Tumor-associated carbohydrate antigens, including sialic acid, are overexpressed due to aberrant glycosylation in various tumor cells and are implicated as a hallmark of cancer progression and poor prognosis in patients with melanoma tumors. CD BioGlyco provides a full range of sialic acid analysis services in malignant melanoma. We are confident to be your essential research assistant in the field of glycobiology.
Malignant melanoma is a malignant tumor of pigment-producing cells (melanocytes), which are located primarily in the skin but also found in the ears, gastrointestinal tract, eyes, oral and genital mucosa, and leptomeninges. Melanoma is one of the most lethal malignancies among human cancers because of its high aggressiveness, rapid metastasis, and resistance to conventional therapies.
Aberrant expression of sialic acids or altered linkage types is closely related to the malignant phenotype and metastatic potential and may have prognostic significance in human cancer. The reports suggest that melanoma progression is associated with the increased expression of α2,3-linked sialic acids on the cell surface and these residues could facilitate melanoma cell interaction with fibronectin.
Sialic acid is a family of acylated derivatives of neuraminic acid that typically occurs as terminal components of the carbohydrate chains of glycoproteins and glycolipids. Increased total serum sialic acid levels are useful non-specific markers for various oncological diseases including melanoma. We evaluate the expression of sialic acids on the cell surface by flow cytometry using lectin: Maackia amurensis (MAA) and Sambucus nigra (SNA).
Fig.1 Cell surface sialylation analysis by flow cytometry using MAA and SNA. (Kolasińska, 2016)
The biosynthesis of sialylated molecules acts as coding systems because of their ability to interact with carbohydrate-binding proteins (including lectins, antibodies, receptors, and enzymes) with high specificity and selectivity. These molecules are also involved in cellular communication, such as cell-cell and cell-matrix interactions and molecular recognition during tumor development and progression.
Sialic acids are usually linked to the endoglycan residue galactose (Gal) via α2,6-or α2,3-linkage, or linked to galactosamine, N-acetylgalactosamine (GalNAC), or N-acetylglucosamine (GlcNAc) via α2,6-linkage. In addition, sialic acids are attached to the C8 position of another sialic acid residue to form a linear α2,8-homopolymer called polysialic acid. The results of the study show that α2,3-sialylation is associated with a more aggressive phenotype in melanoma, whereas the role of α2,6-linked sialic acid appears to be less important in melanoma cell behavior. This signature may be useful in finding new targets for therapeutic approaches and developing new strategies for cancer treatment.
Monoclonal antibodies to tumor-associated antigens help characterize the molecular differences between tumor and normal cells and significantly contribute to the understanding of the functional role of some of these antigens. Several researchers have generated monoclonal antibodies against the carbohydrate fraction of tumor cell-associated glycolipids. For example, monoclonal antibodies against the melanoma-associated gangliosides GD2 and GD3 have been described.
Gangliosides are glycolipids containing sialic acid, which are commonly found in the membranes of all eukaryotic cells. They are associated with a variety of cellular functions, including cell-cell adhesion and communication, and cell-substrate interactions. Recent work has shown that the sialic acid of some gangliosides has an O-acyl group. Scientists have demonstrated that the gangliosides recognized by the monoclonal antibody are also present on human melanoma cells and contain a base-sensitive antigenic epitope involving an O-acyl sialic acid residue.
CD BioGlyco provides customers with comprehensive and reliable sialic acid analysis services in malignant melanoma. If you are interested in our services, please feel free to contact us.
Reference:
