Pleiotropic Effects of 3-O-Decanoylquercetin on U373-MG Human Glioma Cell Line

Gliomas are among the most challenging brain tumors to treat, owing to their marked heterogeneity and the aberrant signaling networks that sustain tumor growth and resistance to therapy. Quercetin, a dietary flavonoid widely found in fruit and vegetables, exhibits documented anticancer activity, prompting the development of optimized derivatives with improved biological potency. In earlier work, we synthesized and evaluated a series of quercetin derivatives and identified the acylated compound 3-O-decanoylquercetin (Q-3-Dec) as particularly effective in reducing glioma cell viability. In this study, we explored Q-3-Dec as a multi-target agent, which concomitantly impairs NF-κB/STAT3-dependent survival signaling, mitochondrial function, and O6-Methylguanine-DNA Methyltransferase (MGMT) expression, a DNA repair enzyme closely associated with chemoresistance, in glioma cells. In U373-MG glioma cells, treatment with 50 μM Q-3-Dec triggered pronounced, time-dependent morphological changes and an early loss of mitochondrial membrane potential after 3 h. With prolonged exposure, Q-3-Dec markedly decreased NF-κB and STAT3 phosphorylation and reduced the expression of the anti-apoptotic proteins Bcl-2 and survivin, alongside a significant decrease in MGMT levels. These combined effects culminated in a progressive increase in cell death, reaching approximately 30% after 48 h. Together, these findings position Q-3-Dec as a multi-node modulator of glioma survival, supporting its potential for further preclinical development to improve future therapeutic strategies against glioma.