The perception of pain is initiated by the transduction of noxious stimuli through specialized ion channels and receptors expressed by primary nociceptive neurons. The molecular mechanisms that orchestrate the expression and function of ion channels relevant for pain processing are poorly understood. We demonstrate here a central role of the transcription factor Smad-interacting protein 1 (Sip1/Zfhx1b/Zeb2), a 2-handed zinc finger DNA-binding protein with essential functions in neural crest and forebrain development, in controlling nociceptive neuron excitability and pain sensitivity. Mutant mice lacking 1 Zfhx1b allele displayed decreased thermal pain responses, whereas mechanical pain was unaffected. In parallel, repetitive firing of capsaicin/heat-sensitive nociceptive DRG neurons was markedly impaired. Analysis of the voltage-gated currents underlying repetitive firing revealed a significant increase in persistent sodium currents and a reduction in delayed rectifier potassium currents. Modeling experiments in conjunction with experimental results suggest that these changes cause a depolarization-induced block of action potential propagation past the DRG axon T-junction. These data suggest that Sip1 controls the transduction properties of heat-sensitive primary sensory neurons and thus thermal pain sensitivity in a novel manner via coordinated changes in DRG-neuron voltage-gated ion channels.

Long noncoding RNAs (LncRNAs) play critical roles in the development and progression of cancers. However, little is known about the function and mechanism of lncRNAs in non-small cell lung cancer (NSCLC). In this study, we investigated the expression and functional role of lncRNA small nucleolar RNA host gene 20 (SNHG20) as well as its underlying mechanism in NSCLC. Our results showed that SNHG20 was significantly up-regulated in NSCLC tissues and cells. High SNHG20 expression was implicated with poor prognosis in NSCLC patients. Moreover, SNHG20 knockdown suppressed proliferation, migration and invasion, and induced apoptosis in NSCLC cells. Furthermore, SNHG20 could function as a competing endogenous RNA (ceRNA) to elevate ZEB2 and RUNX2 expression by sponging miR-154. Rescue assays revealed that miR-154 inhibition could reverse the inhibitory effect of SNHG20 silence on proliferation, migration and invasion in NSCLC cells. More importantly, SNHG20 knockdown suppressed tumor growth in NSCLC in vivo through suppressing miR-154 and elevating ZEB2 and RUNX2 expression. In summary, knockdown of lncRNA SNHG20 suppressed proliferation, migration and invasion, and promotes apoptosis through up-regulating ZEB2 and RUNX2 expression by sponging miR-154 in NSCLC, providing a promising therapeutic target for NSCLC patients.

Epithelial-mesenchymal transition (EMT) is a process implicated in tumor invasion and metastasis. During EMT, epithelial cells undergo molecular changes to acquire mesenchymal phenotypes, which are mediated by EMT-inducing transcription factors. Previously, we showed that ZEB2 cooperates with the transcription factor Sp1 to function as a transcriptional activator of vimentin, integrin α5, and cadherin-11, which promotes cancer cell invasion. We hypothesized that ZEB2, through cooperation with Sp1, would mediate diverse cellular functions beyond EMT and invasion during metastasis. ZEB2 upregulated the expression of Sp1-regulated genes such as survivin, bcl-2, cyclin D1, and vascular endothelial growth factor in an Sp1-dependent manner, resulting in increased cancer cell survival and proliferation and endothelial cell activation in vitro, and increased circulating tumor cell survival and tumor angiogenesis in vivo. In addition, Sp1 enhanced ZEB2 stability, suggesting the presence of a positive feedback loop between ZEB2 and Sp1. Clinical data showed that ZEB2 expression was positively associated with Sp1 expression, and that the expression of both of these factors had prognostic significance for predicting survival in cancer patients. This study suggests that invasion is linked to cancer cell survival and angiogenesis by ZEB2 during cancer progression, and increases our understanding of the pathways via which EMT-inducing transcription factors regulate the complex process of metastasis.

Overexpression and mutational activation of the epidermal growth factor receptor (EGFR) plays an important role in the pathogenesis of non-small cell lung cancer (NSCLC). EGFR tyrosine-kinase inhibitors (TKIs) are given as a primary therapy for advanced patients with EGFR-activating mutations; however, the majority of these tumors relapse and patients eventually develop resistance to TKIs. To address a potential role of protein kinase C (PKC) isozymes in the resistance to TKIs, we used the isogenic NSCLC H1650 cell line and its erlotinib-resistant derivative H1650-M3, a cell line that displays a mesenchymal-like morphology driven by transforming growth factor-β signaling. We found that H1650-M3 cells display remarkable PKCα upregulation and PKCδ downregulation. Notably, silencing PKCα from H1650-M3 cells using RNA interference caused a significant reduction in the expression of epithelial-to-mesenchymal transition (EMT) markers vimentin, Zeb2, Snail, and Twist. Moreover, pharmacological inhibition or PKCα RNA interference depletion and PKCδ restoring sensitized H1650-M3 cells to erlotinib. Whereas ectopic overexpression of PKCα in parental H1650 cells was not sufficient to alter the expression of EMT genes or to confer resistance to erlotinib, it caused downregulation of PKCδ expression, suggesting a unidirectional crosstalk. Finally, mechanistic studies revealed that PKCα upregulation in H1650-M3 cells is driven by transforming growth factor-β. Our results identified important roles for specific PKC isozymes in erlotinib resistance and EMT in lung cancer cells, and highlight PKCα as a potential target for lung cancer treatment.

Gastric cancer (GC) is characterized by extensive local invasion, distant metastasis and poor prognosis. In most cases, GC progression is associated with aberrant expression of cytokines or activation of signaling cascades mediated by tumor-stroma interactions. However, the mechanisms by which these interactions contribute to GC progression are poorly understood. In this study, we find that IL-33 and its receptor ST2L are upregulated in the human GC and served as prognostic markers for poor survival of GC patients. In a co-culture model with GC cells and cancer-associated fibroblasts (CAFs), we further demonstrate that CAFs-derived IL-33 enhances the migration and invasion of GC cells by inducing the epithelial-mesenchymal transition (EMT) through activation of the ERK1/2-SP1-ZEB2 pathway in a ST2L-dependent manner. Furthermore, the secretion of IL-33 by CAFs can be induced by the proinflammatory cytokines TNF-α that is released by GC cells via TNFR2-NF-κB-IRF-1 pathway. Additionally, silencing of IL-33 expression in CAFs or ST2L expression in GC cells inhibits the peritoneal dissemination and metastatic potential of GC cells in nude mice. Taken together, these results characterize a critical role of the interaction between epithelial-stroma mediated by the TNF-α/IL-33/ST2L signaling in GC progression, and provide a rationale for targeting this pathway to treat GC metastasis.

Although the incidence of brain metastasis in gastric cancer is relatively low, its prevalence may increase with improved therapy and longer survival tumors. The molecular mechanisms underlying brain metastases are not well understood. To gain insight into the mechanism of brain metastasis, we studied differences in microRNA (miRNA) expression levels in 8 cases of matched primary gastric adenocarcinoma and brain metastatic adenocarcinoma using the Illumina microRNA microarray chip. We identified 6 upregulated and 2 downregulated miRNAs in all 8 cases simultaneously. Interestingly, 2 out of 8 miRNAs (hsa-miR‑141-3p and hsa-miR-200b-3p) belonged to the miR-200 family. Online microRNA database searching revealed that ZEB2 is the top-ranked target gene for hsa-miR141-3p and hsa-miR-200b-3p, prompting us to focus ZEB2 expression in brain metastatic adenocarcinoma. We confirmed that ZEB2 expression was markedly downregulated in some brain metastatic samples. In addition, decreased ZEB2 expression was noted by western blot analysis of 2 metastatic gastric adenocarcinoma cell types that were derived by in vivo selection following intracardiac injection of gastric cancer cell lines. In conclusion, we demonstrate that expression of miRNA-200 family members and ZEB2 are associated with brain metastases of gastric adenocarcinoma, not only in matched patient samples, but also in metastatic cell lines that were derived by in vivo selection.

Human nasopharyngeal carcinoma (NPC) has the highest metastatic rate in head and neck. However, the mechanisms underlying NPC metastasis remain unclear. Here using propensity-score-matched miRNA microarray analysis, miR-142-3p is identified to be the most correlated with distant-metastasis-free survival and downregulated in paraffin-embedded NPC with distant metastasis, which is validated in both internal cohort and external GEO dataset from Canada. miR-142 locus hypermethylation was observed and found to be associated with miR-142-3p downregulation in metastatic NPC. Furthermore, miR-142-3p was epigenetically silenced by EZH2-recruited DNMT1 and suppressed NPC cell metastasis and EMT. Intersecting PCR array gene profiling with bioinformatic prediction, we identify ZEB2 as a direct and functional target of miR-142-3p in NPC. Reversal of miR-142-3p silencing efficiently suppresses NPC cell invasion and metastasis. Moreover, epigenetic miR-142 hypermethylation is correlated with unfavorable prognosis in both training and validation cohorts. This study identifies miR-142-3p as a key suppressive regulator in NPC metastasis and reveals a DNMT1-mediated epigenetic mechanism for miR-142-3p silencing, providing a potential prognostic marker and therapeutic target to combat NPC metastasis.

Egr2 and 3 are important for maintaining immune homeostasis. Here we define a fundamental function of Egr2 and 3 operating as a checkpoint that controls the transition between clonal expansion and differentiation of effector T cells. Egr2 and 3 deficiency resulted in defective clonal expansion but hyperactivation and excessive differentiation of T cells in response to viral infection. Conversely, sustained Egr2 expression enhanced expansion but severely impaired effector differentiation. Egr2 bound to and controlled the expression of genes regulating proliferation (Myc and Myb) and differentiation repressors (Bcl6, Id3), while repressing transcription factors required for effector function (Zeb2, RORa, RORc, and Bhlhe40). Egr2 and 3 expression in T cells was regulated reciprocally by antigen and IFNγ, providing a mechanism for adjusting proliferation and differentiation of individual T cells. Thus, Egr2 and 3 are upstream regulators of effector CD4 and CD8 T cells that are essential for optimal responses with limited immunopathology.

Epithelial ovarian cancer (EOC) is the most lethal gynecologic malignancy, and its vulnerability to metastasis contributes to the poor outcomes of EOC patients. Long noncoding RNAs (lncRNAs) were verified to play a pivotal role in EOC metastasis. However, the potential role of lncRNA membrane-associated guanylate kinase inverted 1 (MAGI1) intronic transcript (MAGI1-IT1) in EOC is largely unknown. In this study, the function and mechanisms of MAGI1-IT1 in EOC metastasis were explored profoundly. First, MAGI1-IT1 expression was found to be significantly decreased in overexpressing miR-200a EOC cells. Second, MAGI1-IT1 expression was remarkably increased in metastatic EOC tissues, and high MAGI1-IT1 was dramatically associated with EOC FIGO III-IV stage; in addition, MAGI1-IT1 might be related to EOC dissemination via epithelial-mesenchymal transition (EMT). Next, a series of gain- and loss-of-function assays verified that, although MAGI1-IT1 has no significant role in EOC proliferation and subcutaneous xenograft growth, the upregulation of MAGI1-IT1 can remarkably facilitate EOC EMT phenotype, cells migration and invasion ability and intraperitoneal metastasis in nude mice, while downregulation of MAGI1-IT1 led to the opposite effect in vitro. Moreover, MAGI1-IT1 was validated to promote EOC metastasis through upregulation of ZEB1 and ZEB2 by competitively binding miR-200a, and the restrictive effects of MAGI1-IT1 depletion on EOC metastasis could be reversed by inhibition of miR-200a and upregulation of ZEB1 and ZEB2. Collectively, these results suggest that MAGI1-IT1 may work as a ceRNA in promoting EOC metastasis through miR-200a and ZEB1/2 and may be a potential therapeutic target for EOC.

BACKGROUND

We intended to evaluate diagnostic utility of a targeted gene sequencing by using next generation sequencing (NGS) panel in patients with intractable early-onset epilepsy (EOE) and find the efficient analytical step for increasing the diagnosis rate.

METHODS

We assessed 74 patients with EOE whose seizures started before 3 years of age using a customized NGS panel that included 172 genes. Single nucleotide variants (SNVs) and exonic and chromosomal copy number variations (CNVs) were intensively examined with our customized pipeline and crosschecked with commercial or pre-built software. Variants were filtered and prioritized by in-depth clinical review, and finally classified according to the American College of Medical Genetics and Genomics guidelines. Each case was further discussed in a monthly consensus meeting that included the participation of all laboratory personnel, bioinformaticians, geneticists, and clinicians.

RESULTS

The NGS panel identified 28 patients (37.8%) with genetic abnormalities; 25 patients had pathogenic or likely pathogenic SNVs in 17 genes including SXTBP1 (n = 3), CDKL5 (n = 2), KCNQ2 (n = 2), SCN1A (n = 2), SYNGAP1 (n = 2), GNAO1 (n = 2), KCNT1 (n = 2), BRAT1, WWOX, ZEB2, CHD2, PRICKLE2, COL4A1, DNM1, SCN8A, MECP2, SLC9A6 (n = 1). The other 3 patients had pathogenic CNVs (2 duplications and 1 deletion) with varying sizes (from 2.5 Mb to 12 Mb). The overall diagnostic yield was 37.8% after following our step-by-step approach for clinical consensus.

CONCLUSIONS

NGS is a useful diagnostic tool with great utility for patients with EOE. Diagnostic yields can be maximized with a standardized and team-based approach.

Cardiac fibrosis is linked to fibroblast-to-myofibroblast phenoconversion and proliferation but the mechanisms underlying this are poorly understood. Ski is a negative regulator of TGF-β-Smad signaling in myofibroblasts, and might redirect the myofibroblast phenotype back to fibroblasts. Meox2 could alter TGF-β-mediated cellular processes and is repressed by Zeb2. Here, we investigated whether Ski diminishes the myofibroblast phenotype by de-repressing Meox2 expression and function through repression of Zeb2 expression. We show that expression of Meox1 and Meox2 mRNA and Meox2 protein is reduced during phenoconversion of fibroblasts to myofibroblasts. Overexpression of Meox2 shifts the myofibroblasts into fibroblasts, whereas the Meox2 DNA-binding mutant has no effect on myofibroblast phenotype. Overexpression of Ski partially restores Meox2 mRNA expression levels to those in cardiac fibroblasts. Expression of Zeb2 increased during phenoconversion and Ski overexpression reduces Zeb2 expression in first-passage myofibroblasts. Furthermore, expression of Meox2 is decreased in scar following myocardial infarction, whereas Zeb2 protein expression increases in the infarct scar. Thus Ski modulates the cardiac myofibroblast phenotype and function through suppression of Zeb2 by upregulating the expression of Meox2. This cascade might regulate cardiac myofibroblast phenotype and presents therapeutic options for treatment of cardiac fibrosis.

BACKGROUND

Genistein has been known to inhibit proliferation and induce apoptosis in several kinds of cancer cells. While knowledge of genistein in regulating epithelial mesenchymal transition (EMT) of colon cancer cells is unknown.

METHODS

To investigate the effects and mechanisms of genistein on EMT of colon cancer cells, HT-29 cells were used and treated by genistein and TNF-α in this paper. EMT was determined by cell invasion assays using a transwell chamber and the expression changes of EMT-related markers were confirmed by RT-PCR, Western blotting, and immunofluorescence staining.

RESULTS

Genistein inhibited cell migration at 200 μmol/L. Genistein reversed the EMT of colon cancer cells by upregulation of E-cadherin and downregulation of N-cadherin, accompanied by the suppression of EMT related makers, such as Snail2/slug, ZEB1, ZEB2, FOXC1, FOXC2 and TWIST1. Moreover, genistein can inhibit the expression of notch-1, p-NF-κB and NF-κB, while promote the expression of Bax/Bcl-2 and caspase-3 in HT-29 cells.

CONCLUSIONS

The present study demonstrated that genistein suppressed the migration of colon cancer cells by reversal the EMT via suppressing the Notch1/NF-κB/slug/E-cadherin pathway. Genistein may be developed as a potential antimetastasis agent to colon cancer.

Jiawei Foshou San (JFS) is the new formula originated from classic Foshou San formula, composed with ligustrazine, ferulic acid, and tetrahydropalmatine. Previously JFS inhibited the growth of endometriosis (EMS) with unclear mechanism, especially in metastasis, invasion, and epithelial-mesenchymal transition. In this study, network pharmacology was performed to explore potential mechanism of JFS on EMS. Through compound-compound target and compound target-EMS target networks, key targets were analyzed for pathway enrichment. MMP-TIMP were uncovered as one cluster of the core targets. Furthermore, autologous transplantation of EMS rat's model were used to evaluate in vivo effect of JFS on invasion, metastasis and epithelial-mesenchymal transition. JFS significantly suppressed the growth, and reduced the volume of ectopic endometrium, with modification of pathologic structure. In-depth study, invasion and metastasis were restrained after treating with JFS through decreasing MMP-2 and MMP-9, increasing TIMP-1. Meanwhile, JFS promoted E-cadherin, and attenuated N-cadherin, Vimentin, Snail, Slug, ZEB1, ZEB2, Twist. In brief, anti-EMS effect of JFS might be related to the regulation of epithelial-mesenchymal transformation, thereby inhibition of invasion and metastasis. These findings reveal the potential mechanism of JFS on EMS and the benefit for further evaluation.

MicroRNAs (miRs) have been found to play important roles in mediating a variety of biological processes in human cancers, including tumor cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). In the present study, we aimed to investigate the putative role of miR‑200b in the progression of glioma. Real-time RT-PCR data showed that the miR‑200b levels were frequently reduced in primary glioma tissues (n=88) and cell lines, when compared to normal brain tissues (n=25). Moreover, decreased miR‑200b level was tightly associated with the malignant progression of glioma. Overexpression of miR‑200b significantly suppressed cell proliferation, migration, invasion and EMT in glioma U251 and U87 cells. Luciferase reporter assay data further identified ZEB2 as a direct target of miR‑200b, and the protein expression of ZEB2 was markedly reduced after overexpression of miR‑200b in U251 and U87 cells. Furthermore, restoration of ZEB2 effectively reversed the reduced expression of ZEB2, as well as the suppressive effects of miR‑200b overexpression on the proliferation, migration, invasion and EMT in glioma U251 and U87 cells. Moreover, in vivo study showed that overexpression of miR‑200b significantly inhibited tumorigenesis as well as the tumor growth of glioma cells, and effectively protected nude mice from tumor-induced death. Taken together these findings suggest that miR‑200b has suppressive effects on the proliferation, migration, invasion and EMT of glioma cells, partly at least, via targeting ZEB2. Therefore, miR‑200b acts as a novel tumor suppressor in glioma, and thus may become a promising therapeutic candidate for glioma.

Endometrial carcinosarcoma (ECS) represents one of the most extreme examples of tumor heterogeneity among human cancers. ECS is a clinically aggressive, high-grade, metaplastic carcinoma. At the morphological level, intratumor heterogeneity in ECS is due to an admixture of epithelial (carcinoma) and mesenchymal (sarcoma) components that can include heterologous tissues, such as skeletal muscle, cartilage, or bone. Most ECSs belong to the copy-number high serous-like molecular subtype of endometrial carcinoma, characterized by the TP53 mutation and the frequently accompanied by a large number of gene copy-number alterations, including the amplification of important oncogenes, such as CCNE1 and c-MYC. However, a proportion of cases (20%) probably represent the progression of tumors initially belonging to the copy-number low endometrioid-like molecular subtype (characterized by mutations in genes such as PTEN, PI3KCA, or ARID1A), after the acquisition of the TP53 mutations. Only a few ECS belong to the microsatellite-unstable hypermutated molecular type and the POLE-mutated, ultramutated molecular type. A common characteristic of all ECSs is the modulation of genes involved in the epithelial to mesenchymal process. Thus, the acquisition of a mesenchymal phenotype is associated with a switch from E- to N-cadherin, the up-regulation of transcriptional repressors of E-cadherin, such as Snail Family Transcriptional Repressor 1 and 2 (SNAI1 and SNAI2), Zinc Finger E-Box Binding Homeobox 1 and 2 (ZEB1 and ZEB2), and the down-regulation, among others, of members of the miR-200 family involved in the maintenance of an epithelial phenotype. Subsequent differentiation to different types of mesenchymal tissues increases tumor heterogeneity and probably modulates clinical behavior and therapy response.

In Ewing sarcoma, NKX2-2 is a critical activated target of the oncogenic transcription factor EWS/FLI that is required for transformation. However, its biological function in this malignancy is unknown. Here we provide evidence that NKX2-2 mediates the EWS/FLI-controlled block of mesenchymal features. Transcriptome-wide RNA sequencing revealed that NKX2-2 represses cell adhesion and extracellular matrix organization genes. NKX2-2-depleted cells form more focal adhesions and organized actin stress fibers, and spread over a wider area-hallmarks of mesenchymally derived cells. Furthermore, NKX2-2 represses the actin-stabilizing protein zyxin, suggesting that these morphological changes are attributable to zyxin de-repression. In addition, NKX2-2-knockdown cells display marked increases in migration and substrate adhesion. However, only part of the EWS/FLI phenotype is NKX2-2-dependent; consequently, NKX2-2 is insufficient to rescue EWS/FLI repression of mesenchymalization. Strikingly, we found that EWS/FLI-and NKX22-repressed genes are activated by ZEB2, which was previously shown to block Ewing sarcoma epithelialization. Together, these data support an emerging theme wherein Ewing sarcoma cells highly express transcription factors that maintain an undifferentiated state. Importantly, co-opting epithelial and mesenchymal traits by Ewing sarcoma cells may explain how the primary tumor grows rapidly while also "passively" metastasizing, without the need for transitions toward differentiated states, as in carcinomas.

Colorectal cancer (CRC) is a type of cancer with a mortality rate among the highest worldwide owing to its high rate of metastasis. Therefore, inflammation-associated metastasis in the development of CRC is currently a topic of considerable interest. In the present study, the pro-inflammatory cytokine interleukin-4 (IL-4) was identified to promote the epithelial-mesenchymal transition (EMT) of CRC cells. However, the enhancing effect of IL-4 was more evident in HCT116 cells compared with in RKO cells. Accordingly, an increased expression level of STAT6 was observed in HCT116 cells compared with RKO cells. Further investigations identified that E2F1 was required for maintaining the level of signal transducer and activator of transcription 6 (STAT6) in HCT116 cells. Mechanistically, E2F1 induced specificity protein 3 (SP3) directly by binding to the promoter of the STAT6 gene and activating its transcription in CRC cells. As a result, phosphorylation-activated STAT6 increased the expression of several EMT drivers, including zinc finger E-box-binding homeobox (Zeb)1 and Zeb2, which serve a critical function in IL-4-induced EMT. Rescue experiments further confirmed that IL-4-induced EMT relied on an intact E2F1/SP3/STAT6 axis in CRC cells. Finally, analysis of clinical CRC specimens revealed a positive correlation between E2F1, SP3 and STAT6. The ectopically expressed E2F1/SP3/STAT6 axis indicated a poor prognosis in patients with CRC. In conclusion, the E2F1/SP3/STAT6 pathway was identified to be essential for IL-4 signaling-induced EMT and aggressiveness of CRC cells.

Gastric cancer (GC) is a highly heterogeneous disease and one of the major causes of cancer-related mortality worldwide. Diffuse-type gastric adenocarcinoma (or poorly cohesive- with independent cells) is characterized by aggressive behavior (rapid invasion, chemoresistance and peritoneal metastasis), as compared with intestinal-subtype adenocarcinoma. Diffuse subtype GC additionally has a substantially increasing incidence rate in Europe and the USA, and was often associated with younger age. Our objective was to analyze the expression and clinical significance of genes involved in several signaling pathways in diffuse-type GC. Tumors samples and non-malignant gastric tissues were obtained from patients with GC (diffuse-type and intestinal-subtype adenocarcinoma). The expression of 33 genes coding for proteins involved in four categories, growth factors and receptors, epithelial-mesenchymal transition, cell proliferation and migration, and angiogenesis was determined by reverse transcription-quantitative polymerase chain reaction. The expression of 22 genes was significantly upregulated in diffuse-type GC and two were downregulated (including CDH1) compared with normal tissues. Among these genes, acompared with intestinal-subtype adenocarcinoma, diffuse-type GC revealed elevated levels of IGF1 and IGF1R, FGF7 and FGFR1, ZEB2, CXCR4, CXCL12 and RHOA, and decreased levels of CDH1, MMP9 and MKI67. The expression of selected genes was compared with other genes and according to clinical parameters. Furthermore, TGF-β expression was significantly increased in linitis, a sub-population of diffusely infiltrating type associated with extensive fibrosis and tumor invasion. Our study identified new target genes (IGF1, FGF7, CXCR4, TG-β and ZEB2) whose expression is associated with aggressive phenotype of diffuse-type GC.

Circular (circ)RNAs have been implicated in cancer development. However, few studies have examined the role of circRNAs in papillary thyroid cancer (PTC). In this study we found that circNUP214 was upregulated in clinical PTC specimens relative to adjacent normal tissue. In vitro analyses showed that circNUP214 knockdown suppressed PTC cell proliferation, invasion, migration, and tumorigenesis. A luciferase reporter assay confirmed that circNUP214 binds to miR-145, which directly targets zinc finger E-box binding homeobox (ZEB)2. Thus, circNUP214 may play an oncogenic role in PTC by acting as a sponge for miR-145, leading to upregulation of ZEB2. These results provide evidence for a new regulatory mechanism in PTC development involving circNUP214, which can serve as a potential therapeutic target in PTC treatment.

The BZLF1 gene controls the switch between latent and lytic infection by Epstein-Barr virus (EBV). We previously reported that both the ZV and ZIIR elements within the BZLF1 promoter, Zp, are potent transcription silencers within the context of an intact EBV genome. We report here identification of another sequence element, ZV', which synergized with ZV in repressing Zp via binding ZEB1 or ZEB2. We then determined the phenotype of a variant of EBV strain B95.8 in which the ZV, ZV', and ZIIR elements were concurrently mutated. HEK293 cell lines infected with this triple mutant (tmt) virus spontaneously synthesized 6- to 10-fold more viral BZLF1, BRLF1, BMRF1, and BLLF1 RNAs, 3- to 6-fold more viral Zta, Rta, and EAD proteins, 3- to 5-fold more viral DNA, and 7- to 9-fold more infectious virus than did 293 cell lines latently infected with either the ZV ZV' double mutant (dmt) or ZIIR mutant (mt) virus. While ZV ZV' ZIIR tmt EBV efficiently infected human primary blood B cells in vitro, it was highly defective in immortalizing them. Instead of the nearly complete silencing of BZLF1 gene expression that occurs within 4 days after primary infection with wild-type EBV, the ZV ZV' ZIIR tmt-infected cells continued to synthesize BZLF1 RNA, with 90% of them dying within 9 days postinfection. BL41 cells infected with this "superlytic" virus also exhibited increased synthesis of BZLF1 and BMRF1 RNAs. Thus, we conclude that the ZV, ZV', and ZIIR silencing elements act synergistically to repress transcription from Zp, thereby tightly controlling BZLF1 gene expression, which is crucial for establishing and maintaining EBV latency.

Mowat-Wilson syndrome (MWS) is a multiple congenital anomaly syndrome characterized by moderate or severe intellectual disability, a characteristic facial appearance, microcephaly, epilepsy, agenesis or hypoplasia of the corpus callosum, congenital heart defects, Hirschsprung disease, and urogenital/renal anomalies. It is caused by de novo heterozygous loss of function mutations including nonsense mutations, frameshift mutations, and deletions in ZEB2 at 2q22. ZEB2 encodes the zinc finger E-box binding homeobox 2 protein consisting of 1,214 amino acids. Herein, we report 13 nonsense and 27 frameshift mutations from 40 newly identified MWS patients in Japan. Although the clinical findings of all the Japanese MWS patients with nonsense and frameshift mutations were quite similar to the previous review reports of MWS caused by nonsense mutations, frameshift mutations and deletions of ZEB2, the frequencies of microcephaly, Hirschsprung disease, and urogenital/renal anomalies were small. Patients harbored mutations spanning the region between the amino acids 55 and 1,204 in wild-type ZEB2. There was no obvious genotype-phenotype correlation among the patients. A transfection study demonstrated that the cellular level of the longest form of the mutant ZEB2 protein harboring the p.D1204Rfs*29 mutation was remarkably low. The results showed that the 3'-end frameshift mutation of ZEB2 causes MWS due to ZEB2 instability.

It has been shown that microRNA-215 (miR-215) is dysregulated in several human malignancies, and this correlates with tumor progression. However, its expression and function in pancreatic cancer is still unclear. The aim of this study was to explore the effects of miR-215 on pancreatic cancer formation and progression. Using quantitative RT-PCR, we detected miR-215 expression in pancreatic cancer cell lines and primary tumor tissues. The association of miR-215 expression with clinicopathological factors and prognosis was also analyzed. We then observed the effects of miR-215 on the biological behavior of pancreatic cancer cells. Lastly, the potential regulatory function of miR-215 on ZEB2 expression was investigated. miR-215 expression levels were significantly downregulated in pancreatic cancer samples and cell lines. Decreased miR-215 expression was significantly associated with large tumor size, advanced TNM stage, lymph node metastasis, vessel invasion, and lower overall survival. Multivariate regression analysis corroborated that downregulation of miR-215 was an independent unfavorable prognostic factor. Overexpression of miR-215 inhibited pancreatic cancer cell proliferation, invasion, and migration; promoted cell apoptosis in vitro; and suppressed tumorigenicity in vivo. Further, ZEB2 was confirmed as a direct target of miR-215 by using a luciferase reporter assay. These findings indicate that miR-215 may act as a tumor suppressor in pancreatic cancer cells, and could serve as a novel therapeutic target for miR-based therapy.

E-cadherin is a cell-cell adhesion molecule and tumor invasion suppressor gene that is frequently altered in human cancers. It interacts through its cytoplasmic domain with beta-catenin which in turn interacts with the Wnt (wingless) signaling pathway. We have compared the effects of different tumor-derived E-cadherin variants with those of normal E-cadherin on Wnt signaling and on genes involved in epithelial mesenchymal transition. We established an in-house cDNA microarray composed of 1105 different, sequence verified cDNA probes corresponding to 899 unique genes that represent the majority of genes known to be involved in cadherin-dependent cell adhesion and signaling ('Adhesion/Signaling Array'). The expression signatures of E-cadherin-negative MDA-MB-435S cancer cells transfected with E-cadherin variants (in frame deletions of exon 8 or 9, D8 or D9, respectively, or a point mutation in exon 8 (D370A)) were compared to that of wild-type E-cadherin (WT) transfected cells. From the differentially expressed genes, we selected 38 that we subsequently analyzed by quantitative real-time RT-PCR and/or Northern Blot. A total of 92% of these were confirmed as differentially expressed. Most of these genes encode proteins of the cytoskeleton, cadherins/integrins, oncogenes and matrix metalloproteases. No significant expression differences of genes downstream of the Wnt-pathway were found, except in E-cadherin D8 transfected cells where upregulation of three Tcf/Lef-transcribed genes was seen. One possible reason for the lack of expression differences of the Tcf/Lef-regulated genes is upregulation of SFRP1 and SFRP3; both of which are competitive inhibitors of the Wnt proteins. Interestingly, known E-cadherin transcriptional repressors, such as SLUG (SNAI2), SIP1 (ZEB2), TWIST1, SNAIL (SNAI1) and ZEB1 (TCF8), but not E12/E47 (TCF3), had a lack of upregulation in cells expressing mutated E-cadherin compared to WT. In conclusion, E-cadherin mutations have no influence on expression of genes involved in Wnt-signaling, but they may promote their own expression by blocking upregulation of E-cadherin repressors.