Effects Of Highly Expression Of PSA To COS-7 Cell Ethology And Molecular Mechanism Reseach

Polysialic acid (PSA) is a unique carbohydrate composed of a linear homopolymer ofα2,8-linked sialic acid, and it is attached to the fifth immunoglobulin-like domain of the neural cell adhesion molecule (NCAM) via a typical N-linked glycan in vertebrate neural system. Polysialylation of NCAM is catalyzed by two polysialyltransferases: ST8Sia II (STX) and ST8Sia IV (PST). Polysialic acid plays critical roles in neural development by modulating adhesive property of NCAM such as neural cell migration, neurite outgrowth, neural pathfinding and synaptogenesis. It has been verified that PSA is closely correlated to the metastasis and malignance of several tumors such as small cell lung caner, non-small cell lung caner, neuroblastoma and rhabdomyosarcoma. The related research draws more and more interests, and the anti-cancer vaccines against PSA has already been explored and developed for small cell lung cancer treatment in American.The study constructed a polysialic acid (PSA) and neural cell adhesion molecule (NCAM) differently expressing COS-7 cell line by transient cotransfection, and determined the cotransfection efficiency by Western blotting and flow cytometry. Using point adhesion essay and transwell chamber, we demonstrated PSA inhibited the adhesion to basement membrane, promoted the migration and invasion ability. We investigated the related signal molecule, and the results indicated that high level of PSA increased phosphorylation of FGFR,PLCγ,FAK,ERK. We concluded that high level of PSA enhanced cell migration and invasion through FGFR-ERK signal pathway.