LINC00472 suppressed by ZEB1 regulates the miR-23a-3p/FOXO3/BID axis to inhibit the progression of pancreatic cancer.

The tumour-suppressive role of LINC00472 has been extensively reported in various human cancers such as lung, colon and ovarian cancers, yet its function in pancreatic cancer remains unidentified. Here, the current research aimed to explore the role and regulatory axis mediated by LINC00472 in the progression of pancreatic cancer. RT-qPCR was adopted to determine LINC00472 expression in the harvested pancreatic cancer tissues and adjacent normal tissues. Loss-of-function and gain-of-function experiments were performed to examine the effects of LINC00472 on proliferation and apoptosis in vitro and tumorigenesis in vivo. Immunoblotting was performed to detect the expression of several proliferation and apoptosis-related proteins. Bioinformatic analysis, dual-luciferase reporter assay and RNA pull-down were conducted to profile the relationships between LINC00472 and miR-23a-3p, between miR-23a-3p and FOXO3 and between FOXO3 and BID. The LINC00472 expression was down-regulated by ZEB1 in the pancreatic cancer cells and tissues. LINC00472 could competitively bind to miR-23a-3p to enhance the expression of FOXO3, which consequently could promote the BID expression, thereby suppressing proliferation and promoting the apoptosis of pancreatic cancer cells. Meanwhile, the inhibitory role of LINC00472 in tumorigenesis was validated in vivo, and the LINC00472-mediated miR-23a-3p/FOXO3/BID axis was also demonstrated in the nude mouse tumour formation model. The study substantiated the antitumour activity of LINC00472 in pancreatic cancer and proposed a regulatory axis in which LINC00472 competitively binds to miR-23a-3p to enhance the FOXO3 expression and promote BID expression. Consequently, these findings provide theoretical basis for developing potential targets for the treatment of pancreatic cancer.

Musashi2 promotes the progression of pancreatic cancer through a novel ISYNA1-p21/ZEB-1 pathway.

Our previous studies found overexpression of Musashi2 (MSI2) conduced to the progression and chemoresistance of pancreatic cancer (PC) by negative regulation of Numb and wild type p53 (wtp53). Now, we further investigated the novel signalling involved with MSI2 in PC. We identified inositol-3-phosphate synthase 1 (ISYNA1) as a novel tumour suppressor regulated by MSI2. High MSI2 and low ISYNA1 expression were prevalently observed in 91 PC tissues. ISYNA1 expression was negatively correlated with MSI2 expression, T stage, vascular permeation and poor prognosis in PC patients. What's more, patients expressed high MSI2 and low ISYNA1 level had a significant worse prognosis. And in wtp53 Capan-2 and SW1990 cells, ISYNA1 was downregulated by p53 silencing. ISYNA1 silencing promoted cell proliferation and cell cycle by inhibiting p21 and enhanced cell migration and invasion by upregulating ZEB-1. However, MSI2 silencing upregulated ISYNA1 and p21 but downregulated ZEB-1, which can be rescued by ISYNA1 silencing. Moreover, reduction of cell migration and invasion resulting from MSI2 silencing was significantly reversed by ISYNA1 silencing. In summary, MSI2 facilitates the development of PC through a novel ISYNA1-p21/ZEB-1 pathway, which provides new gene target therapy for PC.

EMT transcription factors in cancer development re-evaluated: Beyond EMT and MET.

Reactivation of an embryonic epithelial-to-mesenchymal (EMT) program is commonly accepted as a core component of carcinoma progression. Collectively, EMT and transcription factors (EMT-TFs) of the ZEB, SNAIL and TWIST families are quoted in the same breath for nearly 20years. Recent work on these EMT-TFs has extended their scope, and their typical definition as EMT-inducing factors has become out-of-date. New insights have warranted a re-evaluation of these transcription factors and their pleiotropic functions in physiological and pathological conditions, not solely limited to cell invasion and dissemination.

ZEB1 and IL-6/11-STAT3 signalling cooperate to define invasive potential of pancreatic cancer cells via differential regulation of the expression of S100 proteins.

BACKGROUND: S100 proteins have been implicated in various aspects of cancer, including epithelial-mesenchymal transitions (EMT), invasion and metastasis, and also in inflammatory disorders. Here we examined the impact of individual members of this family on the invasion of pancreatic ductal adenocarcinoma (PDAC) cells, and their regulation by EMT and inflammation. METHODS: Invasion of PDAC cells was analysed in zebrafish embryo xenografts and in transwell invasion assays. Expression and regulation of S100 proteins was studied in vitro by immunoblotting, quantitative PCR and immunofluorescence, and in pancreatic lesions by immunohistochemistry. RESULTS: Whereas the expression of most S100 proteins is characteristic for epithelial PDAC cell lines, S100A4 and S100A6 are strongly expressed in mesenchymal cells and upregulated by ZEB1. S100A4/A6 and epithelial protein S100A14 respectively promote and represses cell invasion. IL-6/11-STAT3 pathway stimulates expression of most S100 proteins. ZEB1 synergises with IL-6/11-STAT3 to upregulate S100A4/A6, but nullifies the effect of inflammation on S100A14 expression. CONCLUSION: EMT/ZEB1 and IL-6/11-STAT3 signalling act independently and congregate to establish the expression pattern of S100 proteins, which drives invasion. Although ZEB1 regulates expression of S100 family members, these effects are masked by IL-6/11-STAT3 signalling, and S100 proteins cannot be considered as bona fide EMT markers in PDAC.

ZEB1 mediates doxorubicin (Dox) resistance and mesenchymal characteristics of hepatocarcinoma cells.

The acquired chemoresistance during long term chemotherapy is one of the most important factors to limit the application of Doxorubicin (Dox) on clinical treatment of hepatocellular carcinoma (HCC) patients. Our present study found that Dox resistant HCC (HCC/Dox) cells had greater capability of in vitro migration and invasion compared to their parental cells. HCC/Dox cells exhibited mesenchymal characteristics, which was evidenced by the up regulation of fibronectin, vimentin while down regulation of E-Cadherin. Zeb1, one powerful epithelial mesenchymal transition related transcription factor (EMT-TF), was markedly upregulated in HCC/Dox cells. Targeted inhibition of Zeb1 via siRNA can suppress the cell migration and re-sensitized cells to Dox treatment. The upregulation of Zeb1 in HCC/Dox cells was due to the increasing protein and mRNA stability of Zeb1. In HCC/Dox cells, the down regulation of SIAH1 mediated the upregulation of protein stability of Zeb1, while decreased levels of miR-3129-5p was responsible for the increasing mRNA stability of Zeb1. Collectively, our data suggested that SIAH1 and miR-3129-5p induced upregulation of Zeb1 mediated the Dox resistance of HCC cells. Targeted inhibition of Zeb1 might be helpful to overcome of Dox resistance of HCC.

Regulation of Proliferation and Epithelial-to-Mesenchymal Transition (EMT) of Gastric Cancer by ZEB1 via Modulating Wnt5a and Related Mechanisms.

BACKGROUND As a member of the zinc-finger E-box binding protein (ZEB) family, ZEB1 can modulate onset and progression of various tumors, but its regulatory effect or mechanism in GC has not been defined. MATERIAL AND METHODS GC tumor tissues and adjacent tissues were collected from GC patients across different TNM stages. Real-time PCR was used to measure ZEB1 expression to analyze its correlation with pathological features of tumors. Cultured GC cell lines SGC-7901 and MGC-803 were randomly assigned into control group, scramble group, and ZEB1 siRNA group. Real-time PCR was employed to analyze ZEB1 expression, and MTT approach was used to measure cell proliferation. Cell apoptosis was evaluated by flow cytometry. Wound healing assay was used to detect its effect on cell migration. Expression of E-cadherin and Vimentin involved in epithelial-to-mesenchymal transition (EMT) was measured by Western blot analysis, along with Wnt5a proteins. RESULTS GC tissues had upregulation of ZEB1 (P<0.05 compared to adjacent tissues), whose expression level was correlated with differentiation grade, lymph node metastasis, and tumor pathological stage (P<0.05). Transfection of ZEB1 siRNA into SGC-7901 or MGC-803 cells can suppress ZEB1 expression, inhibit tumor cell proliferation, enhance apoptosis, and inhibit cell migration. Transfected GC cells had higher E-cadherin expression and decreased Vimentin expression or Wnt5a expression (P<0.05 compared to the control group). CONCLUSIONS ZEB1 expression is increased in GC tumor tissues and is associated with pathological features. The downregulation of ZEB1 can facilitate cell apoptosis via mediating Wnt5a, further suppressing GC cell proliferation and migration, and reducing EMT occurrence.

CLCA2 epigenetic regulation by CTBP1, HDACs, ZEB1, EP300 and miR-196b-5p impacts prostate cancer cell adhesion and EMT in metabolic syndrome disease.

Prostate cancer (PCa) is the most common cancer among men. Metabolic syndrome (MeS) is associated with increased PCa aggressiveness and recurrence. Previously, we proposed C-terminal binding protein 1 (CTBP1), a transcriptional co-repressor, as a molecular link between these two conditions. Notably, CTBP1 depletion decreased PCa growth in MeS mice. The aim of this study was to investigate the molecular mechanisms that explain the link between MeS and PCa mediated by CTBP1. We found that CTBP1 repressed chloride channel accessory 2 (CLCA2) expression in prostate xenografts developed in MeS animals. CTBP1 bound to CLCA2 promoter and repressed its transcription and promoter activity in PCa cell lines. Furthermore, we found that CTBP1 formed a repressor complex with ZEB1, EP300 and HDACs that modulates the CLCA2 promoter activity. CLCA2 promoted PCa cell adhesion inhibiting epithelial-mesenchymal transition (EMT) and activating CTNNB1 together with epithelial marker (CDH1) induction, and mesenchymal markers (SNAI2 and TWIST1) repression. Moreover, CLCA2 depletion in PCa cells injected subcutaneously in MeS mice increased the circulating tumor cells foci compared to control. A microRNA (miRNA) expression microarray from PCa xenografts developed in MeS mice, showed 21 miRNAs modulated by CTBP1 involved in angiogenesis, extracellular matrix organization, focal adhesion and adherents junctions, among others. We found that miR-196b-5p directly targets CLCA2 by cloning CLCA2 3'UTR and performing reporter assays. Altogether, we identified a new molecular mechanism to explain PCa and MeS link based on CLCA2 repression by CTBP1 and miR-196b-5p molecules that might act as key factors in the progression onset of this disease.

Inhibition of the Zeb family prevents murine palatogenesis through regulation of apoptosis and the cell cycle.

Mammalian palate separates the oral and nasal cavities for normal feeding, breathing and speech. The palatal shelves are a pair of maxillary prominences that consist of the neural crest-derived mesenchyme and surrounding epithelium. Palatogenesis is completed by the fusion of the midline epithelial seam (MES) after the medial edge epithelium (MEE) cells make contact between the palatal shelves. Various cellular and molecular events, such as apoptosis, cell proliferation, cell migration, and epithelial-mesenchymal transition (EMT), are involved in palatogenesis. The Zeb family of transcription factors is an essential player during normal embryonic development. The distinct role of the Zeb family has not been thoroughly elucidated to date. In mouse palate, the Zeb family factors are expressed in the palatal mesenchyme until MEE contact. Interestingly, the expression of the Zeb family has also been observed in MES, which is already fused with the mesenchymal region. The regulatory roles of the Zeb family in palatogenesis have not been elucidated to date. The purpose of this study is to determine the Zeb family effects on the cellular events. To investigate the functions of the Zeb family, siRNA targeting Zeb family was used to treat in vitro organ culture for temporary inhibition of the Zeb family during palatogenesis. In the cultured palate containing siRNA, MES was clearly observed, and E-cadherin, an epithelial marker, was still expressed. Inhibition of the Zeb family results in the suppression of apoptosis, increased cell proliferation, and defective cell migration in the developing palate. Our data suggest that the Zeb family plays multiple roles in the stimulation and inhibition of apoptosis and cell proliferation and efficient mesenchymal cell migration during palatogenesis.

Human antigen R enhances the epithelial-mesenchymal transition via regulation of ZEB-1 in the human airway epithelium.

BACKGROUND: Increasing evidence suggests that human antigen R (HuR) is involved in the epithelial-mesenchymal transition (EMT) process of several diseases. However, the role of HuR in EMT in the airway epithelial cells of patients with COPD remains unclear. METHODS: BEAS-2B cells were cultured and treated with 3%CSE. Western blotting, RT-PCR and immunofluoresence were used to detect the expression of HuR, ZEB-1. RNAi was used to suppress HuR expression. Then knockdown of HuR, RT-PCR and Western blotting showed that with siHuR-1 and siHuR-3, clear suppression of HuR expression was confirmed. We chose siHuR-3, the most effective one, to proceed with subsequent experiments. Immunofluorescence analysis, western blotting were used to detect the expression of E-cadherin, vimentin, ZEB-1 and HuR. RESULTS: We show that more HuR expression is enhanced in the airways epithelium of smokers with or without COPD than controls (nonsmoker non-COPD patients). However, there was no definite correlation between HuR expression and FEV1%. Further study reveals that knockdown of HuR significantly increases the apoptosis of BEAS-2B cells and down-regulates ZEB-1 expression. CONCLUSIONS: EMT is partially enhanced through the HuR-binding proteins and its post-transcriptional regulation role in airway epithelium in COPD.

Circulating miR-200c is up-regulated in paediatric patients with familial hypercholesterolaemia and correlates with miR-33a/b levels: implication of a ZEB1-dependent mechanism.

Hypercholesterolaemia provokes reactive oxygen species (ROS) increase and is a major risk factor for cardiovascular disease (CVD) development. We previously showed that circulating miR-33a/b expression levels were up-regulated in children with familial hypercholesterolaemia (FH). miR-33a/b control cholesterol homoeostasis and recently miR-33b has been demonstrated to directly target the transcription factor zinc finger E-box-binding homeobox 1 (ZEB1). The latter acts in a negative feedback loop with the miR-200 family. Our previous studies showed that the ROS-dependent miR-200c up-regulation induces endothelial dysfunction and provokes a ZEB1-dependent apoptosis and senescence. In the present study, we aimed to verify whether circulating miR-200c was induced in FH children, and whether a correlation existed with miR-33a/b Total RNA was extracted from plasma of 28 FH children and 25 age-matched healthy subjects (HS) and miR-200c levels were measured. We found that miR-200c was up-regulated in FH compared with HS (4.00 ± 0.48-fold increase, P<0.05) and exhibited a positive correlation with miR-33a/b. miR-200c did not correlate with plasma lipids, but correlated with C-reactive protein (CRP) plasma levels and glycaemia (GLI). Ordinary least squares (OLS) regression analysis revealed that miR-200c was significantly affected by GLI and by miR-33a (P<0.01; P<0.001 respectively). Moreover, we found that miR-33 overexpression, in different cell lines, decreased ZEB1 expression and up-regulated both the intracellular and the extracellular miR-200c expression levels. In conclusion, circulating miR-200c is up-regulated in FH, probably due to oxidative stress and inflammation and via a miR-33a/b-ZEB1-dependent mechanism. The present study could provide the first evidence to point to the use of miR-33a/b and miR-200c, as early biomarkers of CVD, in paediatric FH.

Long non-coding ribonucleic acid zinc finger antisense 1 promotes the progression of colonic cancer by modulating ZEB1 expression.

BACKGROUND AND AIM: Long non-coding RNA zinc finger antisense 1 (ZFAS1) is frequently amplified in hepatocellular carcinoma and promotes metastasis by increasing zinc finger E-box binding homeobox 1 (ZEB1), which can potentiate the progression of epithelial-to-mesenchymal transition (EMT). However, the expression pattern and role of ZFAS1 in colonic cancer remains unknown. The present study aimed to investigate the role of ZFAS1 and its clinical significance in colonic cancer. METHODS: Paired clinical colonic cancer tissue samples and clinicopathologic characteristics of 73 patients were analyzed. Quantitative real-time polymerase chain reaction analysis was used to evaluate expression levels of ZFAS1 in colonic cancer tissues, cell lines, and plasma. ZEB1 and EMT-related markers expression levels also were explored. Cell biology assays were used to explore the biologic consequences of ZFAS1 in regulating cell proliferation and invasion, as well as the roles in regulating EMT. RESULTS: Zinc finger antisense 1 was up-regulated in colonic cancer tissues compared with adjacent mucosa (P < 0.01), and its expression level was significantly correlated with TNM stage, vascular invasion, and lymph node metastasis (P < 0.05). ZFAS1 and ZEB1 were also increased in patients' plasma. Moreover, ZFAS1 promoted proliferation, invasion, and impeded apoptosis. Knockdown of ZFAS1 decreased expression of ZEB1 and increased the epithelial markers E-cadherin, ZO-1 while decreasing mesenchymal markers vimentin and N-cadherin. CONCLUSIONS: Long non-coding RNA ZFAS1 may function as an oncogene by modulating ZEB1 to induce EMT. Manipulation of ZFAS1 level may be a novel approach to suppress colonic cancer progression. In addition, ZFAS1 in plasma has the potential to be a diagnostic biomarker of colonic cancer.

MiR-301a regulates E-cadherin expression and is predictive of prostate cancer recurrence.

BACKGROUND: MicroRNAs (miRNAs) are small, noncoding RNAs that regulate gene expression post-transcriptionally. Dysregulation of miRNA has been implicated in the development and progression of prostate cancer. Through next generation miRNA sequencing, we recently identified a panel of five miRNAs associated with prostate cancer recurrence and metastasis. Of the five miRNAs, miR-301a had the strongest association with prostate cancer recurrence. Overexpression of miR-301a in prostate cancer cells, PC3, and LNCaP resulted in increased growth both in vitro and in xenografted tumors. We therefore sought to examine its role in prostate carcinogenesis in greater detail. METHODS: We examined the effect of miR-301a expression on biochemical recurrence and metastasis among 585 men treated with radical prostatectomy for prostate cancer. We examined the mechanism of growth deregulation by miR-301a in prostate cancer cells using analysis of the miRome of prostate cancer cell lines, quantitative PCR, and Western blotting. RESULTS: High levels of miR-301a (above the median) were associated with an increased risk of biochemical recurrence (adjusted hazard ratio [aHR] 1.42, 95% confidence interval (CI) 1.06-1.90, P = 0.002) but not of metastasis (aHR 0.84, 95%CI 0.41-1.70, P = 0.6) after adjustment for known prognostic factors. RNA transcriptome sequencing analysis of miR-301a overexpressing prostate cancer cell lines identified the tumor suppressor p63 as a potential direct miR-301a target. Transcriptome sequencing, qPCR and Western blotting showed that miR-301a induced epithelial-mesenchymal transition (EMT) in prostate cancer cells through a pathway initiated by p63 inhibition. Luciferase assay verified p63 as a direct target of miR-301a. Loss of p63 resulted in miR-205 downregulation, releasing Zeb1 and Zeb2 from inhibition, culminating in Zeb1/Zeb2 suppression of E-cadherin. This pathway of growth alteration mediated by miR-301a upregulation was shown to be valid in prostate cancer cell lines and patient-derived tumors. CONCLUSIONS: These data indicate that miR-301a functions as an oncogene in prostate cancer by directly targeting the p63 tumor suppressor leading to loss of E-cadherin and EMT. Hence, miR-301a may serve as a novel biomarker in prostate cancer as well as a therapeutic target for prostate cancer management. Prostate 76:869-884, 2016. © 2016 Wiley Periodicals, Inc.

The long non-coding RNA NEAT1 regulates epithelial to mesenchymal transition and radioresistance in through miR-204/ZEB1 axis in nasopharyngeal carcinoma.

Long non-coding RNAs (lncRNAs) play a critical role in cancer progression, including in nasopharyngeal carcinoma (NPC). However, it is still poorly understood whether lncRNA regulates epithelial to mesenchymal transition (EMT) and radioresistance of NPC cells. We found that lncRNA NEAT1 was significantly upregulated in NPC cell lines and tissues. Knockdown of NEAT1 could sensitize NPC cells to radiation in vitro. Further investigation found that NEAT1 regulated radioresistance by modulating EMT phenotype. Furthermore, we found that there was reciprocal repression between NEAT1 and miR-204. ZEB1 was identified as a downstream target of miR-204 and NEAT1 upregulated ZEB1 expression by negatively regulating miR-204 expression. Taking together, we proposed that NEAT1 regulated EMT phenotype and radioresistance by modulating the miR-204/ZEB1 axis in NPC.

ΔNp63α attenuates tumor aggressiveness by suppressing miR-205/ZEB1-mediated epithelial-mesenchymal transition in cervical squamous cell carcinoma.

Cervical cancer is one of the most common female cancers worldwide. Although the therapeutic outcomes of patients with early-stage cervical cancer have been significantly improved in the past decades, tumor metastasis and recurrence remain the major causes of cervical cancer-related deaths. In cervical squamous cell carcinoma (SCC), the aberrant activation of epithelial-mesenchymal transition (EMT), a crucial process in invasion and metastasis of epithelial cancer, could promote lymph nodal metastasis and recurrence, and predicts poor prognosis. In this study, we show that the expression levels of EMT markers, ß-catenin and Vimentin, are associated with the p63 isoform ΔNp63α in SCC by using immunohistochemistry staining and analysis. Compared to the control SiHa cells (SiHa-NC), the expression of E-cadherin and ß-catenin are upregulated, while Vimentin and ZEB1 are downregulated in the constructed SiHa cell line with stable ΔNp63α overexpression (SiHa-ΔNp63α). Besides, the migration and invasion abilities are also suppressed in SiHa-ΔNp63α cells with a typical epithelial morphology with cobblestone-like shape, suggesting that ΔNp63α is a vital EMT repressor in SCC cells. In addition, the involvement of miR-205/ZEB1 axis in the inhibition effect of ΔNp63α on EMT program is revealed by a miRNA array and confirmed by the subsequent transfection of the miR-205 mimic and antagomir. Moreover, SCC patients with low ΔNp63α expression and high EMT level show more frequent metastasis and recurrence as well as reduced overall survival. Therefore, EMT program and its vital repressor ΔNp63α could be used as biomarkers for tumor metastasis and recurrence in cervical cancer.

microRNA miR-200b affects proliferation, invasiveness and stemness of endometriotic cells by targeting ZEB1, ZEB2 and KLF4.

Endometriosis is characterized by growth of endometrial tissue at ectopic locations. Down-regulation of microRNA miR-200b is observed in endometriosis and malignant disease, driving tumour cells towards an invasive state by enhancing epithelial-to-mesenchymal transition (EMT). miR-200b up-regulation may inhibit EMT and invasive growth in endometriosis. To study its functional impact on the immortalized endometriotic cell line 12Z, the stromal cell line ST-T1b, and primary endometriotic stroma cells, a transient transfection approach with microRNA precursors was employed. Expression of bioinformatically predicted targets of miR-200b was analysed by qPCR. The cellular phenotype was monitored by Matrigel invasion assays, digital-holographic video microscopy and flow cytometry. qPCR revealed significant down-regulation of ZEB1 (P < 0.05) and ZEB2 (P < 0.01) and an increase in E-cadherin (P < 0.01). miR-200b overexpression decreased invasiveness (P < 0.0001) and cell motility (P < 0.05). In contrast, cell proliferation (P < 0.0001) and the stemness-associated side population phenotype (P < 0.01) were enhanced following miR-200b transfection. These properties were possibly due to up-regulation of the pluripotency-associated transcription factor KLF4 (P < 0.05) and require attention when considering therapeutic strategies. In conclusion, up-regulation of miR-200b reverts EMT, emerging as a potential therapeutic approach to inhibit endometriotic cell motility and invasiveness.

miRNA-124 modulates lung carcinoma cell migration and invasion.

OBJECTIVES: Lung cancer remains the leading cause of cancer-related mortality worldwide. Recently, accumulating studies have evidenced that microRNAs (miRNAs) contribute to the carcinogenesis of lung cancer through acting as either oncogenes or tumor suppressors. The purpose of our study was to investigate the functional role of miR-124 in lung cancer. METHODS: The expression of miR-124 was assessed by real-time RT-PCR in non-small cell lung cancer (NSCLC) tissues in comparison to its adjacent normal tissues. After transfection with miR-124 Mimics or negative controls into A549 cells, migration and invasion assays, apoptosis, and cell viability were evaluated. Luciferase reporter assay and RT-PCR were performed to explore whether zinc finger e-box binding homeobox 1 (ZEB1) was a target of miR-124. Further, the effects of miR-124 Mimic on migration and invasion were assessed after overexpression of ZEB1. RESULTS: MiR-124 expression was significantly down-regulated in NSCLC tissues compared to the normal tissue. In in-vitro study, overexpression of miR-124 in A549 cells suppressed cell migration and invasion activity, decreased expression of vimentin, but increased expression of E-cadherin and induced apoptosis. Luciferase reporter assay ensured that ZEB1 was a direct target of miR-124 and was negatively regulated by miR-124. Overexpression of ZEB1 could reverse the effect of miR-124 Mimic on the migration and invasion of the cells. CONCLUSION: The results suggests that miR-124 inhibits lung cancer cell migration and invasion through suppressing epithelial-mesenchymal transition (EMT) and inducing apoptosis of the lung cancer cells.

Zeb1 Is a Potential Regulator of Six2 in the Proliferation, Apoptosis and Migration of Metanephric Mesenchyme Cells.

Nephron progenitor cells surround around the ureteric bud tips (UB) and inductively interact with the UB to originate nephrons, the basic units of renal function. This process is determined by the internal balance between self-renewal and consumption of the nephron progenitor cells, which is depending on the complicated regulation networks. It has been reported that Zeb1 regulates the proliferation of mesenchymal cells in mouse embryos. However, the role of Zeb1 in nephrons generation is not clear, especially in metanephric mesenchyme (MM). Here, we detected cell proliferation, apoptosis and migration in MM cells by EdU assay, flow cytometry assay and wound healing assay, respectively. Meanwhile, Western and RT-PCR were used to measure the expression level of Zeb1 and Six2 in MM cells and developing kidney. Besides, the dual-luciferase assay was conducted to study the molecular relationship between Zeb1 and Six2. We found that knock-down of Zeb1 decreased cell proliferation, migration and promoted cell apoptosis in MM cells and Zeb1 overexpression leaded to the opposite data. Western-blot and RT-PCR results showed that knock-down of Zeb1 decreased the expression of Six2 in MM cells and Zeb1 overexpression contributed to the opposite results. Similarly, Zeb1 promoted Six2 promoter reporter activity in luciferase assays. However, double knock-down of Zeb1 and Six2 did not enhance the apoptosis of MM cells compared with control cells. Nevertheless, double silence of Zeb1 and Six2 repressed cell proliferation. In addition, we also found that Zeb1 and Six2 had an identical pattern in distinct developing phases of embryonic kidney. These results indicated that there may exist a complicated regulation network between Six2 and Zeb1. Together, we demonstrate Zeb1 promotes proliferation and apoptosis and inhibits the migration of MM cells, in association with Six2.

MiR-451a restrains the growth and metastatic phenotypes of papillary thyroid carcinoma cells via inhibiting ZEB1.

MicroRNAs (miRNAs) are known to be critical regulators in cancer progression. MiR-451a is reported to be involved in the progression of many different forms of cancers, including osteosarcoma, colorectal cancer, and breast carcinoma. In this study, we illuminated the possible roles of miR-451a in the development of papillary thyroid carcinoma (PTC) cells in vitro and in vivo. MiR-451a was markedly down-expressed in PTC sample compared with paratumor tissue. Upregulation of miR-451a repressed PTC cells proliferation, migration ability and inhibited the invasiveness of PTC cells in vitro. Additional, miR-451a suppressed PTC cells growth and the lung metastasis of PTC cells in vivo, whereas downregulation of miR-451a caused opposite outcomes. Importantly, miR-451a inversely modulated the expression of Zinc Finger E-Box Binding Homeobox 1 (ZEB1) by directly binding to the 3' untranslated region (UTR) of ZEB1 in PTC cells. The level of ZEB1 was negatively associated with miR-451a level in PTC tissues, and ZEB1 silencing mimicked the suppressive impacts of miR-451a on the proliferation, mobility, and invasive phenotypes of PTC cells. ZEB1 overexpression abrogated the inhibitory impacts of miR-451a on PTC cells. Together, this study revealed that miR-451a restrained the growth and metastatic phenotypes of PTC cells through targeting ZEB1.

Zeb1 promotes corneal neovascularization by regulation of vascular endothelial cell proliferation.

Angiogenesis is required for tissue repair; but abnormal angiogenesis or neovascularization (NV) causes diseases in the eye. The avascular status in the cornea is a prerequisite for corneal clarity and thought to be maintained by the equilibrium between proangiogenic and antiangiogenic factors that controls proliferation and migration of vascular endothelial cells (ECs) sprouting from the pericorneal plexus. VEGF is the most important intrinsic factor for angiogenesis; anti-VEGF therapies are available for treating ocular NV. However, the effectiveness of the therapies is limited because of VEGF-independent mechanism(s). We show that Zeb1 is an important factor promoting vascular EC proliferation and corneal NV; and a couple of small molecule inhibitors can evict Ctbp from the Zeb1-Ctbp complex, thereby reducing EC Zeb1 expression, proliferation, and corneal NV. We conclude that Zeb1-regulation of angiogenesis is independent of Vegf and that the ZEB1-CtBP inhibitors can be of potential therapeutic significance in treating corneal NV.

Silencing of the transcriptional factor ZEB1 alters the steroidogenic pathway, and increases the concentration of testosterone and DHT in DU145 cells.

Prostate cancer (PCa) is the second most common type of male malignancy worldwide. The transcription factor zinc finger E­box binding homeobox 1 (ZEB1) is associated with epithelial­mesenchymal transition and is also involved in regulation of androgen receptor (AR) expression, the main ligands of which are testosterone and dihydrotestosterone (DHT). These androgens are synthesized through the steroidogenic pathway within the prostate, and their synthesis is altered in PCa. The present study aimed to determine the ZEB1­induced alterations in androgen synthesis and AR expression in the DU145 PCa cell line. Reverse transcription­quantitative polymerase chain reaction, western blotting and immunocytochemistry were used to determine the mRNA and protein expression levels, and cellular localization of steroidogenic pathway enzymes in the DU145 cell line in response to ZEB1 silencing. Furthermore, the concentrations of testosterone and DHT were detected in cell culture medium using ELISA. ZEB1­silenced cells exhibited an increase in testosterone and DHT production, an increase in AR expression and an alteration in the steroidogenic pathway. In particular, steroidogenic acute regulatory protein and 5α­reductase 2 expression levels were decreased, whereas cytochrome P450 family 17 subfamily A member 1, 5α­reductase 1, aldo­keto reductase family 1 member D1 and aldo­keto reductase family 1 member C2 expression levels were increased. In conclusion, the present study provided novel information regarding the regulation of intratumoral androgen production in PCa, which is relevant for the progression of the disease to a castration­resistant form.