Matrix metalloproteinases and TGFβ1 modulate oral tumor cell matrix

Circulating microRNA sequencing revealed miRNome patterns in hematology and oncology patients aiding the prognosis of invasive aspergillosis

Invasive aspergillosis (IA) may occur as a serious complication of hematological malignancy. Delays in antifungal therapy can lead to an invasive disease resulting in high mortality. Currently, there are no well-established blood circulating microRNA biomarkers or laboratory tests which can be used to diagnose IA. Therefore, we aimed to define dysregulated miRNAs in hematology and oncology (HO) patients to identify biomarkers predisposing disease. We performed an in-depth analysis of high-throughput small transcriptome sequencing data obtained from the whole blood samples of our study cohort of 50 participants including 26 high-risk HO patients and 24 controls. By integrating in silico bioinformatic analyses of small noncoding RNA data, 57 miRNAs exhibiting significant expression differences (P < 0.05) were identified between IA-infected patients and non-IA HO patients. Among these, we found 36 differentially expressed miRNAs (DEMs) irrespective of HO malignancy. Of the top ranked DEMs, we found 14 significantly deregulated miRNAs, whose expression levels were successfully quantified by qRT-PCR. MiRNA target prediction revealed the involvement of IA related miRNAs in the biological pathways of tumorigenesis, the cell cycle, the immune response, cell differentiation and apoptosis.

Analysis of vascular-associated factors and the prognosis of poorly differentiated hypopharyngeal carcinoma

The aim of the present study was to analyze the characteristics of angiogenic factors in patients with hypopharyngeal cancer, and to study the effects of these factors on induction chemotherapy, patient prognosis and survival. Data from 60 eligible patients with hypopharyngeal cancer that were treated between January 2012 and December 2016 were collected retrospectively. The differential expression of angiogenic factors in tumor and peritumoral tissues was analyzed retrospectively to assess the association between five differentially expressed genes, including interleukin (IL)-1β, transforming growth factor (TGF)-β, matrix metalloproteinase-9 (MMP-9), angiopoietin-2 and interferon-inducible T-cell α chemoattractant, and clinicopathological characteristics in different types of chemotherapy-associated blood vessels within samples of poorly differentiated hypopharyngeal cancer. The χ² test or t-test was used to compare the frequency data, the Kaplan-Meier method was used for survival analysis and the log-rank test was used to compare the Kaplan-Meier curves. P<0.05 was considered to indicate a statistically significant difference. The results of the present study demonstrated that there was a significant difference in the expression levels of vascular-associated factors between hypopharyngeal carcinoma and peritumoral tissues. Additionally, the results revealed a significant difference in the overall survival and prognosis of patients with a decreased vascular classification compared with patients with an unchanged vascular classification, which was assessed using narrowband imaging (NBI) following induction chemotherapy (P<0.05). The results of single factor analysis indicated that IL-1β, TGF-β and MMP-9 were associated with decreased blood vessel classification (P<0.05). In conclusion, IL-1β, TGF-β and MMP-9 may be used as predictors of the effect of induction chemotherapy on poorly differentiated hypopharyngeal cancer. Therefore, when patients with advanced hypopharyngeal cancer undergo chemotherapy, NBI vascular examination and screening for associated vascular factors should be performed before and after chemotherapy. Alterations in vascular classification, assessed using NBI, and abnormal expression of vascular factors may also be used as reference factors for prognosis.

TGF-β, Bone Morphogenetic Protein, and Activin Signaling and the Tumor Microenvironment

The cellular and noncellular components surrounding the tumor cells influence many aspects of tumor progression. Transforming growth factor β (TGF-β), bone morphogenetic proteins (BMPs), and activins have been shown to regulate the phenotype and functions of the microenvironment and are attractive targets to attenuate protumorigenic microenvironmental changes. Given the pleiotropic nature of the cytokines involved, a full understanding of their effects on numerous cell types in many contexts is necessary for proper clinical intervention. In this review, we will explore the various effects of TGF-β, BMP, and activin signaling on stromal phenotypes known to associate with cancer progression. We will summarize these findings in the context of their tumor suppressive or promoting effects, as well as the molecular changes that these cytokines induce to influence stromal phenotypes.

The extracellular matrix glycoprotein tenascin-C and matrix metalloproteinases modify cerebellar structural plasticity by exposure to an enriched environment

The importance of the extracellular matrix (ECM) glycoprotein tenascin-C (TnC) and the ECM degrading enzymes, matrix metalloproteinases (MMPs) -2 and -9, in cerebellar histogenesis is well established. This study aimed to examine whether there is a functional relationship between these molecules in regulating structural plasticity of the lateral deep cerebellar nucleus. To this end, starting from postnatal day 21, TnC- or MMP-9-deficient mice were exposed to an enriched environment (EE). We show that 8 weeks of exposure to EE leads to reduced lectin-based staining of perineuronal nets (PNNs), reduction in the size of GABAergic and increase in the number and size of glutamatergic synaptic terminals in wild-type mice. Conversely, TnC-deficient mice showed reduced staining of PNNs compared to wild-type mice maintained under standard conditions, and exposure to EE did not further reduce, but even slightly increased PNN staining. EE did not affect the densities of the two types of synaptic terminals in TnC-deficient mice, while the size of inhibitory, but not excitatory synaptic terminals was increased. In the time frame of 4-8 weeks, MMP-9, but not MMP-2, was observed to influence PNN remodeling and cerebellar synaptic plasticity as revealed by measurement of MMP-9 activity and colocalization with PNNs and synaptic markers. These findings were supported by observations on MMP-9-deficient mice. The present study suggests that TnC contributes to the regulation of structural plasticity in the cerebellum and that interactions between TnC and MMP-9 are likely to be important for these processes to occur.

Mechanisms of Invasion in Head and Neck Cancer

CONTEXT

The highly invasive properties demonstrated by head and neck squamous cell carcinoma (HNSCC) are often associated with locoregional recurrence and lymph node metastasis in patients and is a key factor leading to an expected 5-year survival rate of approximately 50% for patients with advanced disease. It is important to understand the features and mediators of HNSCC invasion so that new treatment approaches can be developed.

OBJECTIVES

To provide an overview of the characteristics, mediators, and mechanisms of HNSCC invasion.

DATA SOURCES

A literature review of peer-reviewed articles in PubMed on HNSCC invasion.

CONCLUSIONS

Histologic features of HNSCC tumors can help predict prognosis and influence clinical treatment decisions. Cell surface receptors, signaling pathways, proteases, invadopodia function, epithelial-mesenchymal transition, microRNAs, and tumor microenvironment are all involved in the regulation of the invasive behavior of HNSCC cells. Identifying effective HNSCC invasion inhibitors has the potential to improve outcomes for patients by reducing the rate of spread and increasing responsiveness to chemoradiation.

Plasma inflammatory biomarkers for Huntington's disease patients and mouse model

Huntington's disease (HD), caused by expanded CAG repeats encoding a polyglutamine tract in the huntingtin (HTT) protein, presents with a predominant degeneration of neurons in the striatum and cortex. Lines of evidence have observed neuroinflammation, particularly microglial activation, is involved in the pathogenesis of HD. Given that HTT is also expressed in peripheral inflammatory cells, it is possible that inflammatory changes detected in peripheral plasma may be biologically relevant and parallel the neuroinflammatory process of HD patients. By examining the expression levels of 13 microglia-derived inflammatory markers in the plasma of 5 PreHD carriers, 15 HD patients and 16 healthy controls, we found plasma levels of IL-6, MMP-9, VEGF and TGF-β1 were significantly increased in HD patients when compared with the controls, while plasma level of IL-18 were significantly reduced in HD patients compared with controls. Plasma level of IL-6 was reversely correlated with the UHDRS independence scale and functional capacity. To understand the temporal correlation between these inflammatory markers and HD progression, their levels were further tested in plasma from R6/2 mouse HD model at different ages. In rotarod test, R6/2 HD mice started to manifest HD phenotype at 7.5 weeks of age. Higher plasma VEGF levels of R6/2 mice than those of age-matched wild-type (WT) littermates were noted from 7 (presymptomatic stage) to 13 weeks of age (late symptomatic stage). The plasma IL-6 levels of R6/2 mice were higher than those of the WT littermates from 9 (early symptomatic stage) to 13 weeks of age. R6/2 mice demonstrated higher MMP-9 and TGF-β1 levels than their WT littermates from 11 (middle symptomatic stage) to 13 weeks of age. In contrast, the plasma IL-18 level was lower than those in WT littermates since 11 weeks of age. These altered expressions of inflammatory markers may serve as the potential biomarkers for HD onset and progression. Specific inhibition/activation of these inflammatory markers may be the targets of HD drug development.

Tenascin-C and carcinoma cell invasion in oral and urinary bladder cancer

Carcinoma invasion is a complex process regulated by genetic and epigenetic factors as well. A relevant supportive condition for cancer cell migration is the reorganization of the extracellular matrix (ECM), which is realized in an orchestrated multicellular manner including carcinoma cells and stromal fibroblasts. An important key player in the process of ECM reorganization is Tenascin-C (Tn-C). The molecule occurs as different isoforms generated by alternative splicing and de novo glycosylation. Large variants of Tn-C are abundantly re-expressed in the invasive front of many carcinoma types. A special role for initiating migration and accompanied epithelial to mesenchymal transition has been suggested. Here, we review the current knowledge concerning the tumor biological importance of Tn-C, the synthesis and alternative splicing during the invasive process in general, and give an overview on the impact of Tn-C in urothelial carcinoma of the urinary bladder (UBC) and oral squamous cell carcinoma (OSCC).

Migration and invasion of oral squamous carcinoma cells is promoted by WNT5A, a regulator of cancer progression

BACKGROUND

Oral squamous cell carcinoma (OSCC) constitutes 90% of all cancers in the oral cavity, and the prognosis for patients diagnosed with OSCC is still poor. The identification of novel therapeutic targets and prognostic markers for OSCC is therefore essential. Previous studies of OSCC revealed an increased expression of WNT5A in the tumor tissue. However, no functional studies of WNT5A-induced effects in OSCC have been performed.

METHODS

Two different OSCC cell lines were used for analysis of WNT5A expression by Western blot, whereas WNT5A-induced responses were analyzed by measuring calcium (Ca²⁺) signaling, PKC activation, migration and invasion.

RESULTS

Despite the lack of WNT5A expression, both cell lines responded to recombinant WNT5A (rWNT5A) with activation of the non-canonical WNT/Ca²⁺ /PKC pathway. This effect was ascertained to be mediated by WNT5A by use of the WNT5A antagonist, Box5. To investigate how WNT5A affects tumor progression, rWNT5A-induced alterations in BrdU absorbance (reflecting the number of tumor cells) were analyzed. rWNT5A had no effect on BrdU absorbance but instead promoted tumor cell migration and invasion. These results were confirmed by the use of the WNT5A-mimicking peptide Foxy5, while the rWNT5A-induced migration was blocked by secreted Frizzled-related protein 1 (SFRP1), protein kinase C inhibitors or the intracellular Ca²⁺ chelator, MAPT.

CONCLUSIONS

These novel data clearly show that WNT5A activates the non-canonical WNT/Ca²⁺ /PKC pathway and increases migration and invasion of OSCC cells. This may indicate how an increased WNT5A expression in the tumor tissue is likely to promote progression of OSCC.

Matrikine and matricellular regulators of EGF receptor signaling on cancer cell migration and invasion

Cancer invasion is a complex process requiring, among other events, extensive remodeling of the extracellular matrix including deposition of pro-migratory and pro-proliferative moieties. In recent years, it has been described that while invading through matrices cancer cells can change shape and adapt their migration strategies depending on the microenvironmental context. Although intracellular signaling pathways governing the mesenchymal to amoeboid migration shift and vice versa have been mostly elucidated, the extracellular signals promoting these shifts are largely unknown. In this review, we summarize findings that point to matrikines that bind specifically to the EGF receptor as matricellular molecules that enable cancer cell migrational plasticity and promote invasion.

Expression of αvβ6 integrin and collagen fibre in oral squamous cell carcinoma: association with clinical outcomes and prognostic implications

BACKGROUND

This study aims to investigate the expression and significance of the αvβ6 integrin, collagen fibres and matrix metalloproteinases (MMP)-3 in oral squamous cell carcinoma (OSCC) and to analyse the possible regulatory relationships between αvβ6, collagen fibres and MMP-3.

MATERIALS AND METHODS

A series of 80 patients (mean age 56.4 years) diagnosed with OSCC were enrolled. Associations between αvβ6, MMP-3, collagen fibre expression levels and clinicopathological parameters were evaluated using the Fisher exact test. Survival analysis was performed with Kaplan-Meier curves. Spearman rank correlation was used to analyse interactions between αvβ6, MMP-3 and collagen fibres.

RESULTS

αvβ6 and MMP-3 were strongly expressed in human OSCC, especially at the peripheral borders of invasive tumour islands, and collagen fibres were generally disrupted and degraded in the same areas. The expression intensity of αvβ6 was associated with the differentiation state of cells. β6 mRNA was expressed in almost all cancer cells. In carcinomas, αvβ6 and MMP-3 expression were correlated with the distribution of collagen fibres.

CONCLUSIONS

Tumour cells highly expressing αvβ6 have a strong capability for invasion and migration, due to concomitant protease production and the destruction and remodelling of collagen fibres. Increased αvβ6 integrin and MMP-3 expression and collagen fibre changes in human OSCCs are related to unfavourable clinical prognostic factors and decreased survival.

The novel function of advanced glycation end products in regulation of MMP-9 production

BACKGROUND

Advanced glycation end products (AGEs), formed from proteins and peptides by nonenzymatic glycoxidation after contact with aldose sugars, have been implicated in the pathogenesis of age-related cardiac and vascular dysfunction. Our previous study demonstrated significantly elevated levels of AGE and the receptor for AGE (RAGE) in human abdominal aortic aneurysm (AAA) tissues. Inhibition of AGE signaling by targeted gene deletion of RAGE markedly reduced the development of aneurysm in a mouse model of AAA. We also showed that AGE may stimulate aneurysm formation by promoting metalloproteinase (MMP)-9 expression. In this study, we investigated the molecular mechanism underlying this novel function of AGE.

METHODS

The murine macrophage cell line RAW 264.7 was pretreated with AGE, TGF-β, and MAPK inhibitors. The protein was collected for Western blot analysis. Culture supernatants were collected to determine MMP-9 activity by gelatin zymography.

RESULTS

We found that AGE induced the production of MMP-9 in macrophages in a dose-dependent manner. This induction of MMP-9 was markedly diminished by pretreatment with TGF-β. To delineate the underlying molecular mechanism, we showed that AGE increased phosphorylation of p44/42 ERK, p38, JNK, and PI3K in macrophages. Moreover, AGE induced active p65 subunit of NF- κB. Inhibition of ERK (UO126) or p38 (SB203580), but not PI3K (LY294002 or wortmannin), blocked AGE-induced MMP-9 expression. In contrast, inhibition of JNK (SP-600125) significantly enhanced the stimulatory effect of AGE on MMP-9. Furthermore, TGF-β suppressed AGE-induced expression of the active p65 subunit of NF-κB.

CONCLUSIONS

Our data indicate that AGE induces MMP-9 through activation of ERK, p38 mitogen-activated protein and NF-κB, a pathway that is antagonized by TGF-β. This finding in conjunction with previously reported AGE functions in inflammation suggests that anti-AGE therapies could be effective in the prevention of human AAA development and progression.

Dentin sialophosphoprotein (DSPP) gene-silencing inhibits key tumorigenic activities in human oral cancer cell line, OSC2

Background

We determined recently that dentin sialophosphoprotein (DSPP), a member of the SIBLING (Small integrin-binding ligand N-linked glycoproteins) family of phosphoglycoproteins, is highly upregulated in human oral squamous cell carcinomas (OSCCs) where upregulation is associated with tumor aggressiveness. To investigate the effects of DSPP-silencing on the tumorigenic profiles of the oral cancer cell line, OSC2, short-hairpin RNA (shRNA) interference was employed to silence DSPP in OSC2 cells.

Methodology/Principal Findings

Multiple regions of DSPP transcript were targeted for shRNA interference using hDSP-shRNA lentiviral particles designed to silence DSPP gene expression. Control shRNA plasmid encoding a scrambled sequence incapable of degrading any known cellular mRNA was used for negative control. Following puromycin selection of stable lines of DSSP-silenced OSC2 cells, phenotypic hallmarks of oral carcinogenesis were assayed by western blot and RT-PCR analyses, MTT (cell-viability), colony-formation, modified Boyden-Chamber (migration and invasion), and flow cytometry (cell-cycle and apoptosis) analyses. DSPP-silenced OSC2 cells showed altered cell morphology, reduced viability, decreased colony-formation ability, decreased migration and invasion, G0/G1 cell-cycle arrest, and increased tumor cell sensitivity to cisplatin-induced apoptosis. Furthermore, MMP-2, MMP-3, MMP-9, VEGF, Ki-67, p53, and EGFR were down-regulated. There was a direct correlation between the degree of DSPP-silencing and MMP suppression, as indicated by least squares regression: MMP-2 {(y = 0.850x, p<0.001) (y = 1.156x, p<0.001)}, MMP-3 {(y = 0.994x, p<0.001) (y = 1.324x, p = 0.004)}, and MMP-9 {(y = 1.248x, p = 0.005, y = 0.809, p = 0.013)}.

Conclusions/Significance

DSPP-silencing in OSC2 cell decreased salient hallmarks of oral tumorigenesis and provides the first functional evidence of a potential key role for DSPP in oral cancer biology. The down-regulation of MMP-2, MMP-3, MMP-9, p53 and VEGF in DSPP-silenced OSC2 cells provides a significant functional/molecular framework for deciphering the mechanisms of DSPP activities in oral cancer biology.

Aberrant expression of beta-dystroglycan may be due to processing by matrix metalloproteinases-2 and -9 in oral squamous cell carcinoma

Dystroglycan (DG), a non-integrin adhesion molecule, is formed by two subunits, alpha- and beta-DG, which bind to extracellular matrix molecules and cytoskeleton. DG expression is frequently reduced in human cancers and has been related to tumor grade and aggressiveness. The exact proteolytic processing of beta-DG remains largely unknown. In this study, we investigated the correlation of beta-DG degradation with invasiveness in oral squamous cell carcinoma (OSCC) and its possible processing by matrix metalloproteinases (MMP). Immunohistochemical staining was used to assess beta-DG expression in 60 cases of OSCC. The effects of the MMP inhibitor 1,10-phenanthroline on tumour cell invasion and beta-DG degradation were investigated using in vitro invasion assays and immunoblot analysis. Co-immunoprecipitation and N-terminal sequencing were performed to determine the possible cleavage site of beta-DG by MMP. The alpha- and beta-DG expression was reduced or lost in OSCC. In four cell lines studied (SCC-4, SCC-9, SCC-15 and SCC-25), Western blot revealed a 30kDa fragment of beta-dystroglycan (beta-DG30) in addition to beta-DG itself. beta-DG degradation was almost abolished using 1,10-phenanthroline and there was a significant decrease in tumor cell invasion. The N-terminal sequence of beta-DG30 was detected as Ile-Asn-Thr-Asn, or Ile-Val-Thr-Gln. We conclude that beta-DG degradation may play a role both in OSCC invasion and metastasis. MMP activity seems to be one mechanism for beta-DG processing into beta-DG30.

Toremifene decreases type I, type II and increases type III receptors in desmoid and fibroma and inhibits TGFbeta1 binding in desmoid fibroblasts

Tissue infiltration is different in desmoid and fibroma tumours. Both produce high levels of transforming growth factor beta1 (TGFbeta1), which is related to extracellular matrix (ECM) accumulation which in turn regulates cell function and cell migration. Interactions between collagen, proteoglycans and cell surface fibronectin are involved in the assembly and functions of the ECM. As toremifene inhibits collagen and TGFbeta1 synthesis, we tested it in normal, desmoid and fibroma fibroblasts. We will report the changes in glycosaminoglycan (GAG) and collagen synthesis, TGFbeta1 activity, fibronectin mRNA expression and TGFbeta1 receptors after toremifene treatment in normal, fibroma and desmoid fibroblasts. We evaluated GAG and collagen synthesis with 3H-glucosamine and 3H-proline incorporation, TGFbeta1 activity with the ELISA method, TGFbeta1 receptor affinity with 125I-TGFbeta1 binding and total RNA with Northern blot analysis. GAG and collagen synthesis, TGFbeta1 activity and fibronectin levels were higher in fibroma and desmoid than normal fibroblasts. The increase was greater in desmoid than fibroma tumour cells. Toremifene treatment reduced GAG and collagen synthesis, TGFbeta1 activity and fibronectin levels in all cell cultures. The percentage reduction in GAG was similar in all cultures; the reduction in collagen synthesis and TGFbeta1 activity was the highest in desmoid fibroblasts. TGFbeta1 receptors were higher in fibroma and desmoid cells than controls. Toremifene reduced TGFbeta1 receptors only in desmoid fibroblasts, with no effect on the changes in type I, II, and III receptors. Our data show that toremifene modifies the ECM components that regulate cytokine activity and cell migration. The reduction in receptor number only in desmoid cells suggests that toremifene may reduce TGFbeta1's affinity for its receptors. Synthesis of a substance regulating protein kinase activity, which is directly involved in the link between TGFbeta1 and its receptors, cannot be excluded.

Mechanisms of metastasis: epithelial-to-mesenchymal transition and contribution of tumor microenvironment

Every year about 500,000 people in the United States die as a result of cancer. Among them, 90% exhibit systemic disease with metastasis. Considering this high rate of incidence and mortality, it is critical to understand the mechanisms behind metastasis and identify new targets for therapy. In recent years, two broad mechanisms for metastasis have received significant attention: epithelial-to-mesenchymal transition (EMT) and tumor microenvironment interactions. EMT is believed to be a major mechanism by which cancer cells become migratory and invasive. Various cancer cells--both in vivo and in vitro--demonstrate features of epithelial-to-mesenchymal-like transition. In addition, many steps of metastasis are influenced by host contributions from the tumor microenvironment, which help determine the course and severity of metastasis. Here we evaluate the diverse mechanisms of EMT and tumor microenvironment interactions in the progression of cancer, and construct a rational argument for targeting these pathways to control metastasis.

Mesenchymal cells contribute to the synthesis and deposition of the laminin-5 gamma2 chain in the invasive front of oral squamous cell carcinoma

Tumour progression in oral squamous cell carcinoma (OSCC) is associated with a reorganisation of extracellular matrix. Laminin-5 (Ln-5) plays an important role for tumour migration and shows an increased expression in areas of direct tumour/stroma interactions. We have previously shown stromal spot like Ln-5/gamma2 chain deposits distant from the basement membrane region. In this study we have analysed which cell type is responsible for Ln-5/gamma2 chain synthesis in situ. Furthermore, we studied its spatial relation to TGF-beta1 as well as the Ln-5 modulating enzymes matrix metalloproteinase (MMP) 2, membrane type-1 (MT1-) MMP and bone morphogenetic protein (BMP-) 1 by different techniques including triple immunofluorescence labelling and in situ hybridisation in OSCC. We found that the stromal spot-like Ln-5 deposits occurred in the invasive front in the vicinity of mesenchymal cells and vessel structures. In particular, not only carcinoma cells but also mesenchymal cells were shown to express the Ln-5/gamma2 chain mRNA. Moreover, stromal Ln-5 deposits showed a spatial association with TGF-beta1 as well as with MT1-MMP and BMP-1. Based on these findings we suggest that mesenchymal cells contribute to the promotion of tumour cell migration as well as vessel formation in OSCC by providing and organising promigratory Ln-5 fragments.

Desmoid and fibroma tumors differently respond to TGFβ1 stimulus and ECM macromolecule accumulation

Desmoid and fibroma tumours are characterized by cell proliferation, glycosaminoglycan and collagen fibre accumulation, high levels of transforming growth factor beta(1) (TGFbeta(1)) and different patterns of tissue infiltration. TGFbeta(1) is related to extracellular matrix (ECM) composition which, in turn, regulates cell functions and cell migration. In this study we report changes in cell proliferation, glycosaminoglycan (GAG) and collagen synthesis, TGFbeta(1) mRNA expression and fibronectin levels in normal, desmoid and fibroma fibroblast cultures before and after TGFbeta(1) stimulation. Our data showed cell proliferation, GAG and collagen synthesis, transforming growth factor beta(1) mRNA expression and fibronectin levels were significantly higher in desmoid than in fibroma cultures. TGFbeta(1) treatment had no effect on cell proliferation, but increased TGFbeta(1) mRNA expression, GAG, fibronectin and collagen synthesis in desmoid and fibroma fibroblasts. Its effects were more marked in desmoid cells. Fibronectin favours cell migration, while changes in GAG composition alter cell behaviour and ECM organization. In conclusion our data suggest that the different patterns of infiltration in desmoid and fibroma tumours are due to changes in ECM components and cell-ECM interactions which can be ascribed to altered TGFbeta(1) mRNA expression and TGFbeta(1) activity.

Molecular mediators of metastasis in head and neck squamous cell carcinoma

BACKGROUND

The presence of regional metastasis in patients with head and neck squamous cell carcinoma (HNSCC) is a common and adverse event associated with poor prognosis and high mortality. Although significant improvements in standard therapies have increased the efficacy of local tumor management, the high incidence of tumor recurrence has resulted in limited improvements in overall survival rates. Understanding the molecular mechanisms that mediate HNSCC invasion and metastasis may enable identification of novel therapeutic targets for the prevention and management of tumor dissemination.

METHODS

A literature review was performed.

RESULTS

Several biologic mediators and mechanisms that have been implicated in HNSCC metastasis, such as cell adhesion molecules, proteolytic enzymes, growth factor signaling, metastasis suppressor genes, and chemokine receptors were reviewed.

CONCLUSIONS

Prevention of HNSCC metastasis is an important clinical objective that requires an increased understanding of the molecular mechanisms of tumor invasion and dissemination.

Tenascin-C induced signaling in cancer

Tenascin-C is an adhesion modulatory extracellular matrix molecule that is highly expressed in the microenvironment of most solid tumors. High tenascin-C expression reduces the prognosis of disease-free survival in patients with some cancers. The possible role of tenascin-C in tumor initiation and progression is addressed with emphasis on underlying signaling mechanisms. How tenascin-C affects malignant transformation, uncontrolled proliferation, angiogenesis, metastasis and escape from tumor immunosurveillance is summarized. Finally, we discuss how the phenotypes of tenascin-C knock-out mice may help define the roles of tenascin-C in tumorigenesis and how this knowledge could be applied to cancer therapy.

The shed ectodomain of type XIII collagen associates with the fibrillar fibronectin matrix and may interfere with its assembly in vitro

Type XIII collagen is a transmembrane collagen, which is known to exist also as a soluble variant due to ectodomain shedding. Earlier studies with the recombinant ectodomain have shown it to interact in vitro with a number of extracellular matrix proteins, e.g. Fn (fibronectin). In view of its strong binding to Fn, we examined in the present study whether the released soluble ectodomain can bind to the fibrillar Fn matrix under cell-culture conditions and, if so, influence its assembly. In this study, we demonstrate that the type XIII collagen ectodomain of mammalian cells can associate with Fn fibres and may eventually hamper incorporation of the fibrillar Fn meshwork. The association between type XIII collagen and Fn was implicated to be mediated by the C-terminal end of type XIII collagen and the N-terminal end of Fn. The results presented here imply that the shedding of the type XIII collagen ectodomain results in a biologically active molecule capable of remodelling the structure of the pericellular matrix.

Human Cytomegalovirus-Induced Inhibition of Cytotrophoblast Invasion in a First Trimester Extravillous Cytotrophoblast Cell Line

Human cytomegalovirus (HCMV) is the leading cause of congenital viral infection in the United States and intrauterine transmission of HCMV occurs in approximately 40% of pregnant women with primary HCMV infection. Although HCMV infection during pregnancy clearly may be detrimental to fetal development, its consequences on placentation remain largely unexplored. In this study, the effects of HCMV infection on cytotrophoblast (CTB) invasion were investigated utilizing the first trimester extravillous CTB cell line SGHPL-4. HCMV infection significantly inhibited SGHPL-4 proliferation, epidermal growth factor (EGF)- and hepatocyte growth factor (HGF)-induced migration and invasion, as well as the secretion of matrix metalloproteinase (MMP)-2 and MMP-9. Both HCMV and EGF activated the EGF receptor (EGFR), inducing receptor tyrosine phosphorylation at specific residues. Of interest, EGFR was differentially activated by HCMV, and viral gene transcription was not required for the observed inhibitory effect on CTB invasiveness. These findings demonstrate that HCMV infection impairs CTB differentiation along the invasive pathway and that the differential regulation of EGFR by HCMV may contribute to impaired CTB function. Elucidating the mechanisms by which HCMV impairs placentation may be key in understanding fetal and maternal pathologies associated with intrauterine HCMV infection.

Alphavbeta3 integrin and cofilin modulate K1735 melanoma cell invasion

Cytoskeletal reorganization is partially mediated through cofilin, an actin assembly regulatory protein. Cofilin activity is modulated by reversible phosphorylation at Ser3. In this study, using K1735 murine melanoma cells, we examined the relationship between beta3-integrin expression, phosphorylation of cofilin, and metalloproteinase production. The levels of phosphorylated cofilin were 10-fold higher in cells expressing alphavbeta3 than in alphavbeta3-negative cells when plated on vitronectin for 30 min. However, by 60 min, phosphorylation of cofilin was greater in the beta3-negative cells. Expression of the wild type (WT) or non-phosphorylatable cofilin (A3 mutant) increased melanoma cell migration on vitronectin and invasion through a reconstituted basement membrane. Expression of a pseudophosphorylated, poorly active cofilin (E3 mutant) reduced cell motility. Expression of active cofilin accelerated the phosphorylation of FAK at Y397 and at Y576, strongly implicating cofilin as a mediator of cell signaling. The expression of MT1-MMP and MMP2 was also increased by expression of wild type or A3 cofilin. A 50% reduction of both enzymes was observed by the expression of the E3 cofilin. Overexpression of non-phosphorylatable cofilin was sufficient to induce the expression of MT1-MMP and MMP2 in the beta3-negative M2Tbeta3 cells. Interestingly, the invasion of M2Tbeta3 cells could be sustained by overexpression of cofilin A3. These results suggest that the integrin alphavbeta3 and cofilin together regulate K1735 melanoma cell invasion.

Tenascin-C protein is induced by transforming growth factor-beta1 but does not correlate with time to tumor progression in high-grade gliomas

BACKGROUND

Tenascin-C is an extracellular matrix protein known to correlate with prognosis in patients with glioblastoma, probably by stimulation of invasion and neoangiogenesis. Transforming Growth Factor-beta1 (TGF-beta1) plays an important role in the biology of high-grade gliomas, partly by regulating invasion of these tumors into parenchyma. This study was designed to evaluate if TGF-beta1 induces the expression and deposition of Tenascin-C in the extracellular matrix of high-grade gliomas which may be pivotal for the invasion of these tumors into healthy parenchyma.

METHODS

A series of 20 high-grade gliomas was stained immunohistochemically with Tenascin-C- and TGF-beta1- specific antibodies. Expression levels of both proteins were evaluated and correlated with each other, time to progression and molecular and morphological markers of invasion. A quantitative PCR assay was performed evaluating the induction of Tenascin-C mRNA by treatment with TGF-beta1 in vitro.

RESULTS

Tenascin-C was expressed in 18 of 19 (95%) evaluable tumors, whereas 14 of 20 tumors (70%) expressed TGF-beta1 in a significant percentage of cells. Treatment with TGF-beta1 did induce the expression of Tenascin-C at the mRNA and protein level in vitro. The expression of Tenascin-C and TGF-beta1 did neighter statistically correlate with each other nor with time to progression.

CONCLUSION

In our series, Tenascin-C and TGF-beta1 were expressed in the vast majority of high-grade gliomas. We could not detect a correlation of one of the proteins with time to progression. Nevertheless, we describe induction of Tenascin-C by TGF-beta1, possibly providing a mechanism for the invasion of high-grade gliomas into healthy parenchyma.

Three-dimensional growth of extravillous cytotrophoblasts promotes differentiation and invasion

Human trophoblast research relies on a combination of in vitro models, including isolated primary cultures, explant cultures, and trophoblast cell lines. In the present study, we have utilized the rotating wall vessel (RWV) bioreactor to generate a three-dimensional (3-D) model of human placentation for the study of cytotrophoblast (CTB) invasion. The RWV supported the growth of the human CTB cell line SGHPL-4 and allowed for the formation of complex, multilayered 3-D aggregates that were morphologically, phenotypically, and functionally distinct from SGHPL-4 monolayers. The cells cultured three-dimensionally differentiated into an aggressively invasive cell population characterized by the upregulation of matrix metalloproteinase-2 (MMP-2), MMP-3, MMP-9 and urokinase-type plasminogen activator (uPA) secretion and activation. Microarray analysis of the 3-D and 2-D cultured cells revealed increased expression in the 3-D cells of various genes that are known mediators of invasion, including MT1-MMP, PECAM-1 and L-selectin, as well as genes not previously associated with CTB differentiation such as MMP-13 and MT5-MMP. These results were verified by quantitative real-time PCR. These findings suggest that when cultured in 3-D, SGHPL-4 cells closely mimic differentiating in utero CTBs, providing a novel approach for the in vitro study of the molecular mechanisms that regulate CTB differentiation and invasion.

Genetic expression profiles and biologic pathway alterations in head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is associated with considerable mortality and morbidity and is a major public health concern worldwide. To date, > 20 studies incorporating DNA microarray analyses have examined genomewide genetic expression changes associated with the development of HNSCC. The authors identified published reports of genetic expression profiles of HNSCC by Medline database search. They performed a review of the reports to identify genes that have been found repeatedly to exhibit substantially altered expression in HNSCC. Genes with altered expression were subsequently examined in the context of defined biologic systems with the use of GenMapp 2.0 pathway analysis software. Genes most commonly found to exhibit altered expression were those encoding for cytoskeletal and extracellular matrix proteins, inflammatory mediators, proteins involved in epidermal differentiation, and cell adhesion molecules. Results of GenMapp 2.0 analysis suggested global down-regulation of genes that encode for ribosomal proteins and enzymes in the cholesterol biosynthesis pathway; and up-regulation of genes that encode for matrix metalloproteinases and genes that bear on the inflammatory response. The review indicated that there are several genes and pathways that exhibit substantially altered expression in cancerous versus noncancerous states across studies. Further investigation into the genomic, proteomic, and functional consequences of these gene expression alterations may provide insight into the pathophysiology of HNSCC.

Tenascin-C deposition requires β3 integrin and Src

In this study we now show that deposition of the mesenchymal matrix marker, tenascin-C (TN-C), is mediated through beta3 expression and activation of Src. There was a striking upregulation of TN-C matrix organization in cell lines expressing beta3 and activated Src when compared to cell lines with neither of these attributes. When beta3 function was suppressed so was the deposition of TN-C. The same was true for function and activation of Src. When Src was inactive, the deposition of TN-C was low. We also determined that one of the downstream effectors of Src, MAPK, was also required to promote TN-C deposition. When MAPK activation was inhibited, TN-C deposition was also decreased. MMP activation is also implicated in TN-C deposition. The broad spectrum MMP inhibitor, GM6001, suppressed TN-C organization. These results indicate that beta3 integrin ligand binding and the activation of the Src/MAPK/MMP pathway modulate deposition of TN-C.