Histone deacetylase inhibitors upregulate MMP11 gene expression through Sp1/Smad complexes in human colon adenocarcinoma cells

Detection of lymph node metastasis in colon cancer by ectopically expressed fibroblast markers FOXQ1 and THBS2

Introduction

Approximately 25% of colon cancer (CC) patients having curative surgery will relapse. Therefore, it is crucial to identify patients with increased recurrence risk to offer them adjuvant chemotherapy. Three markers with prominent expression in fibroblasts: forkhead box Q1 (FOXQ1), matrix metalloproteinase-11 (MMP11), and thrombospondin-2 (THBS2), and the fibroblast expressed chemokine CXCL12 were selected for studies because of the critical role of fibroblasts in the microenvironment of the tumor.

Methods

The expression levels of the biomarkers were assessed in primary CC tumors, lymph nodes of CC patients and controls, and CC cell lines at mRNA and protein levels by real-time qRT-PCR and immunohistochemistry, respectively.

Results

FOXQ1, MMP11, and THBS2 mRNAs were expressed at significantly higher levels in primary tumors compared to normal colon (P=0.002, P<0.0001, and P<0.0001, respectively). In contrast, CXCL12 mRNA levels were higher in normal colon tissue. FOXQ1, MMP11, and THBS2 levels were also expressed at significantly higher levels in metastasis-positive lymph nodes compared to both metastasis-negative- and control nodes (P<0.0001/P=0.002, P<0.0001/P<0.0001, and P<0.0001/P<0.0001, respectively). Immuno-morphometry revealed that 30-40% of the tumor cells expressed FOXQ1, MMP11, and THBS2. FOXQ1 and THBS2 were barely detected in normal colon epithelium (P<0.0001), while MMP11 was expressed in normal colon epithelium at high levels.

Discussion

We conclude that CC tumor cells show ectopic expression of FOXQ1 and THBS2 possibly making these tumor cells independent of fibroblast cell support. The high expression levels of these two biomarkers in metastatic lymph nodes suggest that they are potential indicators of patients at risk for recurrence.

The expression of matrix metalloproteinase 2, 9 and 11 in Ethiopian breast cancer patients

INTRODUCTION

Matrix metalloproteinases (MMPs) play a pathophysiological role in cancer initiation and progression. Numerous studies have examined an association between MMP-2, MMP-9, and MMP-11 expression and clinicopathological characteristics of breast cancer (BC); however, no research has been done on the MMP expression levels in BC cases from Ethiopia.

MATERIALS AND METHODS

A total of 58 formalin-fixed paraffin-embedded breast tissue samples encompassing 16 benign breast tumors and 42 BC were collected. The RNA was extracted and quantitative reverse-transcription PCR was performed. GraphPad Prism version 8.0.0 was used for statistical analysis.

RESULTS

The MMP-11 expression levels were significantly higher in breast cancer cases than in benign breast tumors (P = 0.012). Additionally, BC cases with positive lymph nodes and ER-positive receptors had higher MMP-11, MMP-9, and MMP-2 expression than cases with negative lymph nodes and ER-negative, respectively. The MMP-11 and MMP-9 expressions were higher in grade III and luminal A-like tumors than in grade I-II and other subtypes, respectively.

CONCLUSION

The MMP-11 expression was higher in BC than in benign breast tumors. Additionally, MMP-11, MMP-9, and MMP-2 were higher in BC with positive lymph nodes and estrogen receptors. Our findings suggest an important impact of MMPs in BC pathophysiology, particularly MMP-11.

Quantitative multiplexed analysis of MMP-11 and CD45 in metastatic breast cancer tissues by immunohistochemistry-assisted LA-ICP-MS

Breast cancer is the leading cause of cancer death and tremendous efforts are undertaken to limit dissemination and to provide effective treatment. Various histopathological parameters are routinely assessed in breast cancer biopsies to provide valuable diagnostic and prognostic information. MMP-11 and CD45 are tumour associated antigens and potentially valuable biomarkers for grading aggressiveness and metastatic probability. This paper presents methods for quantitative and multiplexed imaging of MMP-11 and CD45 in breast cancer tissues and investigates their potential for improved cancer characterisation and patient stratification. An immunohistochemistry (IHC)-assisted LA-ICP-MS method was successfully developed and optimised using lanthanide tagged monoclonal antibodies as proxies to determine spatial distributions and concentrations of the two breast cancer biomarkers. The labelling degree of antibodies was determined via size exclusion-inductively coupled plasma-tandem mass spectrometry (SEC-ICP-MS/MS) employing on-line calibration via post-column isotope dilution analysis. The calibration of spatial distributions of labelled lanthanides in tissues was performed by ablating mould prepared gelatine standards spiked with element standards. Knowledge of labelling degrees enabled the translation of lanthanide concentrations into biomarkers concentrations. k-means clustering was used to select tissue areas for statistical analysis and mean concentrations were compared for sets of metastatic, non-metastatic and healthy samples. MMP-11 was expressed in stroma surrounding tumour areas, while CD45 was predominantly found inside tumour areas of high cell density. There was no significant correlation between CD45 and metastasis (p = 0.70), however, MMP-11 was significantly upregulated (202%) in metastatic samples compared to non-metastatic (p = 0.0077) and healthy tissues (p = 0.0087).

UVB-mediated DNA damage induces matrix metalloproteinases to promote photoaging in an AhR- and SP1-dependent manner

It is currently thought that UVB radiation drives photoaging of the skin primarily by generating ROS. In this model, ROS purportedly activates activator protein-1 to upregulate MMPs 1, 3, and 9, which then degrade collagen and other extracellular matrix components to produce wrinkles. However, these MMPs are expressed at relatively low levels and correlate poorly with wrinkles, suggesting that another mechanism distinct from ROS and MMP1/3/9 may be more directly associated with photoaging. Here we show that MMP2, which degrades type IV collagen, is abundantly expressed in human skin, increases with age in sun-exposed skin, and correlates robustly with aryl hydrocarbon receptor (AhR), a transcription factor directly activated by UV-generated photometabolites. Through mechanistic studies with HaCaT human immortalized keratinocytes, we found that AhR, specificity protein 1 (SP1), and other pathways associated with DNA damage are required for the induction of both MMP2 and MMP11 (another MMP implicated in photoaging), but not MMP1/3. Last, we found that topical treatment with AhR antagonists vitamin B₁₂ and folic acid ameliorated UVB-induced wrinkle formation in mice while dampening MMP2 expression in the skin. These results directly implicate DNA damage in photoaging and reveal AhR as a potential target for preventing wrinkles.

The paradoxical role of matrix metalloproteinase-11 in cancer

The microenvironment surrounding the tumor affects biological processes, such as cell proliferation, angiogenesis, apoptosis, and invasion. Therefore, the ability to change these environments is an important attribute for tumor cells to obtain specific functions necessary for growth and metastasis. Matrix metalloproteinases (MMPs) are zinc-dependent proteolytic metalloenzymes that facilitate protease-dependent tumor progression by degrading extracellular matrix (ECM) proteins, releasing cytokines, growth factors, and other cell surface molecules. As one of the most widely studied MMPs, MMP-11 is an important protease that is expressed in cancer cells, stromal cells, and the adjacent microenvironment. MMP-11 has a dual effect on tumors. On one hand, MMP-11 promotes tumor development by inhibiting apoptosis and promoting the migration and invasion of cancer cells in the early stage. On the other hand, in animal models, MMP-11 has a protective effect on tumor growth and metastasis at an advanced stage. Based on current findings regarding the importance of MMP-11 in altering the tumor microenvironment, there is a need to further understand how stromal cells and the ECM regulate tumor progression, which may result in the re-examination of MMPs as drug targets for cancer and other diseases. In this review, we summarize the dual role of MMP-11 in cancer and its potential clinical significance.

High MMP-11 expression associated with low CD8+ T cells decreases the survival rate in patients with breast cancer

Matrix metalloproteinase-11 (MMP-11) promote cancer invasion and metastasis through degrading the extracellular matrix. Protein degradation by MMP-11 in tumor cells may progressively suppress cancer surveillance activities with blocking immune response in breast cancer. The aim of study is to analyze clinicopathological parameters, molecular interactions and anticancer immune response in patients with MMP-11 expression and to provide candidate target drugs. We investigated the clinicopathologic parameters, specific gene sets, tumor antigenicity, and immunologic relevance according to MMP-11 expression in 226 and 776 breast cancer patients from the Hanyang University Guri Hospital (HUGH) cohort and The Cancer Genome Atlas (TCGA) data, respectively. We analyzed pathway networks and in vitro drug response. High MMP-11 expression was associated with worse survival rate in breast cancer from HUGH cohort and TCGA data (all p < 0.05). In analysis of immunologic gene sets, high MMP-11 expression was related to low immune response such as CD8+T cell, CD4+T cell and B cell. In silico cytometry, there was a decrease of cancer testis antigen and low tumor infiltrating lymphocyte in patient with high MMP-11 expression: activated dendritic cell, CD8+T cell, CD4+ memory T cell, and memory B cell. In pathway networks, MMP-11 was linked to the pathways including low immune response, response to growth hormone and catabolic process. We found that pictilisib and AZ960 effectively inhibited the breast cancer cell lines with high MMP-11 expression. Strategies making use of MMP-11-related hub genes could contribute to better clinical management/research for patients with breast cancer.

Matrix Metalloproteinase 11 as a Novel Tumor Promoter and Diagnostic and Prognostic Biomarker for Pancreatic Ductal Adenocarcinoma

OBJECTIVES

Matrix metalloproteinase 11 (MMP-11) was found to be implicated in tumorigenesis in cancers. However, the significance of MMP-11 in pancreatic ductal adenocarcinoma (PDAC) is unclear.

METHODS

In the study, we detected malignant biological behaviors of pancreatic cancer after downregulation of MMP-11. Furthermore, we explored the possible mechanism, and the diagnostic value of serum MMP-11 level was analyzed in 116 patients with pathologically confirmed PDAC. In addition, we explored their prognostic value in PDAC.

RESULTS

We observed that MMP-11 could be expressed and activated in the cytoplasm of PDAC cells. Immunohistochemistry staining of PDAC tissues showed that MMP-11 was highly expressed in cancerous ductal epithelium instead of cancer stroma. We found that downregulation of MMP-11 inhibited proliferation of PDAC cell lines. The expression levels of cyclin-dependent kinase 4 and cyclin D1 were downregulated after MMP-11 knockdown. As for its clinical value, the serum level of MMP-11 was shown to be a potent promising diagnostic marker for PDAC.

CONCLUSIONS

Matrix metalloproteinase 11 may act as a tumor promoter, playing a positive role in PDAC development. Serum MMP-11 also has great potential to be a promising diagnostic marker for PDAC.

Matrix Metalloproteinase 11 Is a Potential Therapeutic Target in Lung Adenocarcinoma

Lung cancer is one of the leading causes of cancer-associated death, with the etiology largely unknown. The aim of this study was to identify key driver genes with therapeutic potentials in lung adenocarcinoma (LUAD). Transcriptome microarray data from four GEO datasets (GEO: GSE7670, GSE10072, GSE68465, and GSE43458) were jointly analyzed for differentially expressed genes (DEGs). Ontologic analysis showed that most of the upregulated DEGs enriched in collagen catabolic and fibril organization processes were regulated by matrix metalloproteinases (MMPs). Matrix metalloproteinase 11 (MMP11), the highest upregulated MMP family member in LUAD-transformed cells, acted in an autocrine manner and was significantly increased in sera of LUAD patients. MMP11 depletion severely impaired LUAD cell proliferation, migration, and invasion in vitro, in line with retarded tumor growth in xenograft models. Treatment of different human LUAD cell lines with anti-MMP11 antibody significantly retarded cell growth and migration. Administration of anti-MMP11 antibody at a dose of 1 μg/g body weight significantly suppressed tumor growth in xenograft models. These findings indicate that MMP11 is a key cancer driver gene in LUAD and is an appealing target for antibody therapy.

Trichostatin a inhibits phenotypic transition and induces apoptosis of the TAF-treated normal colonic epithelial cells through regulation of TGF-β pathway

Tumor-associated fibroblasts (TAFs) contribute to transdifferentiation of stromal cells in tumor microenvironment. Epithelial-mesenchymal transition (EMT) is a procedure of phenotypic remodeling of epithelial cells and extensively exists in local tumoral stroma. Histone deacetylase (HDAC) inhibitor Tricostatin A (TSA) and sodium butyrate (SB) are reported to play important roles in the regulation of biological behaviour of cancer cells. However, whether TSA or SB is involved in control of EMT in colon epithelial cells induced by TAFs remains unidentified. In present study, we used conditioned medium (CM) form TAF-like CCD-18Co cells to stimulate 2D- and 3D-cultured colon epithelial HCoEpiC cells for 24 h and 4 d. We found that the CCD-18Co CM triggered multiple morphological changes in HCoEpiCs including prolonged cell diameters, down-regulation of E-cadherin and up-regulation of vimentin and α-SMA. Besides, ZEB1 and Snail expression and migration were also promoted by the CM. These phenomena were abolised by 5 μg/ml LY364947, a TGF-β receptor inhibitor. CCD-18Co induced up-regulation of HDAC1 and HDAC2 in the 2D and 3D models, while no change of HDAC4 exprerssion was found. Treatment of 2 μg/ml TSA reversed the CCD-18Co-induced morphological changes and migration of the HCoEpiCs, and suppressed the downregulation of E-cadherin and upregulation of vimentin, α-SMA, ZEB1 and Snail. However, the suppressive effect of 4 mg/ml SB on the EMT was not observed. TSA down-regulated the expressions of Smad2/3, p-Smad2/3 amd HDAC4. Besides, TSA promoted the apoptosis rate (36.84 ± 6.52%) comparing with the CCD-18Co-treated HCoEpiCs (3.52 ± 0.85%, P < 0.05), with promotion of Bax (0.5893±0.0498 in 2D and 0.8867±0.0916 in 3D) and reduction of Bcl-2 (0.0476±0.0053 in 2D and 0.0294±0.0075 in 3D). TSA stimulated expression of phosphorylated-p38 MAPK in 2D (0.3472±0.0249) and 3D (0.3188±0.0248). After pre-treatment with p38 MAPK inhibitor VX-702 (0.5 mg/ml), the apoptosis rate of TSA was decreased in 2D (10.32%) and 3D (5.26%). Our observations demonstrate that epigenetic treatment with HDAC inhibitor TSA may be a useful therapeutic tool for the reversion of TAF-induced EMT in colon epithelium through mediating canonical Smads pathway and non-canonical p38 MAPK signalling.

TGF-β transactivates EGFR and facilitates breast cancer migration and invasion through canonical Smad3 and ERK/Sp1 signaling pathways

Transforming growth factor-beta (TGF-β) functions as a potent proliferation inhibitor and apoptosis inducer in the early stages of breast cancer, yet promotes cancer aggressiveness in the advanced stages. The dual effect of TGF-β on cancer development is known as TGF-β paradox, and the remarkable functional conversion of TGF-β is a pivotal and controversial phenomenon that has been widely investigated for decades. This phenomenon may be attributed to the cross talk between TGF-β signaling and other pathways, including EGF receptor (EGFR) signaling during cancer progression. However, the underlying mechanism by which TGF-β shifts its role from a tumor suppressor to a cancer promoter remains elusive. In this study, TGF-β is positively correlated with EGFR expression in breast cancer tissues, and a functional linkage is observed between TGF-β signaling and EGFR transactivation in breast cancer cell lines. TGF-β promotes the migration and invasion abilities of breast cancer cells, along with the increase in EGFR expression. EGFR is also essential for TGF-β-induced enhancement of these abilities of breast cancer cells. Canonical Smad3 signaling and ERK/Sp1 signaling pathways mediate TGF-β-induced EGFR upregulation. Hence, our study provided insights into a novel mechanism by which TGF-β supports breast cancer progression.

Colorectal Cancer: From the Genetic Model to Posttranscriptional Regulation by Noncoding RNAs

Colorectal cancer is the third most common form of cancer in developed countries and, despite the improvements achieved in its treatment options, remains as one of the main causes of cancer-related death. In this review, we first focus on colorectal carcinogenesis and on the genetic and epigenetic alterations involved. In addition, noncoding RNAs have been shown to be important regulators of gene expression. We present a general overview of what is known about these molecules and their role and dysregulation in cancer, with a special focus on the biogenesis, characteristics, and function of microRNAs. These molecules are important regulators of carcinogenesis, progression, invasion, angiogenesis, and metastases in cancer, including colorectal cancer. For this reason, miRNAs can be used as potential biomarkers for diagnosis, prognosis, and efficacy of chemotherapeutic treatments, or even as therapeutic agents, or as targets by themselves. Thus, this review highlights the importance of miRNAs in the development, progression, diagnosis, and therapy of colorectal cancer and summarizes current therapeutic approaches for the treatment of colorectal cancer.

Insights into the distinct roles of MMP-11 in tumor biology and future therapeutics (Review)

The biological processes of cancer cells such as tumorigenesis, proliferation, angiogenesis, apoptosis and invasion are greatly influenced by the surrounding microenvironment. The ability of solid malignant tumors to alter the microenvironment represents an important characteristic through which tumor cells are able to acquire specific functions necessary for their malignant biological behaviors. Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases with the capacity of remodeling extracellular matrix (ECM) by degrading almost all ECM proteins, which plays essential roles during the invasion and metastasis process of solid malignant tumors, including allowing tumor cells to modify the ECM components and release cytokines, ultimately facilitating protease-dependent tumor progression. MMP-11, also named stromelysin-3, is a member of the stromelysin subgroup belonging to MMPs superfamily, which has been detected in cancer cells, stromal cells and adjacent microenvironment. Differently, MMP-11 exerts a dual effect on tumors. On the one hand MMP-11 promotes cancer development by inhibiting apoptosis as well as enhancing migration and invasion of cancer cells, on the other hand MMP-11 plays a negative role against cancer development via suppressing metastasis in animal models. Overexpression of MMP-11 was discovered in sera of cancer patients compared with normal control group as well as in multiple tumor tissue specimens, such as gastric cancer, breast cancer, and pancreatic cancer. At present, some evidence supports that MMP-11 may work as a significant tumor biomarker for early detection of cancer, tumor staging, prognostic analysis, monitoring recurrence during follow-up and also a potential target for immunotherapy against cancer. In view of the importance of MMP-11 in modifying tumor microenvironment and potent antitumoral effects on solid tumors, there is an urgent need for a deeper understanding of how MMP-11 modulates tumor progression, and exploring its potential clinical application.

Histone deacetylases and mechanisms of regulation of gene expression

In recent years it has become widely recognized that histone modification plays a pivotal role in controlling gene expression and is involved in a wide spectrum of disease regulation. Histone acetylation is a major modification that affects gene transcription and is controlled by histone acetyltransferases (HATs) and histone deacetylases (HDACs). HATs acetylate lysines of histone proteins, resulting in the relaxation of chromatin structure, and they also facilitate gene activation. Conversely, HDACs remove acetyl groups from hyperacetylated histones and suppress general gene transcription. In addition to histones, numerous nonhistone proteins can be acetylated and deacetylated, and they also are involved in the regulation of a wide range of diseases. To date there are 18 HDACs in mammals classified into 4 classes based on homology to yeast HDACs. Accumulating evidence has revealed that HDACs play crucial roles in a variety of biological processes including inflammation, cell proliferation, apoptosis, and carcinogenesis. In this review we summarize the current state of knowledge of HDACs in carcinogenesis and describe the involvement of HDACs in cancer-associated molecular processes. It is hoped than an understanding of the role of HDACs in cancer will lead to the design of more potent and specific drugs targeting selective HDAC proteins for the treatment of the disease.

Mechanisms of Histone Deacetylase Inhibitor-Regulated Gene Expression in Cancer Cells

SIGNIFICANCE

Class I and II histone deacetylase inhibitors (HDACis) are approved for the treatment of cutaneous T-cell lymphoma and are undergoing clinical trials as single agents, and in combination, for other hematological and solid tumors. Understanding their mechanisms of action is essential for their more effective clinical use, and broadening their clinical potential.

RECENT ADVANCES

HDACi induce extensive transcriptional changes in tumor cells by activating and repressing similar numbers of genes. These transcriptional changes mediate, at least in part, HDACi-mediated growth inhibition, apoptosis, and differentiation. Here, we highlight two fundamental mechanisms by which HDACi regulate gene expression—histone and transcription factor acetylation. We also review the transcriptional responses invoked by HDACi, and compare these effects within and across tumor types.

CRITICAL ISSUES

The mechanistic basis for how HDACi activate, and in particular repress gene expression, is not well understood. In addition, whether subsets of genes are reproducibly regulated by these agents both within and across tumor types has not been systematically addressed. A detailed understanding of the transcriptional changes elicited by HDACi in various tumor types, and the mechanistic basis for these effects, may provide insights into the specificity of these drugs for transformed cells and specific tumor types.

FUTURE DIRECTIONS

Understanding the mechanisms by which HDACi regulate gene expression and an appreciation of their transcriptional targets could facilitate the ongoing clinical development of these emerging therapeutics. In particular, this knowledge could inform the design of rational drug combinations involving HDACi, and facilitate the identification of mechanism-based biomarkers of response.

Innate antiviral host defense attenuates TGF-β function through IRF3-mediated suppression of Smad signaling

TGF-β signaling is essential in many processes, including immune surveillance, and its dysregulation controls various diseases, including cancer, fibrosis, and inflammation. Studying the innate host defense, which functions in most cell types, we found that RLR signaling represses TGF-β responses. This regulation is mediated by activated IRF3, using a dual mechanism of IRF3-directed suppression. Activated IRF3 interacts with Smad3, thus inhibiting TGF-β-induced Smad3 activation and, in the nucleus, disrupts functional Smad3 transcription complexes by competing with coregulators. Consequently, IRF3 activation by innate antiviral signaling represses TGF-β-induced growth inhibition, gene regulation and epithelial-mesenchymal transition, and the generation of Treg effector lymphocytes from naive CD4(+) lymphocytes. Conversely, silencing IRF3 expression enhances epithelial-mesenchymal transition, TGF-β-induced Treg cell differentiation upon virus infection, and Treg cell generation in vivo. We present a mechanism of regulation of TGF-β signaling by the antiviral defense, with evidence for its role in immune tolerance and cancer cell behavior.

Histone hyperacetylation up-regulates protein kinase Cδ in dopaminergic neurons to induce cell death: relevance to epigenetic mechanisms of neurodegeneration in Parkinson disease

The oxidative stress-sensitive protein kinase Cδ (PKCδ) has been implicated in dopaminergic neuronal cell death. However, little is known about the epigenetic mechanisms regulating PKCδ expression in neurons. Here, we report a novel mechanism by which the PKCδ gene can be regulated by histone acetylation. Treatment with histone deacetylase (HDAC) inhibitor sodium butyrate (NaBu) induced PKCδ expression in cultured neurons, brain slices, and animal models. Several other HDAC inhibitors also mimicked NaBu. The chromatin immunoprecipitation analysis revealed that hyperacetylation of histone H4 by NaBu is associated with the PKCδ promoter. Deletion analysis of the PKCδ promoter mapped the NaBu-responsive element to an 81-bp minimal promoter region. Detailed mutagenesis studies within this region revealed that four GC boxes conferred hyperacetylation-induced PKCδ promoter activation. Cotransfection experiments and Sp inhibitor studies demonstrated that Sp1, Sp3, and Sp4 regulated NaBu-induced PKCδ up-regulation. However, NaBu did not alter the DNA binding activities of Sp proteins or their expression. Interestingly, a one-hybrid analysis revealed that NaBu enhanced transcriptional activity of Sp1/Sp3. Overexpression of the p300/cAMP-response element-binding protein-binding protein (CBP) potentiated the NaBu-mediated transactivation potential of Sp1/Sp3, but expressing several HDACs attenuated this effect, suggesting that p300/CBP and HDACs act as coactivators or corepressors in histone acetylation-induced PKCδ up-regulation. Finally, using genetic and pharmacological approaches, we showed that NaBu up-regulation of PKCδ sensitizes neurons to cell death in a human dopaminergic cell model and brain slice cultures. Together, these results indicate that histone acetylation regulates PKCδ expression to augment nigrostriatal dopaminergic cell death, which could contribute to the progressive neuropathogenesis of Parkinson disease.

Endothelial cell TIMP-1 is upregulated by shear stress via Sp-1 and the TGFβ1 signaling pathways

Laminar shear stress promotes vascular integrity by inhibiting proteolysis of the extracellular matrix (ECM) surrounding the microvasculature. We hypothesized that the matrix metalloproteinase inhibitor TIMP-1 would be upregulated in endothelial cells exposed to shear stress. Microvascular endothelial cells isolated from rat or mouse skeletal muscles were exposed to laminar shear stress for 2, 4, or 24 h. A biphasic increase in TIMP-1 protein was observed at 2 and 24 h of shear stress exposure. Sp-1 siRNA prevented the increase in TIMP-1 after 2, but not 24, hours of shear exposure. TGFβ production and Smad2/3 phosphorylation are increased by shear stress. Inhibition of TGFβ signaling, either by use of the TGFβ receptor 1 inhibitor SB-431542 or with Smad 2/3 siRNA, abrogated the shear stress-induced increase in TIMP-1 mRNA after 24 h of shear stress exposure. These results suggest that both acute and chronic elevated laminar shear stress act to maintain vessel integrity through increasing TIMP-1 production, but that the TGFβ signaling pathway is essential to maintain TIMP-1 expression during chronic shear stress.

Anti-inflammatory effects of budesonide in human lung fibroblast are independent of histone deacetylase 2

Objective and design

Reduced expression of histone deacetylase 2 (HDAC2) in alveolar macrophages and epithelial cells may account for reduced response of chronic obstructive pulmonary disease (COPD) patients to glucocorticoids. HDAC2 expression and its role in mediating glucocorticoid effects on fibroblast functions, however, has not been fully studied. This study was designed to investigate whether HDAC2 mediates glucocorticoid effects on release of inflammatory cytokines and matrix metalloproteinases (MMPs) from human lung fibroblasts.

Methods

Human lung fibroblasts (HFL-1 cells) were stimulated with interleukin (IL)-1 β plus tumor necrosis factor (TNF)-α in the presence or absence of the glucocorticoid budesonide. Cytokines (IL-6 and IL-8) were quantified by enzyme linked immunosorbent assay (ELISA) and MMPs (MMP-1 and MMP-3) by immunoblotting in culture medium. The role of HDAC2 was investigated using a pharmacologic inhibitor as well as a small interfering ribonucleic acid (siRNA) targeting HDAC2.

Results

We have demonstrated that budesonide concentration-dependently (10⁻¹⁰–10⁻⁷ M) inhibited IL-6, IL-8, MMP-1, and MMP-3 release by HFL-1 cells in response to IL-1β plus TNF-α. While an HDAC inhibitor significantly blocked the inhibitory effect of budesonide on human bronchial epithelial cells (HBECs) and monocytes (THP-1 cells), it did not block the inhibitory effect of budesonide on release of cytokines and MMPs from HFL-1 cells. Similarly, an HDAC2-siRNA blocked budesonide inhibition of cytokine release in HBECs, but it did not block the inhibitory effect of budesonide on HFL-1 cytokine and MMP release. Furthermore, budesonide significantly blocked release of cytokines and MMPs to a similar degree in normal and COPD lung fibroblasts as well as in HFL-1 cells exposed or not exposed to cigarette smoke extract.

Conclusion

These findings suggest that, in contrast to airway epithelial cells and monocytes/macrophages, HDAC2 is not required for budesonide to inhibit MMP and cytokine release by lung fibroblasts and this inhibitory pathway appears to be intact in cultured fibroblasts from COPD patients. These results also suggest that budesonide has the potential to modulate fibroblast-mediated tissue remodeling following airway inflammation in COPD, which is mediated via an HDAC2 independent pathway.

4F2hc-silencing impairs tumorigenicity of HeLa cells via modulation of galectin-3 and β-catenin signaling, and MMP-2 expression

4F2hc is a type-II glycoprotein whose covalent-bound association with one of several described light chains yields a heterodimer mainly involved in large neutral amino acid transport. Likewise, it is well known that the heavy chain interacts with β-integrins mediating integrin-dependent events such as survival, proliferation, migration and even transformation. 4F2hc is a ubiquitous protein whose overexpression has been related to tumor development and progression. Stable silencing of 4F2hc in HeLa cells using an artificial miRNA impairs in vivo tumorigenicity and leads to an ineffective proliferation response to mitogens. 4F2hc colocalizes with β1-integrins and CD147, but this interaction does not occur in lipid rafts in HeLa cells. Moreover, silenced cells present defects in integrin- (FAK, Akt and ERK1/2) and hypoxia-dependent signaling, and reduced expression/activity of MMP-2. These alterations seem to be dependent on the inappropriate formation of CD147/4F2hc/β1-integrin heterocomplexes on the cell surface, arising when CD147 cannot interact with 4F2hc. Although extracellular galectin-3 accumulates due to the decrease in MMP-2 activity, galectin-3 signaling events are blocked due to an impaired interaction with 4F2hc, inducing an increased degradation of β-catenin. Furthermore, cell motility is compromised after protein silencing, suggesting that 4F2hc is related to tumor invasion by facilitating cell motility. Therefore, here we propose a molecular mechanism by which 4F2hc participates in tumor progression, favoring first steps of epithelial-mesenchymal transition by inhibition of β-catenin proteasomal degradation through Akt/GSK-3β signaling and enabling cell motility.