Fig. 3

Pathway enrichment and biological features associated with sialic acid metabolism in gastric cancer. A Venn diagram showing the DEGs among the three SiaM clusters. Common genes were identified from the DEGs between Clusters C and A and between Clusters C and B. Gene Ontology (B) and Kyoto Encyclopedia of Genes and Genomes (C) pathway enrichment for the common DEGs. Gene Ontology pathways included biological processes (blue), cellular components (red), and molecular function (purple). D Heatmap showing the relative activity of cancer hallmark pathways estimated by ssGSEA analysis. Gene set enrichment analysis showing the enrichment score of sialic acid binding signaling in Cluster C compared with those in Clusters A (E) and B (F). G Comparison of the sialic acid accumulation rates among the three SiaM clusters in gastric cancer. The sialic acid accumulation rate was estimated using the delta value between the rate of sialic acid placement onto the cell surface and the rate of sialic acid degradation. The rate of sialic acid placement onto the cell surface was determined by the geometric average of the transcriptional expression of CMAS and specific sialyltransferase genes, whereas the rate of sialic acid degradation was determined by the geometric average of the transcriptional expression of NEU1 and CTSA. H Boxplot showing the differences in the relative activity of several cancer metastasis-related biological processes among the three SiaM clusters in gastric cancer. Cancer metastasis-related biological processes, including cell–cell adhesion, cell contraction, motion and migration, and protrusion, reflect the metastatic potential of tumor cells. *** P < 0.001. GSEA, gene set enrichment analysis; ssGSEA, single-sample gene set enrichment analysis