Abstract 2764 A microtubule targeting agent QTMP induces autophagy in neuroblastoma cells

QTMP(5-(Quinolin-2-yl)-4-(3,4,5-trimethoxyphenyl)-1H-imidazol2-amine) is a tubulin-binding agent that has previously shown potent anti-proliferative activity in various cancer cell lines.In this study, we have examined whether QTMP can induce autophagy in neuroblastoma cells and explored the mechanism of antiproliferative activity of QTMP in neuroblastoma cells.QTMP displayed potent anti-proliferative effects, with IC50 values of 21 1 nM and 9.3 1.3 nM in SH-SY5Y and IMR-32 cells, respectively.In SH-SY5Y cells, short exposure of 4 hours to QTMP significantly depolymerized microtubules.Further, QTMP treatment induced mitotic arrest, as evidenced by increased phospho-histone H3 levels.QTMP also elevated reactive oxygen species (ROS) levels, as assessed by 2 0 ,7 0 -dichlorofluorescein diacetate staining and flow cytometric analysis.ROS production increased from 1 0.3% in control cells to 14 6.4% and 36.7 11% in cells treated with 20 and 40 nM QTMP, respectively.Importantly, ROS scavenging by N-acetylcysteine partially reversed QTMPinduced cytotoxicity in SH-SY5Y cells, increasing its IC50 from 21 1 nM to 27 1 nM, indicating a role for ROS in QTMP's mechanism of action.QTMP further disrupted mitochondrial integrity, as demonstrated by a 48 3% and 73 4% reduction in Rhodamine 123 fluorescence in cells treated with 20 and 40 nM QTMP, respectively.This mitochondrial damage likely contributed to ROS generation and subsequent cellular effects.Moreover, QTMP induced autophagy in SH-SY5Y cells, as shown by elevated levels of autophagy markers LC3BII and ATG-5 in western blot analysis, LC3BII accumulation was observed exclusively in QTMP-treated cells.In addition, ATG-5 levels increased in QTMP-treated cells compared to control.In summary, the results demonstrate that QTMP exerts potent anti-cancer effects by disrupting microtubule dynamics, inducing ROS-mediated mitochondrial damage, and activating autophagy.The findings highlight QTMP as a promising therapeutic candidate.