scholarly journals TGFβ signaling regulates epithelial–mesenchymal plasticity in ovarian cancer ascites-derived spheroids

2015 ◽  
Vol 23 (3) ◽  
pp. 147-159 ◽  
Author(s):  
Samah Rafehi ◽  
Yudith Ramos Valdes ◽  
Monique Bertrand ◽  
Jacob McGee ◽  
Michel Préfontaine ◽  
...  

Epithelial–mesenchymal transition (EMT) serves as a key mechanism driving tumor cell migration, invasion, and metastasis in many carcinomas. Transforming growth factor-beta (TGFβ) signaling is implicated in several steps during cancer pathogenesis and acts as a classical inducer of EMT. Since epithelial ovarian cancer (EOC) cells have the potential to switch between epithelial and mesenchymal states during metastasis, we predicted that modulation of TGFβ signaling would significantly impact EMT and the malignant potential of EOC spheroid cells. Ovarian cancer patient ascites-derived cells naturally underwent an EMT response when aggregating into spheroids, and this was reversed upon spheroid re-attachment to a substratum. CDH1/E-cadherin expression was markedly reduced in spheroids compared with adherent cells, in concert with an up-regulation of several transcriptional repressors, i.e., SNAI1/Snail, TWIST1/2, and ZEB2. Treatment of EOC spheroids with the TGFβ type I receptor inhibitor, SB-431542, potently blocked the endogenous activation of EMT in spheroids. Furthermore, treatment of spheroids with SB-431542 upon re-attachment enhanced the epithelial phenotype of dispersing cells and significantly decreased cell motility and Transwell migration. Spheroid formation was significantly compromised by exposure to SB-431542 that correlated with a reduction in cell viability particularly in combination with carboplatin treatment. Thus, our findings are the first to demonstrate that intact TGFβ signaling is required to control EMT in EOC ascites-derived cell spheroids, and it promotes the malignant characteristics of these structures. As such, we show the therapeutic potential for targeted inhibition of this pathway in ovarian cancer patients with late-stage disease.

2016 ◽  
Vol 38 (2) ◽  
pp. 571-588 ◽  
Author(s):  
Min-Jin Kim ◽  
Sang-A Park ◽  
Chun Hwa Kim ◽  
So-Yeon Park ◽  
Jung-Shin Kim ◽  
...  

Background/Aims: Hypoxia is an environmental factor that aggravates liver fibrosis. HIF1α activates hepatic stellate cells (HSCs) and increases transforming growth factor-β (TGF-β) signaling and the epithelial mesenchymal transition (EMT), accelerating the progression of fibrosis. We evaluated the anti-fibrotic therapeutic potential of a small-molecule inhibitor of TGF-β type I receptor kinase, EW-7197, on HIF1α-derived TGF-β signaling in cholestatic liver fibrosis. Methods: We used a bile duct ligation (BDL)-operated rat model to characterize the role of HIF1α-derived TGF-β signaling in liver fibrosis. Cellular assays were performed in LX-2 cells (human immortalized HSCs). The anti-fibrotic effects of EW-7197 in liver tissues and HSCs were investigated via biochemical assays, immunohistochemistry (IHC), immunofluorescence (IF), chromatin immunoprecipitation (ChIP) assays, real-time PCR, and western blotting. Results: In our BDL rat model, orally administered EW-7197 inhibited fibrosis and attenuated HIF1α-induced activation of HSCs and EMT in vivo. In addition, EW-7197 inhibited HIF1α-derived HSC activation and expression of EMT markers in LX-2 cells in vitro. Conclusion: This study suggests that EW-7197 exhibits potential as a treatment for liver fibrosis because it inhibits HIF1α-induced TGF-β signaling.


2005 ◽  
Vol 16 (4) ◽  
pp. 1987-2002 ◽  
Author(s):  
Ulrich Valcourt ◽  
Marcin Kowanetz ◽  
Hideki Niimi ◽  
Carl-Henrik Heldin ◽  
Aristidis Moustakas

Epithelial-mesenchymal transition (EMT) contributes to normal tissue patterning and carcinoma invasiveness. We show that transforming growth factor (TGF)-β/activin members, but not bone morphogenetic protein (BMP) members, can induce EMT in normal human and mouse epithelial cells. EMT correlates with the ability of these ligands to induce growth arrest. Ectopic expression of all type I receptors of the TGF-β superfamily establishes that TGF-β but not BMP pathways can elicit EMT. Ectopic Smad2 or Smad3 together with Smad4 enhanced, whereas dominant-negative forms of Smad2, Smad3, or Smad4, and wild-type inhibitory Smad7, blocked TGF-β–induced EMT. Transcriptomic analysis of EMT kinetics identified novel TGF-β target genes with ligand-specific responses. Using a TGF-β type I receptor that cannot activate Smads nor induce EMT, we found that Smad signaling is critical for regulation of all tested gene targets during EMT. One such gene, Id2, whose expression is repressed by TGF-β1 but induced by BMP-7 is critical for regulation of at least one important myoepithelial marker, α-smooth muscle actin, during EMT. Thus, based on ligand-specific responsiveness and evolutionary conservation of the gene expression patterns, we begin deciphering a genetic network downstream of TGF-β and predict functional links to the control of cell proliferation and EMT.


Biomolecules ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 348 ◽  
Author(s):  
Ravindran ◽  
Pasha ◽  
Agouni ◽  
Munusamy

Diabetic nephropathy (DN) is the most common cause of chronic kidney disease worldwide. Activation of signaling pathways such as the mammalian target of rapamycin (mTOR), extracellular signal-regulated kinases (ERK), endoplasmic reticulum (ER) stress, transforming growth factor-beta (TGF-β), and epithelial-mesenchymal transition (EMT), are thought to play a significant role in the etiology of DN. Microparticles (MPs), the small membrane vesicles containing bioactive signals shed by cells upon activation or during apoptosis, are elevated in diabetes and were identified as biomarkers in DN. However, their exact role in the pathophysiology of DN remains unclear. Here, we examined the effect of MPs shed from renal proximal tubular cells (RPTCs) exposed to high glucose conditions on naïve RPTCs in vitro. Our results showed significant increases in the levels of phosphorylated forms of 4E-binding protein 1 and ERK1/2 (the downstream targets of mTOR and ERK pathways), phosphorylated-eIF2α (an ER stress marker), alpha smooth muscle actin (an EMT marker), and phosphorylated-SMAD2 and nuclear translocation of SMAD4 (markers of TGF-β signaling). Together, our findings indicate that MPs activate key signaling pathways in RPTCs under high glucose conditions. Pharmacological interventions to inhibit shedding of MPs from RPTCs might serve as an effective strategy to prevent the progression of DN.


2020 ◽  
Vol 295 (40) ◽  
pp. 13798-13811 ◽  
Author(s):  
Yueli Shi ◽  
Xinyu Wang ◽  
Zhiyong Xu ◽  
Ying He ◽  
Chunyi Guo ◽  
...  

Transforming growth factor β (TGFβ) signaling plays an important role in regulating tumor malignancy, including in non–small cell lung cancer (NSCLC). The major biological responses of TGFβ signaling are determined by the effector proteins SMAD2 and SMAD3. However, the regulators of TGFβ–SMAD signaling are not completely revealed yet. Here, we showed that the scaffolding protein PDLIM5 (PDZ and LIM domain protein 5, ENH) critically promotes TGFβ signaling by maintaining SMAD3 stability in NSCLC. First, PDLIM5 was highly expressed in NSCLC compared with that in adjacent normal tissues, and high PDLIM5 expression was associated with poor outcome. Knockdown of PDLIM5 in NSCLC cells decreased migration and invasion in vitro and lung metastasis in vivo. In addition, TGFβ signaling and TGFβ-induced epithelial–mesenchymal transition was repressed by PDLIM5 knockdown. Mechanistically, PDLIM5 knockdown resulted in a reduction of SMAD3 protein levels. Overexpression of SMAD3 reversed the TGFβ-signaling-repressing and anti-migration effects induced by PDLIM5 knockdown. Notably, PDLIM5 interacted with SMAD3 but not SMAD2 and competitively suppressed the interaction between SMAD3 and its E3 ubiquitin ligase STUB1. Therefore, PDLIM5 protected SMAD3 from STUB1-mediated proteasome degradation. STUB1 knockdown restored SMAD3 protein levels, cell migration, and invasion in PDLIM5-knockdown cells. Collectively, our findings indicate that PDLIM5 is a novel regulator of basal SMAD3 stability, with implications for controlling TGFβ signaling and NSCLC progression.


2015 ◽  
Vol 113 (1) ◽  
pp. E71-E80 ◽  
Author(s):  
Miki Nishio ◽  
Keishi Sugimachi ◽  
Hiroki Goto ◽  
Jia Wang ◽  
Takumi Morikawa ◽  
...  

Mps One Binder Kinase Activator (MOB)1A/1B are core components of the Hippo pathway that coactivate large tumor suppressor homolog (LATS) kinases. Mob1a/1b double deficiency in mouse liver (LMob1DKO) results in hyperplasia of oval cells and immature cholangiocytes accompanied by inflammatory cell infiltration and fibrosis. More than half of mutant mice die within 3 wk of birth. All survivors eventually develop liver cancers, particularly combined hepatocellular and cholangiocarcinomas (cHC-CCs) and intrahepatic cholangiocellular carcinomas (ICCs), and die by age 60 wk. Because this phenotype is the most severe among mutant mice lacking a Hippo signaling component, MOB1A/1B constitute the critical hub of Hippo signaling in mammalian liver. LMob1DKO liver cells show hyperproliferation, increased cell saturation density, hepatocyte dedifferentiation, enhanced epithelial–mesenchymal transition and cell migration, and elevated transforming growth factor beta(TGF-β)2/3 production. These changes are strongly dependent on Yes-Associated Protein-1 (Yap1) and partially dependent on PDZ-binding motif (Taz) and Tgfbr2, but independent of connective tissue growth factor (Ctgf). In human liver cancers, YAP1 activation is frequent in cHC-CCs and ICCs and correlates with SMAD family member 2 activation. Drug screening revealed that antiparasitic macrocyclic lactones inhibit YAP1 activation in vitro and in vivo. Targeting YAP1/TAZ with these drugs in combination with inhibition of the TGF-β pathway may be effective treatment for cHC-CCs and ICCs.


2000 ◽  
pp. 243-256 ◽  
Author(s):  
C R Dowling ◽  
G P Risbridger

Successful prostate cancer diagnosis and management continue to provide challenges for the clinician. While interventions aimed at the containment of both early and late disease continue to fail in a significant number of patients, the search for answers must incorporate an analysis of the processes of normal and aberrant growth and development within the gland itself. Inhibin and its structurally related protein, activin, are members of the transforming-growth-factor beta (TGFbeta) superfamily. Originally identified as regulators of FSH, these proteins are now recognised to have widespread biological functions. This might be expected of proteins that are structurally homologous to TGFbeta itself, which is recognised to have regulatory roles in both normal and malignant prostate tissue. The aim of this review is to examine the relationship between inhibins, activins and their related proteins and the development of prostate cancer. The homology with TGF, the pluripotent effects of activin on various tissues and the roles for inhibins in ovarian cancer make activins and inhibins candidate growth factors for involvement at multiple sites in the progression from benign disease to cancer. In compiling this review, we aim to delineate the changes in inhibins and activins in this pathway and in doing so implicate their potential roles in the progression of carcinogenesis. We will compare the changes in inhibin and its related proteins in prostate cancer to those that are known in ovarian cancer. We will discuss the similarities and differences between the putative role of activins and TGFbeta in prostate carcinogenesis. The importance of this review lies in demonstrating that inhibin, an endocrine hormone, and its related proteins may contribute to endocrine-related cancers, such as that of the prostate gland.


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