Publications by authors named "Charlotte Clarisse"

2 Publications

  • Page 1 of 1

Profiling of -acetylated Gangliosides Expressed in Neuroectoderm Derived Cells.

Int J Mol Sci 2020 Jan 6;21(1). Epub 2020 Jan 6.

Univ. Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, F-59000 Lille, France.

The expression and biological functions of oncofetal markers GD2 and GD3 were extensively studied in neuroectoderm-derived cancers in order to characterize their potential as therapeutic targets. Using immunological approaches, we previously identified GD3, GD2, and AcGD2 expression in breast cancer (BC) cell lines. However, antibodies specific for -acetylated gangliosides are not exempt of limitations, as they only provide information on the expression of a limited set of -acetylated ganglioside species. Consequently, the aim of the present study was to use structural approaches in order to apprehend ganglioside diversity in melanoma, neuroblastoma, and breast cancer cells, focusing on -acetylated species that are usually lost under alkaline conditions and require specific analytical procedures. We used purification and extraction methods that preserve the -acetyl modification for the analysis of native gangliosides by MALDI-TOF. We identified the expression of GM1, GM2, GM3, GD2, GD3, GT2, and GT3 in SK-Mel28 (melanoma), LAN-1 (neuroblastoma), Hs 578T, SUM 159PT, MDA-MB-231, MCF-7 (BC), and BC cell lines over-expressing GD3 synthase. Among -acetylated gangliosides, we characterized the expression of AcGM1, AcGD3, AcGD2, AcGT2, and AcGT3. Furthermore, the experimental procedure allowed us to clearly identify the position of the sialic acid residue that carries the -acetyl group on b- and c-series gangliosides by MS/MS fragmentation. These results show that ganglioside -acetylation occurs on both inner and terminal sialic acid residue in a cell type-dependent manner, suggesting different -acetylation pathways for gangliosides. They also highlight the limitation of immuno-detection for the complete identification of -acetylated ganglioside profiles in cancer cells.
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http://dx.doi.org/10.3390/ijms21010370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6981417PMC
January 2020

OGT Controls the Expression and the Glycosylation of E-cadherin, and Affects Glycosphingolipid Structures in Human Colon Cell Lines.

Proteomics 2019 11 20;19(21-22):e1800452. Epub 2019 Aug 20.

Université de Lille, CNRS, UMR 8576, UGSF, Unité de Glycobiologie Structurale et Fonctionnelle, F-59000, Lille, France.

Colorectal cancer (CRC) affects both women and men living in societies with a high sedentary lifestyle. Amongst the phenotypic changes exhibited by tumor cells, a wide range of glycosylation has been reported for colon cancer-derived cell lines and CRC tissues. These aberrant modifications affect different aspects of glycosylation, including an increase in core fucosylation and GlcNAc branching on N-glycans, alteration of O-glycans, upregulated sialylation, and O-GlcNAcylation. Although O-GlcNAcylation and complex glycosylations differ in many aspects, sparse evidences report on the interference of O-GlcNAcylation with complex glycosylation. Nevertheless, this relationship is still a matter of debate. Combining different approaches on three human colon cell lines (HT29, HCT116 and CCD841CoN), it is herein reported that silencing O-GlcNAc transferase (OGT, the sole enzyme driving O-GlcNAcylation), only slightly affects overall N- and O-glycosylation patterns. Interestingly, silencing of OGT in HT29 cells upregulates E-cadherin (a major actor of epithelial-to-mesenchymal transition) and changes its glycosylation. On the other hand, OGT silencing perturbs biosynthesis of glycosphingolipids resulting in a decrease in gangliosides and an increase in globosides. Together, these results provide novel insights regarding the selective regulation of complex glycosylations by O-GlcNAcylation in colon cancer cells.
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http://dx.doi.org/10.1002/pmic.201800452DOI Listing
November 2019