Fig 2: Expression levels of O-linked glycosyltransferases in CCA. The mRNA expression levels of (A) C1GALT1, (B) COSMC, (C) ST6GALNAC1, and (D) B3GNT6 in 90 paired CCA tissues were obtained from the GEO database (GEO series GSE76297).

Fig 3: Expression of aberrant O-glycans in human colorectal cancer. A, Biosynthesis of Tn antigen, and Core 1- and Core3-derived O-glycans. Tn antigen is either modified by T-synthase and its chaperone (Cosmc) to form Core 1-derived O-glycans or processed by C3GnT to form the Core 3 structure. B, Representative H&E staining and immunohistochemical staining of Tn antigen in human primary and metastatic colorectal cancer tissues. Brown indicates positive staining for Tn antigen

Fig 4: T-synthase and its chaperone (Cosmc) are impaired in human colorectal cancer tissues expressing Tn antigen. A, Expression of T-synthase, Cosmc and C3GnT in frozen human colorectal cancer tissues (Tn-positive = 29, Tn-negative = 22) was measured by western blotting. B, T-synthase enzymatic activity was measured in human colorectal cancer tissues (Tn-positive = 32, Tn-negative = 26). C, Analysis of Cosmc DNA methylation by MALDI-TOF mass spectrometry (Tn-positive = 33, Tn-negative = 32). D, Methylation levels of Cosmc in Tn-positive and Tn-negative cancerous tissues. ***P < .001

Fig 5: C1GALT1 is down-regulated in CCA tissues. (A) The C1GALT1 mRNA expression was determined in 29 paired frozen CCA tissues by qPCR. Relative mRNA expression level was normalized to ß-actin as the reference genes and calculated using the 2-??Ct method. Values are expressed as the mean ± SEM of three independent experiments. (B) Immunohistological analysis of C1GALT1 protein expression in 26 CCA tissues (Left panel, ×400 magnification); Scale bar, 100 µm and percentage (%) of tumor cases for C1GALT1 expression in CCA tissues (Right panel). (C) Kaplan–Meier analysis demonstrated cumulative overall survival determined of CCA patients with C1GALT1 negative VS C1GALT1 positive.