Background: Glioblastomas (GBMs) are aggressive malignant brain tumors. Although chemotherapy
with temozolomide (TMZ) can extend patient survival, most patients eventually demonstrate resistance. Therefore,
novel therapeutic agents that overcome TMZ chemoresistance are required to improve patient outcomes.
Purpose: Drug screening is an efficient method to find new therapeutic agents from existing drugs. In this study,
we explored a novel anti-glioma agent by drug screening and analyzed its function with respect to GBM treatment
for future clinical applications.
Methods: Drug libraries containing 1,301 diverse chemical compounds were screened against two glioma stem
cell (GSC) lines for drug candidate selection. The effect of selected agents on GSCs and glioma was estimated
through viability, proliferation, sphere formation, and invasion assays. Combination therapy was performed to
assess its ability to enhance TMZ cytotoxicity against GBM. To clarify the mechanism of action, we performed
methylation-specific polymerase chain reaction, gelatin zymography, and western blot analysis.
Results: The acyl-CoA synthetase inhibitor 2-fluoropalmitic acid (2-FPA) was selected as a candidate anti-glioma
agent. 2-FPA suppressed the viability and stem-like phenotype of GSCs. It also inhibited proliferation and invasion
of glioma cell lines. Combination therapy of 2-FPA with TMZ synergistically enhanced the efficacy of TMZ.
2-FPA suppressed the expression of phosphor-ERK, CD133, and SOX-2; reduced MMP-2 activity; and increased
methylation of the MGMT promoter.
Conclusion: 2-FPA was identified as a potential therapeutic agent against GBM. To extend these findings,
physiological studies are required to examine the efficacy of 2-FPA against GBM in vivo.