Fig. 6: Lysine plays a vital role in protecting GBM cells against lysosomal damage. | Nature Communications

Fig. 6: Lysine plays a vital role in protecting GBM cells against lysosomal damage.

From: Lysine-arginine imbalance overcomes therapeutic tolerance governed by the transcription factor E3-lysosome axis in glioblastoma

Fig. 6

A Results of the metabolomic analysis, showing key nodes in metabolic pathways that have been significantly altered between Lyso-high and Lyso-low groups. The x-axis represents pathway impact, which was computed using topology analysis. B Quantification of lysosomal proteolytic activity measured with DQ-BSA fluorescence in TGS04 cells with flow cytometry after culture in single-amino-acid-depleted NSPC medium for 16–24 h (n = 3 independent experiments). C TGS04 cells expressing EGFP-Gal3 were pretreated in a complete culture medium (control medium) or lysine-depleted medium (w/o Lys) for 16–24 h. Galectin-3 punctation was then observed after 15 min of 50 µM LLOMe treatment. Percent of galectin-3 puncta-positive cells was quantified (n = 3 independent samples). Scale bars, 10 µm. D, E The sphere number (D) and size (E) formed by TGS04 cells were evaluated under lysine-restricted conditions by the sphere formation assay (n = 3). F The sensitivity of TGS04 cells to LLOMe was examined under lysine-restricted and normal conditions by the sphere formation assay (n = 3). For the boxplots (E), the line inside the box shows the median value. The bounds of the box represent the 25th–75th percentiles, with whiskers at minimum and maximum values. Data are presented as the means ± SD. Statistic comparison (A) using a weighted Z-test. Statistic comparison (B–E) using a one-way ANOVA. Statistic comparison (F) using a two-way ANOVA. ns, not significant, ****p < 0.0001. Experiments (D–F) were repeated at least three times with similar results. Source data are provided with this paper.

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