Marie Guilbert

3D collagen type I matrix inhibits the antimigratory effect of doxorubicin

BackgroundThe cell microenvironment, especially extracellular matrix proteins, plays an important role in tumor cell response to chemotherapeutic drugs. The present study was designed to investigate whether this microenvironment can influence the antimigratory effect of an anthracycline drug, doxorubicin, when tumor cells are grown in a matrix of type I collagen, a three-dimensional (3D) context which simulates a natural microenvironment.MethodsTo this purpose, we studied the migratory parameters, the integrin expression, and the activation state of focal adhesion kinase (FAK) and GTPase RhoA involved in the formation of focal adhesions and cell movement. These parameters were evaluated at non toxic concentrations which did not affect HT1080 cell proliferation.ResultsWe show that while doxorubicin decreased cell migration properties by 70% in conventional two-dimensional (2D) culture, this effect was completely abolished in a 3D one. Regarding the impact of doxorubicin on the focal adhesion complexes, unlike in 2D systems, the data indicated that the drug neither affected β1 integrin expression nor the state of phosphorylation of FAK and RhoA.ConclusionThis study suggests the lack of antiinvasive effect of doxorubicin in a 3D environment which is generally considered to better mimic the phenotypic behaviour of cells in vivo. Consistent with the previously shown resistance to the cytotoxic effect in a 3D context, our results highlight the importance of the matrix configuration on the tumor cell response to antiinvasive drugs.

Probing non-enzymatic glycation of type I collagen: a novel approach using Raman and infrared biophotonic methods.

BACKGROUND Non-enzymatic glycation is the main post-translational modification of long-life proteins observed during aging and physiopathological processes such as diabetes and atherosclerosis. Type I collagen, the major component in matrices and tissues, represents a key target of this spontaneous reaction which leads to changes in collagen biomechanical properties and by this way to tissue damages. METHODS The current study was performed on in vitro glycated type I collagens using vibrational microspectroscopies, FT-IR and Raman, to highlight spectral features related to glycation effect. RESULTS AND CONCLUSIONS We report a conservation of the triple-helical structure of type I collagen and noticeable variations in the exposure of proline upon glycation. Our data also show that the carbohydrate band can be a good spectroscopic marker of the glycation level, correlating well with the fluorescent AGEs formation with sugar addition. GENERAL SIGNIFICANCE These non-invasive and label-free methods can shed new light on the spectral features of glycated collagens and represent an effective tool to study changes in the extracellular matrix observed in vivo during aging or on the advent of a pathological situation.

Microscopic structural study of collagen aging in isolated fibrils using polarized second harmonic generation

Polarization resolved second harmonic generation (PSHG) is developed to study, at the microscopic scale, the impact of aging on the structure of type I collagen fibrils in two-dimensional coatings. A ribose-glycated collagen is also used to mimic tissue glycation usually described as an indicator of aging. PSHG images are analyzed using a generic approach of the molecular disorder information in collagen fibrils, revealing significant changes upon aging, with a direct correlation between molecular disorder and fibril diameters.

Impact of carbamylation and glycation of collagen type I on migration of HT1080 human fibrosarcoma cells

Collagen type I is an abundant component of the extracellular matrix and due to its longevity, constitutes a prominent target of non-enzymatic post-translational in vivo modifications such as carbamylation and glycation. These protein modifications involved in aging, renal diseases and diabetes, are linked to elevated cancer risk. In this in vitro study, we investigated the impact of carbamylated and glycated collagen type I on the migratory behavior of the highly invasive HT1080 human fibrosarcoma cells. The proliferation of HT1080 on modified collagens did not differ from that on native form. The glycated collagen delayed the cell adhesion time whereas the carbamylated one had no effect. The migration ability of HT1080 was studied by quantifying single cell speed using videomicroscopy. Glycation strongly inhibited mean cell speed by 47% whereas carbamylation moderately affected it by 12%. In addition, the influence of these collagen modifications on actin and vinculin organization was studied. On the glycated collagen, 63% of cells revealed a dramatic loss of actin stress fibers vs. 28% on the carbamylated one. In these cells, disorganized F-actin was accompanied with a disturbance of vinculin and both proteins were localized at the rim of the cells. Concerning the focal adhesion kinase (FAK) expression, glycated collagen only induced a significant inhibition. Whereas, both collagen modifications provoked a differential inhibition of FAK phosphorylation state by 25% for carbamylation and 60% for glycation. In conclusion, our data suggest that, in vivo, collagen glycation and carbamylation may affect tumor cell metastasis. This suggestion is supported by clinical studies reporting less aggressive tumors in diabetic or uremic patients. Consequently, the impact of such post-translational modifications has to be taken into account in order to better understand the link between aging, diabetes or uremia and cancer progression.

Extracellular Matrix Proteins Modulate Antimigratory and Apoptotic Effects of Doxorubicin

Anticancer drug resistance is a multifactorial process that includes acquired and de novo drug resistances. Acquired resistance develops during treatment, while de novo resistance is the primary way for tumor cells to escape chemotherapy. Tumor microenvironment has been recently shown to be one of the important factors contributing to de novo resistance and called environment-mediated drug resistance (EMDR). Two forms of EMDR have been described: soluble factor-mediated drug resistance (SFM-DR) and cell adhesion-mediated drug resistance (CAM-DR). Anthracyclines, among the most potent chemotherapeutic agents, are widely used in clinics against hematopoietic and solid tumors. Their main mechanism of action relies on the inhibition of topoisomerase I and/or II and the induction of apoptosis. Beyond this well-known antitumor activity, it has been recently demonstrated that anthracyclines may display potent anti-invasive effects when used at subtoxic concentrations. In this paper, we will describe two particular modes of EMDR by which microenvironment may influence tumor-cell response to one of these anthracyclines, doxorubicin. The first one considers the influence of type I collagen on the antimigratory effect of doxorubicin (CAM-DR). The second considers the protection of tumor cells by thrombospondin-I against doxorubicin-induced apoptosis (SFM-DR).

Highlighting the impact of aging on type I collagen: label-free investigation using confocal reflectance microscopy and diffuse reflectance spectroscopy in 3D matrix model

During aging, alterations of extracellular matrix proteins contribute to various pathological phenotypes. Among these alterations, type I collagen cross-linking and associated glycation products accumulation over time detrimentally affects its physico-chemical properties, leading to alterations of tissue biomechanical stability. Here, different-age collagen 3D matrices using non-destructive and label-free biophotonic techniques were analysed to highlight the impact of collagen I aging on 3D constructs, at macroscopic and microscopic levels. Matrices were prepared with collagens extracted from tail tendons of rats (newborns, young and old adults) to be within the physiological aging process. The data of diffuse reflectance spectroscopy reveal that aging leads to an inhibition of fibril assembly and a resulting decrease of gel density. Investigations by confocal reflectance microscopy highlight poor-fibrillar structures in oldest collagen networks most likely related to the glycation products accumulation. Complementarily, an infrared analysis brings out marked spectral variations in the Amide I profile, specific of the peptidic bond conformation and for carbohydrates vibrations as function of collagen-age. Interestingly, we also highlight an unexpected behavior for newborn collagen, exhibiting poorly-organized networks and microscopic features close to the oldest collagen. These results demonstrate that changes in collagen optical properties are relevant for investigating the incidence of aging in 3D matrix models.

Probing single-tumor cell interactions with different-age type I collagen networks by synchrotron-based Fourier transform infrared microspectroscopy

Abstract. We report here on a first study using synchrotron radiation-based Fourier transform infrared microspectroscopy and imaging to investigate HT1080 human fibrosarcoma cells grown onto different-aged type I collagen networks. Spectral images were analyzed with k-means and fuzzy C-means (FCM) clustering algorithms. K-means delineated tumor cells from their surrounding collagen networks and the latter as a function of age mainly due to specific changes in the sugar absorption region. The FCM analysis gave a better nuance of the spectral images. A progression of the biochemical information was observed upon going from the cellular compartments to the pericellular contact regions and to the intact collagens of the different age groups. Two spectral markers based on sugar and protein bands via the intensity ratio (I1032/I1655) and band area ratio (Asugar/Aamide II), showed an increase in advanced glycation endproducts (AGEs) with age. A clear-separation of the three age groups was obtained for spectra originating from the peripheral contact areas mainly due to changes in protein band intensities. The above-described markers decreased to constant levels for the three conditions indicating a masking of the biochemical information. These results hold promises to better understand the impact of age on tumor progression processes while highlighting new markers of the tumor cell invasion front.

The effect of collagen ageing on its structure and cellular behaviour

Collagen is the most important component in extracellular matrix (ECM) and plays a pivotal role in individual tissue function in mammals. During ageing, collagen structure changes, which can detrimentally affect its biophysical and biomechanical properties due to an accumulation of advanced glycation end-products (AGEs). AGEs have been linked to non-enzymatic cross-linking of proteins resulting in the alteration of mechanical properties of the tissue. In this study we investigate the influence of different aged collagens on the mechanical and contractile properties of reconstituted hydrogel constructs seeded with corneal stromal fibroblasts. A non-destructive indentation technique and optical coherence tomography (OCT) are used to determine the elastic modulus and dimensional changes respectively. It is revealed that the youngest collagen constructs have a higher elastic modulus and increased contraction compared to the older collagen. These results provide new insights into the relationship between collagen molecular structures and their biomechanical properties.

Abstract 2105: Advanced glycation end products of type I collagen promote cell proliferation and resistance against doxorubicin in HT-1080 cancer cells.

Resistance to apoptosis and chemotherapy is a critical factor in cancer recurrence and patient relapse. Extracellular matrix via its receptors, the integrins, has emerged as a major pathway contributing to cancer cell survival and resistance to chemotherapy (Aoudjit and Vuori, Chemother Res Pract. 2012;2012:283181). However, the effects of extracellular matrix advanced glycation end products (AGE) on cell proliferation and sensitivity to chemotherapy is not well established. In this study, we investigated whether type I collagen and particularly its AGE are involved in cell proliferation and resistance to doxorubicin in human fibrosarcoma HT-1080 cancer cells. Type I collagen was extracted from rats tail tendons (10 days, 8 and 96 weeks-old) and prepared as already described (Millerot-Serrurot et al., 2010, Cancer Cell Int, 13: 10-26). First, we characterized the glycation pattern of the different collagens using SDS-PAGE electrophoresis and fluorescence spectroscopy. A significant increase in AGE level has been observed in collagen extracted from 8 and 96 weeks-old rats. AGE level was significantly higher in collagen extracted from 96 weeks-old rats when compared to 8 weeks-old ones. Only collagen extracted from 96 weeks-old rats was able to induce 3-fold increase in proliferation of HT-1080 cells. Western-blot analysis showed that activation of MAPK/ERK, but not PI3K/AKT, was required for collagen AGE mediated cell proliferation. The MAPK/ERK inhibitor U0126 abolished this effect. Both collagens were able to inhibit doxorubicin-induced apoptosis in HT-1080 cells. Moreover, protection against apoptosis was significantly higher in the presence of collagen extracted from 96 weeks-old rats. Our data suggest extracellular matrix AGE signalling as an important promoter of cancer cell proliferation and that this pathway may contribute to a new mechanism of drug resistance. Citation Format: Charles Saby, Hassan EL Btaouri, Laurence Van Gulick, Marie Guilbert, Pierre Jeannesson, Hamid Morjani. Advanced glycation end products of type I collagen promote cell proliferation and resistance against doxorubicin in HT-1080 cancer cells. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2105. doi:10.1158/1538-7445.AM2013-2105

Abstract 1383: Impact of carbamylation and glycation of collagen type I on HT1080 cell migration

Carbamylation and glycation are well known as nonenzymatic posttranslational modifications that occur throughout the lifespan of proteins in vivo. Due to its longevity, collagen type I, largely present in connective tissues, becomes a prominent target for such modifications. Protein carbamylation and glycation have been implicated in normal aging and in a number of pathologies like diabetes, renal diseases and cancer. In addition, recent studies suggest a possible link between increased cancer risk and diabetes or end-stage renal disease. Here, we investigate the impact of carbamylation and glycation of collagen on the proliferation and migration capacities of the highly invasive human fibrosarcoma cell line HT1080. For this purpose, collagen type I extracted from rat tail tendons was used for in vitro carbamylation with cyanate or glycation with ribose. The amount of carbamylation and glycation was evaluated respectively via HPLC and spectrofluorimetry, and only the maximum levels of carbamylated and glycated collagens were considered. Tumor cell behavior was then evaluated on coatings of native, carbamylated or glycated collagen. Our results show that the proliferation of HT1080 cells on modified collagens did not differ from that on native form after 1, 2 and 3 days of culture. Concerning tumor cell adhesion, the glycated collagen delayed the adhesion time of seeded cells whereas the carbamylated form had no effect. Using time-lapse videomicroscopy, the migration ability of HT1080 was studied by quantifying single cell speed. Only, the glycated collagen strongly inhibited cell speed migration. We next investigated the effect of these collagen modifications on the organization of actin and vinculin, two proteins involved in cell locomotion. On glycated collagen, cells revealed a dramatic loss of actin stress fibers where disorganized F-actin was principally localized at the rim of the cell. Disturbance of actin integrity was accompanied with a disorganization of vinculin that was also localized at the cell periphery. On the other hand, the cells on carbamylated collagen maintained a fully organized actin network. The impact on the focal adhesion kinase (FAK), which plays a crucial role in focal adhesion formation, was also evaluated. Only glycated collagen induced a significant inhibition of the expression level of FAK, whereas both collagen modifications provoke a differential inhibition of its phosphorylation state that is mainly taking place with glycation. In conclusion, only glycation is demonstrated as an important factor affecting tumor cell migration. This impact has to be certainly considered in order to better understand the link between diabetes, aging and cancer incidence. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1383. doi:10.1158/1538-7445.AM2011-1383