Fig. 5: Alterations in the levels of amino acids in β-catenin- or TCF7L2-depleted cells.

a Metabolite analysis using HepG2 cells treated with control, β-catenin, or TCF7L2 siRNA. Each group was analyzed in triplicate. b, c Quantitative analysis of the indicated metabolites using mass spectrometry in the HepG2 cells treated with control, β-catenin, or TCF7L2 siRNA. The y-axis represents the concentration (pmol/10⁶ cells) of metabolites. b Levels of arginine and histidine. c Levels of lactate and acetyl-CoA. d Metabolic pathway analysis using metabolites that were commonly altered by the knockdown of β-catenin and TCF7L2. FDR q-value < 0.01 was considered significant. e A simplified schematic representation of the urea cycle and related enzymes. ASS1, argininosuccinate synthetase1; ASL, argininosuccinate lyase; OTC, ornithine transcarbamylase. The microarray data (Fig. 1a) were used to generate altered expression values of OTC, ARG1, ASS1, and ASL (fold change) in the cells treated with β-catenin (siβ-9 and siβ-10) or TCF7L2 (siTCF) siRNA compared to control siRNA. Unless specified otherwise, data are represented as the mean ± SD of three independent cultures. Statistical significance was determined by Dunnett’s test. *p < 0.05, **p < 0.01 vs siCtrl.