Bioinformatics insight into glycosyltransferase gene expression in gastric cancer: POFUT1 is a potential biomarker.

Aberrant glycosylation plays an important role in the progression of gastric cancer. Although many enzymes are involved in glycoconjugate synthesis, little information is known about glycosyltransferase (GT)'s alteration in gastric cancer. To give an insight into the differential expression of GTs as obtained from the TCGA database, bioinformatics analysis of 415 gastric cancer samples and 35 normal samples was performed. Using a 0.6-fold change threshold to compare GT expression in normal and cancer tissues, it was noted that 36 GTs were upregulated including POFUT1 and 30 GTs were downregulated in cancer tissues (P < 0.01). Enriched pathway analysis indicated that POFUT1 was correlated positively with cell cycle and cell carcinoma process but correlated negatively with cell adhesion and apoptosis (P < 0.05). Furthermore, immunohistochemistry analysis verified that 33 out of 51 tumor tissues had detectable POFUT1 expression. POFUT1-positive samples were associated with aggressive tumor phenotypes like higher T and N classification (P = 0.026, 0.042) as well as poor differentiation (P = 0.031). No correlation was observed between POFUT1 expression and age, gender, stage, and Lauren classification. These results suggested that POFUT1 is increased and may serve as a potential biomarker in gastric cancer.