References of "Fleron, Maximilien"
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See detailAnti-PSMA antibody-coupled gold nanorods detection by optical and electron microscopies
Schol, Daureen ULg; Fléron, Maximilien ULg; Greisch, Jean françois et al

in Micron (2013), (50), 68-74

While cancer is one of the greatest challenges to public health care, prostate cancer was chosen as cancer model to develop a more accurate imaging assessment than those currently available. Indeed, an ... [more ▼]

While cancer is one of the greatest challenges to public health care, prostate cancer was chosen as cancer model to develop a more accurate imaging assessment than those currently available. Indeed, an efficient imaging technique which considerably improves the sensitivity and specificity of the diagnostic and predicting the cancer behavior would be extremely valuable. The concept of optoacoustic imaging using home-made functionalized gold nanoparticles coupled to an antibody targeting PSMA (prostate specific membrane antigen) was evaluated on different cancer cell lines to demonstrate the specificity of the designed platform. [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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See detailFunctionalized plasmonic gold nanoparticles for optoacoustic cancer detection
Schol, Daureen ULg; Fleron, Maximilien ULg; Greisch, Jean-François et al

Poster (2008, September 12)

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See detailOptoacoustic specific detection of prostate cancer using functionalized gold nanorods
Schol, Daureen ULg; Fleron, Maximilien ULg; Greisch, Jean-François et al

Poster (2008, March 12)

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See detailProteome alteration induced by hTERT transfection of human fibroblast cells
Mazzucchelli, Gabriel ULg; Gabelica, Valérie ULg; Smargiasso, Nicolas ULg et al

in Proteome Science (2008), 6(1), 12

Background: Telomerase confers cellular immortality by elongating telomeres, thereby circumventing the Hayflick limit. Extended-life-span cells have been generated by transfection with the human ... [more ▼]

Background: Telomerase confers cellular immortality by elongating telomeres, thereby circumventing the Hayflick limit. Extended-life-span cells have been generated by transfection with the human telomerase reverse transcriptase (hTERT) gene. hTERT transfected cell lines may be of outstanding interest to monitor the effect of drugs targeting the telomerase activity. The incidence of hTERT gene transfection at the proteome level is a prerequisite to that purpose. The effect of the transfection has been studied on the proteome of human fibroblast (W138). Cytosolic and nuclear fractions of W138 cells, empty vector transfected W138 (W138-HPV) and hTERT W138 cells were submitted to a 2D-DIGE (Two-Dimensional Differential In-Gel Electrophoresis) analysis. Only spots that had a similar abundance in W138 and W138-HPV, but were differentially expressed in W138 hTERT were selected for MS identification. This method directly points to the proteins linked with the hTERT expression. Number of false positive differentially expressed proteins has been excluded by using control W138-HPV cells. The proteome alteration induced by hTERT W138 transfection should be taken into account in subsequent use of the cell line for anti-telomerase drugs evaluation. Results: 2D-DIGE experiment shows that 57 spots out of 2246 are significantly differentially expressed in the cytosolic fraction due to hTERT transfection, and 38 were confidently identified. In the nuclear fraction, 44 spots out of 2172 were selected in the differential proteome analysis, and 14 were identified. The results show that, in addition to elongating telomeres, hTERT gene transfection has other physiological roles, among which an enhanced ER capacity and a potent cell protection against apoptosis. Conclusion: We show that the methodology reduces the complexity of the proteome analysis and highlights proteins implicated in other processes than telomere elongation. hTERT induced proteome changes suggest that telomerase expression enhances natural cell repair mechanisms and stress resistance probably required for long term resistance of immortalized cells. Thus, hTERT transfected cells can not be only consider as an immortal equivalent to parental cells but also as cells which are over-resistant to stresses. These findings are the prerequisite for any larger proteomics aiming to evaluate anti-telomerase drugs proteome alteration and thus therapeutics induced cell reactions. [less ▲]

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See detailLNCaP prostate cancer imaging with biologically functionalized gold nanoparticles in 2D and 3D cell culture
Schol, Daureen ULg; Fleron, Maximilien ULg; Greisch, Jean - François et al

in Anticancer Research (2008), 28

One of the main objectives of this project is to realize and validate a versatile lab system composed of functionalized nanoparticles for diagnosis of different superficial and accessible cancers, e.g ... [more ▼]

One of the main objectives of this project is to realize and validate a versatile lab system composed of functionalized nanoparticles for diagnosis of different superficial and accessible cancers, e.g. prostate cancer. Gold nanorods have been synthesized and functionalized with antibodies targeting specific antigens on cancer cell lines. [less ▲]

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See detailOptoacoustic specific detection of prostate cancer using functionalized gold nanorods
Fleron, Maximilien ULg; Schol, Daureen ULg; Greisch, Jean-François et al

Poster (2007, November 16)

A major challenge in prostate cancer oncology is to develop more accurate imaging assessments than those currently available. Indeed, an efficient imaging technique which significantly improves the ... [more ▼]

A major challenge in prostate cancer oncology is to develop more accurate imaging assessments than those currently available. Indeed, an efficient imaging technique which significantly improves the sensitivity and specificity of the diagnostic and predicting the cancer behaviour would be extremely valuable. This project intends to prove the concept of using optoacoustic imaging in combination with biologically functionalized nanoparticles as an integrated biosensor based system for the production of specific and sensitive data for accurate diagnosis of prostate cancer. This concept results on the use of contrast agents which transform an incident luminous energy into local heating inducing a pressure wave detectable by acoustic (echography). For the optoacoustic detection, the nanoparticles used must present a maximum of absorption in the optical transparency window of the human tissues in order to allow their and subsequently the tissue specific excitations while avoiding unwanted destructive energy transfers. According to these characteristics (energy transfer by thermoelastic reaction), rod-like gold nanoparticles (stick form) with a maximum of absorption towards 760 nm were produced by using a “bottom-up” approach with dynamic templates (surfactant). These nanoparticles are then coupled with an antibody directed against the cancerous cells to guarantee the specific detection of the particles. The development of the biosensor is firstly performed to target the Prostate Specific Membrane Antigen (PSMA), a transmembrane protein considered as a suitable biomarker for prostate cancer. Detection and localisation of PSMA on LNCaP fixed cell surface was performed by immunostainning on monolayer cell culture and on spheroid slices. Then, by backscattered electron (BSE) microscopy analysis and two-photon luminescence imaging, detection of nanoparticles on fixed and living cell surface shows the successful binding of the biosensor to the cells expressing PSMA. In prospect, the detection of the biosensor will be tested on spheroids, on human biopsies and finally on in vivo models (mouse xenograft models). [less ▲]

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See detailOptoacoustic specific detection of prostate cancer using functionalized gold nanorods
Fleron, Maximilien ULg; Schol, Daureen ULg; Greisch, Jean-François et al

Poster (2007, October 10)

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See detailDevelopment of a new integrated biosensor system for an accurate diagnosis of prostate cancer using optoacoustic detection
Fleron, Maximilien ULg; Schol, Daureen ULg; Greisch, Jean-François et al

Poster (2007, June 09)

The prostate cancer is the most common male-specific cancer observed in the European Union and is the second leading cause of cancer death in men in our industrialized countries. The choice of treatment ... [more ▼]

The prostate cancer is the most common male-specific cancer observed in the European Union and is the second leading cause of cancer death in men in our industrialized countries. The choice of treatment and its efficiency is largely dependent on the stage and on the degree of advancement of the cancer when it is diagnosed. Screening procedures like digital rectal examination (DRE) and free prostate specific antigen (PSA) level testing are well established but lack accuracy, yielding only 80% of prostate cancers diagnosed in an early stage. By providing a more accurate and precise tool for diagnosing prostate cancer in its early stages, the percentage of curable cancer patients would increase radically. Current imaging techniques have limited value, thus a major challenge in current prostate cancer oncology is to develop more accurate imaging assessments. An efficient imaging technique which significantly improves the sensitivity and specificity of diagnosing, staging and predicting the behaviour of prostate cancer would be extremely valuable. The ADONIS Project intends to prove the concept of using optoacoustic imaging in combination with biologically functionalized nanoparticles as an integrated biosensor based system for the production of specific and sensitive data for accurate diagnosis of prostate cancer. The achievement of this objective requires excellent know-how on a variety of scientific and technologic fields, brought by the partners of ADONIS, coming from five European countries, such as laser and ultrasound technologies and image reconstruction techniques, the bio-functionalization of nanoparticles, the system integration and, finally, experiments and competent evaluation of the results for their application potential. The development of the biosensor is firstly performed to target the Prostate Specific Membrane Antigen (PSMA), a transmembrane protein considered as a suitable biomarker for prostate cancer and which is under intense investigation for use as an imaging and therapeutic target. To allow the detection optimization of the biosensor, a 3D cellular culture technique (Rotating Cell Culture System) is developed with LNCaP cells (a human prostate carcinoma cell line reported to express PSMA) to be closest to the in vivo aspect for which a three-dimensional aspect of tumor for the biosensor detection is needed. Detection and localisation of PSMA on LNCaP cell surface was performed by immunostainning on monolayer culture and on spheroid slices. Then, by backscattered electron (BSE) microscopy analysis, detection of nanoparticles on cells surface shows the successful binding of the biosensor to the cells expressing PSMA. In prospect, the detection of the biosensor will be tested on large spheroids and finally tested on in vivo model. [less ▲]

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See detailOverview on the ADONIS Project: Accurate Diagnosis of prostate cancer using Optoacoustic detection of biologically functionalized gold Nanoparticles - A new Integrated Biosensor System
Fleron, Maximilien ULg; Schol, Daureen ULg; Greisch, Jean-François et al

Poster (2007, March 21)

Overview on the ADONIS Project: Accurate Diagnosis of prostate cancer using Optoacoustic detection of biologically functionalized gold Nanoparticles - A new Integrated Biosensor System

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