Bone marrow-derived mesenchymal stem cells drive lymphangiogenesis.
Maertens, Ludovic ; Erpicum, Charlotte ; Detry, Benoît et al
in PLoS ONE (2014), 9(9), 106976
It is now well accepted that multipotent Bone-Marrow Mesenchymal Stem Cells (BM-MSC) contribute to cancer progression through several mechanisms including angiogenesis. However, their involvement during ... [more ▼]
It is now well accepted that multipotent Bone-Marrow Mesenchymal Stem Cells (BM-MSC) contribute to cancer progression through several mechanisms including angiogenesis. However, their involvement during the lymphangiogenic process is poorly described. Using BM-MSC isolated from mice of two different backgrounds, we demonstrate a paracrine lymphangiogenic action of BM-MSC both in vivo and in vitro. Co-injection of BM-MSC and tumor cells in mice increased the in vivo tumor growth and intratumoral lymphatic vessel density. In addition, BM-MSC or their conditioned medium stimulated the recruitment of lymphatic vessels in vivo in an ear sponge assay, and ex vivo in the lymphatic ring assay (LRA). In vitro, MSC conditioned medium also increased the proliferation rate and the migration of both primary lymphatic endothelial cells (LEC) and an immortalized lymphatic endothelial cell line. Mechanistically, these pro-lymphangiogenic effects relied on the secretion of Vascular Endothelial Growth Factor (VEGF)-A by BM-MSC that activates VEGF Receptor (VEGFR)-2 pathway on LEC. Indeed, the trapping of VEGF-A in MSC conditioned medium by soluble VEGF Receptors (sVEGFR)-1, -2 or the inhibition of VEGFR-2 activity by a specific inhibitor (ZM 323881) both decreased LEC proliferation, migration and the phosphorylation of their main downstream target ERK1/2. This study provides direct unprecedented evidence for a paracrine lymphangiogenic action of BM-MSC via the production of VEGF-A which acts on LEC VEGFR-2. [less ▲]Detailed reference viewed: 39 (7 ULg)
Influence of tumor inflammatory microenvironment after neoadjuvant radiotherapy on lung metastases occurrence in a mouse model.
Leroi, Natacha ; Blacher, Silvia ; Marée, Raphaël et al
Conference (2014)Detailed reference viewed: 27 (3 ULg)
DeltaNp63 isoform-mediated beta-defensin family up-regulation is associated with (lymph)angiogenesis and poor prognosis in patients with squamous cell carcinoma.
Suarez-Carmona, Meggy ; Hubert, Pascale ; Gonzalez, Arnaud et al
in Oncotarget (2014), 5(7), 1856-1868
Beside a role in normal development/differentiation, high p63 immunoreactivity is also frequently observed in squamous cell carcinoma (SCC). Due to the complexity of the gene, the role of each p63 isotype ... [more ▼]
Beside a role in normal development/differentiation, high p63 immunoreactivity is also frequently observed in squamous cell carcinoma (SCC). Due to the complexity of the gene, the role of each p63 isotype in tumorigenesis is still confusing. Constitutively produced or induced in inflammatory conditions, human beta-defensins (HbetaDs) are cationic peptides involved in host defenses against bacteria, viruses and fungi. Here, we investigated both the role of p63 proteins in the regulation of HbetaDs and the implication of these antimicrobial peptides in tumor (lymph)angiogenesis. Thus, in contrast to TAp63 isotypes, we observed that DeltaNp63 proteins (alpha, beta, gamma) induce HbetaD1, 2 and 4 expression. Similar results were observed in cancer tissues and cell lines. We next demonstrated that DeltaNp63-overexpressing SCC are associated with both a poor prognosis and a high tumor vascularisation and lymphangiogenesis. Moreover, we showed that HbetaDs exert a chemotactic activity for (lymphatic) endothelial cells in a CCR6-dependent manner. The ability of HbetaDs to enhance (lymph)angiogenesis in vivo was also evaluated. We observed that HbetaDs increase the vessel number and induce a significant increase in relative vascular area compared to negative control. Taken together, the results of this study suggest that DeltaNp63-regulated HbetaD could promote tumor (lymph)angiogenesis in SCC microenvironment. [less ▲]Detailed reference viewed: 151 (14 ULg)
DUSP3/VHR is a pro-angiogenic atypical dual-specificity phosphatase
Amand, Mathieu ; Erpicum, Charlotte ; BAJOU, Khalid et al
in Molecular Cancer (2014)
Background DUSP3 phosphatase, also known as Vaccinia-H1 Related (VHR) phosphatase, encoded by DUSP3/Dusp3 gene, is a relatively small member of the dual-specificity protein phosphatases. In vitro studies ... [more ▼]
Background DUSP3 phosphatase, also known as Vaccinia-H1 Related (VHR) phosphatase, encoded by DUSP3/Dusp3 gene, is a relatively small member of the dual-specificity protein phosphatases. In vitro studies showed that DUSP3 is a negative regulator of ERK and JNK pathways in several cell lines. On the other hand, DUSP3 is implicated in human cancer. It has been alternatively described as having tumor suppressive and oncogenic properties. Thus, the available data suggest that DUSP3 plays complex and contradictory roles in tumorigenesis that could be cell type-dependent. Since most of these studies were performed using recombinant proteins or in cell-transfection based assays, the physiological function of DUSP3 has remained elusive. Results Using immunohistochemistry on human cervical sections, we observed a strong expression of DUSP3 in endothelial cells (EC) suggesting a contribution for this phosphatase to EC functions. DUSP3 downregulation, using RNA interference, in human EC reduced significantly in vitro tube formation on Matrigel and spheroid angiogenic sprouting. However, this defect was not associated with an altered phosphorylation of the documented in vitro DUSP3 substrates, ERK1/2, JNK1/2 and EGFR but was associated with an increased PKC phosphorylation. To investigate the physiological function of DUSP3, we generated Dusp3-deficient mice by homologous recombination. The obtained DUSP3-/- mice were healthy, fertile, with no spontaneous phenotype and no vascular defect. However, DUSP3 deficiency prevented neo-vascularization of transplanted b-FGF containing Matrigel and LLC xenograft tumors as evidenced by hemoglobin (Hb) and FITC-dextran quantifications. Furthermore, we found that DUSP3 is required for b-FGF-induced microvessel outgrowth in the aortic ring assay. Conclusions All together, our data identify DUSP3 as a new important player in angiogenesis. [less ▲]Detailed reference viewed: 103 (26 ULg)
Altered alpha-defensin 5 expression in cervical squamocolumnar junction: implication in the formation of a viral/tumour-permissive microenvironment.
Hubert, Pascale ; ; RONCARATI, Patrick et al
in Journal of Pathology (The) (2014), 234(4), 464-77
Human papillomavirus (HPV) infection, particularly type 16, is causally associated with cancer of the uterine cervix, which mainly develops at the squamocolumnar (SC) junction. The progression of cervical ... [more ▼]
Human papillomavirus (HPV) infection, particularly type 16, is causally associated with cancer of the uterine cervix, which mainly develops at the squamocolumnar (SC) junction. The progression of cervical HPV infections into (pre)neoplastic lesions suggests that viral antigens are not adequately recognized by innate immunity or presented to the adaptive immune system. Members of the defensin family have recently been found to inhibit viral and bacterial pathogens, to stimulate the migration of immune cells and to play a role in anticancer responses. In the present study, we focused on the poorly characterized human alpha-defensin 5 (HD-5) and its possible role in these processes. We showed that HD-5 was able to prevent HPV virion entry into cervical keratinocytes and to influence adaptive immunity. Indeed, this peptide specifically induced the chemoattraction and proliferation of both activated T lymphocytes and immature dendritic cells in a CCR2/CCR6-dependent manner and stimulated the infiltration of these professional antigen-presenting cells in a (pre)neoplastic epithelium transplanted in vivo in immunodeficient mice. No chemotactic effect was observed with plasmacytoid dendritic cells, macrophages or natural killer cells. Proliferative and angiogenic effects of HD-5 were also assessed in vitro and in vivo. However there was a striking regional disparity in expression of HD-5, being prominent in ectocervical, vaginal and vulvar neoplasia, while absent, or nearly so, in the cervical SC junction. Taken together, these results suggest one possible explanation for why the SC junction is uniquely vulnerable to both high-risk HPV infection (via reduced HD-5 expression and viral entry) and progression of neoplasia (via altered cell-mediated immune responses and altered microenvironment). Copyright (c) 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [less ▲]Detailed reference viewed: 57 (14 ULg)
A spiked tissue-based approach for quantification of phosphatidylcholines in brain section by MALDI mass spectrometry imaging.
Jadoul, Laure ; Longuespée, Rémi ; Noël, Agnès et al
in Analytical and Bioanalytical Chemistry (2014), sous presse
In the last few years, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) has been successfully used to study the distribution of lipids within tissue sections. However ... [more ▼]
In the last few years, matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MSI) has been successfully used to study the distribution of lipids within tissue sections. However, few efforts have been made to acquire reliable quantitative data regarding the localized concentrations of these molecules. Here we propose an approach based on brain homogenates for the quantification of phosphatidylcholines (PCs) in brain section by MALDI MSI. Homogenates were spiked with a range of PC(16:0 d31/18:1) concentrations. Sections from homogenates and intact brain were simultaneously prepared before being analyzed by MALDI MSI using a Fourier transform ion cyclotron resonance (FT-ICR) analyzer. Standard curves were generated from the signal intensity of the different PC(16:0 d31/18:1) ionic species ([M+H]+, [M+Na]+ and [M+K]+) detected from the homogenate sections. Localized quantitative data were finally extracted by correlating the standard curves with the signal intensities of endogenous PC (especially PC(16:0/18:1)) ionic species detected on different areas of the brain section. They were consistent with quantitative values found in the literature. This work introduces a new method to take directly into account biological matrix effects for the quantification of lipids as well as other endogenous compounds, in tissue sections by MALDI MSI. [less ▲]Detailed reference viewed: 29 (7 ULg)
Improved computer-assisted analysis of the global lymphatic network in human cervical tissues.
Balsat, Cédric ; ; GOFFIN, Frédéric et al
in Modern Pathology : An Official Journal of the United States & Canadian Academy of Pathology, Inc (2014), 27(6), 887-98
Lymphatic dissemination is a key event in cervical cancer progression and related tumor lymphatic markers are viewed as promising prognostic factor of nodal extension. However, validating such parameters ... [more ▼]
Lymphatic dissemination is a key event in cervical cancer progression and related tumor lymphatic markers are viewed as promising prognostic factor of nodal extension. However, validating such parameters requires an objective characterization of the lymphatic vasculature. Here, we performed a global analysis of the lymphatic network using a new computerized method applied on whole uterine cervical digital images. Sixty-eight cases of cervical neoplasia (12 CIN3, 10 FIGO stage 1A and 46 stage IB1) and 10 cases of normal cervical tissue were reacted with antibodies raised against D2-40, D2-40/p16 and D2-40/Ki67. Immunostained structures were automatically detected on whole slides. The lymphatic vessel density (D2-40), proliferating lymphatic vessel density (D2-40/ki67) and spatial lymphatic distribution in respect to the adjacent epithelium were assessed from normal cervix to early cervical cancer and correlated with lymphovascular space invasion and lymph node status. Prominent lymphatic vessel density and proliferating lymphatic vessel density are detected under the transformation zone of benign cervix and no further increase is noted during cancer progression. Notably, a shift of lymphatic vessel distribution toward the neoplastic edges is detected. In IB1 cervical cancer, although intra- and peritumoral lymphatic vessel density are neither correlated with lymphovascular space invasion nor with lymph node metastasis, a specific spatial distribution with more lymphatic vessels in the vicinity of tumor edges is predictive of lymphatic dissemination. Herein, we provide a new computerized method suitable for an innovative detailed analysis of the lymphatic network. We show that the transformation zone of the benign cervix acts as a baseline lymphangiogenic niche before the initiation of neoplastic process. During cancer progression, this specific microenvironment is maintained with lymphatic vessels even in closer vicinity to tumor cells.Modern Pathology advance online publication, 6 December 2013; doi:10.1038/modpathol.2013.195. [less ▲]Detailed reference viewed: 74 (29 ULg)
Blocking lipid synthesis overcomes tumor re-growth and metastasis after anti-angiogenic therapy withdrawal.
Sounni, Nor Eddine ; Cimino, Jonathan ; Blacher, Silvia et al
in Cell Metabolism (2014), 20(2), 280-94
The molecular mechanisms responsible for the failure of antiangiogenic therapies and how tumors adapt to these therapies are unclear. Here, we applied transcriptomic, proteomic, and metabolomic approaches ... [more ▼]
The molecular mechanisms responsible for the failure of antiangiogenic therapies and how tumors adapt to these therapies are unclear. Here, we applied transcriptomic, proteomic, and metabolomic approaches to preclinical models and provide evidence for tumor adaptation to vascular endothelial growth factor blockade through a metabolic shift toward carbohydrate and lipid metabolism in tumors. During sunitinib or sorafenib treatment, tumor growth was inhibited and tumors were hypoxic and glycolytic. In sharp contrast, treatment withdrawal led to tumor regrowth, angiogenesis restoration, moderate lactate production, and enhanced lipid synthesis. This metabolic shift was associated with a drastic increase in metastatic dissemination. Interestingly, pharmacological lipogenesis inhibition with orlistat or fatty acid synthase downregulation with shRNA inhibited tumor regrowth and metastases after sunitinib treatment withdrawal. Our data shed light on metabolic alterations that result in cancer adaptation to antiangiogenic treatments and identify key molecules involved in lipid metabolism as putative therapeutic targets. [less ▲]Detailed reference viewed: 104 (33 ULg)
Estetrol and neuroprotection against perinatal ischemic insult
Tskitishvili, Ekaterine ; Nisolle, Michelle ; Noël, Agnès et al
in Estetrol attenuates neonatal hypoxic-ischemic brain injury (2014)Detailed reference viewed: 34 (7 ULg)
PAI-1 mediates the antiangiogenic and profibrinolytic effects of 16K prolactin.
Bajou, Khalid ; Herkenne, Stéphanie ; et al
in Nature Medicine (2014), sous presse
The N-terminal fragment of prolactin (16K PRL) inhibits tumor growth by impairing angiogenesis, but the underlying mechanisms are unknown. Here, we found that 16K PRL binds the fibrinolytic inhibitor ... [more ▼]
The N-terminal fragment of prolactin (16K PRL) inhibits tumor growth by impairing angiogenesis, but the underlying mechanisms are unknown. Here, we found that 16K PRL binds the fibrinolytic inhibitor plasminogen activator inhibitor-1 (PAI-1), which is known to contextually promote tumor angiogenesis and growth. Loss of PAI-1 abrogated the antitumoral and antiangiogenic effects of 16K PRL. PAI-1 bound the ternary complex PAI-1-urokinase-type plasminogen activator (uPA)-uPA receptor (uPAR), thereby exerting antiangiogenic effects. By inhibiting the antifibrinolytic activity of PAI-1, 16K PRL also protected mice against thromboembolism and promoted arterial clot lysis. Thus, by signaling through the PAI-1-uPA-uPAR complex, 16K PRL impairs tumor vascularization and growth and, by inhibiting the antifibrinolytic activity of PAI-1, promotes thrombolysis. [less ▲]Detailed reference viewed: 93 (32 ULg)
Cell invasion in the spheroid sprouting assay: a spatial organisation analysis adaptable to cell behaviour.
Blacher, Silvia ; Erpicum, Charlotte ; et al
in PLoS ONE (2014), 9(5), 97019
The endothelial cell spheroid assay provides a suitable in vitro model to study (lymph) angiogenesis and test pro- and anti-(lymph) angiogenic factors or drugs. Usually, the extent of cell invasion ... [more ▼]
The endothelial cell spheroid assay provides a suitable in vitro model to study (lymph) angiogenesis and test pro- and anti-(lymph) angiogenic factors or drugs. Usually, the extent of cell invasion, observed through optical microscopy, is measured. The present study proposes the spatial distribution of migrated cells as a new descriptor of the (lymph) angiogenic response. The utility of this novel method rests with its capacity to locally characterise spheroid structure, allowing not only the investigation of single and collective cell invasion but also the evolution of the spheroid core itself. Moreover, the proposed method can be applied to 2D-projected spheroid images obtained by optical microscopy, as well as to 3D images acquired by confocal microscopy. To validate the proposed methodology, endothelial cell invasion was evaluated under different experimental conditions. The results were compared with widely used global parameters. The comparison shows that our method prevents local spheroid modifications from being overlooked and leading to the possible misinterpretation of results. [less ▲]Detailed reference viewed: 42 (6 ULg)
Changes in elastin density in different locations of the vaginal wall in women with pelvic organ prolapse.
DE LANDSHEERE, Laurent ; Blacher, Silvia ; Munaut, Carine et al
in International Urogynecology Journal & Pelvic Floor Dysfunction (2014)
INTRODUCTION AND HYPOTHESIS: The purpose of this study was to analyze the histomorphometric properties of the vaginal wall in women with pelvic organ prolapse (POP). METHODS: In 15 women undergoing ... [more ▼]
INTRODUCTION AND HYPOTHESIS: The purpose of this study was to analyze the histomorphometric properties of the vaginal wall in women with pelvic organ prolapse (POP). METHODS: In 15 women undergoing surgery for POP, full-thickness biopsies were collected at two different sites of location from the anterior and/or posterior vaginal wall. Properties of the precervical area (POP-Q point C/D) were compared with the most distal portion of the vaginal wall (POP-Q point Ba/Bp) using histological staining and immunohistochemistry. The densities of total collagen fibers, elastic fibers, smooth muscle cells, and blood vessels were determined by combining high-resolution virtual imaging and computer-assisted digital image analysis. RESULTS: The mean elastin density was significantly decreased in the lamina propria and muscularis layer of the vaginal wall from the most distal portion of the prolapsed vaginal wall compared with the precervical area. This difference was statistically significant in the lamina propria for both anterior (8.4 +/- 1.2 and 12.1 +/- 2.0, p = 0.048) and posterior (6.8 +/- 0.5 and 10.1 +/- 1.4, p = 0.040) locations, and in the muscularis for the anterior (5.2 +/- 0.4 and 8.4 +/- 1.2, p = 0.009) vaginal wall. There were no statistically significant differences in the mean densities of collagen fibers, smooth muscle cells or blood vessels between the two locations. CONCLUSIONS: In this study, we observed changes in elastin density in two different locations of the vaginal wall from women with POP. The histomorphometric properties of the vaginal wall can be variable from one place to another in the same patient. This result supports the existence of most vulnerable locations within the vaginal wall and the potential benefit of site-specific prolapse surgery. [less ▲]Detailed reference viewed: 68 (14 ULg)
Effects of adenosine on lymphangiogenesis.
Lenoir, Bénédicte ; ; Blacher, Silvia et al
in PloS one (2014), 9(3), 92715
BACKGROUND: The lymphatic system controls tissue homeostasis by draining protein-rich lymph to the vascular system. Lymphangiogenesis, the formation of lymphatic vessels, is a normal event in childhood ... [more ▼]
BACKGROUND: The lymphatic system controls tissue homeostasis by draining protein-rich lymph to the vascular system. Lymphangiogenesis, the formation of lymphatic vessels, is a normal event in childhood but promotes tumor spread and metastasis during adulthood. Blocking lymphangiogenesis may therefore be of therapeutic interest. Production of adenosine is enhanced in the tumor environment and contributes to tumor progression through stimulation of angiogenesis. In this study, we determined whether adenosine affects lymphangiogenesis. METHODS: Lymphatic endothelial cells (HMVEC-dLy) were cultured in presence of adenosine and their proliferation, migration and tube formation was assessed. Gelatin sponges embedded with the stable analogue of adenosine 2-chloro adenosine were implanted in mice ear and lymphangiogenesis was quantified. Mice were intravenously injected with adenoviruses containing expression vector for 5'-endonucleotidase, which plays a major role in the formation of adenosine. RESULTS: In vitro, we observed that adenosine decreased the proliferation of lymphatic endothelial cells, their migration and tube formation. However, in vivo, gelatin sponges containing 2-chloro adenosine and implanted in mice ear displayed an elevated level of lymphangiogenesis (2.5-fold, p<0.001). Adenovirus-mediated over-expression of cytosolic 5'-nucleotidase IA stimulated lymphangiogenesis and the recruitment of macrophages in mouse liver. Proliferation of lymphatic endothelial cells was enhanced (2-fold, p<0.001) when incubated in the presence of conditioned medium from murine macrophages. CONCLUSION: We have shown that adenosine stimulates lymphangiogenesis in vivo, presumably through a macrophage-mediated mechanism. This observation suggests that blockade of adenosine receptors may help in anti-cancer therapies. [less ▲]Detailed reference viewed: 54 (3 ULg)
Gene expression pattern of synovial cells from inflammatory and normal areas of osteoarthritis synovial membrane.
Lambert, Cécile ; ; et al
in Arthritis and Rheumatism (2014), sous presse
Objective: The aim of this study was to compare the gene expression pattern of synovial cells from inflammatory (I) or normal/reactive (N/R) areas of a synovial membrane harvested from the same ... [more ▼]
Objective: The aim of this study was to compare the gene expression pattern of synovial cells from inflammatory (I) or normal/reactive (N/R) areas of a synovial membrane harvested from the same osteoarthritis (OA) patient. Methods: Synovial tissues were obtained from 12 knee OA patients at the time of total knee replacement. The inflammatory status of the synovial membrane was characterized according to macroscopic criteria and sorted as N/R and I. Biopsies were cultured separately for 7 days. Microarray gene expression profiling between N/R and I areas was performed. Western blot and immunohistochemistry confirmed the identified genes that were differentially expressed. Results: 896 differentially expressed genes between N/R and I zones were identified. The key pathways were related to inflammation, cartilage metabolism, Wnt signaling and angiogenesis. In the inflammatory network, TREM1 and S100A9 were strongly up-regulated. MMP-3 and -9, cathepsin H and S were significantly up-regulated in the cartilage catabolism pathway, whereas the most up-regulated anabolism enzyme was HAS1. Wnt-5A and LRP5 were up-regulated whereas FZD2 and DKK3 were down-regulated in the Wnt signaling. Finally, STC1, a protein involved in angiogenesis was identified as the most up-regulated gene in I zones compared to N/R zones. Conclusion: This study is the first to identify different expression pattern between two areas of the synovial membrane in the same patient. These differences concern several key pathways involved in OA pathogenesis. This analysis also provides information regarding new genes and proteins as potential targets for the future therapeutic. (c) 2013 American College of Rheumatology. [less ▲]Detailed reference viewed: 45 (6 ULg)
MMP-Mediated Collagen Remodeling and Vessel Functions
Noël, Agnès ; Sounni, Nor Eddine
in BRIX, K.; STOCKER, W. (Eds.) Proteases: Structure and Function, (2014)Detailed reference viewed: 40 (6 ULg)
Z-VAD-FMK treatment prevents granulosa cells apoptosis induced by etoposide but not by hypoxia and serum starvation in vitro
Fransolet, Maïté ; HENRY, Laurie ; Foidart, Jean-Michel et al
Poster (2013, December 05)Detailed reference viewed: 15 (0 ULg)
Z-VAD-FMK treatment prevents granulosa cells apoptosis induced by etoposide but not by hypoxia and serum starvation in vitro
Fransolet, Maïté ; HENRY, Laurie ; Foidart, Jean-Michel et al
Poster (2013, November 07)Detailed reference viewed: 21 (1 ULg)
Molecular mechanisms of type I collagen-induced apoptosis in breast carcinoma cells
Maquoi, Erik ; Assent, Delphine ; Foidart, Jean-Michel et al
Poster (2013, September 27)
Objective: As invading breast carcinoma cells breach the underlying basement membrane, they become confronted with a dense three-dimensional reactive stroma dominated by type I collagen. To develop ... [more ▼]
Objective: As invading breast carcinoma cells breach the underlying basement membrane, they become confronted with a dense three-dimensional reactive stroma dominated by type I collagen. To develop metastatic capabilities, invading tumour cells must acquire the capacity to negotiate this hostile microenvironment. By enmeshing cells in a dense fibrillar network, type I collagen acts as a physical barrier for cell migration as well as an endogenous antigrowth signal, partly by inducing apoptosis in epithelial cells. Aberrant cell survival resulting from an acquired resistance toward apoptosis represents a prominent hallmark of cancers. However, the molecular mechanisms implicated in collagen-induced apoptosis remain poorly defined. Here, we investigate the molecular mechanisms by which type I collagen induces apoptosis in breast carcinoma cells and identify MMP-14, a membrane-anchored matrix metalloproteinase, as a key anti-apoptotic factor. Methods: To investigate the induction of apoptosis by collagen, human breast adenocarcinoma MCF-7 cells overexpressing or not MMP-14 were plated on plastic plates or embedded within three dimensional type I collagen gels (Col3D). Cell death was evaluated by measuring cytoplasmic histone-associated DNA fragments (Cell Death Detection ELISA). The percentage of cells with an apoptotic nuclear morphology was also determined. The interactions between cancer cells and Col3D were analyzed by confocal microscopy and the impact of Col3D on the transcriptome of cancer cells was investigated using Illumina HT-12 BeadArrays. Results: When cultured within Col3D gels, MCF-7 cells displayed a round morphology and a cell death characterized by a Z-VAD-FMK-dependent chromatin condensation, nuclear segmentation and oligonucleosomal DNA fragmentation was induced. Transfection of MCF-7 cells with MMP-14 cDNA promoted the interactions between cells and collagen and prevented apoptosis. A transcriptomic analysis revealed that culturing MCF-7 cells within Col3D altered the expression of about 700 genes, irrespective of MMP-14 expression. Col3D modulated the expression of several apoptosis-related genes. Interestingly, MMP-14 activity was sufficient to prevent the Col3D-dependent induction of Bcl2-Interacting Killer (BIK), a pro-apoptotic member of the Bcl-2 family. Conclusions: Our results shed light on the molecular mechanisms by which a collagen-rich microenvironment triggers apoptosis in invading breast cancer cells. Furthermore, we demonstrate that MMP-14 promotes tumour progression by circumventing apoptosis. [less ▲]Detailed reference viewed: 129 (7 ULg)