Published online Nov 15, 2022. doi: 10.4251/wjgo.v14.i11.2097
Peer-review started: March 25, 2022
First decision: June 2, 2022
Revised: June 16, 2022
Accepted: October 17, 2022
Article in press: October 17, 2022
Published online: November 15, 2022
Processing time: 235 Days and 9.9 Hours
The prognosis of infiltrative gastric cancer (IGC) patients remains relatively poor. Therefore, it is necessary to explore the molecular mechanisms underlying the occurrence and development of IGC.
The proteomic signatures of IGC remain unknown.
To profile the proteome of IGC.
The proteins from IGC and normal tissue samples were analyzed by high performance liquid chromatography tandem mass spectrometry and searched against the database via Maxquant software. The differentially expressed proteins (DEPs) were screened using |log2(Fold Change)| > 1 and P-adj < 0.01 as the thresholds. The expression levels of some proteins were verified by Western blotting. The interaction network of DEPs was constructed using the STRING database, and the key proteins were visualized using Cytoscape cytoHubba software. Finally, clusterProfiler, STRING and DAVID were used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of DEPs, with P < 0.05 as the threshold.
A total of 7361 DEPs were identified, of which 94 were significantly up-regulated and 223 were significantly down-regulated in IGC relative to normal gastric tissues. The top 10 up-regulated proteins were MRTO4, BOP1, PES1, WDR12, BRIX1, NOP2, POLR1C, NOC2L, MYBBP1A and TSR1, and the top 10 down-regulated proteins were NDUFS8, NDUFS6, NDUFA8, NDUFA5, NDUFC2, NDUFB8, NDUFB5, NDUFB9, UQCRC2 and UQCRC1. The up-regulated proteins were enriched for 9 biological processes including DNA replication, ribosome biogenesis and initiation of DNA replication, and the cellular component MCM complex. Among the down-regulated proteins, 17 biological processes were enriched, including glucose metabolism, pyruvic acid metabolism and fatty acid β-oxidation. In addition, the mitochondrial inner membrane, mitochondrial matrix and mitochondrial proton transport ATP synthase complex were among the 6 enriched cellular components among the down-regulated proteins, and 11 molecular functions including reduced nicotinamide adenine dinucleotide dehydrogenase activity, acyl-CoA dehydrogenase activity and nicotinamide adenine dinucleotide binding were also enriched. The significant KEGG pathways for the up-regulated proteins were DNA replication, cell cycle and mismatch repair, whereas 18 pathways including oxidative phosphorylation, fatty acid degradation and phenylalanine metabolism were significantly enriched among the down-regulated proteins.
The proteins involved in cell cycle regulation, DNA replication and mismatch repair, and metabolism were significantly altered in IGC, which provides a basis for the future identification of novel biomarkers.
This study reveals the proteomic signature of IGC.