References of "Hennequière, Vincent"
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See detailMyoferlin is a key regulator of EGFR activity in breast cancer.
Turtoi, Andrei ULg; Blomme, Arnaud ULg; Bellahcene, Akeila ULg et al

in Cancer Research (2013)

Myoferlin is a member of the ferlin family of proteins that participate in plasma membrane fusion, repair and endocytosis. While some reports have implicated myoferlin in cancer, the extent of its ... [more ▼]

Myoferlin is a member of the ferlin family of proteins that participate in plasma membrane fusion, repair and endocytosis. While some reports have implicated myoferlin in cancer, the extent of its expression in and contributions to cancer are not well established. In this study, we show that myoferlin is overexpressed in human breast cancers and that it is has a critical role in controlling degradation of the EGFR after its activation and internalization in breast cancer cells. Myoferlin depletion blocked EGF-induced cell migration and epithelial-to-mesenchymal transition. Both effects were induced as a result of impaired degradation of phosphorylated EGFR via dysfunctional plasma membrane caveolae and alteration of caveolin homooligomerization. In parallel, myoferlin depletion reduced tumor development in a chicken chorioallantoic membrane xenograft model of human breast cancer. Considering the therapeutic significance of EGFR targeting, our findings identify myoferlin as an novel candidate function to target for future drug development. [less ▲]

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See detailThe angiogenesis suppressor gene AKAP12 is under the epigenetic control of HDAC7 in endothelial cells.
Turtoi, Andrei ULg; Mottet, Denis ULg; Matheus, Nicolas ULg et al

in Angiogenesis (2012)

Histone deacetylases (HDACs) are a family of 18 enzymes that deacetylate lysine residues of both histone and nonhistone proteins and to a large extent govern the process of angiogenesis. Previous studies ... [more ▼]

Histone deacetylases (HDACs) are a family of 18 enzymes that deacetylate lysine residues of both histone and nonhistone proteins and to a large extent govern the process of angiogenesis. Previous studies have shown that specific inhibition of HDAC7 blocks angiogenesis both in vitro and in vivo. However, the underlying molecular mechanisms are not fully understood and hence preclude any meaningful development of suitable therapeutic modalities. The goal of the present study was to further the understanding of HDAC7 epigenetic control of angiogenesis in human endothelial cells using the proteomic approach. The underlying problem was approached through siRNA-mediated gene-expression silencing of HDAC7 in human umbilical vein endothelial cells (HUVECs). To this end, HUVEC proteins were extracted and proteomically analyzed. The emphasis was placed on up-regulated proteins, as these may represent potential direct epigenetic targets of HDAC7. Among several proteins, A-kinase anchor protein 12 (AKAP12) was the most reproducibly up-regulated protein following HDAC7 depletion. This overexpression of AKAP12 was responsible for the inhibition of migration and tube formation in HDAC7-depleted HUVEC. Mechanistically, H3 histones associated with AKAP12 promoter were acetylated following the removal of HDAC7, leading to an increase in its mRNA and protein levels. AKAP12 is responsible for protein kinase C mediated phosphorylation of signal transducer and activator of transcription 3 (STAT3). Phosphorylated STAT3 increasingly binds to the chromatin and AKAP12 promoter and is necessary for maintaining the elevated levels of AKAP12 following HDAC7 knockdown. We demonstrated for the first time that AKAP12 tumor/angiogenesis suppressor gene is an epigenetic target of HDAC7, whose elevated levels lead to a negative regulation of HUVEC migration and inhibit formation of tube-like structures. [less ▲]

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See detailNovel post-digest isotope coded protein labeling method for phospho- and glycoproteome analysis
Fleron, Maximilien ULg; Greffe, Yannick ULg; Musmeci, Davide ULg et al

in Journal of Proteomics (2010), 73(10), 1986-2005

In the field of proteomics there is an apparent lack of reliable methodology for quantification of posttranslational modifications. Present study offers a novel post-digest ICPL quantification strategy ... [more ▼]

In the field of proteomics there is an apparent lack of reliable methodology for quantification of posttranslational modifications. Present study offers a novel post-digest ICPL quantification strategy directed towards characterization of phosphorylated and glycosylated proteins. The value of the method is demonstrated based on the comparison of two prostate related metastatic cell lines originating from two distinct metastasis sites (PC3 and LNCaP). The method consists of protein digestion, ICPL labeling, mixing of the samples, PTM enrichment and MS-analysis. Phosphorylated peptides were isolated using TiO(2), whereas the enrichment of glycosylated peptides was performed using hydrazide based chemistry. Isolated PTM peptides were analyzed along with non enriched sample using 2D-(SCX-RP)-Nano-HPLC-MS/MS instrumentation. Taken together the novel ICPL labeling method offered a significant improvement of the number of identified (∼600 individual proteins) and quantified proteins (>95%) in comparison to the classical ICPL method. The results were validated using alternative protein quantification strategies as well as label-free MS quantification method. On the biological level, the comparison of PC3 and LNCaP cells has shown specific modulation of proteins implicated in the fundamental process related to metastasis dissemination. Finally, a preliminary study involving clinically relevant autopsy cases reiterated the potential biological value of the discovered proteins. [less ▲]

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See detailNovel Relative ICPL Based Quantitative Phospho- and Glycoproteome Analysis Method
Fleron, Maximilien ULg; Greffe, Yannick ULg; Massart, Anne-Cécile ULg et al

Poster (2010, April 16)

Large scale proteomic analysis remains challenging partially because proteins are inhomogeneous and often influenced by a variety of structural modifications. In particular, these specific chemical ... [more ▼]

Large scale proteomic analysis remains challenging partially because proteins are inhomogeneous and often influenced by a variety of structural modifications. In particular, these specific chemical modifications called posttranslational modifications (PTM) are crucial determinants for the protein function and biological role. Up to now there have been a growing number of studies describing the enrichment and identification of PTM. However, a significant dearth of data offering a reliable methodology for PTM quantification does exist. The present work aims at developing a label based protein PTM quantification strategy and demonstrating its value on comparative analysis of cells originating from two distinct prostate metastasis sites. PC3 and LNCaP cells isolated from bone and lymph node prostate cancer metastasis sites respectively, were lysed and spiked with three non-human proteins serving as internal standards. Following this, the samples were reduced and alkylated, digested with trypsin and subjected to peptide ICPL (isotope coded protein label) labeling. The two peptide containing samples were joined together followed by the affinity isolation of phospho- (using TiO2 metal affinity chromatography) and glycopeptides (oxidized glycans were bound on hydrazide resin). The enriched fraction as well as the flow-through were analyzed on a 2D-(SCX and C18-RP)-nano-HPLC system. The peptide identification and quantification was conducted using electrospray ion-trap mass spectrometer (Bruker, HCT-ultra). Validation of the differentially modulated proteins was conducted in several biological and technical replicates using the label free MSe based quantification strategy. This PTM based, novel relative protein quantification using post-digest ICPL has detected over 598 individual proteins. Of these more than 95 % have been successfully quantified. PTM enrichment methodologies allowed an isolation rate of 91 % and 50 % for phosphorylated and glycosylated proteins respectively. The detailed comparison of PC3 and LNCaP cells has shown specific overexpression of selected proteins indicating differences between these two prostate metastatic cell lines. Several of these modulated proteins have been previously described to be related to prostate cancer (e.g. annexin A2 and vimentin) while others could be considered as potentially novel. These proteins might be implicated in the fundamental process related to metastasis dissemination. However, because of the known discrepancy between cell systems and clinical material, the present study can be regarded only as a step towards elucidation of these complex interactions. [less ▲]

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