Fig. 1

Expression patterns of GYS1 and glycogen in breast cancer patients. a Schematic overview of glycogen metabolism and the role of GYS1, which catalyzes formation of the α-1,4-glycosidic bonds between UDP-glucose molecules. b Overall survival of respectively all (left panel) and triple-negative (right panel) breast cancer patients from the METABRIC cohort (n = 1904) with respectively high or low GYS1 mRNA expression in their primary tumor [22]. Curves are separated by the median GYS1 expression. c Representative examples of differing staining patterns in glycogen-rich and glycogen-poor primary breast tumor areas. 60 × magnification, scalebar represents 20 μm. d Tukey boxplots of staining scores of all primary breast tumors by clinical subtype. Displayed are median, interquartile range (boxes) and 1.5 × interquartile range (whiskers). e Scatterplot of GYS1 (x-axis) and glycogen H-scores (y-axis) and Ki67 proliferation index (dot size) of primary breast tumors, stratified by subtype (color). f Tukey boxplots of staining scores of primary breast tumors, stratified by Ki67 proliferation index. Displayed are median, interquartile range (boxes) and 1.5 × interquartile range (whiskers). g Spearman correlations (lower left triangle) and corresponding P-values (upper right triangle) of staining scores with tumor size and Ki67 index. CI = confidence interval; GBE = glycogen branching enzyme; GYS = glycogen synthase; HR = hazard ratio; PYG = glycogen phosphorylase; UDP = uridine diphosphate