Pseudoscleroderma associated with lung cancer: correlation of collagen type I and connective tissue growth factor gene expression

Hsa-miR-379 down-regulates Rac1/MLK3/JNK/AP-1/Collagen I cascade reaction by targeting connective tissue growth factor in human alveolar basal epithelial A549 cells

OBJECTIVE

This study was aimed to screen and identify miRNAs that could regulate human CTGF gene and downstream cascade reaction Rac1/MLK3/JNK/AP-1/Collagen I by bioinformatics and experimental means.

METHODS

TargetScan and Tarbase were used to predict miRNAs that may have regulatory effects on human CTGF gene. The dual-luciferase reporter gene assay was employed to verify the results obtained in bioinformatics. Human alveolar basal epithelial A549 cells were exposed to silica (SiO₂) culture medium for 24 h to establish an in vitro model of pulmonary fibrosis, and bleomycin (BLM) of 100 ng/mL was used as a positive control. The miRNA and mRNA expression levels were determined by RT-qPCR, and the protein levels were measured by western blot in hsa-miR-379-3p overexpression group or not.

RESULTS

A total of 9 differentially expressed miRNAs that might regulate the human CTGF gene were predicted. Hsa-miR-379-3p and hsa-miR-411-3p were selected for the subsequent experiments. The results of the dual-luciferase reporter assay showed that hsa-miR-379-3p could bind to CTGF, but hsa-miR-411-3p could not. Compared with the control group, SiO₂ exposure (25 and 50 μg/mL) could significantly reduce the expression level of hsa-miR-379-3p in A549 cells. SiO₂ exposure (50 μg/mL) could significantly increase the mRNA expression levels of CTGF, Collagen I, Rac1, MLK3, JNK, AP1, and VIM in A549 cells, while CDH1 level was significantly decreased. Compared with SiO₂ + NC group, the mRNA expression levels of CTGF, Collagen I, Rac1, MLK3, JNK, AP1, and VIM were significantly decreased, and CDH1 level was significantly higher when hsa-miR-379-3p was overexpressed. At the same time, overexpression of hsa-miR-379-3p improved the protein levels of CTGF, Collagen I, c-Jun and phospho-c-Jun, JNK1 and phospho-JNK1 significantly compared with SiO₂ + NC group.

CONCLUSION

Hsa-miR-379-3p was demonstrated for the first time that could directly target and down-regulate human CTGF gene, and further affect the expression levels of key genes and proteins in Rac1/MLK3/JNK/AP-1/Collagen I cascade reaction.

Cutaneous Manifestations of Scleroderma and Scleroderma-Like Disorders: a Comprehensive Review

Scleroderma refers to an autoimmune connective tissue fibrosing disease, including three different subsets: localized scleroderma, limited cutaneous systemic sclerosis, and diffuse cutaneous systemic sclerosis with divergent patterns of organ involvement, autoantibody profiles, management, and prognostic implications. Although systemic sclerosis is considered the disease prototype that causes cutaneous sclerosis, there are many other conditions that can mimic and be confused with SSc. They can be classified into immune-mediated/inflammatory, immune-mediated/inflammatory with abnormal deposit (mucinoses), genetic, drug-induced and toxic, metabolic, panniculitis/vascular, and (para)neoplastic disorders according to clinico-pathological and pathogenetic correlations. This article reviews the clinical presentation with emphasis on cutaneous disease, etiopathogenesis, diagnosis, and treatment options available for the different forms of scleroderma firstly and for scleroderma-like disorders, including scleromyxedema, scleredema, nephrogenic systemic fibrosis, eosinophilic fasciitis, chronic graft-versus-host disease, porphyria cutanea tarda, diabetic stiff-hand syndrome (diabetic cheiroartropathy), and other minor forms. This latter group of conditions, termed also scleroderma mimics, sclerodermiform diseases, or pseudosclerodermas, shares the common thread of skin thickening but presents with distinct cutaneous manifestations, skin histology, and systemic implications or disease associations, differentiating each entity from the others and from scleroderma. The lack of Raynaud's phenomenon, capillaroscopic abnormalities, or scleroderma-specific autoantibodies is also important diagnostic clues. As cutaneous involvement is the earliest, most frequent and characteristic manifestation of scleroderma and sclerodermoid disorders, dermatologists are often the first-line doctors who must be able to promptly recognize skin symptoms to provide the affected patient a correct diagnosis and appropriate management.

Autoimmune paraneoplastic syndromes associated to lung cancer: A systematic review of the literature: Part 2: Hematologic, cutaneous and vascular syndromes

The development of new immune treatment in oncology and particularly for lung cancer may induce new complications, particularly activation or reactivation of auto-immune diseases. In this context, a systematic review on the auto-immune paraneoplastic syndromes associated with lung cancer appears useful. This article is the second of a series of five and deals with hematologic, cutaneous and vascular syndromes.

Atypical clinical presentation of a subset of patients with anti-RNA polymerase III--non-scleroderma cases associated with dominant RNA polymerase I reactivity and nucleolar staining

Introduction

Anti-RNA polymerase III (RNAP III) antibodies are highly specific markers of scleroderma (systemic sclerosis, SSc) and associated with a rapidly progressing subset of SSc. The clinical presentation of anti-RNAP III positive patients, onset of Raynaud's phenomenon (RP) and SSc in unselected patients in a rheumatology clinic were evaluated.

Methods

Autoantibodies in sera from 1,966 unselected patients (including 434 systemic lupus erythematosus (SLE), 119 SSc, 85 polymyositis/dermatomyositis (PM/DM)) in a rheumatology clinic were screened by radioimmunoprecipitation. Anti-RNAP III positive sera were also tested by immunofluorescence antinuclear antibodies and anti-RNAP III ELISA. Medical records of anti-RNAP III positive patients were reviewed.

Results

Among 21 anti-RNAP III positive patients, 16 met the American College of Rheumatology (ACR) SSc criteria at the initial visit but 5 did not; diagnoses were vasculitis, early polyarthritis, renal failure with RP, interstitial lung disease, and Sjögren's syndrome. The first two patients developed rapidly progressive diffuse SSc. An additional case presented with diffuse scleroderma without RP and RP developed two years later. Anti-RNAP III antibodies in these 6 cases of atypical clinical presentation were compared with those in 15 cases of typical (SSc with RP) cases. Anti-RNAP III levels by ELISA were lower in the former group (P = 0.04 by Mann-Whitney test) and 3 of 6 were negative versus only 1 of 15 negative in the latter (P < 0.05 by Fisher's exact test). Three cases of non-SSc anti-RNAP III positive patients had predominant reactivity with RNAP I with weak RNAP III reactivity and had a strong nucleolar staining. Three anti-RNAP III patients, who did not have RP at the initial visit, developed RP months later. Scleroderma developed prior to RP in 5 out of 16 (31%) in the anti-RNAP III group, but this was rare in patients with other autoantibodies. The interval between the onset of RP to scleroderma was short in anti-RNAP III positive patients.

Conclusions

Anti-RNAP III antibodies are highly specific for SSc; however, a subset of anti-RNAP III positive patients do not present as typical SSc. The interval between RP and scleroderma in this group is short, and 31% of patients developed scleroderma prior to RP in this group. Anti-RNAP III positive patients may not present as typical SSc and detecting anti-RNAP III may have predictive value.

More Than Structural Cells, Fibroblasts Create and Orchestrate the Tumor Microenvironment

The tumor microenvironment comprises many cell types including infiltrating immune cells such as lymphocytes, endothelial cells and a complex stroma consisting mainly of fibroblasts. Fibroblasts are heterogeneous and consist of Thy-1+ and Thy-1- subsets that define different biosynthetic and differentiation potential. They produce mediators linked to carcinogenesis and metastasis, including Cox-2 and PGE2, both of which are also increased in most cancers. This review will highlight the emerging role of the complex fibroblastic stroma in establishing a microenvironment supporting malignant transformation, tumor growth and attenuation of host anti-tumor immune responses.

Breast cancer and systemic sclerosis: a clinical description of 21 patients in a population-based cohort study

Previous studies have demonstrated an increased risk of breast cancer among patients with systemic sclerosis (scleroderma). To describe the clinical characteristics of 21 patients with both systemic sclerosis and breast cancer, and compare their risk factors to female scleroderma patients without breast cancer, in a population-based cohort study of South Australia. Subjects with scleroderma and breast cancer were identified from the South Australian Scleroderma Register with cross-linking to the South Australian Cancer Registry, last updated to the end of December 2005. Clinical information was obtained from standardised self-administered questionnaires and case note reviews. Odds ratios for the risk factors for breast cancer in scleroderma were determined, and clinical variables were analysed using chi square, Fisher's exact, Mann-Whitney and t tests. At the end of December 2005 there were a total of 389 female patients with scleroderma. Of these, 21 (5.4%) had been diagnosed with breast cancer. The mean age of onset of scleroderma was 43.5 years, and the mean age of breast cancer was 60.5 years in those with scleroderma and breast cancer. The majority (71.4%) had limited scleroderma, with anti-centromere antibody being the most prevalent serological abnormality. In 16 (76%) patients the diagnosis of breast cancer occurred on an average of 22.3 years after the onset of their first scleroderma symptom. When compared to 48 controls, scleroderma patients with breast cancer were found to have a higher incidence of a positive family history of breast cancer (Fisher's exact test, p = 0.04) and a lower incidence of hormone-replacement therapy use (Fisher's exact test, p = 0.0026). This population-based cohort study provides evidence that the majority of patients with scleroderma and breast cancer have limited scleroderma and anti-centromere antibody. Given the increased incidence of solid tumours in systemic sclerosis, we suggest regular screening of female patients for breast cancer, especially in those with a family history.

Mechanical tension and integrin alpha 2 beta 1 regulate fibroblast functions

The extracellular matrix (ECM) environment in connective tissues provides fibroblasts with a structural scaffold and modulates cell shape, but it also profoundly influences the fibroblast phenotype. Here we studied fibroblasts cultured in a three-dimensional network of native collagen, which was either mechanically stressed or relaxed. Mechanical load induces fibroblasts that synthesize abundant ECM and a characteristic array of cytokines/chemokines. This phenotype is reminiscent of late granulation tissue or scleroderma fibroblasts. By contrast, relaxed fibroblasts are characterized by induction of proteases and a subset of cytokines that does not overlap with that of mechanically stimulated cells. Thus, the biochemical composition and physical nature of the ECM exert powerful control over the phenotypes of fibroblasts, ranging from "synthetic" to "inflammatory" phenotypes. Interactions between fibroblasts and collagen fibrils are mostly mediated by a subset of beta 1 integrin receptors. Fibroblasts utilize alpha 1 beta 1, alpha 2 beta 1, and alpha 11 beta 1 integrins for establishing collagen contacts and transducing signals. In vitro assays and mouse genetics have demonstrated individual tasks served by each receptor, but also functional redundancy. Unraveling the integrated functions of fibroblasts, collagen integrin receptors, collagen fibrils, and mechanical tension will be important to understand the molecular mechanisms underlying tissue repair and fibrosis.

Pseudoscleroderma associated with cancer

In the period 1994-2002, we saw 71 patients with sclerotic skin changes; 66 were diagnosed with systemic sclerosis (SSc) while five (7%) were diagnosed with pseudoscleroderma associated with various malignancies. The mean duration of disease in these five patients was significantly shorter than that of patients with SSc. The incidence of positive antinuclear antibodies, Raynaud's phenomenon or oesophageal involvement in patients with pseudoscleroderma was significantly lower than that in patients with SSc. The distributions of skin sclerosis varied in each case. Serum basic fibroblast growth factor (bFGF) levels in the five patients with pseudoscleroderma were very elevated compared with levels in controls. Elevated expression of bFGF was detected on fibroblasts of affected skin and in one lung-cancer tissue sample obtained by excision.

Breast cancer and scleroderma

INTRODUCTION

Epidemiologic studies have shown that patients with scleroderma have an increased risk of cancer.

METHODS

The authors report eight cases and retrospectively review the published data on the possible association between breast cancer and scleroderma of the cutaneous and systemic forms. The records of all patients with scleroderma and breast cancer who were hospitalized during 1980-2002 in the Chaim Sheba Medical Center were surveyed. A literature search for breast cancer and scleroderma was performed.

RESULTS

The clinical data of 65 women patients with breast cancer and scleroderma, eight of whom were hospitalized in the Chaim Sheba Medical Center and 57 who were reported in the literature, are summarized. In 29 patients (44%), scleroderma appeared before or simultaneously with the diagnosis of breast cancer. While a higher frequency of systemic scleroderma was described in this group, a higher rate of cutaneous scleroderma appeared in the group where scleroderma followed breast cancer diagnosis (p<0.001).

CONCLUSIONS

Large-scale case-control studies are needed to substantiate the possible association between scleroderma-both cutaneous and systemic-and breast cancer.

Structural and functional properties of CCN proteins

The CCN family currently comprises six members (CCN1-6) that regulate diverse cell functions, including mitogenesis, adhesion, apoptosis, extracellular matrix (ECM) production, growth arrest, and migration. These properties can result in a multiplicity of effects during development, differentiation, wound healing, and disease states, such as tumorigenesis and fibrosis. CCN proteins have emerged as major regulators of chondrogenesis, angiogenesis, and fibrogenesis. CCN proteins are mosaic in nature and consist of up to four structurally conserved modules, at least two of which are involved in binding to cell surfaces via molecules that include integrins, heparan sulfate proteoglycans, and low-density lipoprotein receptor-related protein. CCN proteins use integrins as signal transducing receptors to regulate context-dependent responses in individual cell types. The involvement of integrins in mediating CCN signaling allows for considerable plasticity in response because some effects are specific for certain integrin subtypes and integrin signaling is coordinated with other signaling pathways in the cell. In addition to their own biological properties, CCN proteins regulate the functions of other bioactive molecules (e.g., growth factors) via direct binding interactions. CCN molecules demonstrate complex multifaceted modes of action and regulation and have emerged as important matricellular regulators of cell function.

Fatal exacerbation of paraneoplastic systemic sclerosis after neoadjuvant chemotherapy in a breast cancer patient

Paraneoplastic systemic sclerosis (SSc) occurs in about 3%-7% of individuals with SSc. There are reports of accelerated SSc syndromes associated in particular with breast cancer. Further exacerbations of the rheumatic condition may be induced by treatment of the cancer. We report a 30-year-old African-American woman with a contiguous diagnosis of breast cancer and paraneoplastic SSc. She was treated with neoadjuvant chemotherapy and developed an accelerated SSc syndrome with pericarditis and cardiac tamponade, with lethal results. This case report stresses the need for control of the rheumatic condition prior to the initiation of antineoplastic therapy.

Expression of connective tissue growth factor (CCN2) in desmoplastic small round cell tumour

BACKGROUND

Desmoplastic small round cell tumour (DSRCT) is a rare and often fatal abdominal tumour that is distinguished by well defined islands of cells, surrounded by prominent desmoplastic stroma. As in certain other tumours, the function of the Wilms's tumour protein (WT1) in repressing gene transcription is lost in DSRCT.

AIMS

To assess the expression and localisation of connective tissue growth factor (CCN2) in DSRCT because this protein is transcriptionally repressed by WT1 and is associated with the production of abundant extracellular matrix.

METHODS

CCN2 was assessed by in situ hybridisation and immunohistochemistry.

RESULTS

CCN2 mRNA and protein were colocalised to the tumour cells themselves, in addition to stromal fibroblasts and vascular endothelial cells.

CONCLUSIONS

These data show that CCN2 is produced in high amounts by several cell types in DSRCT, and highlight a potential role for this factor in the autocrine and paracrine regulation of tumour cell growth, matrigenesis, and angiogenesis.

Expression of connective tissue growth factor is increased in injured myocardium associated with protein kinase C beta2 activation and diabetes

Protein kinase C (PKC) beta isoform activity is increased in myocardium of diabetic rodents and heart failure patients. Transgenic mice overexpressing PKCbeta2 (PKCbeta2Tg) in the myocardium exhibit cardiomyopathy and cardiac fibrosis. In this study, we characterized the expression of connective tissue growth factor (CTGF) and transforming growth factor beta (TGFbeta) with the development of fibrosis in heart from PKCbeta2Tg mice at 4-16 weeks of age. Heart-to-body weight ratios of transgenic mice increased at 8 and 12 weeks, indicating hypertrophy, and ratios did not differ at 16 weeks. Collagen VI and fibronectin mRNA expression increased in PKCbeta2Tg hearts at 4-12 weeks. Histological examination revealed myocyte hypertrophy and fibrosis in 4- to 16-week PKCbeta2Tg hearts. CTGF expression increased in PKCbeta2Tg hearts at all ages, whereas TGFbeta increased only at 8 and 12 weeks. In 8-week diabetic mouse heart, CTGF and TGFbeta expression increased two- and fourfold, respectively. Similarly, CTGF expression increased in rat hearts at 2-8 weeks of diabetes. This is the first report of increased CTGF expression in myocardium of diabetic rodents suggesting that cardiac injury associated with PKCbeta2 activation, diabetes, or heart failure is marked by increased CTGF expression. CTGF could act independently or together with other cytokines to induce cardiac fibrosis and dysfunction.

Mechanical stress is required for high-level expression of connective tissue growth factor

We used gene array technology to analyze differences in gene expression between mechanically stressed and relaxed fibroblasts. A number of stress-responsive genes that showed a two- to sixfold difference in their relative expression were identified. Connective tissue growth factor (CTGF) was among those genes that showed the most striking up-regulation by mechanical stress. Its regulation occurred at the transcriptional level and was reversible. A new steady state level of CTGF mRNA was reached within less than 6 h after stress relaxation. Mechanical stress was absolutely required for sustained high-level expression; TGF-beta, which is also known to stimulate CTGF synthesis, was not sufficient on its own. Experiments with specific inhibitors suggested that a protein kinase and a tyrosine phosphatase were involved in the transduction of the mechanical stimulus to gene expression. Since CTGF controls the synthesis of several extracellular matrix proteins, it is likely that this growth factor is responsible for the increased synthesis of collagen I and other matrix proteins in stressed fibroblasts.

Lefty contributes to the remodeling of extracellular matrix by inhibition of connective tissue growth factor and collagen mRNA expression and increased proteolytic activity in a fibrosarcoma model

Homeostasis of the extracellular matrix (ECM) of tissues is regulated by controlling deposition and degradation of ECM proteins. The breakdown of ECM is essential in blastocyst implantation and embryonic development, tissue morphogenesis, menstrual shedding, bone formation, tissue resorption after delivery, and tumor growth and invasion. TGF-beta family members are one of the classes of proteins that actively participate in the homeostasis of ECM. Here, we report on the effect of lefty, a novel member of the TGF-beta family, on the homeostasis of extracellular matrix in a fibrosarcoma model. Fibroblastic cells forced to express lefty by retroviral transduction lost their ability to deposit collagen in vivo. This event was associated with down-regulation of the steady-state level of connective tissue growth factor that induces collagen type I mRNA. In addition, lefty transduction significantly decreased collagen type I mRNA expression and simultaneously increased collagenolytic, gelatinolytic, elastolytic, and caseinolytic activities in vivo by the transduced fibroblasts. These findings provide a new insight on the actions of lefty and suggest that this cytokine plays an active role in remodeling of the extracellular matrix in vivo.

Pathogenesis of diabetic nephropathy: focus on transforming growth factor-beta and connective tissue growth factor

Although considerable improvement in the prognosis of diabetic nephropathy has been achieved in recent years due to intensive insulin and angiotensin-converting enzyme inhibitor treatment, these approaches do not provide complete protection against progression of diabetic nephropathy. An urgent need for additional novel therapies to prevent or further slow the progression of diabetic nephropathy motivated us to provide an up-to-date review with particular emphasis on the potential role of two growth factors--transforming growth factor-beta and connective tissue growth factor--in the pathogenesis of diabetic nephropathy. The most intensively studied to date, transforming growth factor-beta appears to play a central role in the pathogenesis of diabetic nephropathy. Recently, attention has focused on connective tissue growth factor, which mimics the biological activity of transforming growth factor-beta in profibrotic tissue formation. Thus, acting as a downstream mediator of the profibrotic activity of transforming growth factor-beta, connective tissue growth factor may constitute a more specific target for future antifibrotic therapies.

Connective tissue growth factor: an attractive therapeutic target in fibrotic renal disease

Despite diverse initiating insults, glomerulosclerosis and tubulointerstitial fibrosis are pathological features common to most forms of progressive renal disease. Control of systemic hypertension and blockade of the renin-angiotensin system ameliorate the rate of progression of chronic renal disease; however they generally fail to completely arrest the scarring process. While the chain of events leading to scarring are still being defined, TGF-beta is a cytokine that plays a pivotal role in the pathogenesis of glomerulosclerosis and tubulointerstitial fibrosis [1]. Given the pleiotropic effects of TGF-beta, significant attention has focused on the potential of its downstream mediators as therapeutic targets. Connective tissue growth factor (CTGF) is a member of the CCN gene family, which includes CyR61 (cysteine rich 61), Nov (Nephroblastoma overexpressed) and the WISP family (for review see [2,3,4]). These immediate-early genes coordinate complex biologic processes during differentiation and tissue repair [5]. Increased expression of CTGF has been detected in experimental and human renal fibrosis where it correlates with glomerulosclerosis and the degree of tubulointerstitial fibrosis [6]. In these settings CTGF expression is regulated at least in part by TGF-beta. This review details the biology of CTGF with specific reference to its potential as a therapeutic target in renal fibrosis.

Connective tissue growth factor: what's in a name?

Connective tissue growth factor (CTGF) is a member of the recently described CCN gene family which contains CTGF itself, cyr61, nov, elm1, Cop1, and WISP-3. CTGF is transcriptionally activated by several factors although its stimulation by transforming growth factor beta (TGF-beta) has attracted considerable attention. CTGF acts to promote fibroblast proliferation, migration, adhesion, and extracellular matrix formation, and its overproduction is proposed to play a major role in pathways that lead to fibrosis, especially those that are TGF-beta-dependent. This includes fibrosis of major organs, fibroproliferative diseases, and scarring. CTGF also appears to play a role in the extracellular matrix remodeling that occurs in normal physiological processes such as embryogenesis, implantation, and wound healing. However, recent advances have shown that CTGF is involved in diverse autocrine or paracrine actions in several other cell types such as vascular endothelial cells, epithelial cells, neuronal cells, vascular smooth muscle cells, and cells of supportive skeletal tissues. Moreover, in some circumstances CTGF has negative effects on cell growth in that it can be antimitotic and apoptotic. In light of these discoveries, CTGF has been implicated in a diverse variety of processes that include neovascularization, transdifferentiation, neuronal scarring, atherosclerosis, cartilage differentiation, and endochondral ossification. CTGF has thus emerged as a potential important effector molecule in both physiological and pathological processes and has provided a new target for therapeutic intervention in fibrotic diseases.