Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Corneal epithelial stem cells are located in the basal layer of the limbus between the cornea and the conjunctiva. Regulation of these limbal epithelial progenitor cells by the stromal niche dictates corneal surface health. To further characterize this process, limbal explants were cultured at the air-fluid interface, termed air-lifting, to stimulate the niche. As compared to submerged cultures, air-lifting significantly promoted epithelial stratification, migration, proliferation, and intrastromal invasion by limbal epithelial cells. Epithelial intrastromal invasion was noted when the limbal, but not corneal, epithelium was recombined with the limbal stroma containing live, but not dead, cells. Invading limbal basal cells displayed up-regulated nuclear expression of p63 and Ki67, down-regulated E-cadherin and cornea-specific keratin 3, and switched expression of beta-catenin from intercellular junctions to the nucleus and cytoplasm, indicating the activation of the Wnt/beta-catenin pathway. Invaded cells isolated by collagenase from the stroma of air-lifted, but not submerged, explants showed vivid clonal growth on 3T3 fibroblast feeder layers and complete epithelial-mesenchymal transition by expressing nuclear p63 and cytoplasmic S100A4. These findings collectively suggest that epithelial-mesenchymal transition via the Wnt/beta-catenin pathway influences the fate of limbal epithelial cells, likely to be progenitor cells, between regeneration and fibrosis when the stromal niche is activated.
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PMID:Intrastromal invasion by limbal epithelial cells is mediated by epithelial-mesenchymal transition activated by air exposure. 1604 25

The metastasis-associated protein S100A4 promotes the progression of cancer by regulating the remodelling of the extracellular matrix. The expression of S100A4 in vivo is shown and the functional role of S100A4 in the pathogenesis of osteoarthritis and rheumatoid arthritisis is explored. The expression of S100A4 in rheumatoid arthritis, osteoarthritis and normal synovial tissues was determined by immunohistochemistry. The expression of matrix metalloproteinase (MMP) mRNA was measured in rheumatoid arthritis and osteoarthritis synovial fibroblasts treated and untreated with S100A4 oligomer by real-time polymerase chain reaction. Levels of released MMPs were confirmed by ELISA in cell culture supernatants. S100A4 protein was expressed in rheumatoid arthritis and osteoarthritis synovial tissues, in contrast with normal synovium. S100A4 up regulated MMP-3 mRNA in rheumatoid arthritis synovial fluid, with a peak after 6 h. This resulted in release of MMP-3 protein. MMP-1, MMP-9 and MMP-13 mRNA were also up regulated in synovial fluid, but with different kinetics. MMP-14 mRNA showed no change. Thus, S100A4 protein is expressed in synovial tissues of patients with rheumatoid arthritis and osteoarthritis in contrast with healthy people. It induces the expression and release of MMP-3 and other MMPs from synovial fluid. The data suggest that S100A4-producing cells could be involved in the pathogenesis of osteoarthritis and rheumatoid arthritis, including pannus formation and joint destruction.
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PMID:S100A4 is expressed at site of invasion in rheumatoid arthritis synovium and modulates production of matrix metalloproteinases. 1710 52

AP-2alpha, interleukin-4 (IL-4), E-cadherin, fibulin 1D, p16(INK4alpha), PTEN, RKIP, and S100A4 are determinants (suppressors, except for S100A4) of cancer cell invasiveness and other traits of cancer progression, which are located upstream of matrix metalloproteinases (MMPs) in cell signaling pathways. We will refer to them as upstream cancer-progression determinants (UCPDs, for brevity). MMP-1, MMP-2, MMP-9, MMP-11, MMP-13, MMP-14, MMP-16, and MMP-19 are enhancers of cancer cell invasiveness and other traits of cancer progression, in MDA-MB-231 breast cancer cells. We are interested in pathway links from UCPDs to gene expression of cancer cell MMPs in MDA-MB-231 cells. To test models about these links, wild-type copies of UCPDs were transiently overexpressed and then MMP mRNAs were measured by reverse transcription real-time PCR. The present results show that each of eight UCPDs is linked to the gene expression of a unique set of MMPs. This indicates that the effects are sequence-specific and that each UCPD reaches these MMP expressions through different sets of signaling pathways. We have detected 20 new pathway links, 11 are downregulatory and nine are upregulatory; 15 are new links in any cell, and five are new links in breast cancer. In seven links, three cancer-progression suppressing UCPDs unexpectedly enhance the gene expression of five cancer-progression promoting MMPs.
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PMID:New pathway links from cancer-progression determinants to gene expression of matrix metalloproteinases in breast cancer cells. 1865 63

Epithelial-mesenchymal transition (EMT) is a highly conserved morphogenetic process by which epithelial cells lose their basic morphological characteristics such as cell-cell contact and gain mesenchymal properties such as increased motility and invasiveness. To gain insights into proteins released from cells that modulate the EMT process, we compared secretome protein expression profiles of MDCK cells and Ras-transformed MDCK cells (21D1) that stably express oncogenic Ras using 2D-DIGE/LC-MS/MS. Differentially expressed secretome proteins were compared with their corresponding gene expression profiles using the Affymetrix GeneChip system. Down-regulated proteins were predominantly involved with cell-cell contact and cell-matrix adhesion (e.g., desmocollin 2, clusterin, collagen XVII and transforming growth factor-beta induced protein ig-h3), while up-regulated proteins were proteases and factors that promote migration (MMP-1, kallikrein 6, TIMP-1, and S100A4/metastasin). Many of the secretome proteins identified in this study have not been previously identified in the context of EMT and may shed light on the underlying mechanisms associated with this cellular process.
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PMID:Secretome-based proteomic profiling of Ras-transformed MDCK cells reveals extracellular modulators of epithelial-mesenchymal transition. 1929 74

Brain metastases are a devastating consequence of cancer and currently there are no specific biomarkers or therapeutic targets for risk prediction, diagnosis, and treatment. Here the proteome of the brain metastatic breast cancer cell line 231-BR has been compared with that of the parental cell line MDA-MB-231, which is also metastatic but has no organ selectivity. Using SILAC and nanoLC-MS/MS, 1957 proteins were identified in reciprocal labeling experiments and 1584 were quantified in the two cell lines. A total of 152 proteins were confidently determined to be up- or down-regulated by more than twofold in 231-BR. Of note, 112/152 proteins were decreased as compared with only 40/152 that were increased, suggesting that down-regulation of specific proteins is an important part of the mechanism underlying the ability of breast cancer cells to metastasize to the brain. When matched against transcriptomic data, 43% of individual protein changes were associated with corresponding changes in mRNA, indicating that the transcript level is a limited predictor of protein level. In addition, differential miRNA analyses showed that most miRNA changes in 231-BR were up- (36/45) as compared with down-regulations (9/45). Pathway analysis revealed that proteome changes were mostly related to cell signaling and cell cycle, metabolism and extracellular matrix remodeling. The major protein changes in 231-BR were confirmed by parallel reaction monitoring mass spectrometry and consisted in increases (by more than fivefold) in the matrix metalloproteinase-1, ephrin-B1, stomatin, myc target-1, and decreases (by more than 10-fold) in transglutaminase-2, the S100 calcium-binding protein A4, and l-plastin. The clinicopathological significance of these major proteomic changes to predict the occurrence of brain metastases, and their potential value as therapeutic targets, warrants further investigation.
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PMID:Proteotranscriptomic Profiling of 231-BR Breast Cancer Cells: Identification of Potential Biomarkers and Therapeutic Targets for Brain Metastasis. 2604 46

Gliomas are aggressive brain tumors that are resistant to conventional chemotherapy and radiotherapy. Much of this resistance is attributed to endogenous nitric oxide (NO). Recent studies revealed that 5-aminolevulinic acid (ALA)-based photodynamic therapy (PDT) has advantages over conventional treatments for glioblastoma. In this study, we used an in vitro model to assess whether NO from glioblastoma cells can interfere with ALA-PDT. Human U87 and U251 cells expressed significant basal levels of neuronal NO synthase (nNOS) and its inducible counterpart (iNOS). After an ALA/light challenge, iNOS level increased three- to fourfold over 24 h, whereas nNOS remained unchanged. Elevated iNOS resulted in a large increase in intracellular NO. Extent of ALA/light-induced apoptosis increased substantially when an iNOS inhibitor or NO scavenger was present, implying that iNOS/NO was acting cytoprotectively. Moreover, cells surviving a photochallenge exhibited a striking increase in proliferation, migration and invasion rates, iNOS/NO again playing a dominant role. Also observed was a large iNOS/NO-dependent increase in matrix metalloproteinase-9 activity, decrease in tissue inhibitor of metalloproteinase-1 expression and increase in survivin and S100A4 expression, each effect being consistent with accelerated migration/invasion as a prelude to metastasis. Our findings suggest introduction of iNOS inhibitors as pharmacologic adjuvants for glioblastoma PDT.
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PMID:Antagonistic Effects of Endogenous Nitric Oxide in a Glioblastoma Photodynamic Therapy Model. 2760 31

S100A4 protein is expressed in fibroblasts during tissue remodelling and in cancer stem cells and it induces the metastatic spread of tumor cells. In mast cells (MCs) S100A4 have been found in some pathological conditions, but its function in normal MCs remains to be described. The purpose of this study was to characterize the cellular localization of the S100A4 protein in MCs of human tissues with inflammatory or tumor disorders and, to determine the consequence of reducing its expression in MC response. We found that tissue resident MCs stained positive to S100A4. Both human HMC-1 cell line and resting CD34+-derived MCs expressed S100A4, whose levels were differentially modulated upon MC activation. Downregulation of the S100A4 protein resulted in MC growth inhibition, enhanced apoptosis and deregulation of MMP-1 and MMP-10 production. Our results suggest that S100A4 is also playing a role in the MC life cycle and functions.
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PMID:Expression and modulation of S100A4 protein by human mast cells. 3009 76