Dual regulation of stromelysin-3 by fibroblast growth factor-2 in murine osteoblasts

Circulating MMP11 and specific antibody immune response in breast and prostate cancer patients

Background

Tumor Associated Antigens are characterized by spontaneous immune response in cancer patients as a consequence of overexpression and epitope-presentation on MHC class I/II machinery. Matrix Metalloprotease 11 (MMP11) expression has been associated with poor prognosis for several cancer types, including breast and prostate cancer.

Methods

MMP11 expression was determined by immunoistochemistry in breast and prostate cancer samples. Circulating MMP11 protein as well as the spontaneous immune responses against MMP11 were analyzed in a set of breast and prostate cancer patients.

Results

In plasma samples MMP11 protein was present in 5/13 breast cancer patients and in 1/12 prostate cancer patients. An antibody response was observed in 7/13 breast cancer patients and in 3/12 prostate cancer patients.

Conclusions

These findings further suggest MMP11 as a promising biomarker for these tumor types and a suitable target for cancer immunotherapy strategies.

Cancer secretomics reveal pathophysiological pathways in cancer molecular oncology

Emerging proteomic tools and mass spectrometry play pivotal roles in protein identification, quantification and characterization, even in complex biological samples. The cancer secretome, namely the whole collection of proteins secreted by cancer cells through various secretory pathways, has only recently been shown to have significant potential for diverse applications in oncoproteomics. For example, secreted proteins might represent putative tumor biomarkers or therapeutic targets for various types of cancer. Consequently, many proteomic strategies for secretome analysis have been extensively deployed over the last few years. These efforts generated a large amount of information awaiting deeper mining, better understanding and careful interpretation. Distinct sub-fields, such as degradomics, exosome proteomics and tumor-host cell interactions have been developed, in an attempt to provide certain answers to partially elucidated mechanisms of cancer pathobiology. In this review, advances, concerns and challenges in the field of secretome analysis as well as possible clinical applications are discussed.

Identification of matrix metalloproteinase 11 as a predictive tumor marker in serum based on gene expression profiling

PURPOSE

Prognostic markers discovery is a strategy for early diagnosis and individualization therapy for human cancer. In this study, we focus to integrate different methods to identify specific biomarker and elucidate its clinical significance.

EXPERIMENTAL DESIGN

A powerful tool named Digital Gene Expression Display online was applied to isolate differentially expressed genes correlated with gastric cancer. Matrix metalloproteinase 11 (MMP11) was selected and confirmed at both mRNA and protein level in 10 cell lines, 123 cases of tumor tissues, and 305 cases of gastric cancer serum specimen by semiquantitative PCR, immunohistochemistry staining, and ELISA techniques, respectively.

RESULTS

Our data showed that overexpression of MMP11 at mRNA and protein level was consistently detected in cell lines and primary tumors compared with matched normal tissues. Importantly, serum MMP11 levels were also significantly elevated in gastric cancer patients compared with those of the control subjects (P < 0.001), and the positive expression was well correlated with metastasis in gastric cancer patients (P = 0.009). Furthermore, we have shown that overexpression of MMP11 was associated with the malignant proliferation of AGS cells.

CONCLUSIONS

Combination of gene expression profiling and specific clinical resource is a promising approach to validate gene expression patterns associated with malignant phenotype. As a secreted protein, MMP11 may play an important role in carcinogenesis and has potential implication as a biomarker for the diagnosis and prognosis of human cancers including gastric cancer.

Reduced collagen degradation in polytraumas with traumatic brain injury causes enhanced osteogenesis

Patients with traumatic brain injury (TBI) and skeletal injuries have increased rates of excessive bone healing (EH = hypertrophic callus formation and/or heterotopic ossification). Polytrauma patients are often attributed higher rates of delayed fracture union. This study compares 182 total fractures in 29 isolated polytrauma patients (POLY) and 48 patients after TBI and polytrauma (TBI+POLY), examining the clinical parameters of EH versus delay. A subset of 28 patients (13 TBI+POLY, 15 POLY) underwent serological testing for the following bone turnover parameters: carboxy-terminal extension peptide of type 1 procollagen (P1CP), pyridinolene cross-linked carboxy-terminal telopeptide (1CTP), insulin-like growth factor-1 (IGF-1), insulin-like growth factor binding protein-3 (IGFBP-3), and basic fibroblast growth factor (bFGF). There were higher rates of delayed union in the POLY patients (45% vs. 23%) and EH in the TBI+POLY patients (33% vs. 17%) (not significant = NS). More delayed unions were observed in diaphyseal fractures suffered by POLY (28%) than in TBI+POLY (15%) patients (NS). EH after pelvic fracture was apparent in 52% TBI+POLY and in 21% POLY fractures (NS). P1CP levels did not differ between the groups, but the collagen breakdown parameter 1CTP was significantly higher in the POLY group (p = 0.01-0.04). IGF-1 levels were below normal in both groups, and did not differ. IGFBP-3, an IGF-1-inhibiting and collagenase-3-activating protein, was significantly higher in POLY patients (p = 0.017-0.037). bFGF levels did not vary between groups. Increased serum levels of 1CTP and IGFBP-3 in POLY patients suggest that EH in TBI patients is secondary to decreased collagen breakdown rather than increased synthesis.

Sprouty genes are expressed in osteoblasts and inhibit fibroblast growth factor-mediated osteoblast responses

Fibroblast growth factors (FGFs) and fibroblast growth factor receptors (FGFRs) are major regulators of skeletal growth and development. Signal transduction via FGFRs is complex and mediates proliferation, differentiation, or migration depending upon the cellular context. Members of the Spry gene family antagonize the FGFR signal transduction pathway and inhibit lung morphogenesis, angiogenesis, and chondrogenesis. We examined the expression of Spry2 in the osteoblastic MC3T3-E1 cell line. MC3T3-E1 cells express Spry2 in response to FGF1 stimulation. Treatment of MC3T3-E1 cells with FGF1 results in the expression of Spry2 in a manner consistent with an early response gene. Pharmacological inhibitors of mitogen-activated protein kinase activation inhibit FGF1-induced expression of Spry2 mRNA. Transient overexpression of Spry2 in MC3T3-E1 resulted in decreased FGF1-mediated extracellular signal-regulated kinase phosphorylation and FGF1-stimulated osteopontin promoter activity. Furthermore, we show that Spry2 interacts with Raf-1 in a glutathione-S-transferase pulldown assay and that this interaction may involve multiple sites. Finally, Spry2 expression precedes the onset of the expression of osteoblast differentiation markers in an in vitro assay of primary osteoblast differentiation. Taken together, these results indicate that Spry2 expression is an early response to stimulation by FGF1 in MC3T3-E1 cells and acts as a feedback inhibitor of FGF1-induced osteoblast responses, possibly through interaction with Raf1.

Expression profiling and cellular localization of genes associated with the hair cycle induced by wax depilation

The hair cycle is a highly regulated process controlled by multiple factors. Systematic analysis of gene expression patterns in each stage of the hair cycle would provide information useful for understanding this complicated process. To identify genes associated with the hair cycle, we used DNA microarray hybridization to analyze sequential gene expression patterns in mouse skin following hair cycle synchronization by wax depilation. Messenger RNA levels in mouse skin at various times after depilation were compared with those prior to depilation (resting phase). According to their expression patterns, upregulated genes were categorized into four groups: early anagen, middle anagen, late anagen/early catagen, and middle/late catagen, and processes that take place in each stage were evaluated. We identified 12 new components that are specifically expressed in the hair follicle, 11 genes in anagen including carbonic anhydrase 6, cytokeratin 12, and matrix metalloproteinase-11 in catagen that were confirmed using in situ hybridization. The strategy used here allowed us to identify unknown genes or process previously not suspected to have a role in hair biology. These analyses will contribute to elucidating the mechanisms of hair cycle regulation and should lead to the identification of novel molecular targets for hair growth and/or depilation agents.

Functions and regulations of fibroblast growth factor signaling during embryonic development

Fibroblast growth factors (FGF) are secreted molecules which function through the activation of specific tyrosine kinases receptors, the FGF receptors that transduce the signal by activating different pathways including the Ras/MAP kinase and the phospholipase-C gamma pathways. FGFs are involved in the regulation of many developmental processes including patterning, morphogenesis, differentiation, cell proliferation or migration. Such a diverse set of activities requires a tight control of the transduction signal which is achieved through the induction of different feedback inhibitors such as the Sproutys, Sef and MAP kinase phosphatase 3 which are responsible for the attenuation of FGF signals, limiting FGF activities in time and space.

Expression of stromelysin-3 (matrix metalloproteinase-11) in macrophages of murine thymus following thymocyte apoptosis

High expression of stromelysin-3 (ST-3), also known as matrix metalloproteinase-11, has been implicated in tumor progression and intense tissue remodeling. Nonetheless, details of the cell type(s) expressing ST-3 are less well defined. Here, we report that ST-3 expression was elevated in mouse thymus following thymocyte apoptosis after administration of anti-CD3 Ab. TUNEL analysis revealed that many thymocytes in the cortical region were induced to apoptotic cell death 14 h after the injection. After an additional 2-6 h, ST-3 expression in the thymus was more apparent. Co-staining analysis by anti-ST-3 and F4/80 Abs showed that most F4/80-positive macrophages were also positive for ST-3. Murine peritoneal macrophages were found to constitutively express ST-3, and exposure to apoptotic cells hardly affected ST-3 expression in the macrophages. Taken together, our results indicate that ST-3 is not involved in the execution process of thymocyte apoptosis, and the increased levels of ST-3 in the thymus may be due to the presence of macrophages responsible for clearance of apoptotic cells.

Induction of stromelysin-1 (MMP-3) by fibroblast growth factor-2 (FGF-2) in FGF-2-/- microvascular endothelial cells requires prolonged activation of extracellular signal-regulated kinases-1 and -2 (ERK-1/2)

Basic fibroblast growth factor (FGF-2) and matrix metalloproteinases (MMPs) play key roles in vascular remodeling. Because FGF-2 controls a number of proteolytic activities in various cell types, we tested its effect on vascular endothelial cell expression of MMP-3 (stromelysin-1), a broad-spectrum proteinase implicated in coronary atherosclerosis. Endothelial cells (EC) from FGF-2-/- mice are highly responsive to exogenous FGF-2 and were therefore used for this study. The results showed that treatment of microvascular EC with human recombinant FGF-2 results in strong induction of MMP-3 mRNA and protein expression. Upregulation of MMP-3 mRNA by FGF-2 requires de novo protein synthesis and activation of the ERK-1/2 pathway. FGF-2 concentrations (5-10 ng/ml) that induce rapid and prolonged (24 h) activation of ERK-1/2 upregulate MMP-3 expression. In contrast, lower concentrations (1-2 ng/ml) that induce robust but transient (<8 h) ERK-1/2 activation are ineffective. Inhibition of ERK-1/2 activation at different times (-0.5 h to +8 h) of EC treatment with effective FGF-2 concentrations blocks MMP-3 upregulation. Thus, FGF-2 induces EC expression of MMP-3 with a threshold dose effect that requires sustained activation of the ERK-1/2 pathway. Because FGF-2 controls other EC functions with a linear dose effect, these features indicate a unique role of MMP-3 in vascular remodeling.

Fibroblast growth factor signaling controlling osteoblast differentiation

Fibroblast growth factors (FGFs) play important roles in skeletal development and postnatal osteogenesis. FGF signaling controls bone formation by regulating the expression of various genes involved in osteoprogenitor cell replication, osteoblast differentiation and apoptosis. Recent genetic manipulation of FGF expression in mice and studies of the phenotype induced by gain-of-function mutations in FGF receptors in humans revealed the important role of FGF signaling in osteoblast function and differentiation. Additionally, cell biology studies allowed to identify some signaling pathways that are involved in the control of FGF actions in osteoblasts. This led to a better understanding of the functional role of FGF signaling in the control of gene expression in osteoblasts. The elucidation of molecular mechanisms by which FGF signaling promotes osteoblast gene expression and differentiation may help to find novel molecular targets and develop new therapeutic approaches to promote bone formation in human bone disorders.

The metastasis-associated metalloproteinase stromelysin-3 is induced by transforming growth factor-beta in osteoblasts and fibroblasts

Bone matrix serves as a reservoir of growth factors important in growth and tissue remodeling, and transforming growth factor-beta (TGF-beta) is abundant in bone matrix. Normal processes, such as remodeling, and pathological processes, such as osteolytic metastasis, cause the release of growth factors from the matrix, allowing them to influence the behavior of cells within their microenvironment. Breast cancer metastases frequently establish themselves in the bone compartment, often causing localized osteolysis. Stromelysin-3 is a matrix metalloproteinase associated with tumor metastases. Its expression in host tissues favors the homing and survival of malignant epithelial cells in early tumorigenesis by releasing and/or activating growth factors sequestered in the extracellular matrix. Osteoblasts express stromelysin-3, and Northern and Western blot analysis show that its messenger RNA and protein levels are increased by TGF-beta. Nuclear run-off assays demonstrate activation of gene transcription, and experiments using transcription inhibitors demonstrate stabilization of stromelysin-3 messenger RNA by TGF-beta. Importantly, TGFbeta induces stromelysin-3 in fibroblasts by similar mechanisms, indicating that it is likely to stimulate stromelysin-3 expression in breast stroma. Stimulation of stromelysin-3 expression by TGF-beta in fibroblasts and osteoblasts could play a role in the metastasis of breast cancer cells and their homing and survival in bone.

Messenger ribonucleic acid expression of 16 matrix metalloproteinases in bone-implant interface tissues of loose artificial hip joints

Matrix metalloproteinases (MMPs) have been reported to be the major factors responsible for aseptic loosening of artificial hip joints. So far, messenger ribonucleic acid (mRNA) expression patterns of seven MMPs have been reported, but that of many other MMPs which have been newly discovered or recently considered to be responsible for prosthetic loosening is still unknown. In this study, mRNA expression pattern of 16 different types of MMPs were analyzed to evaluate which MMPs were locally produced and contributed to prosthetic loosening. Synovium-like interface tissues between bone and prosthesis were collected from 18 cases of aseptic loose artificial hip joint at revision surgery. Six cases of normal synovium were used as controls. Total RNA was extracted by single-step acid guanidinium-thiocyanate-phenol-chloroform procedure. mRNA expression of MMPs was analyzed by semiquantitative reverse transcription-polymerase chain reaction. Based on local expression pattern of MMPs at the mRNA level, aseptic loose artificial hip joint was characterized by elevated expression of MMP-1, MMP-9, MMP-10, MMP-12, and MMP-13; moderate expression of MMP-2, MMP-7, MMP-8, MMP-11, membrane type (MT)1-MMP (MMP-14), MT2-MMP (MMP-15), MT3-MMP (MMP-16), MT4-MMP (MMP-17), and MMP-19; lower expression of MMP-3; and little significance of MMP-20. The MMPs detected in this study can potentially degrade almost all components of the periprosthetic extracellular matrix. Thus, many MMP type enzymes possibly contribute to prosthetic loosening and osteolysis through pathologic extracellular matrix degradation and connective tissue/bone remodeling around prostheses.

Osteopenia and decreased bone formation in osteonectin-deficient mice

Bone continuously remodels in response to mechanical and physiological stresses, allowing vertebrates to renew bone as adults. Bone remodeling consists of the cycled synthesis and resorption of collagenous and noncollagenous extracellular matrix proteins, and an imbalance in this process can lead to disease states such as osteoporosis, or more rarely, osteopetrosis. There is evidence that the extracellular matrix glycoprotein osteonectin or secreted protein acidic and rich in cysteine (BM-40) may be important in bone remodeling. Osteonectin is abundant in bone and is expressed in areas of active remodeling outside the skeleton. In vitro studies indicate that osteonectin can bind collagen and regulate angiogenesis, metalloproteinase expression, cell proliferation, and cell-matrix interactions. In some osteopenic states, such as osteogenesis imperfecta and selected animal models for bone fragility, osteonectin expression is decreased. To determine the function of osteonectin in bone, we used contact x-ray, histomorphometry, and Northern blot analysis to characterize the skeletal phenotype of osteonectin-null mice. We found that osteonectin-null mice have decreased bone formation and decreased osteoblast and osteoclast surface and number, leading to decreased bone remodeling with a negative bone balance and causing profound osteopenia. These data indicate that osteonectin supports bone remodeling and the maintenance of bone mass in vertebrates.

Transcriptional induction of stromelysin-3 in mesodermal cells is mediated by an upstream CCAAT/enhancer-binding protein element associated with a DNase I-hypersensitive site

Stromelysin-3 (ST3) is a matrix metalloproteinase whose synthesis is markedly increased in stromal fibroblasts of most invasive human carcinomas. In the present study, we have investigated the molecular mechanisms by which high levels of ST3 expression can be induced. In contrast to the early and transient induction of interstitial collagenase by 12-O-tetradecanoylphorbol-13-acetate (TPA), the fibroblastic induction of ST3 was found to be delayed and to require protein neosynthesis. We demonstrated that this induction is transcriptional and does not result from changes in RNA stability. By looking next to promoter regions accessible to DNase I upon gene induction, we have identified two distal elements and have characterized their role in the transcriptional regulation of ST3. The first one is a TPA-responsive element that controls the base-line ST3 promoter activity but is not required for its activation. We demonstrate that ST3 gene induction is actually mediated by the second element, a C/EBP-binding site, by showing: (i) that this element becomes accessible in cells induced to express ST3, (ii) that endogenous C/EBPbeta binds to the ST3 promoter, and (iii) that this binding leads to ST3 transcriptional activation. Our study provides new insights into the regulation of ST3 and suggests an additional role for C/EBP transcription factors in tissue remodeling processes associated with this MMP.