We previously reported on the accumulation of a substantial amount of free N-acetylneuraminic acid (Neu5Ac)-containing complex-type N-glycans in human pancreatic cancer cells (Yabu M, Korekane H, Takahashi H, Ohigashi H, Ishikawa O, Miyamoto Y. 2012.
Accumulation of free Neu5Ac-containing complex-type N-glycans in human pancreatic cancers. Glycoconjugate J Epub ahead of print). In the present paper, we further extend our cancer glycomic study of human prostate cancer. Specifically, we demonstrate that, in addition to the free Neu5Ac-containing N-glycans, significant amounts of free deaminoneuraminic acid (KDN)-containing N-glycans had accumulated in the prostate cancer tissues from four out of five patients. Indeed in one of the four cases, the free KDN-glycans accumulated as major components in prostate cancer tissue. The structures of the KDN-containing free oligosaccharides were analyzed by a variety of methods. Specifically we used fluorescent labeling with aminopyridine combined with two dimensional mapping, KDNase digestion and mass spectrometry to facilitate identification. The analysis also utilized newly synthesized KDN-linked oligosaccharides as standards. The prostate-specific glycans were composed of five species having the following sequence, KDN-Gal-GlcNAc-Man-Man-GlcNAc (α2,6-KDN-linked glycans being the dominant form). The most abundant free KDN-containing N-glycan was KDNα2-6Galβ1-4GlcNAcβ1-2Manα1-3Manβ1-4GlcNAc followed by KDNα2-6Galβ1-4GlcNAcβ1-2Manα1-6Manβ1-4GlcNAc. This is the first study to show unequivocal chemical evidence for the occurrence of KDN-glycoconjugates in human tissues together with their detailed structures. These oligosaccharides might be developed as tumor markers, especially for prostate cancer.
Written by:
Yabu M, Korekane H, Hatano K, Kaneda Y, Nonomura N, Sato C, Kitajima K, Miyamoto Y. Are you the author?
Department of Immunology, Osaka Medical Center for Cancer and Cardiovascular Diseases, 1-3-3 Nakamichi, Higashinari-ku, Osaka 537-8511, Japan.
Reference: Glycobiology. 2012 Sep 12. Epub ahead of print.
doi: 10.1093/glycob/cws132
PubMed Abstract
PMID: 22975979
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