Dynamic change of neural cell adhesion molecule polysialylation on human neuroblastoma (IMR-32) and rat pheochromocytoma (PC-12) cells during growth and differentiation.
Polysialic acid (PSA) is a regulatory epitope of neural cell adhesion molecule (NCAM) in homophilic adhesion of neural cells mediated by NCAM, is also known to be re-expressed in several human tumors, thus serves as an oncodevelopmental antigen. In this study, using a recently developed ultrasensitive chemical method in addition to immunochemical methods, growth stage-dependent and retinoic acid (RA)-induced differentiation-dependent changes of PSA expression in human neuroblastoma (IMR-32) and rat pheochromocytoma (PC-12) cells were analyzed both qualitatively and quantitatively. Both IMR-32 and PC-12 cells expressed PSA on NCAM, and the level of PSA expressed per unit weight of cells increased with post-inoculation incubation time. The most prominent feature was seen at the full confluence stage. RA induced neuronal differentiation in both IMR-32 and CP-12 cells that paralleled the change in the PSA level. Chemical analysis revealed the presence of NCAM glycoforms differing in the degree of polymerization (DP) of oligo/polysialyl chains, whose DP was smaller than 40. DP distribution of PSA was different between the cell lines and was changed by the growth stage and the RA treatment. Thus DP analysis of PSA is important in understanding both mechanism and biological significance of its regulated expression.
Poongodi
Geetha L
GL
Institute of Biological Chemistry, Academia Sinica, Taipei 115-29, Taiwan.
Suresh
Nimmagadda
N
Gopinath
Subash C B
SC
Chang
Tschining
T
Inoue
Sadako
S
Inoue
Yasuo
Y
D000310:Adrenal Gland Neoplasms / Q000473:pathology; D000818:Animals; D001932:Brain Neoplasms / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology*; D002455:Cell Division / Q000502:physiology*; D006801:Humans; D007700:Kinetics; D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism*; D009447:Neuroblastoma / Q000473:pathology; D016716:PC12 Cells; D010673:Pheochromocytoma / Q000473:pathology; D051381:Rats; D012794:Sialic Acids / Q000378:metabolism*; D013997:Time Factors; D014407:Tumor Cells, Cultured
D039842:Neural Cell Adhesion Molecule L1; D019006:Neural Cell Adhesion Molecules; D012794:Sialic Acids; C103469:polysialyl neural cell adhesion molecule