References of "Noël, Agnès"
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See detailFunctional analysis of dual-specificity protein phosphatases in angiogenesis
Amand, Mathieu; ERPICUM, Charlotte ULg; Gilles, Christine ULg et al

in Pulido, Rafael (Ed.) Protein Tyrosine Phosphatases: Methods and Protocols (in press)

Therapeutic perspectives targeting angiogenesis in cancer stimulated an intense investigation of the mechanisms triggering and governing angiogenic processes. Several publications have highlighted the ... [more ▼]

Therapeutic perspectives targeting angiogenesis in cancer stimulated an intense investigation of the mechanisms triggering and governing angiogenic processes. Several publications have highlighted the importance of typical dual-specificity phosphatases (DSPs) or MKPs in endothelial cells and their role in controlling different biological functions implicated in angiogenesis such as migration, proliferation, apoptosis, tubulogenesis and cell adhesion. However, among atypical DSPs, the only one investigated in angiogenesis was DUSP3. We recently identified this DSP as new key player in endothelial cells and angiogenesis. In this chapter we provide with detailed protocols and models used to investigate the role of DUSP3 in endothelial cells and angiogenesis. We start the chapter with an overview of the role of several DSPs in angiogenesis. We continue with providing a full description of a highly efficient transfection protocol to deplete DUSP3 using small interfering RNA (siRNA) in the primary Human Umbilical Vein Endothelial Cells (HUVEC). We next describe the major assays used to investigate different processes involved in angiogenesis such as tube formation assay, proliferation assay and spheroids sprouting assay. We finish the chapter by validating our results in DUSP3-knockout mice using in vivo angiogenesis assays such as Matrigel plug and Lewis lung carcinoma cell subcutaneous xenograft model followed by anti-CD31 immunofluorescence and ex vivo aortic ring assay. All methods described can be adapted to other phosphatases and signaling molecules. [less ▲]

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See detailEstetrol Attenuates Neonatal Hypoxic-Ischemic Encephalopathy: Preclinical Studies
Tskitishvili, Ekaterine ULg; Nisolle, Michelle ULg; Noël, Agnès ULg et al

Poster (2016, June 17)

Brain hypoxia and ischemia due to systemic hypoxemia and reduced cerebral blood flow (CBF) are the primary causes of neonatal hypoxic-ischemic encephalopathy (HIE) accompanied by gray and white matter ... [more ▼]

Brain hypoxia and ischemia due to systemic hypoxemia and reduced cerebral blood flow (CBF) are the primary causes of neonatal hypoxic-ischemic encephalopathy (HIE) accompanied by gray and white matter injuries occurring in neonates. Perinatal HIE still remains a challenge in perinatal medicine. About 20% of affected newborns die in the postnatal period, and an additional 25% will sustain childhood disabilities. So far no medical treatment provides important neuroprotection against HIE. Studies of new neuroprotective agents in animal models of HIE may have importance for the development of new compounds and treatment strategies for this pathological condition. Estetrol (E4) is a recently described estrogen with four hydroxyl-groups that is synthesized exclusively during pregnancy by the human fetal liver. It has important antioxidative activity. To study the neuroprotective and therapeutic effects of E4 in vivo neonatal HIE model of 7-day-old newborn rat pups was used. Rat pups body temperatures were examined along with their body and brain weights. Brains were studied at the level of the hippocampus and cortex. Intact cell counting and expressions of markers for neuronal cell viability (microtubule-associated protein-2 (MAP-2)), neurogenesis (doublecortin (DCX)) and angiogenesis (vascular-endothelial growth factor (VEGF)) were evaluated by histo- and immunohistochemistry. The serum levels of brain damage markers (S100B and glial fibrillary acidic protein (GFAP)) were measured by ELISA. Our results demonstrate for the first time that E4 has a significant neuroprotective and therapeutic effects. It decreases the early gray matter loss and promotes neuro- and angiogenesis in vivo. Estetrol treatment has no effects on body weight, brain weight or body temperature. Taken together, E4 might become an important safe and physiological substance to treat neonatal HIE. [less ▲]

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See detailNovel application assigned to toluquinol: inhibition of lymphangiogenesis by interfering with VEGF-C/VEGFR-3 signaling pathway.
Garcia-Caballero, Melissa; BLACHER, Silvia ULg; Paupert, J. et al

in British Journal of Pharmacology (2016), 173(12), 1966-87

BACKGROUND AND PURPOSE: Lymphangiogenesis is an important biological process associated with the pathogenesis of several diseases, including metastatic dissemination, graft rejection, lymphedema and other ... [more ▼]

BACKGROUND AND PURPOSE: Lymphangiogenesis is an important biological process associated with the pathogenesis of several diseases, including metastatic dissemination, graft rejection, lymphedema and other inflammatory disorders. The development of new drugs blocking lymphangiogenesis has become a promising therapeutic strategy. In this study, we aim at investigating the ability of toluquinol, a 2-methyl-hydroquinone isolated from the culture broth of the marine fungus Penicillium sp. HL-85-ALS5-R004, to inhibit lymphangiogenesis in vitro, ex vivo and in vivo. EXPERIMENTAL APPROACH: We used human lymphatic endothelial cells (LEC) to analyze the effect of toluquinol in 2D and 3D in vitro cultures, and in the ex vivo mouse lymphatic ring assay. For in vivo approaches, the transgenic Fli1:eGFPy1 zebrafish, the mouse ear sponges and cornea models were used. Western-blotting and apoptosis analyses were carried out to search for drug targets. KEY RESULTS: Toluquinol inhibited LEC proliferation, migration, tubulogenesis and sprouting of new lymphatic vessels. Furthermore, toluquinol induced LEC apoptosis after 14 h of treatment in vitro, blocked the thoracic duct development in zebrafish, and reduced the VEGF-C-induced lymphatic vessel formation and corneal neovascularization in mice. Mechanistically, we are providing evidence that this drug abrogates the VEGF-C-induced VEGFR-3 phosphorylation in a dose-dependent manner, and represses Akt and ERK1/2 phosphorylations. CONCLUSIONS AND IMPLICATIONS: Based on these findings, we propose toluquinol as a new candidate with pharmacological potential for the treatment of lymphangiogenesis-related pathologies. Notably, its ability to suppress corneal neovascularization paves the way for applications in vascular ocular pathologies. This article is protected by copyright. All rights reserved. [less ▲]

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See detailEstetrol, a natural SERM exhibiting combined estrogenic and anti-estrogenic properties on mammary gland and breast cancer
Gallez, Anne ULg; Gérard, Céline ULg; BLACHER, Silvia ULg et al

Poster (2016, May 30)

The increased risk of breast cancer and thromboembolism in women who take hormone replacement therapy (HRT) is a major public health problem. The discovery of new drugs with better safety profile would ... [more ▼]

The increased risk of breast cancer and thromboembolism in women who take hormone replacement therapy (HRT) is a major public health problem. The discovery of new drugs with better safety profile would provide useful advances for patient care. Estetrol (E4) is a liver friendly promising candidate for HRT. In preclinical and/or clinical studies, E4 has been effective against the main symptoms of menopause from a starting dose of 0.3 mg/kg/day. The aim of this study was to define the impact of E4 on mammary gland and breast cancer development. Our preclinical data show that E4 is less efficient than estradiol (E2) to induce mammary gland growth. Treatment with several concentrations of E4 has shown that E4 did not increase tumor development, when it is used at 0.3 mg/kg/day. However, at 3 mg/kg/day, E4 increased tumor growth similarly to E2 (0.08 mg/kg/day). E4 presents also some anti-estrogenic effects on mammary gland and antitumor activity on breast cancer by decreasing the strong proliferative effect of E2. While ERα is the predominant receptor mediating its effects, the dual weak-estrogenic/anti-estrogenic feature of E4 results from differential signaling pathways activation. Both nuclear and rapid extra-nuclear signaling pathways are necessary for a complete estrogenic effect of E4. However, the antitumor action of E4 is not due to a capacity to antagonize E2-induced nuclear activity. In conclusion, our results support that E4, if it is used in strictly controlled clinical applications, could have no or only limited impact on breast and breast cancer. [less ▲]

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See detailUse of Estetrol with other Steroids for Attenuation of Neonatal Hypoxic-Ischemic brain injury:to combine or not to combine?
Tskitishvili, Ekaterine ULg; Pequeux, Christel ULg; Munaut, Carine ULg et al

in Oncotarget (2016)

Estetrol (E4), estradiol (E2) and progesterone (P4) have important antioxidative and neuroprotective effects in neuronal system. We aimed to study the consequence of combined steroid therapy in neonatal ... [more ▼]

Estetrol (E4), estradiol (E2) and progesterone (P4) have important antioxidative and neuroprotective effects in neuronal system. We aimed to study the consequence of combined steroid therapy in neonatal hypoxic-ischemic encephalopathy (HIE). In vitro the effect of E4 combined with other steroids on oxidative stress and the cell viability in primary hippocampal cultures was evaluated by lactate dehydrogenase and cell survival assays. In vivo neuroprotective and therapeutic efficacy of E4 combined with other steroids was studied in HIE model of immature rats. The rat pups rectal temperature, body and brain weights were evaluated. The hippocampus and the cortex were investigated by histo/immunohistochemistry: intact cell number counting, expressions of markers for early gray matter lose, neuro- and angiogenesis were studied. Glial fibrillary acidic protein was evaluated by ELISA in blood samples. In vitro E4 and combinations of high doses of E4 with P4 and/or E2 significantly diminished the LDH activity and upregulated the cell survival. In vivo pretreatment or treatment by different combinations of E4 with other steroids had unalike effects on body and brain weight, neuro- and angiogenesis, and GFAP expression in blood. The combined use of E4 with other steroids has no benefit over the single use of E4. [less ▲]

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See detailEstetrol, a natural SERM exhibiting combined estrogenic and antiestrogenic properties on mammary gland and breast cancer
Gérard, Céline ULg; Gallez, Anne ULg; BLACHER, Silvia ULg et al

Conference (2016, May 09)

The increased risk of breast cancer and thromboembolism in women who take Hormone Replacement Therapy (HRT) currently is a major public health problem. The discovery of novel molecules with better safety ... [more ▼]

The increased risk of breast cancer and thromboembolism in women who take Hormone Replacement Therapy (HRT) currently is a major public health problem. The discovery of novel molecules with better safety profile would provide useful advances for patient care. Estretrol (E4) appears as a promising candidate for HRT. Indeed, in contrast to current treatment containing ethinyl estradiol or estradiol (E2), E4 has a minimal impact on liver cells activity supporting a decreased incidence on thromboembolic events. In preclinical studies, E4 has been effective against the main symptoms of menopause such as hot flushes, vaginal atrophy, and osteoporosis, from a starting dose of 0.3 mg/kg/day. The aim of this study was to define the impact of E4 on mammary gland and breast cancer development when it is used at concentrations effective for menopause symptom relief. We report preclinical data showing that E4 is less efficient than E2 to induce mammary gland growth. Treatment of estrogen receptor (ER)-positive breast cancer with several concentrations of E4 has shown that 0.3 mg/kg/day E4 did not increase tumor development. However, at 3mg/kg/day, E4 increased the growth of hormone-dependent tumors and their metastatic dissemination in ovariectomized and intact mice. This effect was similar to the one observed with E2 used at 0.08 mg/kg/day. E4 presents also some anti-estrogenic effects on mammary gland and antitumor activity on breast cancer by decreasing the strong proliferative effect of E2. While ERα is the predominant receptor mediating its effects, the dual weak-estrogenic/anti-estrogenic feature of E4 results from differential signaling pathways activation. Both nuclear and rapid extranuclear signaling pathways are necessary for a complete estrogenic effect of E4. However, the antitumor action of E4 is not due to a capacity to antagonize E2-induced nuclear activity. In conclusion, our results support that E4, if it is used in strictly controlled clinical applications, could have no or only limited impact on breast and breast cancer. [less ▲]

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See detailNeonatal Hypoxic-Ischemic Encephalopathy: a new view of an old problem
Tskitishvili, Ekaterine ULg; VIELLEVOYE, Renaud ULg; Gérard, Céline et al

in Références en Gynécologie Obstétrique (2016), 17(1-1),

Neonatal hypoxic-ischemic encephalopathy (HIE) remains a challenge of perinatal medicine. It is an important cause of long term morbidity, including motor and behavioral deficits, mental retardation ... [more ▼]

Neonatal hypoxic-ischemic encephalopathy (HIE) remains a challenge of perinatal medicine. It is an important cause of long term morbidity, including motor and behavioral deficits, mental retardation, seizures and cerebral palsy, and mortality in newborns. This paper reviews the pathophysiology and current concepts of the management of neonatal HIE as well as the future potential neuroprotective strategies for attenuation of this disease. [less ▲]

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See detailFrom Metabolomics Study of Age-Related Macular Degeneration (AMD) to the Development of New Pyruvate Dehydrogenase Kinase Inhibitors (PDK)
Arslan, Deniz ULg; Schoumacher, Matthieu ULg; Pirotte, Bernard ULg et al

Poster (2016, May)

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population of industrialized countries. This blindness results from the deterioration of the macula, a small part of ... [more ▼]

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population of industrialized countries. This blindness results from the deterioration of the macula, a small part of the retina specialized for the high-acuity vision. Exudative AMD, called “wet”, is characterized by the formation of new blood vessels growing under the retina according to a process named choroidal neovascularization (CNV). Currently, the aetiology and pathogenesis of AMD remain unclear. Nevertheless, a recent metabolomics study performed on the serum of “wet” AMD patients and on a CNV murine model, that mimics the effect of “wet” AMD, have demonstrated that lactate level is clearly involved in the severity of the pathology as well as the relationship between lactate, CNV and AMD. According to this result, we suggest a new therapeutic approach of AMD based on the normalization of blood lactate level. The modulation of the lactate plasma concentration by treatment of the animals with synthetic compounds and more specifically Pyruvate Dehydrogenase Kinase (PDK) inhibitors significantly decrease the CNV. PDK and its four isoforms (PDK1-4) regulate the activity of the pyruvate dehydrogenase complex (PDH), a mitochondrial enzyme that plays a major role in the metabolic pathway of glucose, by reversible phosphorylation. Starting from these results, development of new PDK inhibitors could open the way to innovative treatment opportunities in AMD disease. Different analogues of (R)-3,3,3-trifluoro-2-hydroxy-2-methylpropanamide (fig.1) have been already synthetized and pharmacological evaluation is currently in progress. According to the results obtained, various pharmacomodulations will be investigated [less ▲]

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See detailFrom Metabolomics to Identification of a new therapeutic approach for Age-Related Macular Degeneration (AMD)
Schoumacher, Matthieu ULg; De Tullio, Pascal ULg; LAMBERT, Vincent ULg et al

Poster (2016, May)

Age-related macular degeneration (AMD) is the leading cause of vision loss in the western world among people aged 50 or older. 90% of all vision loss due to AMD result from the exudative form, which is ... [more ▼]

Age-related macular degeneration (AMD) is the leading cause of vision loss in the western world among people aged 50 or older. 90% of all vision loss due to AMD result from the exudative form, which is characterized by choroidal neovascularization (CNV). Age-related changes that induce pathologic CNV are incompletely understood and critical issues remain to be addressed. Metabolomics is defined as the comprehensive study of endogenous metabolites changes in various biological systems. This newly emerging “omic” science provides a unique opportunity to correlate variation of the metabolome with pathological occurrence or progression and/or to identify metabolites that are implicated in the disease. We apply a 1H NMR metabolomics approach on sera collected from AMD patient and healthy volunteers and form a mice model of laser-induced CNV which mimics the effect of exudative AMD. After post-processing treatments, the different spectra were analyzed by statistical discriminant methodologies (PCA, ICA, PLS-DA, O-PLS-DA). These approaches allow the differentiation between control and AMD patients and between laser-induced mice and the control mice group. Moreover, the same discriminating spectral zones have been identified in human and mice model, leading to the emergence of different putative biomarkers. Among these markers, lactate emerges as a key metabolite in both settings. Mechanistically, lactate produced locally and by inflammatory cells, plays a critical role in the onset of the inflammatory and angiogenic phases. In mice model of laser-induced CNV, normalization of circulating lactate by dichloroacetate a pyruvate dehydrogenase kinase (PDK) inhibitor, decreases CNV development. Our data support the innovative concept of lactate as a parainflammation- and angio-metabolite associated to AMD and CNV progression. Moreover, control of blood lactate level via inhibition of PDK provides new options for the treatment of exudative AMD. This study demonstrates the ability of metabolomics for drug target discovery and opens new perspectives for AMD treatment and patient follow-up. [less ▲]

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See detailImpacts of Ionizing Radiation on the Different Compartments of the Tumor Microenvironment
Leroi, Natacha ULg; LALLEMAND, François ULg; COUCKE, Philippe ULg et al

in Frontiers in Pharmacology (2016), 7

During the last decade, the initial cancer cell-centered view of tumors has greatly evolved to an integrated vision of tumor biology taking into account the key contribution of the TME. Obviously, the ... [more ▼]

During the last decade, the initial cancer cell-centered view of tumors has greatly evolved to an integrated vision of tumor biology taking into account the key contribution of the TME. Obviously, the different compartments of TME are closely related and contribute not only to tumor progression, but also to its response to treatments. Importantly, the TME evolves over time during the different steps of cancer development and is also affected by different therapeutic modalities. Although, improvements have been achieved regarding RT delivery to the primary tumor, ionizing radiation also target nontumor cells that influence tumor growth and metastatic dissemination. Different approaches have been proposed to overcome the radioresistance of cancer cells. The TME-mediated radioresistance is now the object of researches, which has been elegantly reviewed recently by Barker et al. (2015) and severalarticles pointed out the importance of treatments that modify the TME and likely radiosensitize tumor (Ansiaux et al., 2005; Crokart et al., 2005b; Frérart et al., 2008). However, the impact of anti-cancer treatments on the TME and consequently on the tumor phenotype, response to treatment and metastases, is often neglected. Here we pointed out the impact of RT on the TME. Recent findings emphasize the interest to optimize RT (i.e., dose per fraction) and timing of surgery (Leroi et al., 2015; Surace et al., 2015) in order to prevent metastatic spreading. The future challenge in RT will be to define the most appropriate combinations between RT, and other therapeutic modalities with the optimal sequence and timing of treatments. In this context, investigation of the TME-related acquired resistance will be essential and will provide important innovative data. [less ▲]

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See detailFeasibility study of repetitive diffusion MRI after Neoadjuvant radiotherapy for following tumor microenvironment.
LALLEMAND, François ULg; Leroi, Natacha ULg; Bahri, Mohamed Ali ULg et al

Conference (2016, March 22)

Purpose/Objective. Neoadjuvant radiotherapy (NeoRT) improves tumor local control and tumor resection in many cancers. The timing between the end of the NeoRT and surgery is mostly driven by the occurrence ... [more ▼]

Purpose/Objective. Neoadjuvant radiotherapy (NeoRT) improves tumor local control and tumor resection in many cancers. The timing between the end of the NeoRT and surgery is mostly driven by the occurrence of side effects or the tumor downsizing. We previously demonstrated in an in vivo model that the timing of surgery and the schedule of NeoRT influenced the tumor dissemination. Here, our aim is to evaluate with functional MRI (fMRI) the impact of the radiation treatment on the tumor microenvironment and subsequently to identify non-invasive markers helping to determine the best timing to perform surgery for avoiding tumor spreading. First, we needed to demonstrate the feasibility of repetitive MRI imaging after NeoRT in mice. Material/methods. We used two models of NeoRT we previously developed in mice: MDA-MB 231 and 4T1 cells implanted in the flank of mice. When tumors reached the planned volume, they are irradiated with 2x5 Gy and then surgically removed at different time points after RT. In the mean time between the end of RT and the surgical procedure, mice were imaged in a 9,4T Agilent® MRI. Diffusion Weighted (DW) -MRI was performed every 2 days between RT and surgery. For each tumors we acquired 8 slices of 1 mm thickness and 0.5 mm gap with an “in plane voxel resolution” of 0.5 mm. For DW-MRI, we performed FSEMS (Fast Spin Echo MultiSlice) sequences, with 9 different B-values (from 40 to 1000) and B0, in the 3 main directions. We also performed IVIM (IntraVoxel Incoherent Motion) analysis, in the aim to obtain information on intravascular diffusion, related to perfusion (F: perfusion factor) and subsequently tumor vessels perfusion. Results. As preliminary results, with the MBA-MB 231 we observed a significant increase of F at day 6 after irradiation than a decrease and stabilization until surgery. No other modifications of the MRI signal, ADC, D or D* were observed. We observed similar results with 4T1 cells, F increased at day 3 than returned to initial signal. The difference in the timing of the peak of F can be related to the difference in tumor growth between MBA-MB 231 and 4T1 (four weeks vs one week). Conclusion. For the first time, we demonstrate the feasibility of repetitive fMRI imaging in mice models after NeoRT. With these models, we show a significant peak of the perfusion factor (F) at day 6 or day 3. This change occurs between the two previous time points of surgery demonstrating a difference in the metastatic spreading. Indeed, after a NeoRT of 2X5Gy we observed more metastases in the lung when MDA-MB 231 tumor bearing mice are operated 4 days after RT compared to 11 days. These preliminary results are very promising for identifying noninvasive markers for determining the best timing for surgery. [less ▲]

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See detailEstetrols’ Potential for Neuroprotection Following the injury to the Developing Brain: Preclinical Studies
Tskitishvili, Ekaterine ULg; Nisolle, Michelle ULg; Noël, Agnès ULg et al

in The 17th World Congress of Gynecological Endocrinology, Florence 2-5 March 2016 (2016, March)

Context: Hypoxic-Ischemic encephalopathy (HIE) remains a major cause of perinatal brain injury. The brain rapidly increases in size, shape and complexity during the second and third trimesters. A sentinel ... [more ▼]

Context: Hypoxic-Ischemic encephalopathy (HIE) remains a major cause of perinatal brain injury. The brain rapidly increases in size, shape and complexity during the second and third trimesters. A sentinel event in late pregnancy or the intrapartum period may have an acute profound effect on a previously neurologically intact fetus, leading to the development of (HIE). The nature of the deficits is dependent on the gestational age and severity of the insult, though it is seldom reported in preterm infants. Studies in animal models of HIE may provide important information for the development of treatment for this pathological condition. Estetrol (E4) is a recently described estrogen with four hydroxyl-groups that is synthesized exclusively during pregnancy by the human fetal liver. Objective: In this study, we evaluated E4’s neuroprotective and therapeutic potency in neonatal (in vivo) HIE model of the immature 7-day-old newborn rat. Methods: Rat pups body temperatures were examined along with their body and brain weights. Brains were studied at the level of the hippocampus and cortex. Intact cell counting and expressions of markers for neuronal early grey matter damage (microtubule-associated protein-2 (MAP-2)), neurogenesis (doublecortin (DCX)) and angiogenesis (vascular-endothelial growth factor (VEGF)) were evaluated by histo- and immunohistochemistry. The serum levels of two markers of brain damage (S100B and glial fibrillary acidic protein (GFAP)) were measured by ELISA. Results: Our results demonstrate that E4 has a significant neuroprotective and therapeutic effects. Estetrol decreases the early gray matter loss, and promotes neuro- and angiogenesis in vivo. Estetrol treatment has no effects on body weight, brain weight or body temperature. Conclusion: Taken together, E4 might become an important safe and physiological substance to treat neonatal HIE. [less ▲]

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See detailDynamics of Internalization and Recycling of the Pro-Metastatic Membrane Type 4-Matrix Metalloproteinase (MT4-MMP) in Breast Cancer Cells
Truong, Alice ULg; Yip, Cassandre ULg; PAYE, Alexandra ULg et al

in FEBS Journal (2016), 283(4), 704-22

MT4-MMP (MMP17) is a glycosylphosphatidyl inositol (GPI)-anchored membrane-type MMP expressed on the cell surface of human breast cancer cells. In triple negative breast cancer cells, MT4-MMP promotes ... [more ▼]

MT4-MMP (MMP17) is a glycosylphosphatidyl inositol (GPI)-anchored membrane-type MMP expressed on the cell surface of human breast cancer cells. In triple negative breast cancer cells, MT4-MMP promotes primary tumor growth and lung metastases. Although trafficking and internalization of the transmembrane MT1-MMP have been extensively investigated, little is known about the regulatory mechanisms of the GPI-anchored MT4-MMP. Here, we investigated the fate and cellular trafficking of MT4-MMP by analyzing its homophilic complex interactions, internalization and recycling dynamics compared to an inert form, MT4-MMP-E249A. Oligomeric and dimeric complexes were analyzed by co-transfection of cells with FLAG- or Myc-tagged MT4-MMP by reducing and non-reducing immunoblots and co-immunoprecipitation experiments. The trafficking of MT4-MMP was studied using an antibody feeding assay and confocal microscopy analysis or cell surface protein biotinylation and Western blot analysis. We demonstrate that MT4-MMP forms homophilic complexes at the cell surface, internalizes in early endosomes, and some of the enzyme is either auto-degraded or recycled to the cell surface. Our data indicate that MT4-MMP is internalized by the CLIC/GEEC pathway, a mechanism that differs from other MT-MMP members. Although MT4-MMP localizes with caveolin-1, MT4-MMP internalization was not affected by inhibitors of caveolin-1 or clathrin endocytosis pathways but was reduced by cdc42 or RhoA silencing with siRNA. We provide a new mechanistic insight into the regulatory mechanisms of MT4-MMP, which may have implications in the design of novel therapeutic strategies for metastatic breast cancer. This article is protected by copyright. All rights reserved. [less ▲]

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See detailImpact of estetrol on breast cancer development, metastatic dissemination and angiogenesis
Gallez, Anne ULg; Gérard, Céline ULg; BLACHER, Silvia ULg et al

Poster (2016)

The increased risk of breast cancer and thromboembolism in women who take Hormone Replacement Therapy (HRT) currently is a major public health problem. The discovery of novel molecules with better safety ... [more ▼]

The increased risk of breast cancer and thromboembolism in women who take Hormone Replacement Therapy (HRT) currently is a major public health problem. The discovery of novel molecules with better safety profile would provide useful advances for patient care. Estretrol (E4) appears as a promising candidate for HRT. Indeed, in contrast to current treatment containing ethinyl estradiol or estradiol (E2), E4 has a minimal impact on liver cells activity supporting a decreased incidence on thromboembolic events. In preclinical studies, E4 has been effective against the main symptoms of menopause such as hot flushes, vaginal atrophy, and osteoporosis, from a starting dose of 0.3 mg/kg/day. The aim of this study was to define the impact of E4 on breast cancer development when it is used at concentrations effective for menopause symptom relief. Treatment of estrogen receptor (ER)-positive breast cancer-developing mice (MMTV-PyMT) with several concentrations of E4 has shown that 0.3 mg/kg/day E4 did not increase tumor development and metastasis dissemination. However, at 3mg/kg/day, E4 increased the growth of hormone-dependent tumors and their metastatic dissemination in ovariectomized and intact mice. This effect was similar to the one observed with E2 used at 0.08 mg/kg/day. In an in vivo model of ER-negative tumors, we observed that 3mg/kg/day E4 improved tumor growth by increasing angiogenesis, and subsequently decreasing necrosis and tumor hypoxia. In contrast, 0.3 mg/kg/day E4 did not induce any of these effects on ER-negative tumors and tumor microenvironment. In conclusion, we have shown that 0.3 mg/kg/day E4, already reported to prevent menopause symptoms, does not increase breast tumor growth, metastasis dissemination, and angiogenesis. However, similarly to E2, higher concentrations of E4 are pro-tumorous. These results support that E4, if it is used in strictly controlled clinical applications, could have no or only limited impact on breast cancer. [less ▲]

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See detailTissue factor induced by epithelial-mesenchymal transition triggers a pro-coagulant state that drives metastasis of circulating tumor cells.
Bourcy, Morgane ULg; Suarez-Carmona, Meggy ULg; Lambert, Justine ULg et al

in Cancer Research (2016)

Epithelial-mesenchymal transition (EMT) is prominent in circulating tumor cells (CTC), but how it influences metastatic spread in this setting is obscure. Insofar as blood provides a specific ... [more ▼]

Epithelial-mesenchymal transition (EMT) is prominent in circulating tumor cells (CTC), but how it influences metastatic spread in this setting is obscure. Insofar as blood provides a specific microenvironment for tumor cells, we explored a potential link between EMT and coagulation that may provide EMT-positive CTC with enhanced colonizing properties. Here we report that EMT induces tissue factor (TF), a major cell-associated initiator of coagulation and related pro-coagulant properties in the blood. TF blockade by antibody or shRNA diminished the pro-coagulant activity of EMT-positive cells, confirming a functional role for TF in these processes. Silencing the EMT transcription factor ZEB1 inhibited both EMT-associated TF expression and coagulant activity, further strengthening the link between EMT and coagulation. Accordingly, EMT-positive cells exhibited a higher persistance/survival in the lungs of mice colonized after intravenous injection, a feature diminished by TF or ZEB1 silencing. In tumor cells with limited metastatic capability, enforcing expression of the EMT transcription factor Snail increased TF, coagulant properties and early metastasis. Clinically, we identified a subpopulation of CTC expressing vimentin and TF in the blood of metastatic breast cancer patients consistent with our observations. Overall, our findings define a novel EMT-TF regulatory axis which triggers local activation of coagulation pathways to support metastatic colonization of EMT-positive CTC. [less ▲]

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