Claire Bouvard - Academia.edu (original) (raw)

Papers by Claire Bouvard

Research paper thumbnail of Low-Molecular-Weight Fucoidan Induces Endothelial Cell Migration via the PI3K/AKT Pathway and Modulates the Transcription of Genes Involved in Angiogenesis

Marine Drugs, 2015

Low-molecular-weight fucoidan (LMWF) is a sulfated polysaccharide extracted from brown seaweed th... more Low-molecular-weight fucoidan (LMWF) is a sulfated polysaccharide extracted from brown seaweed that presents antithrombotic and pro-angiogenic properties. However, its mechanism of action is not well-characterized. Here, we studied the effects of LMWF on cell signaling and whole genome expression in human umbilical vein endothelial cells and endothelial colony forming cells. We observed that LMWF and vascular endothelial growth factor had synergistic effects on cell signaling, and more interestingly that LMWF by itself, in the absence of other growth factors, was able to trigger the activation of the PI3K/AKT pathway, which plays a crucial role in angiogenesis and vasculogenesis. We also observed that the effects of LMWF on cell migration were PI3K/AKT-dependent and that LMWF modulated the expression of genes involved at different levels of the neovessel formation process, such as cell migration and cytoskeleton organization, cell mobilization and homing. This provides a better understanding of LMWF's mechanism of action and confirms that it could be an interesting therapeutic approach for vascular repair.

Research paper thumbnail of Cancer stem cells as a target population for drug discovery

Future Medicinal Chemistry, 2014

for Cancer stem cells (CSCs) have been identified in a growing list of malignancies and are belie... more for Cancer stem cells (CSCs) have been identified in a growing list of malignancies and are believed to be responsible for cancer initiation, metastasis and relapse following certain therapies, even though they may only represent a small fraction of the cells in a given cancer. Like somatic stem cells and embryonic stem cells, CSCs are capable of self-renewal and differentiation into more mature, less tumorigenic cells that make up the bulk populations of cancer cells. Elimination of CSCs promises intriguing therapeutic potential and this concept has been adopted in preclinical drug discovery programs. Herein we will discuss the progress of these efforts, general considerations in practice, major challenges and possible solutions.

Research paper thumbnail of Targeting Human C-Type Lectin-like Molecule-1 (CLL1) with a Bispecific Antibody for Immunotherapy of Acute Myeloid Leukemia

Angewandte Chemie International Edition, 2014

Acute myeloid leukemia (AML), which is the most common acute adult leukemia and the second most c... more Acute myeloid leukemia (AML), which is the most common acute adult leukemia and the second most common pediatric leukemia, still has a poor prognosis. Human C-type lectin-like molecule-1 (CLL1) is a recently identified myeloid lineage restricted cell surface marker, which is overexpressed in over 90% of AML patient myeloid blasts and in leukemic stem cells. Here, we describe the synthesis of a novel bispecific antibody, αCLL1-αCD3, using the genetically encoded unnatural amino acid, p-acetylphenylalanine. The resulting αCLL1-αCD3 recruits cytotoxic T cells to CLL1 positive cells, and demonstrates potent and selective cytotoxicity against several human AML cell lines and primary AML patient derived cells in vitro. Moreover, αCLL1-αCD3 treatment completely eliminates established tumors in an U937 AML cell line xenograft model. These results validate the clinical potential of CLL1 as an AML-specific antigen for the generation of a novel immunotherapeutic for AML.

Research paper thumbnail of Conditional ablation of alpha6 integrin subunit in mouse endothelium reduces post-ischemic angiogenesis

Vascular Pharmacology, 2012

Research paper thumbnail of Arterioscler Thromb Vasc Biol-2010-Bouvard-1569-75

Research paper thumbnail of ATV200582-supplement material

Research paper thumbnail of Tie2-dependent deletion of α6 integrin subunit in mice reduces tumor growth and angiogenesis

International Journal of Oncology, 2014

The α6 integrin subunit (α6) has been implicated in cancer cell migration and in the progression ... more The α6 integrin subunit (α6) has been implicated in cancer cell migration and in the progression of several malignancies, but its role in tumor angiogenesis is unclear. In mice, anti-α6 blocking antibodies reduce tumor angiogenesis, whereas Tie1-dependent α6 gene deletion enhances neovessel formation in melanoma and lung carcinoma. To clarify the discrepancy in these results we used the cre-lox system to generate a mouse line, α6fl/fl-Tie2Cre + , with α6 gene deletion specifically in Tie2-lineage cells: endothelial cells, pericytes, subsets of hematopoietic stem cells, and Tie2-expressing monocytes/macrophages (TEMs), known for their proangiogenic properties. Loss of α6 expression in α6fl/fl-Tie2Cre + mice reduced tumor growth in a murine B16F10 melanoma model. Immunohistological analysis of the tumors showed that Tie2-dependent α6 gene deletion was associated with reduced tumor vascularization and with reduced infiltration of proangiogenic Tie2-expressing macrophages. These findings demonstrate that α6 integrin subunit plays a major role in tumor angiogenesis and TEM infiltration. Targeting α6 could be used as a strategy to reduce tumor growth.

Research paper thumbnail of Tie2-dependent knockout of  6 integrin subunit in mice reduces post-ischaemic angiogenesis

Cardiovascular Research, 2012

Integrins a6b1 and a6b4 are receptors for laminins, the main components of the basement membrane ... more Integrins a6b1 and a6b4 are receptors for laminins, the main components of the basement membrane underlying the endothelial cells. In vitro, a6 integrin subunit (a6) expression at the surface of endothelial cells and their progenitors (EPCs) is up-regulated by pro-angiogenic growth factors and is crucial for adhesion, migration, and pseudotube formation. We investigated the role for a6 in post-ischaemic vascular repair in vivo.

Research paper thumbnail of  6-Integrin Subunit Plays a Major Role in the Proangiogenic Properties of Endothelial Progenitor Cells

Arteriosclerosis, Thrombosis, and Vascular Biology, 2010

Research paper thumbnail of Endothelial podosome rosettes regulate vascular branching in tumour angiogenesis

Nature Cell Biology, 2014

Research paper thumbnail of Low-Molecular-Weight Fucoidan Induces Endothelial Cell Migration via the PI3K/AKT Pathway and Modulates the Transcription of Genes Involved in Angiogenesis

Marine Drugs, 2015

Low-molecular-weight fucoidan (LMWF) is a sulfated polysaccharide extracted from brown seaweed th... more Low-molecular-weight fucoidan (LMWF) is a sulfated polysaccharide extracted from brown seaweed that presents antithrombotic and pro-angiogenic properties. However, its mechanism of action is not well-characterized. Here, we studied the effects of LMWF on cell signaling and whole genome expression in human umbilical vein endothelial cells and endothelial colony forming cells. We observed that LMWF and vascular endothelial growth factor had synergistic effects on cell signaling, and more interestingly that LMWF by itself, in the absence of other growth factors, was able to trigger the activation of the PI3K/AKT pathway, which plays a crucial role in angiogenesis and vasculogenesis. We also observed that the effects of LMWF on cell migration were PI3K/AKT-dependent and that LMWF modulated the expression of genes involved at different levels of the neovessel formation process, such as cell migration and cytoskeleton organization, cell mobilization and homing. This provides a better understanding of LMWF's mechanism of action and confirms that it could be an interesting therapeutic approach for vascular repair.

Research paper thumbnail of Cancer stem cells as a target population for drug discovery

Future Medicinal Chemistry, 2014

for Cancer stem cells (CSCs) have been identified in a growing list of malignancies and are belie... more for Cancer stem cells (CSCs) have been identified in a growing list of malignancies and are believed to be responsible for cancer initiation, metastasis and relapse following certain therapies, even though they may only represent a small fraction of the cells in a given cancer. Like somatic stem cells and embryonic stem cells, CSCs are capable of self-renewal and differentiation into more mature, less tumorigenic cells that make up the bulk populations of cancer cells. Elimination of CSCs promises intriguing therapeutic potential and this concept has been adopted in preclinical drug discovery programs. Herein we will discuss the progress of these efforts, general considerations in practice, major challenges and possible solutions.

Research paper thumbnail of Targeting Human C-Type Lectin-like Molecule-1 (CLL1) with a Bispecific Antibody for Immunotherapy of Acute Myeloid Leukemia

Angewandte Chemie International Edition, 2014

Acute myeloid leukemia (AML), which is the most common acute adult leukemia and the second most c... more Acute myeloid leukemia (AML), which is the most common acute adult leukemia and the second most common pediatric leukemia, still has a poor prognosis. Human C-type lectin-like molecule-1 (CLL1) is a recently identified myeloid lineage restricted cell surface marker, which is overexpressed in over 90% of AML patient myeloid blasts and in leukemic stem cells. Here, we describe the synthesis of a novel bispecific antibody, αCLL1-αCD3, using the genetically encoded unnatural amino acid, p-acetylphenylalanine. The resulting αCLL1-αCD3 recruits cytotoxic T cells to CLL1 positive cells, and demonstrates potent and selective cytotoxicity against several human AML cell lines and primary AML patient derived cells in vitro. Moreover, αCLL1-αCD3 treatment completely eliminates established tumors in an U937 AML cell line xenograft model. These results validate the clinical potential of CLL1 as an AML-specific antigen for the generation of a novel immunotherapeutic for AML.

Research paper thumbnail of Conditional ablation of alpha6 integrin subunit in mouse endothelium reduces post-ischemic angiogenesis

Vascular Pharmacology, 2012

Research paper thumbnail of Arterioscler Thromb Vasc Biol-2010-Bouvard-1569-75

Research paper thumbnail of ATV200582-supplement material

Research paper thumbnail of Tie2-dependent deletion of α6 integrin subunit in mice reduces tumor growth and angiogenesis

International Journal of Oncology, 2014

The α6 integrin subunit (α6) has been implicated in cancer cell migration and in the progression ... more The α6 integrin subunit (α6) has been implicated in cancer cell migration and in the progression of several malignancies, but its role in tumor angiogenesis is unclear. In mice, anti-α6 blocking antibodies reduce tumor angiogenesis, whereas Tie1-dependent α6 gene deletion enhances neovessel formation in melanoma and lung carcinoma. To clarify the discrepancy in these results we used the cre-lox system to generate a mouse line, α6fl/fl-Tie2Cre + , with α6 gene deletion specifically in Tie2-lineage cells: endothelial cells, pericytes, subsets of hematopoietic stem cells, and Tie2-expressing monocytes/macrophages (TEMs), known for their proangiogenic properties. Loss of α6 expression in α6fl/fl-Tie2Cre + mice reduced tumor growth in a murine B16F10 melanoma model. Immunohistological analysis of the tumors showed that Tie2-dependent α6 gene deletion was associated with reduced tumor vascularization and with reduced infiltration of proangiogenic Tie2-expressing macrophages. These findings demonstrate that α6 integrin subunit plays a major role in tumor angiogenesis and TEM infiltration. Targeting α6 could be used as a strategy to reduce tumor growth.

Research paper thumbnail of Tie2-dependent knockout of  6 integrin subunit in mice reduces post-ischaemic angiogenesis

Cardiovascular Research, 2012

Integrins a6b1 and a6b4 are receptors for laminins, the main components of the basement membrane ... more Integrins a6b1 and a6b4 are receptors for laminins, the main components of the basement membrane underlying the endothelial cells. In vitro, a6 integrin subunit (a6) expression at the surface of endothelial cells and their progenitors (EPCs) is up-regulated by pro-angiogenic growth factors and is crucial for adhesion, migration, and pseudotube formation. We investigated the role for a6 in post-ischaemic vascular repair in vivo.

Research paper thumbnail of  6-Integrin Subunit Plays a Major Role in the Proangiogenic Properties of Endothelial Progenitor Cells

Arteriosclerosis, Thrombosis, and Vascular Biology, 2010

Research paper thumbnail of Endothelial podosome rosettes regulate vascular branching in tumour angiogenesis

Nature Cell Biology, 2014