ABSTRACT
OBJECTIVE@#To explore the role of Runt-related transcription factor 3 (RUNX3) in metabolic regulation of trastuzumab-resistant gastric cancer cells and investigate the mechanism of RUNX3 knockdown-mediated reversal of trastuzumab resistance.@*METHODS@#We performed a metabolomic analysis of trastuzumab-resistant gastric cancer cells (NCI N87R) and RUNX3 knockdown cells (NCI N87R/RUNX3) using ultra performance liquid chromatography (UPLC) coupled with Q Exactive Focus Orbitrap mass spectrometry (MS). Multivariate combined with univariate analyses and MS/MS ion spectrums were used to screen the differential variables. MetaboAnalyst 5.0 database was employed for pathway enrichment analysis. Differential metabolites-genes regulatory relationships were constructed based on OmicsNet database. The changes in GSH/GSSG and NADPH/NADP ratios in NCI N87R/RUNX3 cells were measured using detection kits.@*RESULTS@#The metabolic profile of NCI N87R cells was significantly altered after RUNX3 knockdown, with 81 differential metabolites identified to contribute significantly to the classification, among which 43 metabolites were increased and 38 were decreased (P < 0.01). In NCI N87R cells, RUNX3 knockdown resulted in noticeable alterations in 8 pathways involving glutamine metabolism, glycolysis, glycerophospholipid, nicotinate-nicotinamide and glutathione metabolism, causing also significant reduction of intracellular GSH/GSSG and NADPH/NADP ratios (P < 0.01). The differential metabolites-genes network revealed a regulatory relationship between the metabolic molecules and genes.@*CONCLUSION@#RUNX3 reverses trastuzumab resistance in gastric cancer cells by regulating energy metabolism and oxidation-reduction homeostasis and may serve as a potential therapeutic target for trastuzumab-resistant gastric cancer.