Sialic acid plays an important role in thyroid cancer cell proliferation and secretory activity. CD BioGlyco has extensive experience in sialic acid analysis and provides sialic acid analysis services in thyroid cancer. We have the confidence to be your professional research assistant in the field of glycobiology.
Thyroid cancer is one of the highly malignant diseases originating from endocrine glands. Histological evaluation is often complicated by the difficulty in distinguishing between benign and malignant lesions. In recent years, its incidence has rapidly increased. Thyroid cancers include papillary thyroid carcinoma (PTC), follicular thyroid cancer (FTC), poorly differentiated thyroid cancer (PDTC), and anaplastic thyroid cancer (ATC). Of these, PTC is the most common follicular cell-derived carcinoma, accounting for approximately 90% of all newly diagnosed thyroid cancer cases.
Abnormal glycosylation of cell structures, including changes in sialylation, is a feature of the neoplastic transformation process. Sialic acid is an important component of cell glycoconjugates and is involved in various biological functions. Sialic acid is also an important component of cellular receptors, may modulate their function, and may be important for cell adhesion. Some studies have shown that sialic acid plays an important role in thyroid cell proliferation and secretory activity under physiological conditions. It is related to the thyrotropin receptor and plays a key role in its structure and function.
Fig.1 Sialylation in evasion of cell death pathways. (Dobie, 2021)
Neoplastic transformation of the thyroid gland is accompanied by changes in sialylation that can be assessed histopathologically using lectin histochemistry. There are three Sialic Acid-binding Lectins used in lectin histochemistry: Tritrichomonas mobilizes lectin (TML), which recognizes sialic acid without linkage preference; Maackia amurensis leukoagglutinin (MAL), which preferentially binds α-2,3-linked sialic acid; and Sambucus nigra agglutinin (SNA), which preferentially binds α-2,6-linked sialic acid, are used for detection of sialylated glycoconjugates in thyroid gland specimens.
A recent study shows that cell surface glycan chains of thyroid cancer cells include a large number of α-2,6, α-2,3, sialic acid, and α-1,6 fucose residues. We can differentiate α2,6- and α2,3-linked sialic acids by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS). We have established a rapid, comprehensive, and reliable analytical method to identify and quantify global proteomes, intact N-glycopeptides, and denials-N-glycopeptides in the plasma and urine of female patients with PTC by LC-MS/MS in label-free analysis.
Thyroglobulin (Tg) is the major secretory protein of the thyroid follicular cell and serves as the biochemical substrate for thyroxine synthesis and storage. Sialic acid is the terminal monosaccharide residue of B carbohydrate chains of the Tg molecule. According to the research, the sialic acid content is significantly lower in cancerous Tg compared to Tg from normal human thyroid.
Fig.2 Glycosylation of the key thyroid proteins. (Ząbczyńska, 2018)
Thyroglobulin antibodies (TgAb), mainly containing immunoglobulin G (IgG), are commonly found in healthy individuals. The reports have shown that the glycosylation levels of TgAb IgG differed in various thyroid diseases, suggesting an important role of glycosylation on antibodies in the pathogenesis of thyroid diseases. In PTC patients, the rate of TgAb positivity is around 20%, approximately twice the TgAb positivity rate in the general population. We determine IgG concentration using an enzyme-linked immunosorbent assay and assess TgAb IgG glycosylation using a lectin microassay.
CD BioGlyco employs various approaches to provide you with professional and rapid sialic acid analysis services in thyroid cancer. If you want to know more about the service, please feel free to contact us and we will respond as soon as possible.