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.

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.

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 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.

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.

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.

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.

The roles of ZEB1 in tumorigenic progression and epigenetic modifications.

Highly expressed Zinc-finger E-box binding protein 1 (ZEB1) is significantly associated with the malignancy of various cancers. Signal transduction and activation of ZEB1 play important roles in cancer transformation and epithelial-mesenchymal transition (EMT). Emerging evidence suggests that ZEB1 drives the induction of EMT with activation of stem cell traits, immune evasion and epigenetic reprogramming. As an ideal target for EMT research, ZEB1 has been extensively studied for decades. However, the link between ZEB1 and epigenetic regulation of EMT has only recently been discovered. ZEB1 facilitates the epigenetic silencing of E-cadherin by recruiting multiple chromatin enzymes of E-cadherin promoter, such as histone deacetylases (HDACs), DNA methyltransferase (DNMT) and ubiquitin ligase. Destruction of the connection between ZEB1 and these chromatin-modifying enzymes may represent an efficient for treating cancer. In this review, we outlined the biological function of ZEB1 in tumorigenic progression and epigenetic modifications and elucidate its transcriptional network, which is a suitable potential target for the design of novel anticancer drugs.

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.

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.

Simple classifiers for molecular subtypes of colorectal cancer.

BACKGROUND AND STUDY AIM: Colorectal cancer (CRC) is a heterogeneous disease entity with a diverse biological pathogenesis. This study aims to validate the two studies published in 2013 which established a separate CRC molecular subtype classification by utilizing a rapidly accessible miniclassifier, and verify a simplified version thereof. PATIENTS AND METHODS: Participants diagnosed with CRC (n = 568) were subtyped in three classifications for characteristic, and prognostic purposes. Colorectal cancer subtypes (CCS) were classified as: i) CCS1 (CDX2+, microsatellite stable (MSS)/microsatellite instability (MSI)-low), ii) CCS2 (MSI-high), and iii) CCS3 (FRMD6/ZEB1/HTR2B +, CDX2-, MSS/MSI-low]. Simplified CCS (SiCCS) subtypes were grouped as: i) CDX2 (CDX2+, MSS/MSI-low, ZEB1 ≤ 2), ii) MSI-H (MSI-high, CDX2/FRMD6/ZEB1/HTR2B +/-), and iii) ZEB1 (ZEB1 ≥ 2, CDX2-, MSS/MSI-low). New molecular classification (NMC) subtypes were defined as: i) enterocyte (E-C) (MUC2 +), ii) goblet-like (G-L) (MUC2 + and TFF3 +), iii) transit-amplifying (T-A) (CFTR +), and iv) stem-like (S-L) (ZEB1 +). RESULTS: In total, 53.5% (n = 304) CCS, 58.3% (n = 331) SiCCS, and 37.7% (n = 214) NMC tumours could be evaluated. CCS2 and MSI-H CRCs had the most favourable survival outcome, whereas the CCS3, ZEB1 and S-L subtypes showed the poorest prognosis. A significant overlap between CCS3, ZEB1, and S-L tumours was demonstrated. CONCLUSION: There is still a need for a consensus gene expression-based subtyping classification system for CRCs, thereby allowing the categorization of most CRC tumours. This study reveals that a simple and rapidly accessible process could replace the complicated, costly and mostly inapproachable methods clinical practices that have been introduced in the majority of previous studies.

[Knock-down of ZEB1 inhibits the proliferation, invasion and migration of gastric cancer cells].

Objective To down-regulate the expression of zinc-finger E-box binding homeobox 1 (ZEB1) gene by shRNA, and investigate its effect on invasion, migration and proliferation, as well as the related gene expressions of lncRNA HOTAIR and E-cadherin in human gastric cancer BGC823 cells. Methods RNA interfering (RNAi) was used to knock down ZEB1 in gastric cancer BGC823 cells. The recombinant plasmid shZEB1 was constructed and transfected into the gastric cancer BGC823 cells by LipofectamineTM 2000, and the stably transfected cells were isolated by G418 selection and limited dilution. The expression of ZEB1 mRNA and protein was detected by real-time quantitative PCR and Western blot analysis. Cell proliferation was determined by MTT assay, and the invasion and migration abilities of BGC823 cells were monitored by TranswellTM invasion assay and wound healing assay, respectively. The expressions of lncRNA HOTAIR and E-cadherin mRNA were detected by real-time quantitative PCR. Results After ZEB1 expression was successfully down-regulated in BGC823 cells by siRNA, the proliferation, invasion and migration rates in shZEB1 transfection group were significantly lower than those in control group; meanwhile, the expression of lncRNA HOTAIR was reduced and E-cadherin expression was enhanced. Conclusion Knock-down of ZEB1 expression by RNA interference can decease lncRNA HOTAIR expression and restrain cell proliferation, invasion and migration in gastric cancer BGC823 cells.

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.

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.

miR-875-5p counteracts epithelial-to-mesenchymal transition and enhances radiation response in prostate cancer through repression of the EGFR-ZEB1 axis.

Radiotherapy is one of the main treatment choices for non-metastatic prostate cancer (PCa), although development of radioresistance limits its effectiveness. Mounting evidence supports the ability of microRNAs to interfere with different radioresistance-associated pathways, suggesting their potential as radiosensitizers. Here, we demonstrate that reconstitution of miR-875-5p, whose expression is down-regulated in PCa clinical samples and directly correlates with that of E-cadherin, was able to enhance radiation response in PCa cell lines and xenografts through EGFR direct targeting. Consistent with the established role of EGFR in sustaining epithelial-to-mesenchymal transition (EMT) and promoting DNA repair following radiation-induced nuclear translocation, we found that miR-875-5p reconstitution in PCa cells counteracted EMT and impaired DNA lesion clearance. Down-regulation of the EMT-inducing transcription factor ZEB1, which also plays a role in homologous recombination-mediated repair of DNA lesions by regulating CHK1 expression, was found to be a major determinant of miR-875-5p-induced radiosensitization, as confirmed by phenocopy experiments showing that siRNA-mediated ZEB1 knock-down was able to reproduce the microRNA radiosensitizing effect. Overall, our data support the clinical interest in developing a novel therapeutic approach based on miR-875-5p reconstitution to increase PCa response to radiotherapy.

ZEB1 induces LOXL2-mediated collagen stabilization and deposition in the extracellular matrix to drive lung cancer invasion and metastasis.

Lung cancer is the leading cause of cancer-related deaths, primarily due to distant metastatic disease. Metastatic lung cancer cells can undergo an epithelial-to-mesenchymal transition (EMT) regulated by various transcription factors, including a double-negative feedback loop between the microRNA-200 (miR-200) family and ZEB1, but the precise mechanisms by which ZEB1-dependent EMT promotes malignancy remain largely undefined. Although the cell-intrinsic effects of EMT are important for tumor progression, the reciprocal dynamic crosstalk between mesenchymal cancer cells and the extracellular matrix (ECM) is equally critical in regulating invasion and metastasis. Investigating the collaborative effect of EMT and ECM in the metastatic process reveals increased collagen deposition in metastatic tumor tissues as a direct consequence of amplified collagen gene expression in ZEB1-activated mesenchymal lung cancer cells. In addition, collagen fibers in metastatic lung tumors exhibit greater linearity and organization as a result of collagen crosslinking by the lysyl oxidase (LOX) family of enzymes. Expression of the LOX and LOXL2 isoforms is directly regulated by miR-200 and ZEB1, respectively, and their upregulation in metastatic tumors and mesenchymal cell lines is coordinated to that of collagen. Functionally, LOXL2, as opposed to LOX, is the principal isoform that crosslinks and stabilizes insoluble collagen deposition in tumor tissues. In turn, focal adhesion formation and FAK/SRC signaling is activated in mesenchymal tumor cells by crosslinked collagen in the ECM. Our study is the first to validate direct regulation of LOX and LOXL2 by the miR-200/ZEB1 axis, defines a novel mechanism driving tumor metastasis, delineates collagen as a prognostic marker, and identifies LOXL2 as a potential therapeutic target against tumor progression.

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.