The abnormal glycosylation process of stomach cancer cells increases the sialic acid level on the surface of malignant and transformed cells. CD BioGlyco is confident to provide our clients with high-quality Sialic Acid Analysis Services for stomach cancer.
Stomach cancer, also known as gastric cancer, begins in the stomach lining and progresses slowly. Untreated, it forms a mass (tumor) and grows deeper into your stomach walls. The tumor may spread to nearby organs like your liver and pancreas. Reported causative factors of stomach cancer include Helicobacter pylori infection, cigarette smoking, and diet. As one of the most common cancers, stomach cancer has the third-highest lethality and fourth-highest morbidity of all cancers all over the world. The high mortality is caused by difficulties in early-stage detection, tumor recurrence, metastasis, and lack of effective therapeutic response.
Of the various sugars that make up N-linked and O-linked glycans, sialic acids at the terminal end of glycans are of paramount importance. Sialic acids are the most prevalent terminal monosaccharides of glycoconjugates that are attached to glycoproteins and glycolipids in the membrane of cells. The reports have shown that carcinogenesis, invasion, and metastasis of tumor cells are relevant to aberrant expression of terminal sialic acids, and specifically α2,3-linked sialic acids. Researchers have found that a high level of α2,3-linked sialic acids is associated with the metastatic potential of stomach cancer cells. The results provide evidence that α2,3-linked sialic acids could be an important molecular marker to determine malignant properties and a target for molecular therapy in patients with stomach cancer.
Fig.1 Sialic acid in immune system evasion. (Dobie, 2021)
We have measured the expression of α2,3-linked sialic acid residues using Specific Lectin and analyzed the potential of invasion and metastasis of gastric cancer. The expression of α2,3-linked sialic acid residues in stomach cancer samples is evaluated using Maackia amurensis leukoagglutinin (MAL) histochemical staining analysis. Then the assays of cytochemical staining and flow cytometry are employed to determine the MAL positive cells in the gastric cancer cell lines. Finally, the activities of invasion and migration are evaluated using the assays of cell adhesion and transwell chamber.
Fig.2 Histochemical staining with MAL in stomach cancer tissues. (Wang, 2009)
The increased sialylation of Thomsen-Friedenreich (TF)-specific antibodies combined with a low level of anti-TF IgM is strongly related to gastric cancer and patients’ survival, which is used as a novel biomarker for the detection and prognosis of cancer. The sialic acid-specific Sambucus nigra agglutinin lectin reactivity of anti-TF IgG determined in the total IgG purified from the serum of patients with stomach cancer was significantly decreased compared to that of healthy blood donors and patients with nonmalignant gastric diseases. The level of anti-TF IgG, IgM, and IgA was determined by the enzyme-linked immunosorbent assay (ELISA) as described elsewhere.
Serum markers such as a pepsinogen I/II ratio, sialyl Lewis a, and carcinoembryonic antigen (CEA) have been widely used for gastric disorders in clinics. For example, Sialyl Lewis a as a biomarker is applicable for the recurrence of stomach cancer. We determine the levels of serum sialyl Lewis a and CEA tumor marker in an autoanalyzer with chemiluminescent immunoassay using commercial kits.
Haptoglobin is a highly sialylated glycoprotein with four N-glycosylation sites at Asn 184, 207, 211, and 241. It is regarded as a signature molecule to display aberrant glycosylation in inflammatory disorders (e.g., liver cirrhosis and pancreatitis) and various types of cancer (e.g., colon cancer, lung cancer, liver cancer, prostate cancer, and pancreas cancer). We have developed a targeted glycoproteomic approach using chip-based nano liquid chromatography coupled to quadrupole time-of-flight mass spectrometer (nano-LC-QTOF MS) and MS/MS following antibody-assisted targeted purification to discover glycan signatures of serum haptoglobin for stomach cancer. Haptoglobin from cancer serum samples shows significantly higher levels of fucosylation and branching, indicating that this glycoprotein is relevant to stomach cancer.
CD BioGlyco employs various approaches to provide you with professional and rapid sialic acid analysis services in stomach cancer. If you want to know more about the service, please feel free to contact us.