Publications by authors named "Jean-Marc Le Doussal"

3 Publications

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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

Identification of 9-O-acetyl-N-acetylneuraminic acid (Neu5,9Ac) as main O-acetylated sialic acid species of GD2 in breast cancer cells.

Glycoconj J 2019 02 5;36(1):79-90. Epub 2019 Jan 5.

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

Mainly restricted to the nervous system in healthy adults, complex gangliosides such as GD3 and GD2 have been shown to be involved in aggressiveness and metastasis of neuro-ectoderm derived tumors such as melanoma and neuroblastoma. Interestingly, O-acetylated forms of GD2, not expressed in human peripheral nerve fibers, are highly expressed in GD2+ tumor cells. Very little information is known regarding the expression of O-acetylated disialogangliosides in breast cancer (BC) cell lines. Here, we analyzed the expression of GD2, GD3 and their O-acetylated forms O-acetyl-GD2 (OAcGD2) and O-acetyl-GD3 (OAcGD3) in BC cells. We used Hs 578T and SUM159PT cell lines, as well as cell clones over-expressing GD3 synthase derived from MDA-MB-231 and MCF-7. Using flow cytometry and immunocytochemistry/confocal microscopy, we report that BC cells express b-series gangliosides GD3 and GD2, as well as significant amounts of OAcGD2. However, OAcGD3 expression was not detected in these cells. O-acetylation of gangliosides isolated from BC cells was examined by LC-MS analysis of sialic acid DMB-derivatives. We report that the main acetylated form of sialic acid expressed in BC gangliosides is 9-O-acetyl-N-acetylneuraminic acid (Neu5,9Ac). These results highlight a close interrelationship between Neu5,9Ac and OAcGD2 expression, and suggest that OAcGD2 is synthetized from GD2 and not from OAcGD3 in BC cells.
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http://dx.doi.org/10.1007/s10719-018-09856-wDOI Listing
February 2019

Gene expression profile predicts outcome after anthracycline-based adjuvant chemotherapy in early breast cancer.

Breast Cancer Res Treat 2011 Jun 29;127(2):363-73. Epub 2010 Jun 29.

Département d'Oncologie Moléculaire, Centre de Recherche en Cancérologie de Marseille, UMR891 Inserm, Institut Paoli-Calmettes (IPC), Marseille, France.

Prognosis of early beast cancer is heterogeneous. Today, no histoclinical or biological factor predictive for clinical outcome after adjuvant anthracycline-based chemotherapy (CT) has been validated and introduced in routine use. Using DNA microarrays, we searched for a gene expression signature associated with metastatic relapse after adjuvant anthracycline-based CT without taxane. We profiled a multicentric series of 595 breast cancers including 498 treated with such adjuvant CT. The identification of the prognostic signature was done using a metagene-based supervised approach in a learning set of 323 patients. The signature was then tested on an independent validation set comprising 175 similarly treated patients, 128 of them from the PACS01 prospective clinical trial. We identified a 3-metagene predictor of metastatic relapse in the learning set, and confirmed its independent prognostic impact in the validation set. In multivariate analysis, the predictor outperformed the individual current prognostic factors, as well as the Nottingham Prognostic Index-based classifier, both in the learning and the validation sets, and added independent prognostic information. Among the patients treated with adjuvant anthracycline-based CT, with a median follow-up of 68 months, the 5-year metastasis-free survival was 82% in the "good-prognosis" group and 56% in the "poor-prognosis" group. Our predictor refines the prediction of metastasis-free survival after adjuvant anthracycline-based CT and might help tailoring adjuvant CT regimens.
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http://dx.doi.org/10.1007/s10549-010-1003-zDOI Listing
June 2011