6275

S100A4

BACKGROUND: Depletion of glomerular podocytes is an important feature of progressive diabetic nephropathy. Although the most plausible explanation for this podocyte depletion is detachment from the glomerular basement membrane after cellular apoptosis, the mechanism is unclear. Fibroblast-specific protein 1 (FSP1; encoded by the S100A4 gene) is a member of the S100 family of calcium-binding proteins and is constitutively expressed in the cytoplasm of tissue fibroblasts or epithelial cells converted into fibroblasts by means of epithelial-mesenchymal transition. STUDY DESIGN: Retrospective cross-sectional analysis. SETTINGS & PARTICIPANTS: 109 patients with type 2 diabetes mellitus, of whom 43 (39%) underwent kidney biopsy. PREDICTOR: Clinical stage (4 categories) and histological grade (5 categories) of diabetic nephropathy. OUTCOME: FSP1 expression in podocytes in urine and glomeruli in kidney biopsy specimens. MEASUREMENTS: Immunohistochemistry, real-time polymerase chain reaction, and in situ hybridization. RESULTS: 38 of 109 patients (35%) were normoalbuminuric, 16 (15%) had microalbuminuria, 8 (7%) had macroalbuminuria, and 47 (43%) had decreased kidney function. Approximately 95% of podocytes in urine sediment were not apoptotic, and 86% expressed FSP1. The number of FSP1-positive podocytes in urine sediment was significantly larger in patients with macroalbuminuria than in those with normoalbuminuria (P = 0.03). Intraglomerular expression of FSP1 occurred almost exclusively in podocytes from patients with diabetes, and the number of FSP1-positive podocytes was larger in glomeruli showing diffuse mesangiopathy than in those showing focal mesangiopathy (P = 0.01). The number also was larger in glomeruli with nodular lesions than in those without nodular lesions (P < 0.001). FSP1-positive podocytes selectively expressed Snail1 and integrin-linked kinase, a known trigger for epithelial-mesenchymal transition. LIMITATIONS: Nonrepresentative study population. CONCLUSIONS: These results suggest that the appearance of FSP1 in podocytes of patients with diabetes is associated with more severe clinical and pathological findings of diabetic nephropathy, perhaps because of induction of podocyte detachment through epithelial-mesenchymal transition-like phenomena.

PURPOSE: The expression of LIM and SH3 protein 1 (LASP1) was upregulated in colorectal cancer cases, thereby contributing to the aggressive phenotypes of colorectal cancer cells. However, we still cannot decipher the underlying molecular mechanism associated with colorectal cancer metastasis. EXPERIMENTAL DESIGN: In this study, IHC was performed to investigate the expression of proteins in human colorectal cancer tissues. Western blot analysis was used to assess the LASP1-induced signal pathway. Two-dimensional difference gel electrophoresis was performed to screen LASP1-modulated proteins and uncover the molecular mechanism of LASP1. TGFbeta was used to induce an epithelial-mesenchymal transition (EMT). RESULTS: LASP1 expression was correlated with the mesenchymal marker vimentin and was inversely correlated with epithelial markers, namely, E-cadherin and beta-catenin, in clinical colorectal cancer samples. The gain- and loss-of-function assay showed that LASP1 induces EMT-like phenotypes in vitro and in vivo. S100A4, identified as a LASP1-modulated protein, was upregulated by LASP1. Moreover, it is frequently coexpressed with LASP1 in colorectal cancer. S100A4 was required for EMT, and an increased cell invasiveness of colorectal cancer cell is induced by LASP1. Furthermore, the stimulation of TGFbeta resulted in an activated Smad pathway that increased the expression of LASP1 and S100A4. The depletion of LASP1 or S100A4 expression inhibited the TGFbeta signaling pathway. Moreover, it significantly weakened the proinvasive effects of TGFbeta on colorectal cancer cells. CONCLUSION: These findings elucidate the central role of LASP1 in the TGFbeta-mediated EMT process and suggest a potential target for the clinical intervention in patients with advanced colorectal cancer.CI - (c)2014 American Association for cancer Research.

INTRODUCTION: The onset of distal metastasis, which underlies the high mortality of breast cancers, warrants substantial studies to depict its molecular basis. Nuclear factor of activated T cells 5 (NFAT5) is upregulated in various malignancies and is critically involved in migration and invasion of neoplastic cells. Nevertheless, the metastasis-related events potentiated by this transcriptional factor and the mechanism responsible for NFAT5 elevation in carcinoma cells remain to be fully elucidated. METHODS: The correlation of NFAT5 with breast cancer invasiveness was investigated in vitro and clinically. The genes transcriptionally activated by NFAT5 were probed and their roles in breast cancer progression were dissected. The upstream regulators of NFAT5 were studied with particular attempt to explore the involvement of non-coding RNAs, and the mechanism underlying the maintenance of NFAT5 expression was deciphered. RESULTS: In metastatic breast cancers, NFAT5 promotes epithelial-mesenchymal transition (EMT) and invasion of cells by switching on the expression of the calcium binding protein S100A4, and facilitates the angiogenesis of breast epithelial cells and thus the development of metastases by transcriptionally activating vascular endothelial growth factor C (VEGF-C). NFAT5 is directly targeted by miR-568, which is in turn suppressed by the long non-coding RNA, Hotair, via a documented in trans gene silencing pattern, that is recruitment of the polycomb complex (Polycomb Repressive Complex 2; PRC2) and LSD1, and consequently methylation of histone H3K27 and demethylation of H3K4 on the miR-568 loci. CONCLUSION: This study unravels a detailed role of NFAT5 in mediating metastatic signaling, and provides broad insights into the involvement of Hotair, in particular, by transcriptionally regulating the expression of microRNA(s), in the metastasis of breast cancers.

Numerous studies have shown that S100A4 acquires its metastasis-promoting effects via inducing epithelial-mesenchymal transition (EMT). However, its role and mechanism in EMT in breast cancer had not been clearly elucidated. Herein, we showed that the knockdown of S100A4 expression in breast cancer cell lines, MDA-MB-231 and MDA-MB-468, inhibited not only cell invasion ability greatly, but also the occurrence of EMT significantly. In addition, S100A4 knockdown could also decrease the expression of MMP2, a promoter and a mediator of the EMT processes in cancer. Above all, restoring the expression of MMP2 in MDA-MB-231 and MDA-MB-468 could not only rescue the invasion ability inhibited by knockdown of S100A4, but also reverse the EMT suppressed by knockdown of S100A4. In summary, our results indicated that S100A4 could promote the invasion ability of breast cancer cells via EMT, more importantly, it could participate in EMT via regulating MMP2 in breast cancer. Therefore, S100A4 could be a candidate biomarker for defining breast cancer metastasis and useful target for therapy.

epithelial-mesenchymal transition (EMT) is a major cause of endometrial cancer (EC) to initiate invasion and metastasis. S100A4, a calcium-binding protein, is implicated in multistage of tumorigenesis and tumor progression. The correlation between S100A4 and EMT in EC is still unclear. This study was aimed to clarify the role of S100A4 in EC and the relationship between S100A4 expression and EMT markers. S100A4, E-cadherin, and vimentin were detected in tissues of EC patients (n=50) by immunohistochemistry. The impact of S100A4 on EC cell proliferation, migration and invasion was investigated via RNA interference, and the correlation between S100A4 and EMT markers were also explored. The results showed that S100A4 was significantly increased in epithelial cells of EC compared with the normal endometrium (P<0.05), also S100A4 level was positively related to age (P=0.021), histological grade (P<0.001), and lymph node metastasis (P<0.001). Additionally, silencing of S100A4 remarkably attenuated EC cell migration and invasion. Significant morphological change accompanied with the downregulation of EMT markers, E-cadherin and vimentin were also observed. Aberrant S100A4 expression may predict EC progression and play an important role in regulating EC cell invasion through EMT regulation. Hence, S100A4 is a promising therapeutic target.

miR-187-3p, a novel cancer-related microRNA, was previously reported to play promoting or suppressive roles in different malignancies. However, the expression level, biological function, and underlying mechanisms of miR-187-3p in hepatocellular carcinoma (HCC) remain unknown. This study demonstrated that miR-187-3p was significantly down-regulated in HCC tissues and cell lines, and was associated with advanced TNM stage and metastasis in HCC. Functional studies confirmed that miR-187-3p could inhibit the metastasis of HCC both in vitro and in vivo. Moreover, we proved that miR-187-3p could prevent the epithelial-mesenchymal transition (EMT) of HCC cells. Mechanically, S100A4 was a direct downstream target of miR-187-3p, and mediated the functional influence of miR-187-3p in HCC. Furthermore, miR-187-3p and S100A4 expression was evidently correlated with adverse clinical features and poor prognosis of HCC. Lastly, we showed that hypoxia was responsible for the significantly decreased level of miR-187-3p in HCC, and miR-187-3p was involved in the promoting effects of hypoxia on the metastasis and EMT of HCC cells. Taken together, miR-187-3p inhibits the metastasis and EMT in HCC by targeting S100A4. miR-187-3p can serve as a prognostic indicator and a promising therapeutic target for HCC patients.CI - Copyright (c) 2016 Elsevier Ireland Ltd. All rights reserved.

BACKGROUND: Dysregulation of microRNAs (miRNAs) is actively involved in the pathogenesis and tumorigenicity of colorectal cancer (CRC). miR-296 was found to play either oncogenic or tumor suppressive role in human cancers. However, the status of miR-296 and its function in CRC remain unknown. METHODS: The expression of miR-296 was confirmed by qRT-PCR in CRC tissues and cells, and its level was altered by corresponding miRNA vectors. Wound healing and Transwall assays were performed to detect the migration and invasion of CRC cells. The levels of proteins were measured using immunoblotting, immunohistochemistry and immunofluorescence. RESULTS: Underexpression of miR-296 was disclosed in CRC tissues and cells. Its decreased level was evidently correlated with adverse clinical parameters and poor prognosis of CRC patients. In vitro experiments indicated that miR-296 inhibited CRC cell migration and invasion. Mechanically, miR-296 inhibited the epithelial-mesenchymal transition (EMT) of CRC cells. A negative correlation between miR-296 and S100A4 expression was observed in CRC tissues. Luciferase reporter assays indicated that miR-296 inversely regulated the luciferase activity of 3'-UTR of S100A4. Herein, S100A4 was found to be a downstream molecule of miR-296 in CRC. Furthermore, S100A4 mediated the anti-metastatic effects of miR-296 on EMT, migration and invasion of CRC cells. CONCLUSIONS: miR-296 functions as an anti-metastatic factor mainly by suppressing S100A4 in CRC. It potentially acts as a prognostic predictor and a drug-target for CRC patients.

Extracellular matrix deposition during tubulointerstitial fibrosis (TIF), a central pathological process in patients with diabetic nephropathy (DN), is driven by locally activated, disease-relevant myofibroblasts. Myofibroblasts can arise from various cellular sources, e.g., tubular epithelial cells via a process named epithelial-to-mesenchymal transition (EMT). Transforming growth factor beta 1 (TGF-beta1) and its downstream Smad signaling play a critical role in both TIF and EMT. Whereas Smad3 is one central mediator, the role of the other prominently expressed variant, Smad2, is not completely understood. In this study, we sought to analyze the role of renal Smad2 in the development of TIF and EMT during streptozotocin-induced DN by using a fibroblast-specific protein 1 (FSP1)-promotor-driven SMAD2 knockout mouse model with decreased tubular, endothelial, and interstitial Smad2 expression. In contrast to wild-type diabetic mice, diabetic SMAD2 knockout mice showed the following features: (1) significantly reduced DN and TIF (shown by KIM1 expression; periodic acid Schiff staining; collagen I and III, fibronectin, and connective tissue growth factor deposition); (2) significantly reduced tubular EMT-like changes (e.g., altered Snail1, E-cadherin, matrix metalloproteinase 2, and vimentin deposition); and (3) significantly decreased expression of myofibroblast markers (alpha-smooth muscle actin, FSP1). As one mechanism for the protection against diabetes-induced TIF and EMT, decreased Smad3 protein levels and, as a possible consequence, reduced TGF-beta1 levels were observed in diabetic SMAD2 knockout mice. Our findings thus support the important role of Smad2 for pro-fibrotic TGF-beta/Smad3 signaling in experimental DN.