Fibulin-5 function during tumorigenesis.
Albig Allan R,Schiemann William P
Future oncology (London, England)
Tumorigenesis is the process by which normal cells evolve the capacity to evade and overcome the constraints normally placed upon their growth and survival. During cancer progression, indolent tumors experience an array of genetic and epigenetic events that ultimately coordinate the development of tumor metastasis, which is the most lethal facet of cancer and the leading cause of cancer-related death. The therapeutic necessity to combat tumor metastasis continues to drive investigations aimed at identifying novel regulators of this deadly process. Fibulin-5 is a newly described extracellular matrix protein that is important for normal embryonic development and organogenesis. Fibulin-5 expression may also be associated with the suppression of tumor formation through its control of cell proliferation, motility and angiogenic sprouting. Here, the tumor suppressing activities of fibulin-5 are reviewed, and the potential use and targeting of fibulin-5 to combat growth and metastasis of human malignancies is discussed.
10.1517/14796694.1.1.23
Fibulin-5 binds human smooth-muscle cells through alpha5beta1 and alpha4beta1 integrins, but does not support receptor activation.
The Biochemical journal
Fibulin-5, an extracellular matrix glycoprotein expressed in elastin-rich tissues, regulates vascular cell behaviour and elastic fibre deposition. Recombinant full-length human fibulin-5 supported primary human aortic SMC (smooth-muscle cell) attachment through alpha5beta1 and alpha4beta1 integrins. Cells on fibulin-5 spread poorly and displayed prominent membrane ruffles but no stress fibres or focal adhesions, unlike cells on fibronectin that also binds these integrins. Cell migration and proliferation were significantly lower on fibulin-5 than on fibronectin. Treatment of cells on fibulin-5 with a beta1 integrin-activating antibody induced stress fibres, increased attachment, migration and proliferation, and stimulated signalling of epidermal growth factor receptor and platelet-derived growth factor receptors alpha and beta. Fibulin-5 also modulated fibronectin-mediated cell spreading and morphology. We have thus identified the beta1 integrins on primary SMCs that fibulin-5 interacts with, and have shown that failure of fibulin-5 to activate these receptors limits cell spreading, migration and proliferation.
10.1042/BJ20070400
Fibulin-5 antagonizes vascular endothelial growth factor (VEGF) signaling and angiogenic sprouting by endothelial cells.
Albig Allan R,Schiemann William P
DNA and cell biology
Fibulin-5 (FBLN-5) is a widely expressed, integrin-binding extracellular matrix protein that mediates endothelial cell adhesion and scaffolds cells to elastic fibers. It is also a gene target of TGF-beta in fibroblasts and endothelial cells that regulates cell proliferation and motility in a context-specific manner. Whereas FBLN-5 expression is low in adult vasculature, its expression is high in developing and injured vasculature, implicating FBLN-5 in regulating angiogenesis and endothelial cell function. We show here that TGF-beta stimulates FBLN-5 expression in endothelial cells, and that this response was inhibited by coadministration of the proangiogenic factor, VEGF. FBLN-5 expression was downregulated significantly during endothelial cell tubulogenesis, implying that FBLN-5 expression antagonizes angiogenesis. Accordingly, FBLN-5 overexpression in or recombinant FBLN-5 treatment of endothelial cells abrogated their ability to undergo angiogenic sprouting, doing so by inhibiting endothelial cell proliferation and invasion through Matrigel matrices. Moreover, FBLN-5 antagonized VEGF signaling in endothelial cells, as well as enhanced their expression of the antiangiogenic factor, thrombospondin-1. Finally, the ability of FBLN-5 to antagonize angiogenic processes was determined to be independent of its integrin-binding RGD motif. Collectively, our findings establish FBLN-5 as a novel antagonist of angiogenesis and endothelial cell activities, and offer new insights into why tumorigenesis downregulates FBLN-5 expression.
10.1089/104454904323145254
Fibulin-5 suppresses lung cancer invasion by inhibiting matrix metalloproteinase-7 expression.
Yue Wen,Sun Quanhong,Landreneau Rodney,Wu Chuanyue,Siegfried Jill M,Yu Jian,Zhang Lin
Cancer research
The high mortality rate of lung cancer is largely due to the spread of disease to other organs. However, the molecular changes driving lung cancer invasion and metastasis remain unclear. In this study, we identified fibulin-5, a vascular ligand for integrin receptors, as a suppressor of lung cancer invasion and metastasis. Fibulin-5 was silenced by promoter hypermethylation in a majority of lung cancer cell lines and primary tumors. It inhibited lung cancer cell invasion and down-regulated matrix metalloproteinase-7 (MMP-7), which promoted lung cancer cell invasion. Knockdown of fibulin-5 was sufficient to stimulate cell invasion and MMP-7 expression. The expression levels of fibulin-5 and MMP-7 were inversely correlated in lung tumors. Suppression of MMP-7 expression by fibulin-5 was mediated by an integrin-binding RGD motif via the extracellular signal-regulated kinase (ERK) pathway. Furthermore, overexpression of fibulin-5 in H460 lung cancer cells inhibited metastasis in mice. Collectively, these results suggest that epigenetic silencing of fibulin-5 promotes lung cancer invasion and metastasis by activating MMP-7 expression through the ERK pathway.
10.1158/0008-5472.CAN-09-0398
Fibulin-5 is down-regulated in urothelial carcinoma of bladder and inhibits growth and invasion of human bladder cancer cell line 5637.
Hu Zheng,Ai Qing,Xu Hua,Ma Xin,Li Hong-Zhao,Shi Tao-Ping,Wang Chao,Gong Dao-Jing,Zhang Xu
Urologic oncology
PURPOSE:The expression of fibulin-5 was investigated in urothelial carcinomas of bladder and in normal bladder samples. The effects of fibulin-5 on cell proliferation, motility, and invasion were further explored in bladder cancer cell line 5637. MATERIALS AND METHODS:The expression of fibulin-5 in 20 bladder carcinoma samples and 7 normal bladder samples were detected by Western blot. Fibuin-5 cDNA was cloned into p-EGFP-N1 vector and transfected into bladder cancer cell line 5637. Growth curves were estimated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide assay and cell number count. The migration and invasion of the transfected cells and the control cells were measured by Boyden chamber assay. RESULTS:Compared with 1.16 ± 0.28 in the normal control, the mean ± SD expression of fibulin-5 in low grade tumors and high grade tumors were 0.57 ± 0.32 and 0.44 ± 0.42 (P = 0.002 and P = 0.018, respectively), while the expression in Ta-T1 tumors and T2+ tumors were 0.55 ± 0.31 and 0.49 ± 0.43 (P = 0.002 and P = 0.015, respectively). The differences between low grade and high grade tumors or Ta-T1 and T2+ tumors were not statistically significant (P = 0.362 and P = 0.589, respectively). The growth rate of the fibulin-5 transfected GFP-F5 cells was remarkably reduced than that of the untransfected cells or the empty vector transfected GFP-t cells. Besides, compared with control cells, the GFP-F5 cells showed significant inhibition of cell invasion with slight inhibition of cell migration. CONCLUSIONS:Fibulin-5 is down-regulated in urothelial carcinoma of bladder and acts as a tumor suppressor gene by inhibiting proliferation and invasion of bladder cancer cells.
10.1016/j.urolonc.2009.06.004
Nogo-B promotes the epithelial-mesenchymal transition in HeLa cervical cancer cells via Fibulin-5.
Xiao Wei,Zhou Shumin,Xu Hua,Li Heng,He Guoqing,Liu Yingle,Qi Yipeng
Oncology reports
Cervical cancer is a common malignancy in women worldwide, and the occurrence of invasion and metastasis is the major cause for most cancer-related deaths. Epithelial-mesenchymal transition (EMT) has been implicated in the metastasis of primary tumors and provides molecular mechanisms for cervical cancer metastasis. We previously reported that Nogo-B mediates cell motility by binding Fibulin-5. Herein, we show that the increased expression of Nogo-B is correlated with the degree of cervical cancer metastasis. In HeLa cervical cancer cells, overexpression of Nogo-B induces the EMT and promotes cell migration and invasion, while inhibiting cell adhesion. Furthermore, we found that Nogo-B accumulates and co-localizes with Fibulin-5 in pseudopods, and the downstream effects of overexpression of Nogo-B on cell motility could be partially abolished by RNA interference against Fibulin-5. These results suggest that Nogo-B functions as an inducer of cervical cancer metastasis and that this effect is mediated, at least in part, through Fibulin-5.
10.3892/or.2012.2069
Oncogenic fibulin-5 promotes nasopharyngeal carcinoma cell metastasis through the FLJ10540/AKT pathway and correlates with poor prognosis.
Hwang Chung-Feng,Shiu Li-Yen,Su Li-Jen,Yu-Fang Yin ,Wang Wei-Sheng,Huang Shun-Chen,Chiu Tai-Jan,Huang Chao-Cheng,Zhen Yen-Yi,Tsai Hsin-Ting,Fang Fu-Min,Huang Tai-Lin,Chen Chang-Han
PloS one
BACKGROUND:Nasopharyngeal carcinoma (NPC) is known for its high metastatic potential and locoregional recurrence, although the molecular alterations that are driving NPC metastasis remain unclear at this time. This study aimed to examine the expression of fibulin-5 in NPC, correlate the results with clinicopathological variables and survival, and to investigate the role of fibulin-5 in human NPC cell lines. MATERIAL AND METHODS:Standard semi-quantitative-RT-PCR, quantitative-RT-PCR, immunoblotting, and immunohistochemistry were used to investigate the mRNA and protein expression profiles of fibulin-5 in normal and NPC tissues. Immunohistochemistry of fibulin-5 was correlated with clinicopathological characteristics by univariate analyses. NPC cells overexpressing fibulin-5 or fibulin-5-siRNA cells were generated by stable transfection to characterize the molecular mechanisms of fibulin-5-elicited cell growth and metastasis. RESULTS:Our results demonstrated that fibulin-5 overexpression in NPC specimens and significantly correlated with advanced tumor metastasis indicating a poor 5-year overall survival. Fibulin-5 was mainly expressed in the nucleus in human NPC specimens and cell lines. Functionally, fibulin-5 overexpression yielded fast growth in NPC cells. In addition, fibulin-5 promotes cell metastasis in NPC cells through increased FLJ10540 and phosphor-AKT activity. In contrast, siRNA depletion of fibulin-5 suppressed FLJ10540 expression and phosphor-AKT activity. Suppression of either fibulin-5 or FLJ10540 can cause significant inhibition with regards to cell motility in NPC cells. Finally, immunohistochemical analysis of human aggressive NPC specimens showed a significant and positive correlation between fibulin-5 and FLJ10540 expression. CONCLUSION:Higher fibulin-5 expression is not only an important indicator of poor survival, but also contributes to the development of new therapeutic strategies in the FLJ10540/AKT pathway for NPC treatment.
10.1371/journal.pone.0084218
Fibulin-5 inhibits hepatocellular carcinoma cell migration and invasion by down-regulating matrix metalloproteinase-7 expression.
Tu Kangsheng,Dou Changwei,Zheng Xin,Li Chao,Yang Wei,Yao Yingmin,Liu Qingguang
BMC cancer
BACKGROUND:Fibulin-5 has been considered as a tumor suppressor through inhibiting tumor growth and invasion. Reduced expression of Fibulin-5 is frequently observed in various human cancers. In this study, we investigate the clinical significance of Fibulin-5 and its role in hepatocellular carcinoma (HCC) cell migration and invasion. METHODS:The expression of Fibulin-5 was evaluated by qRT-PCR and immunoblotting in HCC and matched noncancerous tissues. Fibulin-5 was over-expressed or knocked down by a retrovirus-mediated expression plasmid or a specific siRNA in HCC cells. Boyden chamber and Transwell assays were used to test HCC cell migration and invasion. Immunostaining was performed to determine matrix metalloproteinase-7 (MMP-7) expression in HCC specimens. MMP-7 retroviruses and siRNA were used to alter MMP-7 expression in HCC cells. RESULTS:In our study, the expression levels of Fibulin-5 protein and mRNA were down-regulated in HCC tissues as compared with those in matched noncancerous tissues. Reduced expression of Fibulin-5 was observed in all HCC cell lines (HepG2, SMMC-7721, MHCC97L, Hep3B, MHCC97H and HCC-LM3) as compare with that in a non-transformed hepatic cell line (LO2). Low expression of Fibulin-5 was significantly correlated with poor prognostic features including multiple tumor nodes, venous infiltration, high Edmondson-Steiner grading and advanced tumor-node-metastasis (TNM) tumor stage. Furthermore, we demonstrated that Fibulin-5 was a novel independent prognostic marker for predicting 5-year survival of HCC patients. Our in vitro studies showed that Fibulin-5 overexpression inhibited HCC cell migration and invasion. While Fibulin-5 knockdown increased the number of migrated and invaded HCC cells. Fibulin-5 negatively regulated MMP-7 abundance in HCC cells. Moreover, the inverse correlation between Fibulin-5 and MMP-7 expressions was observed in HCC tissues. Mechanistically, we disclosed that MMP-7 knockdown reduced the number of migrated and invaded HCC cells. Restoring MMP-7 expression abrogated the suppressive effect of Fibulin-5 on HCC cell migration and invasion in vitro, suggesting that Fibulin-5 exerted its anti-metastatic function, at least in part, by down-regulating the expression of MMP-7 in HCC cells. CONCLUSIONS:These results indicate that Fibulin-5 may serve as a prognostic biomarker and inhibits HCC invasion and metastasis by suppressing MMP-7 expression.
10.1186/1471-2407-14-938
Fibulin-5 is a prognostic marker that contributes to proliferation and invasion of human glioma cells.
Sheng Xu-Dong,Chen Hu,Wang Hui,Ding Zhi-Bin,Xu Gang-Zhu,Zhang Jun-Feng,Lu Wen-Chao,Wu Tao,Zhao Ling
Asian Pacific journal of cancer prevention : APJCP
Fibulin-5 has recently been considered as a potential tumor suppressor in human cancers. Several studies have shown that it is down-regulated in a variety of tumor types and inhibits tumor growth and metastasis. This study was aimed to investigate the clinical significance of fibulin-5 in glioma and its role in cell proliferation and invasion. We found that the expression of fibulin-5 in glioma tissues was significantly lower than those in normal brain (NB) tissues. Negative expression was significantly correlated with advanced clinical stage (grade III+IV). Furthermore, Fibulin-5 negative expression was correlated with a shorter overall survival of glioma patients. Multivariate Cox repression analysis indicated that fibulin-5 was an independent factor for predicting overall survival of glioma patients. Overexpression obviously inhibited cell proliferation in U251 and U87 cells. Furthermore, it significantly reduced the number of migrating and invading glioma cells. In conclusion, impaired expression of fibulin-5 is correlated with the advanced tumor stage in glioma. Otherwise, Fibulin-5 is an independent prognostic marker for predicting overall survival of glioma patients. Mechanistically, it may function as a tumor suppressor via inhibiting cell proliferation and invasion in gliomas.
10.7314/apjcp.2015.16.2.769
Fibulin-5 inhibits Wnt/β-catenin signaling in lung cancer.
Chen Xiaojun,Song Xiaomeng,Yue Wen,Chen Dongshi,Yu Jian,Yao Zhi,Zhang Lin
Oncotarget
Metastatic lung cancer is incurable and a leading cause of cancer death in the United States. However, the molecular mechanism by which lung cancer cells invade other tissues has remained unclear. We previously identified fibulin-5, an extracellular matrix protein, as a frequently silenced gene in lung cancer and a suppressor of cell invasion. In this study, we found fibulin-5 functions by inhibiting the Wnt/β-catenin pathway. The Cancer Genome Atlas (TCGA) datasets show a strong association between loss of fibulin-5 expression and poor outcomes of lung cancer patients, and also activation of the Wnt target genes MMP-7 and c-Myc. Fibulin-5 impedes Wnt/β-catenin signaling by inhibiting extracellular signal-regulated kinase (ERK) to activate glycogen synthase kinase-3 β (GSK3β), which downregulates β-catenin and prevents its nuclear accumulation, leading to suppression of MMP-7 and c-Myc expression. These effects of fibulin-5 are mediated by its amino-terminal integrin-binding RGD motif. Fibulin-5 also blocks Wnt/β-catenin signaling in vivo in H460 metastasis and H1299 tumor models. Furthermore, knockdown of β-catenin suppresses metastasis of H460 tumors, while knockdown of GSK3β promotes metastasis of fibulin-5-expressing H1752 tumors. Together, our results suggest that fibulin-5 functions as a metastasis suppressor in lung cancer by modulating tumor microenvironment to suppress Wnt/β-catenin signaling.
10.18632/oncotarget.3609
Effect of fibulin-5 on adhesion, migration and invasion of hepatocellular carcinoma cells via an integrin-dependent mechanism.
Tang Jia-Cheng,Liu Jing-Hua,Liu Xiao-Long,Liang Xiao,Cai Xiu-Jun
World journal of gastroenterology
AIM:To elucidate the role of fibulin-5 (FBLN-5) as a suppressor of hepatocellular carcinoma (HCC) cell metastasis via integrin. METHODS:The expression of FBLN-5 was determined by immunohistochemistry in 140 HCC samples and matched normal tissues, and was further confirmed by RT-PCR and Western blot analyses in various cell lines. Recombinant FBLN-5 was expressed in Escherichia coli BL21(DE3), purified and used in cell attachment assays. Expression of a specific plasmid or a specific siRNA in HCC cells resulted in the overexpression or knockdown of FBLN-5, respectively. Further, the migration and invasion of HCC cells were investigated using the Boyden chamber and transwell assays. The concentration of secreted matrix metalloproteinase 7 (MMP-7) was determined using ELISA. RESULTS:FBLN-5 expression was found to be downregulated in HCC. Its expression was significantly correlated with advanced tumor metastasis; this was indicative of poor 5-year overall survival. Recombinant full-length human FBLN-5 promoted the attachment of HCC cells via integrins: it inhibited HCC cell adhesion and migration to fibronectin in a concentration-dependent manner. It also inhibited HCC cell migration and invasion through an integrin-binding arginine-glycine-aspartic acid (RGD) motif by downregulating MMP-7. CONCLUSION:These results suggest that lower FBLN-5 expression is an important indicator of poor survival and that FBLN-5 inhibits HCC motility via an integrin-dependent mechanism. RGD-dependent suppression of MMP-7 by FBLN-5 might contribute to the development of new therapeutic strategies for HCC.
10.3748/wjg.v21.i39.11127
Fibulin-5 downregulates Ki-67 and inhibits proliferation and invasion of breast cancer cells.
Mohamedi Yamina,Fontanil Tania,Solares Laura,Garcia-Suárez Olivia,García-Piqueras Jorge,Vega Jose A,Cal Santiago,Obaya Alvaro J
International journal of oncology
Fibulins not only function as molecular bridges within the cellular microenvironment but also influence cell behavior. Thus, fibulins may contribute to create a permissive microenvironment for tumor growth but can also stimulate different mechanisms that may impede tumor progression. This is the case with Fibulin-5, which has been shown to display both tumor-promoting and tumor-protective functions by mechanisms that are not totally defined. We show new evidence on the tumor-protective functions displayed by Fibulin-5 in MCF-7, T47D and MDA-MB-231 breast cancer cells including the inhibition of invasion and proliferation capacity and hampering the ability to form mammospheres. Reduction in the level of phosphorylation of Ser residues involved in the nuclear translocation of β-catenin may underlie these antitumor effects. We also found that Fibulin-5 reduces the level of expression of Ki-67, a nuclear protein associated with cell proliferation. Moreover, reduction in Fibulin-5 expression corresponds to an increase of Ki-67 detection in breast tissue samples. Overall, our data provide new insights into the influence of Fibulin-5 to modify breast cancer cell behavior and contribute to better understand the connections between fibulins and cancer.
10.3892/ijo.2016.3394
IDH1 mutation promotes lung cancer cell proliferation through methylation of Fibulin-5.
Yan Bingdi,Hu Yanbing,Ma Tiangang,Wang Yanjun
Open biology
Mutation in isocitrate dehydrogenase () leads to an aberrant function of the enzyme, leading to the production of hydroxyglutarate, as well as changes in cellular metabolism, DNA methylation and histone modification. Previous studies uncovered mutations in in several malignancies, with the most frequent mutation being IDH1 R132H. It has been demonstrated that IDH1 expression is induced in non-small-cell lung cancer (NSCLC). However, the contribution of IDH1 mutation in the malignant transformation and development of NSCLC is unclear. In our study, we show that IDH1 R132H enhanced the migration and proliferation of NSCLC cells. Moreover, IDH1 R132H was a crucial modulator of 2-hydroxyglutarate, whose production from cells with IDH1 mutation promoted the binding of DNA-methyltransferase 1 (DNMT1) to the Fibulin-5 promoter, leading to its methylation. As a result, Fibulin-5 silencing in cells with IDH1 mutation enhanced the migration and proliferation of NSCLC cells. We show that the IDH1 mutation was present in tissues sampled from patients with NSCLC, which was reversely linked to Fibulin-5 expression. In this study, we suggest an innovative model for IDH1 R132H/Fibulin-5 pathway, which could throw light upon the activity of IDH1 R132H in NSCLC.
10.1098/rsob.180086
Fibulin-5 promotes airway smooth muscle cell proliferation and migration via modulating Hippo-YAP/TAZ pathway.
Fu Jia,Zheng Mao,Zhang Xiaofang,Zhang Yufeng,Chen Yao,Li Hua,Wang Xiaowei,Zhang Jinjun
Biochemical and biophysical research communications
Asthma is a common chronic disease mainly occurs from childhood. Increased airway smooth muscle mass is involved in the pathogenesis of asthma. Fibulin-5 was upregulated in the lung tissues of patients with COPD and idiopathic pulmonary fibrosis. This study aimed to investigate Fibulin-5 expression in asthmatic patients and the effect and mechanism of Fibulin-5 on the proliferation and migration of airway smooth muscle cells (ASMCs). The expression of Fibulin-5, YAP, and TAZ in the induced sputum of 38 asthmatic children (19 mild and 19 moderate asthmatics) and 19 healthy controls was determined. The effects and mechanisms of Fibulin-5 on the proliferation and migration of ASMCs were analyzed through upregulating Fibulin-5. We found compared with healthy controls, the expression of Fibulin-5, YAP, and TAZ was increased in the induced sputum of asthmatic children and much higher in moderate asthmatics. Fibulin-5 overexpression promoted the proliferation and migration of ASMCs, upregulated the expression of YAP and TAZ, and reduced the levels of p-YAP and p-TAZ. YAP inhibitor (Peptide 17) abrogated the proliferation and migration of ASMCs induced by Fibulin-5 overexpression in a dose-dependent manner. Additionally, Fibulin-5 overexpression enhanced its binding capacity of β1 integrin, and β1 integrin blocking antibody partly reversed the effect of Fibulin-5 overexpression on the levels of YAP and TAZ. In conclusion, Fibulin-5 expression is correlated with the pathogenesis of childhood asthma. It may function at least partly through binding to β1 integrin and modulating Hippo-YAP/TAZ pathway to promote the proliferation and migration of ASMCs.
10.1016/j.bbrc.2017.09.105
Screening of significant biomarkers related with prognosis of liver cancer by lncRNA-associated ceRNAs analysis.
He Jiefeng,Zhao Haichao,Deng Dongfeng,Wang Yadong,Zhang Xiao,Zhao Haoliang,Xu Zongquan
Journal of cellular physiology
This study aimed to identify significant biomarkers related to the prognosis of liver cancer using long noncoding RNA (lncRNA)-associated competing endogenous RNAs (ceRNAs) analysis. Differentially expressed mRNA and lncRNAs between liver cancer and paracancerous tissues were screened, and the functions of these mRNAs were predicted by gene ontology and pathway enrichment analyses. A ceRNA network consisting of differentially expressed mRNAs and lncRNAs was constructed. LncRNA FENDRR and lncRNA HAND2-AS1 were hub nodes in the ceRNA network. A risk score assessment model consisting of eight genes (PDE2A, ESR1, FBLN5, ALDH8A1, AKR1D1, EHHADH, ADRA1A, and GNE) associated with prognosis were developed. Multivariate Cox regression suggested that both pathologic_T and risk group could be regarded as independent prognostic factors. Furthermore, a nomogram model consisting of pathologic_T and risk group showed a good prediction ability for predicting the survival rate of liver cancer patients. The nomogram model consisting of pathologic_T and a risk score assessment model could be regarded as an independent factor for predicting prognosis of liver cancer.
10.1002/jcp.29151
Antitumor Potential of Fibulin-5 in Breast Cancer Cells Depends on Its RGD Cell Adhesion Motif.
Mohamedi Yamina,Fontanil Tania,Cobo Teresa,Vega José A,Cobo Juan Luis,Pérez-Basterrechea Marcos,Cobo Juan,Obaya Álvaro J,Cal Santiago
Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology
BACKGROUND/AIMS:Different components of the tumor microenvironment can be either tumor-promoting or tumor-suppressive agents depending on factors which are not fully understood. Fibulins are components of the extracellular matrix from different tissues and constitute a clear example of this dual function. In fact, fibulins may either support tumor growth or abolish progression of malignant cells depending on the crosstalk between tumor cells and their surrounding stroma through mechanisms that remain to be elucidated. Among all fibulins, fibulin-5 contains a particular structural hallmark which consists in the presence of a RGD motif within its architecture. Previous reports have highlighted the importance of the interaction of this motif with integrins, and not only in normal functions but also in a tumor context. METHODS:Site-Directed Mutagenesis technique was employed to introduce the change RGD to RGE (RGD-to-RGE) within Fbln5 cDNA sequence. Cell proliferation was measured using the MTT assay or by counting Ki-67 positive cell nuclei. Cell adhesion was analysed using culture plates coated with different extracellular matrix components. Cell invasion was evaluated using 24-well Matrigel-coated invasion chambers, and mammosphere formation was monitored using ultralow attachment culture plates. BALB/c mice were employed to induce subcutaneous tumors. RESULTS:The RGD-to-RGE change alters the capacity of breast cancer cells to adhere to different extracellular matrix proteins as well as to αβ and αβ integrins, and promotes protumor effects using different cell-based assays. Moreover, 4T1 cells, a mouse breast cancer cell line model, shows an increased capacity to generate tumors when exogenously expresses fibulin-5 with a RGD-to-RGE change, and such capacity is similar to that shown for 4T1 cells with an interfered Fbln5 gene. CONCLUSION:These data highlight the importance of the RGD motif of fibulin-5 to induce antitumor effects and provide new insights into the involvement of fibulins in tumor processes.
10.33594/000000123
Fibulin-5 initiates epithelial-mesenchymal transition (EMT) and enhances EMT induced by TGF-beta in mammary epithelial cells via a MMP-dependent mechanism.
Lee Yong-Hun,Albig Allan R,Regner MaryAnn,Schiemann Barbara J,Schiemann William P
Carcinogenesis
Epithelial-mesenchymal transition (EMT) is a normal physiological process that regulates tissue development, remodeling and repair; however, aberrant EMT also elicits disease development in humans, including lung fibrosis, rheumatoid arthritis and cancer cell metastasis. Transforming growth factor-beta (TGF-beta) is a master regulator of EMT in normal mammary epithelial cells (MECs), wherein this pleiotropic cytokine also functions as a potent suppressor of mammary tumorigenesis. In contrast, malignant MECs typically evolve resistance to TGF-beta-mediated cytostasis and develop the ability to proliferate, invade and metastasize when stimulated by TGF-beta. It therefore stands to reason that establishing how TGF-beta promotes EMT may offer new insights into targeting the oncogenic activities of TGF-beta in human breast cancers. By monitoring alterations in the actin cytoskeleton and various markers of EMT, we show here that the TGF-beta gene target, fibulin-5 (FBLN5), initiates EMT and enhances that induced by TGF-beta. Whereas normal MECs contain few FBLN5 transcripts, those induced to undergo EMT by TGF-beta show significant upregulation of FBLN5 messenger RNA, suggesting that EMT and the dedifferentiation of MECs override the repression of FBLN5 expression in polarized MECs. We also show that FBLN5 stimulated matrix metalloproteinase expression and activity, leading to MEC invasion and EMT, to elevated Twist expression and to reduced E-cadherin expression. Finally, FBLN5 promoted anchorage-independent growth in normal and malignant MECs, as well as enhanced the growth of 4T1 tumors in mice. Taken together, these findings identify a novel EMT and tumor-promoting function for FBLN5 in developing and progressing breast cancers.
10.1093/carcin/bgn199
Fibulin-5 is a tumour suppressor inhibiting cell migration and invasion in ovarian cancer.
Heo Jin Hyung,Song Ji-Ye,Jeong Ju-Yeong,Kim Gwangil,Kim Tae Heon,Kang Haeyoun,Kwon Ah-Young,An Hee Jung
Journal of clinical pathology
AIMS:Fibulin-5 is an extracellular matrix (ECM) glycoprotein which has a role in the organisation and stabilisation of ECM structures and regulating cell proliferation and tumourigenesis. Here, the expression of fibulin-5 and its functional effects on the migration and invasion of ovarian cancer cells were assessed. METHODS:Expression of fibulin-5 was detected in 44 ovarian tumour tissues by qRT-PCR, Western blotting and immunohistochemistry. We performed cell migration and invasion assays, and cell cycle analysis in fibulin-5 transfected SKOV3 (SKOV3-FBLN5) cells and the parental SKOV3 cells. We further examined the expression of three tissue inhibitors of metalloproteinases (TIMPs) and seven matrix metalloproteinases (MMPs) by RT-PCR. RESULTS:mRNA and protein expression of fibulin-5 were down-regulated (0.05-fold and 0.1-fold) in ovarian carcinomas compared with control tissues (p<0.01 and p=0.022). In wound-healing and invasion assays, significantly fewer SKOV3-FBLN5 cells than SKOV3 control cells migrated and invaded (39.1%, p=0.046 and 70%, p=0.03, respectively), which was reversed by siRNA-treatment. Overexpression of fibulin-5 induced G2/M arrest and increased cyclin B1, CDC2 and CDC25C. Expression of TIMP-2 (0.56-fold), MMP-3 (0.43-fold) and MMP-13 (0.18-fold) was lower and MMP-9 expression (2.20-fold) was higher in SKOV3-FBLN5 cells than in control cells. CONCLUSIONS:Fibulin-5 is significantly down-regulated in ovarian carcinoma and acts as a tumour suppressor by inhibiting the migration and invasion of ovarian cancer cells.
10.1136/jclinpath-2015-203129
Loss of fibulin-5 binding to beta1 integrins inhibits tumor growth by increasing the level of ROS.
Schluterman Marie K,Chapman Shelby L,Korpanty Grzegorz,Ozumi Kiyoshi,Fukai Tohru,Yanagisawa Hiromi,Brekken Rolf A
Disease models & mechanisms
Tumor survival depends in part on the ability of tumor cells to transform the surrounding extracellular matrix (ECM) into an environment conducive to tumor progression. Matricellular proteins are secreted into the ECM and impact signaling pathways that are required for pro-tumorigenic activities such as angiogenesis. Fibulin-5 (Fbln5) is a matricellular protein that was recently shown to regulate angiogenesis; however, its effect on tumor angiogenesis and thus tumor growth is currently unknown. We report that the growth of pancreatic tumors and tumor angiogenesis is suppressed in Fbln5-null (Fbln5(-/-)) mice compared with wild-type (WT) littermates. Furthermore, we observed an increase in the level of reactive oxygen species (ROS) in tumors grown in Fbln5(-/-) animals. Increased ROS resulted in elevated DNA damage, increased apoptosis of endothelial cells within the tumor, and represented the underlying cause for the reduction in angiogenesis and tumor growth. In vitro, we identified a novel pathway by which Fbln5 controls ROS production through a mechanism that is dependent on beta1 integrins. These results were validated in Fbln5(RGE/RGE) mice, which harbor a point mutation in the integrin-binding RGD motif of Fbln5, preventing its interaction with integrins. Tumor growth and angiogenesis was reduced in Fbln5(RGE/RGE) mice, however treatment with an antioxidant rescued angiogenesis and elevated tumor growth to WT levels. These findings introduce a novel function for Fbln5 in the regulation of integrin-induced ROS production and establish a rationale for future studies to examine whether blocking Fbln5 function could be an effective anti-tumor strategy, alone or in combination with other therapies.
10.1242/dmm.003707
Fibulin-5 is up-regulated by hypoxia in endothelial cells through a hypoxia-inducible factor-1 (HIF-1α)-dependent mechanism.
Guadall Anna,Orriols Mar,Rodríguez-Calvo Ricardo,Calvayrac Olivier,Crespo Javier,Aledo Rosa,Martínez-González José,Rodríguez Cristina
The Journal of biological chemistry
Hypoxia modulates gene expression and affects multiple aspects of endothelial cell biology. Fibulin-5 (FBLN5) is an extracellular matrix protein essential for elastic fiber assembly and vasculogenesis that participates in vascular remodeling and controls endothelial cell adhesion, motility, and proliferation. In this context, we aimed to analyze FBLN5 regulation by hypoxia in endothelial cells. Hypoxia (1% O(2)) increased FBLN5 mRNA levels in endothelial cells in a time-dependent manner. Maximal induction (∼2.5-fold) was achieved after 24 h of hypoxia. This effect paralleled an increase in both intracellular and extracellular FBLN5 protein levels. The increase in FBLN5 mRNA levels observed in hypoxic cells was blocked by inhibitors of the PI3K/Akt/mTOR pathway (LY294002 and rapamycin) and mimicked by dimethyl oxal glycine, which prevents proline hydroxylase-mediated degradation of HIF-1α. Silencing of HIF-1α completely prevented hypoxia-induced FBLN5 up-regulation. Accordingly, both hypoxia and HIF-1α overexpression increased FBLN5 transcriptional activity. Serial promoter deletion and mutagenesis studies revealed the involvement of a putative hypoxia response element (HRE) located at -78 bp. In fact, EMSA and ChIP assays demonstrated increased HIF-1 binding to this site in hypoxic cells. Interestingly, the rate of endothelial cells undergoing apoptosis in cultures exposed to hypoxia increased in FBLN5 knockdown cells, suggesting that hypoxia-induced FBLN5 expression contributes to preserve cell survival. These results provide evidence that HIF-1 signaling underlies the increase of FBLN5 expression elicited by hypoxia in endothelial cells and suggest that FBLN5 induction could be involved in the adaptive survival response of endothelial cells to hypoxia.
10.1074/jbc.M110.162917
Overexpression of fibulin-5 in retinal pigment epithelial cells inhibits cell proliferation and migration and downregulates VEGF, CXCR4, and TGFB1 expression in cocultured choroidal endothelial cells.
Li Fuliang,Xu Haiwei,Zeng Yuxiao,Yin Zheng Qin
Current eye research
PURPOSE OF THE STUDY:Age-related macular degeneration (AMD) is the most common cause of irreversible vision loss. Fibulin-5 (FBLN5) plays a pleiotropic role in the pathogenesis of AMD. We examined whether the in vitro overexpression of FBLN5 in retinal pigment epithelial (RPE) cells alters the proliferation and migration of cocultured choroidal endothelial cells (CECs) and explored the possible mechanisms involved. MATERIALS AND METHODS:A recombinant lentiviral vector carrying the Fbln5 gene was generated to transduce rat RPE cells. The expression of FBLN5 in transduced RPE cells was detected by quantitative real-time PCR and Western blot. The transduced RPE cells were then cocultured with rhesus macaque CECs in a Transwell coculture system. The impact of overexpression of FBLN5 in RPE cells on CEC proliferation and migration was assessed, as well as the impact on the mRNA expressions of vascular endothelial growth factor (VEGF), C-X-C chemokine receptor type 4 (CXCR4), and transforming growth factor β1 (TGFB1). RESULTS:Our results showed that a recombinant lentivirus carrying the Fbln5 gene, which could induce overexpression of FBLN5 in RPE cells, was successfully generated. Overexpression of FBLN5 in RPE cells inhibited cell proliferation and migration and downregulated the mRNA expressions of VEGF, CXCR4, and TGFB1 in cocultured CECs. CONCLUSIONS:These findings suggest that FBLN5 may interfere with choroidal neovascularization by downregulating VEGF, CXCR4, and TGFB1 expression and inhibiting CEC proliferation and invasion, intensifying interest in FBLN5 as a target for therapeutic intervention in neovascular AMD.
10.3109/02713683.2012.665561
Fibulin-5 Blocks Microenvironmental ROS in Pancreatic Cancer.
Wang Miao,Topalovski Mary,Toombs Jason E,Wright Christopher M,Moore Zachary R,Boothman David A,Yanagisawa Hiromi,Wang Huamin,Witkiewicz Agnieszka,Castrillon Diego H,Brekken Rolf A
Cancer research
Elevated oxidative stress is an aberration seen in many solid tumors, and exploiting this biochemical difference has the potential to enhance the efficacy of anticancer agents. Homeostasis of reactive oxygen species (ROS) is important for normal cell function, but excessive production of ROS can result in cellular toxicity, and therefore ROS levels must be balanced finely. Here, we highlight the relationship between the extracellular matrix and ROS production by reporting a novel function of the matricellular protein Fibulin-5 (Fbln5). We used genetically engineered mouse models of pancreatic ductal adenocarcinoma (PDAC) and found that mutation of the integrin-binding domain of Fbln5 led to decreased tumor growth, increased survival, and enhanced chemoresponse to standard PDAC therapies. Through mechanistic investigations, we found that improved survival was due to increased levels of oxidative stress in Fbln5-mutant tumors. Furthermore, loss of the Fbln5-integrin interaction augmented fibronectin signaling, driving integrin-induced ROS production in a 5-lipooxygenase-dependent manner. These data indicate that Fbln5 promotes PDAC progression by functioning as a molecular rheostat that modulates cell-ECM interactions to reduce ROS production, and thus tip the balance in favor of tumor cell survival and treatment-refractory disease.
10.1158/0008-5472.CAN-15-0744
Down-regulation of Fibulin-5 is associated with aortic dilation: role of inflammation and epigenetics.
Orriols Mar,Varona Saray,Martí-Pàmies Ingrid,Galán María,Guadall Anna,Escudero José Román,Martín-Ventura José Luis,Camacho Mercedes,Vila Luis,Martínez-González José,Rodríguez Cristina
Cardiovascular research
AIMS:Destructive remodelling of extracellular matrix (ECM) and inflammation lead to dilation and ultimately abdominal aortic aneurysm (AAA). Fibulin-5 (FBLN5) mediates cell-ECM interactions and elastic fibre assembly and is critical for ECM remodelling. We aimed to characterize FBLN5 regulation in human AAA and analyse the underlying mechanisms. METHODS AND RESULTS:FBLN5 expression was significantly decreased in human aneurysmatic aortas compared with healthy vessels. Local FBLN5 knockdown promoted aortic dilation and enhanced vascular expression of inflammatory markers in Ang II-infused C57BL/6J mice. Inflammatory stimuli down-regulated FBLN5 expression and transcriptional activity in human aortic vascular smooth muscle cells (VSMC). Further, aortic FBLN5 expression was reduced in LPS-challenged mice. A SOX response element was critical for FBLN5 promoter activity. The SOX9 expression pattern in human AAA parallels that of FBLN5, and like FBLN5, it was reduced in TNFα-stimulated VSMC. Interestingly, SOX9 over-expression prevented the cytokine-mediated reduction of FBLN5 expression and transcription. The inhibition of Class I histone deacetylases (HDACs) by MS-275 or gene silencing attenuated the inflammation-mediated decrease of FBLN5 expression in VSMC and in the vascular wall. Consistently, HDAC inhibition counteracted the reduction of SOX9 expression induced by inflammatory stimuli and prevented the TNFα-mediated decrease in the binding of SOX9 to FBLN5 promoter normalizing FBLN5 expression. CONCLUSION:We evidence the deregulation of FBLN5 in human AAA and identify a SOX9/HDAC-dependent mechanism involved in the down-regulation of FBLN5 by inflammation. HDAC inhibitors or pharmacological approaches that aimed to preserve FBLN5 could be useful to prevent the disorganization of ECM induced by inflammation in AAA.
10.1093/cvr/cvw082
Hypoxia and Transforming Growth Factor β Cooperate to Induce Fibulin-5 Expression in Pancreatic Cancer.
Topalovski Mary,Hagopian Michelle,Wang Miao,Brekken Rolf A
The Journal of biological chemistry
The deposition of extracellular matrix (ECM) is a defining feature of pancreatic ductal adenocarcinoma (PDA), where ECM signaling can promote cancer cell survival and epithelial plasticity programs. However, ECM signaling can also limit PDA tumor growth by producing cytotoxic levels of reactive oxygen species. For example, excess fibronectin stimulation of α5β1 integrin on stromal cells in PDA results in reduced angiogenesis and increased tumor cell apoptosis because of oxidative stress. Fibulin-5 (Fbln5) is a matricellular protein that blocks fibronectin-integrin interaction and thus directly limits ECM-driven reactive oxygen species production and supports PDA progression. Compared with normal pancreatic tissue, Fbln5 is expressed abundantly in the stroma of PDA; however, the mechanisms underlying the stimulation of Fbln5 expression in PDA are undefined. Using in vitro and in vivo approaches, we report that hypoxia triggers Fbln5 expression in a TGF-β- and PI3K-dependent manner. Pharmacologic inhibition of TGF-β receptor, PI3K, or protein kinase B (AKT) was found to block hypoxia-induced Fbln5 expression in mouse embryonic fibroblasts and 3T3 fibroblasts. Moreover, tumor-associated fibroblasts from mouse PDA were also responsive to TGF-β receptor and PI3K/AKT inhibition with regard to suppression of Fbln5. In genetically engineered mouse models of PDA, therapy-induced hypoxia elevated Fbln5 expression, whereas pharmacologic inhibition of TGF-β signaling reduced Fbln5 expression. These findings offer insight into the signaling axis that induces Fbln5 expression in PDA and a potential strategy to block its production.
10.1074/jbc.M116.730945
Endometrial miR-200c is altered during transformation into cancerous states and targets the expression of ZEBs, VEGFA, FLT1, IKKβ, KLF9, and FBLN5.
Panda Harekrushna,Pelakh Leslie,Chuang Tsai-Der,Luo Xiaoping,Bukulmez Orhan,Chegini Nasser
Reproductive sciences (Thousand Oaks, Calif.)
A number of microRNAs (miRNAs), including miR-200 family, are aberrantly expressed in endometriosis and endometrial cancer. Here we assessed the expression and functional aspects of miR-200c in endometrial tissues (N = 52) from normal endometrial biopsies (N = 15), endometrial tissues including those exposed to hormonal therapies (N = 20), and grade I-III endometrial cancer (N = 17). miR-200c expression was elevated in normal endometrial biopsies from mid- and late-luteal phase, and in endometrial tumors as compared to endometrial tissues from peri- and postmenopausal period (P < .05) and its pattern of temporal expression displayed an inverse relationship with the expression of ZEBs. The expression of E-cadherin (CDH1) varied, but expressed at low levels, specifically in endometrial tissues and endometrial tumors. The endometrial expression of ZEBs and CDH1 in patients who were exposed to Depo-Provera and gonadotropin-releasing hormone agonist GnRHa displayed a trend toward lower expression as compared to proliferative phase; however, treatment of Ishikawa cells with 17β-estradiol, progesterone, and medroxy progesterone acetate had modest effects on the expression of miR-200c and ZEBs without affecting CDH1 expression. Gain of function of miR-200c in Ishikawa cells repressed ZEBs, as well as VEGFA, FLT1, IKKβ, and KLF9 expression at transcriptional and translational levels through direct interaction with their respective 3'untranslated regions and increased the rate of their proliferation. These results indicated that endometrial miR-200c expression undergoes dynamic changes during transition from normal into cancerous states; possibly influenced by hormonal milieu and by targeting the expression of specific genes with key regulatory functions in cellular transformation, inflammation, and angiogenesis may influence these events during normal and disease progression.
10.1177/1933719112438448
miR-200c is aberrantly expressed in leiomyomas in an ethnic-dependent manner and targets ZEBs, VEGFA, TIMP2, and FBLN5.
Chuang Tsai-Der,Panda Harekrushna,Luo Xiaoping,Chegini Nasser
Endocrine-related cancer
MicroRNA-200c (miR-200c) through repression of specific target genes has been associated with cellular transition, tumorigenesis, and tissue fibrosis. We explored the expression and functional aspects of miR-200c in genesis of leiomyomas (LYO), benign uterine tumors with fibrotic characteristic. Using LYO and matched myometrium (MYO; n=76) from untreated and from patients exposed to hormonal therapies (GNRH agonist (GNRHa), Depo-Provera, and oral contraceptives), we found that miR-200c was expressed at significantly lower levels (P<0.05) in LYO as compared with MYO. These levels were lower in LYO from African Americans as compared with Caucasians, patients experiencing abnormal uterine bleeding and those exposed to GNRHa therapy. Gain-of-function of miR-200c in isolated leiomyoma smooth muscle cells (LSMCs), myometrial smooth muscle cells (MSMCs), and leiomyosarcoma cell line (SKLM-S1) repressed ZEB1/ZEB2 mRNAs and proteins, with concurrent increase in E-cadherin (CDH1) and reduction in vimentin expression, phenotypic alteration, and inhibition of MSMC and LSMC proliferations. We further validated TIMP2, FBLN5, and VEGFA as direct targets of miR-200c through interaction with their respective 3' UTRs, and other genes as determined by microarray analysis. At tissue levels, LYO expressed lower levels of TIMP2 and FBLN5 mRNAs but increased protein expressions, which to some extent altered due to hormonal exposure. Given the regulatory functions of ZEBs, VEGFA, FBLN5, and TIMP2 on cellular activities that promote cellular transition, angiogenesis, and matrix remodeling, we concluded that altered expression of miR-200c may have a significant impact on the outcome of LYO growth, maintenance of their mesenchymal and fibrotic characteristics, and possibly their associated symptoms.
10.1530/ERC-12-0007
miR-370-3p as a Novel Biomarker Promotes Breast Cancer Progression by Targeting FBLN5.
Mao Jiahui,Wang Lingxia,Wu Junying,Wang Yichun,Wen Huiyan,Zhu Xueming,Wang Bo,Yang Huan
Stem cells international
miRNAs play a crucial part in multiple biological processes of cell proliferation, migration, apoptosis, and chemoresistance. In cancer, miRNAs can be divided into oncogenes or tumor suppressors on the basis of their functions in the carcinogenic process. The purpose of this study was to explore the roles and clinical diagnostic value of miR-370-3p in breast cancer. Our results demonstrated that miR-370-3p significantly promoted proliferation, metastasis, and stemness of breast cancer and . In particular, clinical data revealed that high expression of serum miR-370-3p and exosomal miR-370-3p from breast cancer patients was remarkably correlated with lymphatic metastasis and tumor node metastasis (TNM) stages. Mechanistically, miR-370-3p inhibited FBLN5 expression and activated the NF-B signaling pathway to promote breast cancer cell proliferation, migration, and stemness. FBLN5 expression was significantly decreased in breast cancer cells and tumor tissues of breast cancer patients. Our research identified that miR-370-3p promoted breast cancer progression by inhibiting FBLN5 expression and activating the NF-B signaling pathway. Serum exosomal miR-370-3p would provide a potential biomarker for the diagnosis of breast cancer.
10.1155/2021/4649890
Knockdown of ubiquitin-conjugating enzyme E2T (UBE2T) suppresses lung adenocarcinoma progression via targeting fibulin-5 (FBLN5).
Bioengineered
Lung adenocarcinoma (LUAD) is the main histological type of lung cancer, which is the leading cause of cancer-related deaths. Accumulating evidence has displayed that UBE2T is related to tumor progression. However, its role in LUAD has not been fully elucidated. The expression of UBE2T was detected in LUAD tissues by qRT-PCR, western blotting, and immunohistochemistry. UBE2T shRNAs were transfected into LUAD cells to analyze the consequent alteration in function through CCK-8 assay, Edu assay, transwell assay, and TUNEL staining. The potential mechanism of UBE2T was analyzed through GEPIA and verified using ChIP, EMSA, and GST pull-down assays. Furthermore, a xenograft mouse model was used to assess UBE2T function . Results showed that UBE2T level was significantly elevated in LUAD tissues and high UBE2T expression was associated with poor overall survival and disease-free survival. Results from the loss-of-function experiments showed that UBE2T modulated LUAD cell proliferation, migration, invasion, and apoptosis. The mechanism analysis demonstrated that silence of UBE2T increased FBLN5 expression and inhibited the activation of p-ERK, p-GSK3β, and β-catenin. Moreover, following knockdown of UBE2T, the cell proliferation, migration, and invasion were decreased, and sh-FBLN5 partially reverse the decrease. In experiments, it was found that UBE2T knockdown inhibits the tumor growth in LUAD. Immunohistochemically, there was a reduction in Ki67 and an increase in FBLN5 in UBE2T shRNA-treated tumor tissues. In conclusion, UBE2T might be a potential biomarker of LUAD, and targeting the UBE2T/FBLN5 axis might be a novel treatment strategy for LUAD.
10.1080/21655979.2022.2060162