we further focused on a miRNA cluster (C14q32 or C14MC) dysregulated in medulloblastoma (MB). The research posed the question of whether miRNA expression within sEVs would be altered after chemotherapy treatment in MB, and if these miRNA-mediated sEVs could serve as theranostic biomarkers monitoring treatment efficacy. MB03 and ONS-76 cell lines were treated with combination treatments including cyclophosphamide with cisplatin or vincristine (CP+CIS; CP+VIN). Treatment concentrations were determined based on IC50 values, and sEVs were isolated using size exclusion chromatography post-treatment. Isolated sEVs were successfully characterized using various methods, including transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), fluorescent NTA (f-NTA), and western blot. Profiling of miRNA expression from C14MC was measured using quantitative real time PCR (qPCR) using the 2^∆∆Ct method and small RNA sequencing was performed to identify candidate sEV miRNAs. Characterization of sEV confirmed the presence of sEV from our isolated samples. Profiling of miRNA expression from the C14MC cluster revealed differential expression of sEV miRNA in both MB03 and ONS-76 cells when treated with CP+CIS and CP+VIN. Among the identified candidates, miR-134, miR-494, miR-495, and miR-539 were significantly upregulated, while miR-376c was significantly downregulated compared to control/without treatment in MB03 treated CP+CIS, likewise, miR-134 and miR-758 were significantly upregulated compared to control/without treatment in ONS-76 treated CP+VIN. From our NGS results, we identified differentially expressed miRNAs which were significant in MB03 (miR-206, miR-1910, let-7f and miR-92b) and CP+CIS treatment (miR-221, miR-10b and miR-10a) compared to ONS-76, which are not within the C14MC cluster that may also serve as potential theranostic biomarker. Taken together, these findings suggest the potential use of the identified sEV derived miRNAs as non-invasive biomarkers to distinguish MB subtypes and evaluate treatment efficacy, with validation assays required for confirmation.

Keywords: Combination chemotherapy, sEVs, miRNAs, theranostic, biomarkers.

Citation

Amusan, O. (2024). The Theranostic Role of Small Extracellular Vesicle Mediated microRNA in Medulloblastoma. (Thesis). University of Salford

• Thesis Type: Thesis
• Deposit Date: Mar 25, 2024
• Publicly Available Date: Mar 27, 2026
• Keywords: Combination chemotherapy, sEVs, miRNAs, theranostic, biomarkers
• Award Date: Mar 26, 2024