Circulating Proteins as Diagnostic Markers in Gastric Cancer

Abstract

Gastric cancer (GC) is a highly malignant disease affecting humans worldwide and has a poor prognosis. Most GC cases are detected at advanced stages due to the cancer lacking early detectable symptoms. Therefore, there is great interest in improving early diagnosis by implementing targeted prevention strategies. Markers are necessary for early detection and to guide clinicians to the best personalized treatment. The current semi-invasive endoscopic methods to detect GC are invasive, costly, and time-consuming. Recent advances in proteomics technologies have enabled the screening of many samples and the detection of novel biomarkers and disease-related signature signaling networks. These biomarkers include circulating proteins from different fluids (e.g., plasma, serum, urine, and saliva) and extracellular vesicles. We review relevant published studies on circulating protein biomarkers in GC and detail their application as potential biomarkers for GC diagnosis. Identifying highly sensitive and highly specific diagnostic markers for GC may improve patient survival rates and contribute to advancing precision/personalized medicine.

Keywords: biomarkers; circulating biomarkers; exosomes; gastric cancer; liquid biopsy; plasma proteins; proteomics; saliva proteins; serum proteins; urine proteins.

Figure 1

Schematic illustration of analytical workflow for biomarker discovery. Saliva, ascites, urine, gastric juice, urine, and blood are collected; proteins/exosomes are enriched and analyzed; data are elaborated; and putative biomarkers are discovered. Their abundances are usually compared with clinical information to achieve early detection. Created with BioRender.com, accessed on 31 October 2023.

Figure 2

Diagram showing the top 10 most significant Gene Ontology (GO) biological processes of plasma/serum proteins found to be associated with gastric cancer diagnosis in the last 10 years (Table 1; p < 0.05; FDR < 0.05). The diagram results from the interrogation of proteins listed in Table 1 with DAVID 6.8 (https://doi.org/10.1038/nprot.2008.211, accessed on 11 September 2023). For each GO biological process, the list of involved proteins is reported (UniProtKB entry protein; https://www.uniprot.org/, accessed on 11 September 2023). KEGG pathways are listed next to the signal transduction bia Alikhani ological process.