Abstract 5546: Sorting to enrich for chemotherapeutic-resistant glioma cells based on unique membrane properties

The purpose of this study was to leverage dielectrophoresis (DEP) as a novel method for sorting glioma cells based on their innate cell electrophysiological properties. Glioblastoma, astrocytoma, and oligodendroglioma comprise a class of aggressive and deadly brain tumors, termed as diffuse gliomas, with 20,000 cases diagnosed annually in the US. The current standard chemotherapy treatment, temozolomide (TMZ), is insufficient as the 5-year survival rate of glioblastoma patients has remained at roughly 8%. One major contributing factor to treatment inefficacy is the presence of TMZ-resistant cells within tumors that lead to chemoresistance and tumor recurrence. Thus, there is an unmet need to further understand the molecular properties of TMZ-resistant cells which could enable more effective means of targeting them and improve patient outcomes. Here we utilized microfluidic sorting devices and applied DEP, a phenomenon by which non-uniform electric fields induce differential movement of cells, as a novel label-free technique to sort glioma cells based on their membrane electrophysiological properties. With this technique, we successfully sorted cells from glioblastoma and oligodendroglioma established cell lines, which yielded fractions that differed in membrane capacitance, the membrane’s ability to store charge. Interestingly, the DEP-sorted cell fractions also exhibited significant differences in TMZ resistance, indicating that DEP can be used robustly to enrich for TMZ-resistant cells across different gliomas. Further, differences in TMZ resistance were coupled with membrane capacitance differences. Since we previously identified links between membrane capacitance and cell-surface glycosylation, we utilized lectin analysis to assess the glycan expression of DEP-sorted oligodendroglioma cells and found inverse correlation between TMZ resistance and mannose glycan expression. Collectively, our study concluded the novel finding that (a) TMZ-resistant glioma cells can be enriched by DEP, and (b) TMZ resistance is correlated with membrane capacitance and cell surface glycosylation. These results could enable downstream molecular characterization of TMZ-resistant cells to uncover less explored mechanisms of TMZ resistance and the development of more effective treatment strategies for gliomas that specifically target membrane properties such as glycosylation. Citation Format: Vi P. Dang, Alan Y. Jiang, Jaclyn N. Hanamoto, Nicole S. Lav, Christopher R. Douglas, Daniela A. Bota, Lisa A. Flanagan. Sorting to enrich for chemotherapeutic-resistant glioma cells based on unique membrane properties [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 5546.