Search results for "Extracellular Matrix"
showing 10 items of 420 documents
Tumor and its microenvironment: a synergistic interplay.
2013
The mutual and interdependent interaction between tumor and its microenvironment is a crucial topic in cancer research. Recently, it was reported that targeting stromal events could improve efficacies of current therapeutics and prevent metastatic spreading. Tumor microenvironment is a "complex network" of different cell types, soluble factors, signaling molecules and extracellular matrix components, which orchestrate the fate of tumor progression. As by definition, cancer stem cells (CSCs) are proposed to be the unique cell type able to maintain tumor mass and survive outside the primary tumor at metastatic sites. Being exposed to environmental stressors, including reactive oxygen species …
Production of superoxide by human malignant melanoma cells.
1998
Metastasis is a complicated multi-step process involving interactions between tumour cells, the extracellular matrix and the vessel walls. Experimental observations suggest that leucocyte migration and function could be a suitable model in order to understand tumour cell dissemination. In the present report we show and quantify the production of free radicals by human malignant melanoma cells (St-ml12) by means of a spectrophotometrical method, using an enzyme immunoassay reader. Endothelial cells and activated polymorphonuclear leucocytes were used as controls. Melanoma cells without stimulants produced large amounts of superoxide anion at an increasing rate in relation to time, which coul…
Medication for Acromegaly Reduces Expression of MUC16, MACC1 and GRHL2 in Pituitary Neuroendocrine Tumour Tissue
2021
Acromegaly is a disease mainly caused by pituitary neuroendocrine tumor (PitNET) overproducing growth hormone. First-line medication for this condition is the use of somatostatin analogs (SSAs), that decrease tumor mass and induce antiproliferative effects on PitNET cells. Dopamine agonists (DAs) can also be used if SSA treatment is not effective. This study aimed to determine differences in transcriptome signatures induced by SSA/DA therapy in PitNET tissue. We selected tumor tissue from twelve patients with somatotropinomas, with half of the patients receiving SSA/DA treatment before surgery and the other half treatment naive. Transcriptome sequencing was then carried out to identify diff…
Mammary-derived growth inhibitor (MDGI) interacts with integrin α-subunits and suppresses integrin activity and invasion
2010
The majority of mortality associated with cancer is due to formation of metastases from the primary tumor. Adhesion mediated by different integrin heterodimers has an important role during cell migration and invasion. Protein interactions with the β1-integrin cytoplasmic tail are known to influence integrin affinity for extracellular ligands, but regulating binding partners for the α-subunit cytoplasmic tails have remained elusive. In this study, we show that mammary-derived growth inhibitor (MDGI) (also known as FABP-3 or H-FABP) binds directly to the cytoplasmic tail of integrin α-subunits and its expression inhibits integrin activity. In breast cancer cell lines, MDGI expression correlat…
Differential inhibition of renal cancer cell invasion mediated by fibronectin, collagen IV and laminin.
2000
Invasion of tumor cells into the extracellular matrix is an essential step in the formation of metastases in renal cancer. Cell adhesion molecules such as beta(1)-integrins, which bind to the RGD sequence (arginine-glycine-asparagine) and CD44 are involved in this process. We examined the invasion of a renal carcinoma cell line (CCF-RC1) into the extracellular matrix compounds fibronectin, collagen IV and laminin and the effect of TGFbeta and IFNgamma on this process. The inhibitory effect of an antibody against the beta(1)-subunit of integrins (CD29), as well as a pentapeptide including the RGD sequence, was also evaluated. A micro-chemotaxis chamber, including a polycarbonate membrane wit…
Biotensegrity of the Extracellular Matrix: Physiology, Dynamic Mechanical Balance, and Implications in Oncology and Mechanotherapy
2014
Cells have the capacity to convert mechanical stimuli into chemical changes. This process is based on the tensegrity principle, a mechanism of tensional integrity. To date, this principle has been demonstrated to act in physiological processes such as mechanotransduction and mechanosensing at different scales (from cell sensing through integrins to molecular mechanical interventions or even localized massage). The process involves intra- and extracellular components, including the participation of extracellular matrix (ECM) and microtubules that act as compression structures, and actin filaments which act as tension structures. The nucleus itself has its own tensegrity system which is impli…
WIN55,212-2-induced expression of Mir-29b1 favours the suppression of osteosarcoma cell migration in a SPARC-independent manner
2019
WIN55,212-2 (WIN) is a synthetic agonist of cannabinoid receptors that displays promising antitumour properties. The aim of this study is to demonstrate that WIN is able to block the migratory ability of osteosarcoma cells and characterize the mechanisms involved. Using wound healing assay and zymography, we showed that WIN affects cell migration and reduces the activity of the metalloproteases MMP2 and MMP9. This effect seemed to be independent of secreted protein acidic and rich in cysteine (SPARC), a matricellular protein involved in tissue remodeling and extracellular matrix deposition. SPARC release was indeed prevented by WIN, and SPARC silencing by RNA interference did not influence …
Genetic abrogation of the fibronectin-α5β1 integrin interaction in articular cartilage aggravates osteoarthritis in mice.
2018
The balance between synthesis and degradation of the cartilage extracellular matrix is severely altered in osteoarthritis, where degradation predominates. One reason for this imbalance is believed to be due to the ligation of the α5β1 integrin, the classic fibronectin (FN) receptor, with soluble FN fragments instead of insoluble FN fibrils, which induces matrix metalloproteinase (MMP) expression. Our objective was to determine whether the lack of α5β1-FN binding influences cartilage morphogenesis in vivo and whether non-ligated α5β1 protects or aggravates the course of osteoarthritis in mice. We engineered mice (Col2a-Cre;Fn1RGE/fl), whose chondrocytes express an α5β1 binding-deficient FN, …
Haem oxygenase-1 regulates catabolic and anabolic processes in osteoarthritic chondrocytes
2007
Pro-inflammatory cytokines, matrix metalloproteinases (MMPs) and other catabolic factors participate in the pathogenesis of cartilage damage in osteoarthritis (OA). Pro-inflammatory cytokines such as interleukin-1β (IL-1β) mediate cartilage degradation and might be involved in the progression of OA. Previously, we found that haem oxygenase-1 (HO-1) is down-regulated by pro-inflammatory cytokines and up-regulated by IL-10 in OA chondrocytes. The aim of this study was to determine whether HO-1 can modify the catabolic effects of IL-1β in OA cartilage and chondrocytes. Up-regulation of HO-1 by cobalt protoporphyrin IX significantly reduced glycosaminoglycan degradation elicited by IL-1β in OA …
PLLA scaffolds produced by thermally induced phase separation (TIPS) allow human chondrocyte growth and extracellular matrix formation dependent on p…
2016
Damage of hyaline cartilage species such as nasoseptal or joint cartilage requires proper reconstruction, which remains challenging due to the low intrinsic repair capacity of this tissue. Implantation of autologous chondrocytes in combination with a biomimetic biomaterial represents a promising strategy to support cartilage repair. The aim of this work was to assess the viability, attachment, morphology, extracellular matrix (ECM) production of human articular and nasoseptal chondrocytes cultured in vitro in porous poly(L-lactic) (PLLA) scaffolds of two selected pore sizes (100 and 200 μm). The PLLA scaffolds with 100 and 200 μm pore sizes were prepared via ternary thermally induced ph…