References of "Kischel, Philippe"
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See detailVersican overexpression in human breast cancer lesions: Known and new isoforms for stromal tumor targeting.
Kischel, Philippe ULg; Waltregny, David ULg; Dumont, Bruno ULg et al

in International Journal of Cancer = Journal International du Cancer (2010), 126(3), 640-50

Proteoglycans play a key role in cancer development and progression by participating in the constitution of a specific fertile tumor microenvironment. As they are largely overexpressed in the malignant ... [more ▼]

Proteoglycans play a key role in cancer development and progression by participating in the constitution of a specific fertile tumor microenvironment. As they are largely overexpressed in the malignant stroma, proteoglycans provide a reservoir of potential new targets for anticancer therapies, because they can serve to convey toxic payloads in the close proximity of cancer cells and subsequently destroy them. In this context, versican, a proteoglycan largely overexpressed in several solid cancers, bears the potential to be such an ideal target. As 4 main versican isoforms have been characterized, we sought to determine which isoform could represent the best target in human breast cancer. We used a series of 10 primary breast cancer lesions that were characterized as overexpressing the versican protein, when compared with matched normal breast tissues, using shotgun mass spectrometry and immunohistochemistry experiments. Quantitative polymerase chain reaction and western-blotting experiments were used to evaluate versican isoform expression in breast cancer/normal tissue pairs for which ARN quality was excellent. All known isoforms were significantly overexpressed in the malignant lesions, both at the mRNA and at the protein levels. In the course of this study, we also identified and cloned a new alternatively spliced versican isoform, referred to as V4, which was also found to be upregulated in human breast cancer. This study provides for the first time a comprehensive mRNA and protein analysis of versican isoforms expression in human breast tissues, and offers insights into which therapeutic strategy would be best suited to target versican in human breast cancer lesions. [less ▲]

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See detailCharacterization of an antibody panel for immunohistochemical analysis of canine muscle cells
Gofflot, Stéphanie ULg; Kischel, Philippe ULg; Thielen, Caroline ULg et al

in Veterinary Immunology and Immunopathology (2008), 125(3-4), 225-33

Immunohistochemistry is an indispensable tool in the assessment and characterization of lineage-specific differentiation of grafted cells in cell-based-therapy. This strategy is under investigation for ... [more ▼]

Immunohistochemistry is an indispensable tool in the assessment and characterization of lineage-specific differentiation of grafted cells in cell-based-therapy. This strategy is under investigation for the treatment of many muscle disorders and different animals such as dogs are used as models to study the tissue regeneration. The aim of the present study was to characterize an antibody panel for the analysis of canine muscle cells, useful in routinely processed formalin-fixed paraffin-embedded tissues. Overall, 12 antibodies (8 mouse monoclonal and 4 goat polyclonal), validated for use on human tissues tested for cross-reactivity on canine smooth muscle (bladder, intestine, and uterus), skeletal muscle and heart. Specific staining was achieved with eight antibodies, of which six were cytoplasmic markers (desmin, HDAC8, MHC, SMA, Troponin I and Troponin T) and two were cardiac nuclear markers (GATA-4 and Nkx-2.5). This antibody panel may be useful not only for the evaluation of cell-based therapies in muscle disorders, but also for the evaluation of canine soft tissue neoplasms in veterinary pathology. [less ▲]

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See detailCell membrane proteomic analysis identifies proteins differentially expressed in osteotropic human breast cancer cells.
Kischel, Philippe ULg; Guillonneau, Francois; Dumont, Bruno ULg et al

in Neoplasia : An International Journal for Oncology Research (2008), 10(9), 1014-20

Metastatic breast cancer cells are characterized by their high propensity to colonize the skeleton and form bone metastases, causing major morbidity and mortality. Identifying key proteins involved in the ... [more ▼]

Metastatic breast cancer cells are characterized by their high propensity to colonize the skeleton and form bone metastases, causing major morbidity and mortality. Identifying key proteins involved in the osteotropic phenotype would represent a major step toward the development of both new prognostic markers and new effective therapies. Cell surface proteins differentially expressed in cancer cells are preferred potential targets for antibody-based targeted therapies. In this study, using cell surface biotinylation and a mass spectrometric approach, we have compared the profile of accessible cell surface proteins between the human breast cancer cell line MDA-MB-231 and its highly osteotropic B02 subclone. This strategy allowed the identification of several proteins either up- or downregulated in the osteotropic cell line, and differential protein expressions were validated using antibody-based techniques. Class I HLAs were down-regulated in the bone metastatic variant, whereas alpha(v)beta(3) integrins, among others, were consistently up-regulated in this latter cell line. These results show that comprehensive profiling of the cell surface proteome of mother cancerous cell lines and derived organ-specific metastatic cell lines provides an effective approach for the identification of potential accessible marker proteins for both prognosis and antibody-based targeted therapies. [less ▲]

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See detailIdentification of new accessible tumor antigens in human colon cancer by ex vivo protein biotinylation and comparative mass spectrometry analysis.
Conrotto, Paolo; Roesli, Cristof; Rybak, Jascha et al

in International Journal of Cancer = Journal International du Cancer (2008), 123(12), 2856-2864

One of the most promising new strategies for the development of efficacious cancer therapies relies on the targeted delivery of biopharmaceutical to the tumor environment by the use of selective and ... [more ▼]

One of the most promising new strategies for the development of efficacious cancer therapies relies on the targeted delivery of biopharmaceutical to the tumor environment by the use of selective and specific antibodies. The identification of accessible perivascular proteins selectively overexpressed in cancer tissue may facilitate the development of antibody-based biopharmaceutical administration. This approach is potentially highly selective and specific, combining the presence of tumor biomarkers readily accessible from the blood vessels and the high rate of angiogenesis characteristic of cancer tissues. We performed ex vivo perfusions of surgically resected human colon cancer using a reactive ester derivative of biotin, thus achieving a selective covalent modification of accessible proteins in vascular structures and stroma. After extraction and purification, biotinylated proteins were digested and the resulting peptides submitted to a comparative mass spectrometry-based proteomic analysis, revealing quantitative differences between normal and cancer colon. Sixty-seven of the total 367 proteins identified were found to be preferentially expressed at the tumor site. We generated human monoclonal antibodies against 2 potential tumor targets, NGAL and GW112, and we proved their selective expression in cancer colon and not or barely in healthy tissues. This article presents the first proteomic analysis of human colorectal cancer structures readily accessible from the tumor vasculature, revealing the overexpression of novel tumor antigens which may serve as selective targets for antibody-based imaging and therapeutic biomolecular strategies. (c) 2008 Wiley-Liss, Inc. [less ▲]

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See detailIdentification of accessible human cancer biomarkers using ex vivo chemical proteomic strategies
Kischel, Philippe ULg; Waltregny, David ULg; Castronovo, Vincenzo ULg

in Expert Review of Proteomics (2007), 4(6), 727-739

One promising avenue towards the development of more selective, better anticancer drugs lies in the targeted delivery of bioactive compounds to the tumor environment by means of binding molecules specific ... [more ▼]

One promising avenue towards the development of more selective, better anticancer drugs lies in the targeted delivery of bioactive compounds to the tumor environment by means of binding molecules specific for tumor-associated biomarkers. Eligibility of such markers for therapeutic ideally use three criteria: accessibility from the bloodstream; expression at sufficient level, and no (or much lower) expression in normal tissues. Most current discovery strategies (such as biomarker searching into body fluids) provide no clue as to whether proteins of interest are accessible, in human tissues, to suitable high-affinity ligands, such as systemically delivered monoclonal antibodies. To address this limitation, our group recently developed two methodologies based on chemical proteomic modifications, enabling the discovery of proteins accessible from the bloodstream and the extracellular space in human pathological tissues. In this review, we will discuss the potential benefits of these methodologies for the fast discovery of therapeutically valuable biomarkers. [less ▲]

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See detailIdentification of specific reachable molecular targets in human breast cancer using a versatile ex vivo proteomic method
Castronovo, Vincenzo ULg; Kischel, Philippe ULg; Guillonneau, Francois et al

in Proteomics (2007), 7(8), 1188-1196

Targeting of tumoral tissues is one of the most promising approaches to improve both the efficacy and safety of anticancer treatments. The identification of valid targets, including proteins specifically ... [more ▼]

Targeting of tumoral tissues is one of the most promising approaches to improve both the efficacy and safety of anticancer treatments. The identification of valid targets, including proteins specifically and abundantly expressed in cancer lesions, is of utmost importance. Despite state-of-the-art technologies, the discovery of cancer-associated target proteins still faces the limitation, in human tissues, of antigen accessibility to suitable high-affinity ligands such as human mAb bound to bioactive molecules. Terminal perfusion of tumor-bearing mice or ex vivo perfusion of human cancer-bearing organs with a reactive biotin ester solution has successfully led to the identification of novel accessible biomarkers. This methodology is however restricted to perfusable organs, and excludes most of the tissues of interest to targeted therapies, e.g. primary breast cancer and metastases. Herein, we report on the development of a new chemical proteomic method that bypasses the perfusion step and thus offers the potential to identify accessible molecular targets in virtually all types of animal and human tissues. We have validated our new procedure by identifying biomarkers selectively expressed in human breast carcinoma. Overall, this powerful technology may lay the ground not only for custom-made therapies in cancer, but also for the development of therapies that need to be selectively delivered in a specific tissue. [less ▲]

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See detailA chemical proteomics approach for the identification of accessible antigens expressed in human kidney cancer
Castronovo, Vincenzo ULg; Waltregny, David ULg; Kischel, Philippe ULg et al

in Molecular & Cellular Proteomics (2006), 5(11), 2083-2091

A promising avenue toward the development of more selective anticancer drugs consists in the targeted delivery of bioactive molecules to the tumor environment by means of binding molecules specific to ... [more ▼]

A promising avenue toward the development of more selective anticancer drugs consists in the targeted delivery of bioactive molecules to the tumor environment by means of binding molecules specific to tumor-associated markers. We have used a chemical proteomics approach based on the ex vivo perfusion and biotinylation of accessible structures within surgically resected human kidneys with tumor to gain information about accessible and abundant antigens that are overexpressed in human cancer. This procedure led to the selective labeling with biotin of vascular structures. Biotinylated proteins were purified on streptavidin resin and identified using mass spectrometric methodologies, revealing 637 proteins, 184 of which were only found in tumor specimens and 223 of which were only found in portions of normal kidneys. Immunohistochemical and PCR analysis confirmed that several of the putative cancer antigens identified in this study are indeed preferentially expressed in tumors. In conclusion, we have developed a methodology that allows the identification of accessible biomarkers in human tissues. The tumor-associated antigens identified in this study may be suitable targets for antibody-based anticancer therapies. The experimental approach described here should be applicable to other surgical specimens and to other pathologies as well as to the study of basic physiological and immunological processes. [less ▲]

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See detailExpression and functional properties of four slow skeletal troponin T isoforms in rat muscles
Kischel, Philippe ULg; Bastide, Bruno; Muller, Marc ULg et al

in American Journal of Physiology - Cell Physiology (2005), 289(2), 437-443

We investigated the expression and functional properties of slow skeletal troponin T(sTnT) isoforms in rat skeletal muscles. Four sTnT cDNAs were cloned from the slow soleus muscle. Three isoforms were ... [more ▼]

We investigated the expression and functional properties of slow skeletal troponin T(sTnT) isoforms in rat skeletal muscles. Four sTnT cDNAs were cloned from the slow soleus muscle. Three isoforms were found to be similar to sTnT1, sTnT2, and sTnT3 isoforms described in mouse muscles. A new rat isoform, with a molecular weight slightly higher than that of sTnT3, was discovered. This fourth isoform had never been detected previously in any skeletal muscle and was therefore called sTnTx. From both expression pattern and functional measurements, it appears that sTnT isoforms can be separated into two classes, high-molecular-weight ( sTnT1, sTnT2) and low-molecular-weight ( sTnTx, sTnT3) isoforms. By comparison to the apparent migration pattern of the four recombinant sTnT isoforms, the newly described low-molecular-weight sTnTx isoform appeared predominantly and typically expressed in fast skeletal muscles, whereas the higher-molecular-weight isoforms were more abundant in slow soleus muscle. The relative proportion of the sTnT isoforms in the soleus was not modified after exposure to hindlimb unloading (HU), known to induce a functional atrophy and a slow-to-fast isoform transition of several myofibrillar proteins. Functional data gathered from replacement of endogenous troponin complexes in skinned muscle fibers showed that the sTnT isoforms modified the Ca2+ activation characteristics of single skeletal muscle fibers, with sTnT2 and sTnT1 conferring a similar increase in Ca2+ affinity higher than that caused by low-molecular-weight isoforms sTnTx and sTnT3. Thus we show for the first time the presence of sTnT in fast muscle fibers, and our data show that the changes in neuromuscular activity on HU are insufficient to alter the sTnT expression pattern. [less ▲]

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See detailDe novo backbone and sequence design of an idealized alpha/beta-barrel protein: Evidence of stable tertiary structure
Offredi, Fabrice; Dubail, Fabien; Kischel, Philippe ULg et al

in Journal of Molecular Biology (2003), 325(1), 163-174

We have designed, synthesized, and characterized a 216 amino acid residue sequence encoding a putative idealized alpha/beta-barrel protein. The design was elaborated in two steps. First, the idealized ... [more ▼]

We have designed, synthesized, and characterized a 216 amino acid residue sequence encoding a putative idealized alpha/beta-barrel protein. The design was elaborated in two steps. First, the idealized backbone was defined with geometric parameters representing our target fold: a central eight parallel-stranded beta-sheet surrounded by eight parallel alpha-helices, connected together with short structural turns on both sides of the barrel. An automated sequence selection algorithm, based on the dead-end elimination theorem, was used to find the optimal amino acid sequence fitting the target structure. A synthetic gene coding for the designed sequence was constructed and the recombinant artificial protein was expressed in bacteria, purified and characterized. Far-UV CD spectra with prominent bands at 222nm and 208nm revealed the presence of alpha-helix secondary structures (50%) in fairly good agreement with the model. A pronounced absorption band in the near-UV CD region, arising from immobilized aromatic side-chains, showed that the artificial protein is folded in solution. Chemical unfolding monitored by tryptophan fluorescence revealed a conformational stability (DeltaG(H2O)) of 35kJ/mol. Thermal unfolding monitored by near-UV CD revealed a cooperative transition with an apparent T(m) of 65 degrees C. Moreover, the artificial protein did not exhibit any affinity for the hydrophobic fluorescent probe 1-anilinonaphthalene-8-sulfonic acid (ANS), providing additional evidence that the artificial barrel is not in the molten globule state, contrary to previously designed artificial alpha/beta-barrels. Finally, 1H NMR spectra of the folded and unfolded proteins provided evidence for specific interactions in the folded protein. Taken together, the results indicate that the de novo designed alpha/beta-barrel protein adopts a stable three-dimensional structure in solution. These encouraging results show that de novo design of an idealized protein structure of more than 200 amino acid residues is now possible, from construction of a particular backbone conformation to determination of an amino acid sequence with an automated sequence selection algorithm. [less ▲]

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See detailPattern recognition with a digital holographic microscope working in partially coherent illumination
Dubois, Frank; Minetti, Christophe; Monnom, Olivier et al

in Applied Optics (2002), 41(20), 4108-4119

We describe the implementation of the automatic spatial-frequency-selection filter for recognition of patterns obtained with a digital holographic microscope working with a partially coherent source. The ... [more ▼]

We describe the implementation of the automatic spatial-frequency-selection filter for recognition of patterns obtained with a digital holographic microscope working with a partially coherent source. The microscope provides the complex-optical-amplitude field that allows a refocusing plane-by-plane of the sample under investigation by numerical computation of the optical propagation. By inserting a correlation filter in the propagation equation, the correlation between the filter and the propagated optical field is obtained. In this way, the pattern is located in the direction of the optical axis. Owing to the very weak noise level generated by the partially coherent source, the correlation process is shift invariant. Therefore the samples can be located in the three dimensions. To have a robust recognition process, a generalized version of the automatic spatial-frequency-selection filters has been implemented. The method is experimentally demonstrated in a two-class problem for the recognition of protein crystals. (C) 2002 Optical Society of America. [less ▲]

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