Abnormal sialylation and fucosylation of saliva glycoproteins: Characteristics of lung cancer-specific biomarkers

Abstract

Dysregulated surface glycoproteins play an important role in tumor cell proliferation and progression. Abnormal glycosylation of these glycoproteins may activate tumor signal transduction and lead to tumor development. The tumor microenvironment alters its molecular composition, some of which regulate protein glycosylation biosynthesis. The glycosylation of saliva proteins in lung cancer patients is different from healthy controls, in which the glycans of cancer patients are highly sialylated and hyperfucosylated. Most studies have shown that O-glycans from cancer are truncated O-glycans, while N-glycans contain fucoses and sialic acids. Because glycosylation analysis is challenging, there are few reports on how glycosylation of saliva proteins is related to the occurrence or progression of lung cancer. In this review, we discussed glycoenzymes involved in protein glycosylation, their changes in tumor microenvironment, potential tumor biomarkers present in body fluids, and abnormal glycosylation of saliva or lung glycoproteins. We further explored the effect of glycosylation changes on tumor signal transduction, and emphasized the role of receptor tyrosine kinases in tumorigenesis and metastasis.

Proteomic Analysis of Lung Cancer Types—A Pilot Study

“…Numerous reviews have been published describing potential novel biomarkers for LC identified by proteomics studies, such as GRIP and coiled-coil domain-containing protein 2 (GCC2), Cystatin A, macrophage migration inhibitory factor (MIF), Thymosin β4, and Fascin [ 9 , 10 ]. Most potential blood [ 11 , 12 , 13 ] and saliva [ 14 ] markers identified for early diagnosis have not been implemented in clinical practice yet. The analysis of fresh-frozen or formalin-fixed paraffin-embedded (FFPE) tissue specimens/sections provides the basis of cancer research; several studies have been published previously about the proteomic characterization of NSCLC tissue [ 15 , 16 , 17 , 18 ].…”

Proteomics and Biochemical Analyses of Secreted Proteins Revealed a Novel Mechanism by Which ADAM12S Regulates the Migration of Gastric Cancer Cells

“…In our proteomic study, we used the SPECS method to enrich the secreted glycosylated proteins for their identification because glycosylated proteins play important roles in cancer development and progression . However, during the biochemical validation, in order to prevent the interference of FBS with immunoblotting, we used a medium without FBS to culture cells and immunoblotted the cultured medium after concentrating.…”

“…In our proteomic study, we used the SPECS method to enrich the secreted glycosylated proteins for their identification because glycosylated proteins play important roles in cancer development and progression. 51 However, during the biochemical validation, in order to prevent the interference of FBS with immunoblotting, we used a medium without FBS to culture cells and immunoblotted the cultured medium after concentrating. Although our experiments revealed the similar upregulation of CD146 in these two cases, we are not sure whether other proteins exhibit similar or different behaviors under two different culture conditions.…”

Advances in glycopeptide enrichment methods for the analysis of protein glycosylation over the past decade

“…Protein glycosylation is inherently related to the physiological state of cells, and its abnormal regulation manifests the occurrence and development of diseases. This is partly due to the differential expression and availability of GTFs or GSs in the disease microenvironment [6, 7]. OGA (O‐GlcNAcase) and OGT dynamically regulate Ser/Thr O‐GlcNAcylation in diseases [8].…”