Many proteins associated with the regulation of cell growth are glycosylated (1). O-glycosylation has not been examined and few specific inhibitors exist for study of O-glycosyation pathways (2). A series of analogues of benzyl-O-N-acetyl-D-galactosamine (benzyl-O-GalNAc) were synthesised chemically. These included phenylethyl and cyclohexyl-O-glycosides and the corresponding azides and two C-glycosides as benzyl- and phenylethyl derivatives. The compounds were tested in PC/AA/C1, PC/AA/C1/SB10C, HCA7/C29 and CaCO-2 colorectal cancer cell lines. The different cell lines showed variable susceptibility to the inhibitors with PC/AA/C1/SB10C and HCA7/C29>>PC/AA/C1>>CaCO-2. In the susceptible cell lines PC/AA/SB10C and HCA7/C29, all inhibitors induced apoptosis, tested with acridine orange/propidium bromide staining and PARP cleavage. In the same cell lines all inhibitors blocked proliferation, tested with bromdeoxyuridine labelling. The susceptible cell lines showed aryl glycan formation with each inhibitor (3). These were extracted and analysed by MALDI TOF mass spectrometry (4). Each inhibitor showed characteristic structures which could be mapped onto known glycosylation pathways. Gene array analysis of PC/AA/C1/SB10C cells exposed to benzyl-O-GalNAc, benzyl-O-Gal-azide and benzyl-C-GalNAc identified apoptosis and proliferation genes as targets. The genomic response to the inhibitors thus gives support to the results obtained with growth analysis and the biochemical and chemical findings. Target pathways relevant to cell growth and mediated by O-glycosylation have been identified by this work and form the basis for future study.
Life Sciences 2007 (2007) Proc Life Sciences, C84
Research Symposium: O-Glycan regulation of apoptosis and proliferation in colorectal cancer cell lines
G. Patsos1, C. Robbe-Masselot2, A. Klein3, V. Hebbe-Viton4, R. San Martin4, D. Masselot4, C. Paraskeva5, M. Graessmann3, T. Gallagher4, T. Corfield1</s
1. Clinical Science at South Bristol, University of Bristol, Bristol, BANES, United Kingdom. 2. UMR CNRS /USTL 8576 Glycobiologie Structurale et Fonctionnelle', Université des Sciences et Technologies Lille1, Villeneuve d'Ascq , France. 3. Institut für Molekularbiologie und Bioinformatik , Charité-Universitätsmedizin Berlin, Berlin, Germany. 4. Chemistry, University of Bristol, Bristol, United Kingdom. 5. Cellular and Molecular Medicine, University of Bristol, Bristol, United Kingdom.
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Where applicable, experiments conform with Society ethical requirements.