Reciprocal Interplay Between Fibrillar Collagens and Collagen-Binding Integrins: Implications in Cancer Progression and Metastasis.

Cancers are complex ecosystems composed of malignant cells embedded in an intricate microenvironment made of different non-transformed cell types and extracellular matrix (ECM) components. The tumor microenvironment is governed by constantly evolving cell-cell and cell-ECM interactions, which are now recognized as key actors in the genesis, progression and treatment of cancer lesions. The ECM is composed of a multitude of fibrous proteins, matricellular-associated proteins, and proteoglycans. This complex structure plays critical roles in cancer progression: it functions as the scaffold for tissues organization and provides biochemical and biomechanical signals that regulate key cancer hallmarks including cell growth, survival, migration, differentiation, angiogenesis, and immune response. Cells sense the biochemical and mechanical properties of the ECM through specialized transmembrane receptors that include integrins, discoidin domain receptors, and syndecans. Advanced stages of several carcinomas are characterized by a desmoplastic reaction characterized by an extensive deposition of fibrillar collagens in the microenvironment. This compact network of fibrillar collagens promotes cancer progression and metastasis, and is associated with low survival rates for cancer patients. In this review, we highlight how fibrillar collagens and their corresponding integrin receptors are modulated during cancer progression. We describe how the deposition and alignment of collagen fibers influence the tumor microenvironment and how fibrillar collagen-binding integrins expressed by cancer and stromal cells critically contribute in cancer hallmarks.info:eu-repo/semantics/publishe

Remodelling of the fibre-aggregate structure of collagen gels by cancer-associated fibroblasts: a time-resolved grey-tone image analysis based on stochastic modelling

peer reviewedSolid tumors consist of tumor cells associated with stromal and immune cells, secreted factors and extracellular matrix (ECM), that together constitute the tumor microenvironment. Among stromal cells, activated fibroblasts, known as cancer-associated fibroblasts (CAFs) are of particular interest. CAFs secrete a plethora of ECM components including collagen and modulate the architecture of the ECM, thereby influencing cancer cell migration. The characterization of the collagen fibre network and its space and time-dependent microstructural modifications is key to investigating the interactions between cells and the ECM. Developing image analysis tools for that purpose is still a challenge because the structural complexity of the collagen network calls for specific statistical descriptors. Moreover, the low signal-to-noise ratio of imaging techniques available for time-resolved studies rules out standard methods based on image segmentation. In this work, we develop a novel approach based on the stochastic modelling of the gel structure and on grey-tone image analysis. The method is then used to study the remodelling of a collagen matrix by migrating breast cancer-derived CAFs in a three-dimensional spheroid model of cellular invasion. Specifically, the structure of the collagen at the scale of a few microns is found to consist in regions with high fibre density separated by depleted regions, which can be thought of as aggregates and pores. The approach we develop captures this two-scale structure with a clipped Gaussian field model to describe the aggregates-and-pores large-scale structure, and a homogeneous Boolean model to describe the small-scale fibre network within the aggregates. The model parameters are identified by fitting the grey-tone histograms and correlation functions of confocal microscopy images. The method applies to unprocessed grey-tone images, and it can therefore be used with low magnification, noisy time-lapse reflectance images. When applied to the spheroid time-resolved images, the method reveals different matrix densification mechanisms for the matrix in direct contact or far from the cells

Nouveaux procédés de microscopie tridimensionnelle et algorithmes de traitement et quantification d'images pour étudier les modèles in vitro de sphéroïde associés au cancer

Recent progresses in 3D microscopy techniques revolutionise our way to study biological processes involved in cancer metastasis thanks to innovative imaging of biological models. In vitro spheroid model consists in an aggregate of one or several cell types labelled using fluorescent dyes or constructs and embedded in fibrillar type I collagen matrix. Studying spheroid invasion properties involves the use of various microscopy techniques and the development of adapted processing and quantification algorithms

Detection and quantification of human and bovine novoviruses by a TaqMan RT-PCR assay with a control for inhibition.

Noroviruses are single-stranded RNA viruses belonging to the family Caliciviridae. They are a major cause of epidemic and sporadic gastroenteritis in humans and calves. Reverse transcription-polymerase chain reaction (RT-PCR) has become the ‘‘gold standard’’ for detection of noroviruses in faecal and environmental samples. However, false negative results due to co-concentration of RT-PCR inhibitors are a continuous concern. A TaqMan real-time RT-PCR assay making use of a foreign internal RNA control and a RNA standard was developed. Very interestingly, this method is capable of detecting human noroviruses belonging to genogroups I and II, and bovine noroviruses belonging to genogroup III. Inhibitors were removed efficiently by 1/10 dilution of the sample or addition of bovine serum albumin to the RT-PCR mix. This assay was validated with human and bovine stool samples previously tested for norovirus by conventional RT-PCR. The ability to detect norovirus in stool samples that were negative by conventional RT-PCR assay demonstrate the higher sensitivity of the TaqMan assay compared to the conventional RT-PCR assay. This real-time RT-PCR assay allows the detection of both human and bovine noroviruses, avoids false negative results and is able to quantify the level of norovirus contamination.RF6/85 et SD/AF/0

Impact of cancer associated fibroblasts-derived cathepsin B on breast cancer progression

Tumors arise in a complex ecosystem gover ned by interactions established between cancer cells and the microenvironment. This one is constituted on one side by a multitude of different non-cancerous cell types (e.g.: stromal and immune cells) and on the other side by components of the extracellular matrix. During cancerogenesis fibroblasts are activated and differenciated into cancer associated fibroblasts (CAFs). Nevertheless, the precise functions of CAFs in cancer progression are not fully understood. Among proteases implicated in both ECM remodeling and cancer progression, cathepsin B (Ctsb), a lysosomial cystein protease, has been detected in cancer cells and in tumor-associated macrophages. Ctsb expression is associated with a poor prognosis in breast cancer patients. However, the contribution of CAF-derived Ctsb to tumor progression is unknown. By using the MMTV-PyMT mouse model of breast cancer, our preliminary data reveal that CAFs express Ctsb at higher levels than cancer cells. Our data show that Ctsb deficiency impairs the capacity of CAFs to interact with collagen fibers and strongly diminishes the migration of CAFs in a 3D spheroid model. Further more, we demonstrate that the invasion of Ctsb-/- CAFs is restored upon addition of conditioned medium collected from WT CAFs but Further more, the invasion of Ctsb-/- CAFs is restored upon addition of conditioned medium collected from wild-type (WT) CAFs but also by durotaxis or by deletion of Cathepsin Z (Ctsz). Collectively these data suggest that Ctsb represents a key regulator of the complex cross-talk established between CAFs, the ECM and cancer cells

Short-chain fructooligosaccharide supplementation during gestation and lactation or after weaning differentially impacts pig growth and IgA response to influenza vaccination

International audienceShort-chain fructooligosaccharides (scFOS) in the maternal diet during gestation and lactation positively modulate gut microbiota and maturation of the intestinal immune system in the offspring. The effect of maternal and post-weaning scFOS supplementation on the efficiency of the humoral response to influenza vaccination was evaluated. Seventeen sows received a standard or a scFOS supplemented diet for the last 4 weeks of gestation and lactation. From weaning, 128 pigs were fed a standard or a scFOS supplemented diet for 7 weeks. Post-weaning scFOS diet increased anti-influenza IgA levels in pig serum and faeces whereas maternal scFOS supplementation moderated the decrease of piglet growth induced by sow seropositivity to influenza during lactation and further resulted in a higher body weight at 10 weeks of age. This study confirms a potential interest of early scFOS supplementation to enhance vaccine response and to promote growth

Impact of cancer associated fibroblasts-derived cathepsin B on breast cancer progression

Tumors arise in a complex ecosystem gover ned by interactions established between cancer cells and the microenvironment. This one is constituted on one side by a multitude of different non-cancerous cell types (e.g.: stromal and immune cells) and on the other side by components of the extracellular matrix. During cancerogenesis fibroblasts are activated and differenciated into cancer associated fibroblasts (CAFs). Nevertheless, the precise functions of CAFs in cancer progression are not fully understood. Among proteases implicated in both ECM remodeling and cancer progression, cathepsin B (Ctsb), a lysosomial cystein protease, has been detected in cancer cells and in tumor-associated macrophages. Ctsb expression is associated with a poor prognosis in breast cancer patients. However, the contribution of CAF-derived Ctsb to tumor progression is unknown. By using the MMTV-PyMT mouse model of breast cancer, our preliminary data reveal that CAFs express Ctsb at higher levels than cancer cells. Our data show that Ctsb deficiency impairs the capacity of CAFs to interact with collagen fibers and strongly diminishes the migration of CAFs in a 3D spheroid model. Further more, we demonstrate that the invasion of Ctsb-/- CAFs is restored upon addition of conditioned medium collected from WT CAFs but Further more, the invasion of Ctsb-/- CAFs is restored upon addition of conditioned medium collected from wild-type (WT) CAFs but also by durotaxis or by deletion of Cathepsin Z (Ctsz). Collectively these data suggest that Ctsb represents a key regulator of the complex cross-talk established between CAFs, the ECM and cancer cells