We previously revealed that epithelial-to-mesenchymal transition (EMT) was mediated by ΔNp63β, a splicing variant of ΔNp63, in oral squamous cell carcinoma (OSCC). Recent studies have highlighted the involvement of microRNA (miRNA) in EMT of cancer cells, though the mechanism remains unclear. To identify miRNAs responsible for ΔNp63β-mediated EMT, miRNA microarray analyses were performed by ΔNp63β-overexpression in OSCC cells; SQUU-B, which lacks ΔNp63 expression and displays EMT phenotypes. miRNAs microarray analyses revealed miR-205 was the most up-regulated following ΔNp63β-overexpression. In OSCC cells, miR-205 expression was positively associated with ΔNp63 and negatively with zinc-finger E-box binding homeobox (ZEB) 1 and ZEB2, potential targets of miR-205. miR-205 overexpression by miR-205 mimic transfection into SQUU-B cells led to decreasing ZEB1, ZEB2, and mesenchymal markers, increasing epithelial markers, and reducing cell motilities, suggesting inhibition of EMT phenotype. Interestingly, the results opposite to this phenomenon were obtained by transfection of miR-205 inhibitor into OSCC cells, which express ΔNp63 and miR-205. Furthermore, target protector analyses revealed direct regulation by miR-205 of ZEB1 and ZEB2 expression. These results showed tumor-suppressive roles of ΔNp63β and miR-205 by inhibiting EMT thorough modulating ZEB1 and ZEB2 expression in OSCC.

Renal cell carcinoma (RCC) represents the main renal tumors and are highly metastatic. They are heterogeneous tumors and are subdivided in 12 different subtypes where clear cell RCC (ccRCC) represents the main subtype. Tumor extracellular matrix (ECM) is composed, in RCC, mainly of different fibrillar collagens, fibronectin, and components of the basement membrane such as laminin, collagen IV, and heparan sulfate proteoglycan. Little is known about the role of these ECM components on RCC cell behavior. Analysis from The Human Protein Atlas dataset shows that high collagen 1 or 4A2, fibronectin, entactin, or syndecan 3 expression is associated with poor prognosis whereas high collagen 4A3, syndecan 4, or glypican 4 expression is associated with increased patient survival. We then analyzed the impact of collagen 1, fibronectin 1 or Matrigel on three different RCC cell lines (Renca, 786-O and Caki-2) in vitro. We found that all the different matrices have little effect on RCC cell proliferation. The three cell lines adhere differently on the three matrices, suggesting the involvement of a different set of integrins. Among the 3 matrices tested, collagen 1 is the only component able to increase migration in the three cell lines as well as MMP-2 and 9 activity. Moreover, collagen 1 induces MMP-2 mRNA expression and is implicated in the epithelial to mesenchymal transition of two RCC cell lines via Zeb2 (Renca) or Snail 2 (Caki-2) mRNA expression. Taken together, our results show that collagen 1 is the main component of the ECM that enhances tumor cell invasion in RCC, which is important for the metastasic process.

The microgravitational environment is known to affect the cellular behaviour inducing modulation of gene expression and enzymatic activities, epigenetic modifications and alterations of the structural organization. Simulated microgravity, obtained in the laboratory setting through the use of a Random Positioning Machine (RPM), represents a well recognized and useful tool for the experimental studies of the cellular adaptations and molecular changes in response to weightlessness. Short exposure of cultured human keratinocytes to the RPM microgravity influences the cellular circadian clock oscillation. Therefore, here we searched for changes on the regenerative ability and response to tissue damage of human epidermal cells through the analysis of the effects of the simulated microgravity on the re-epithelialization phase of the repair and wound healing process. Combining morphological, biochemical and molecular approaches, we found that the simulated microgravity exposure of human keratinocytes promotes a migratory behavior and triggers the epithelial-mesenchymal transition (EMT) through expression of the typical EMT transcription factors and markers, such as Snail1, Snail2 and ZEB2, metalloproteases, mesenchymal adhesion molecules and cytoskeletal components.

The aim of this study was to investigate the possible influences of circPRKCI abnormal expression on lipopolysaccharide (LPS)-induced HK2 cell injury and its mechanism. The circPRKCI level was identified in serum samples from patients with urosepsis and healthy subjects, as well as LPS-treated HK2 cells by qRT-PCR. Cell viability, apoptosis, expression of proteins associated with apoptosis, and expression of pro-inflammatory cytokines in LPS-treated HK2 cells were measured. Effects of circPRKCI abnormal expression on LPS-induced HK2 cell injury were then evaluated. Afterward, the binding miRNA of circPRKCI and target gene of miRNA were identified, and the involvements of NF-kB pathway signaling pathway with the effects of circPRKCI were finally studied. CircPRKCI was significantly down-regulated in serum samples from patients with urosepsis and LPS-treated HK2 cells. LPS-induced decrease of cell viability, increase of cell apoptosis, as well as elevated productions of tumor necrosis factor (TNF)-α, interleukins (IL)-1β, IL-6, and IL-8 in HK2 cells were attenuated by overexpressed circPRKCI. In addition, circPRKCI negatively regulated the expression of miR-545, and miR-545 up-regulation reversed the inhibiting effects of circPRKCI overexpression on LPS-induced HK2 cell injury. Moreover, zinc finger E-box-binding homeobox 2 (ZEB2) was identified as a target gene of miR-545, and ZEB2 overexpression partly reversed the effects of miR-545 up-regulation on LPS-induced HK2 cell injury. Furthermore, NF-kB pathway was revealed to be associated to the effects of circPRKCI on LPS-induced HK2 cell injury. This research indicated that the highly expressed circPRKCI relieved inflammatory injury induced by LPS in HK2 cells by suppressing miR-545/ZEBs and depressing the briskness of NF-kB pathway.

The transcription factor Sip1 (Zeb2) plays multiple roles during CNS development from early acquisition of neural fate to cortical neurogenesis and gliogenesis. In humans, SIP1 (ZEB2) haploinsufficiency leads to Mowat-Wilson syndrome, a complex congenital anomaly including intellectual disability, epilepsy and Hirschsprung disease. Here we uncover the role of Sip1 in retinogenesis. Somatic deletion of Sip1 from mouse retinal progenitors primarily affects the generation of inner nuclear layer cell types, resulting in complete loss of horizontal cells and reduced numbers of amacrine and bipolar cells, while the number of Muller glia is increased. Molecular analysis places Sip1 downstream of the eye field transcription factor Pax6 and upstream of Ptf1a in the gene network required for generating the horizontal and amacrine lineages. Intriguingly, characterization of differentiation dynamics reveals that Sip1 has a role in promoting the timely differentiation of retinal interneurons, assuring generation of the proper number of the diverse neuronal and glial cell subtypes that constitute the functional retina in mammals.

Mowat-Wilson syndrome (MOWS) is caused by de novo heterozygous mutation at ZEB2 (SIP1, ZFHX1B) gene, and exhibit moderate to severe intellectual disability (ID), a characteristic facial appearance, epilepsy and other congenital anomalies. Establishing a murine MOWS model is important, not only for investigating the pathogenesis of this disease, but also for identifying compounds that may improve the symptoms. However, because the heterozygous Zeb2 knockout mouse could not be maintained as a mouse line with the inbred C57BL/6 background, it was difficult to use those mice for the study of MOWS. Here, we systematically generated de novo Zeb2 Δex7/+ mice by inducing the Zeb2 mutation in the germ cells using conditional recombination system. The de novo Zeb2 Δex7/+ mice with C57BL/6 background developed multiple defects relevant to MOWS, including craniofacial abnormalities, defective corpus callosum formation and the decreased number of parvalbumin interneurons in the cortex. In behavioral analyses, these mice showed reduced motor activity, increased anxiety and impaired sociability. Notably, during the Barnes maze test, immobile Zeb2 mutant mice were observed over repeated trials. In contrast, neither the mouse line nor the de novo Zeb2 Δex7/+ mice with the closed colony ICR background showed cranial abnormalities or reduced motor activities. These results demonstrate the advantages of using de novo Zeb2 Δex7/+ mice with the C57BL/6 background as the MOWS model. To our knowledge, this is the first time an inducible de novo mutation system has been applied to murine germline cells to produce an animal model of a human congenital disease.

In human embryonic stem cells (ESCs) the transcription factor Zeb2 regulates neuroectoderm versus mesendoderm formation, but it is unclear how Zeb2 affects the global transcriptional regulatory network in these cell-fate decisions. We generated Zeb2 knockout (KO) mouse ESCs, subjected them as embryoid bodies (EBs) to neural and general differentiation and carried out temporal RNA-sequencing (RNA-seq) and reduced representation bisulfite sequencing (RRBS) analysis in neural differentiation. This shows that Zeb2 acts preferentially as a transcriptional repressor associated with developmental progression and that Zeb2 KO ESCs can exit from their naïve state. However, most cells in these EBs stall in an early epiblast-like state and are impaired in both neural and mesendodermal differentiation. Genes involved in pluripotency, epithelial-to-mesenchymal transition (EMT), and DNA-(de)methylation, including Tet1, are deregulated in the absence of Zeb2. The observed elevated Tet1 levels in the mutant cells and the knowledge of previously mapped Tet1-binding sites correlate with loss-of-methylation in neural-stimulating conditions, however, after the cells initially acquired the correct DNA-methyl marks. Interestingly, cells from such Zeb2 KO EBs maintain the ability to re-adapt to 2i + LIF conditions even after prolonged differentiation, while knockdown of Tet1 partially rescues their impaired differentiation. Hence, in addition to its role in EMT, Zeb2 is critical in ESCs for exit from the epiblast state, and links the pluripotency network and DNA-methylation with irreversible commitment to differentiation. Stem Cells 2017;35:611-625.

BACKGROUND

Smad-interacting protein 1 (also named Zeb2 and Zfhx1b) is a transcription factor that plays an important role in neuronal development and, when mutated, causes Mowat-Wilson syndrome (MWS). A corresponding mouse model carrying a heterozygous Zeb2 deletion was comprehensively analysed in the German Mouse Clinic. The most prominent phenotype was the reduced pain sensitivity. In this study, we investigated the role of Zeb2 in inflammatory and neuropathic pain.

METHODS

For this, we tested mutant Zeb2 animals in different models of inflammatory pain like abdominal constriction, formalin and carrageenan test. Furthermore, we studied the pain reactivity of the mice after peripheral nerve ligation. To examine the nociceptive transmission of primary sensory dorsal root ganglia (DRG) neurons, we determined the neuronal activity in the spinal dorsal horn after the formalin test using staining of c-Fos. Next, we characterized the neuronal cell population in the DRGs and in the sciatic nerve to study the effect of the Zeb2 mutation on peripheral nerve morphology.

RESULTS

The present data show that Zeb2 is involved in the development of primary sensory DRG neurons, especially of C- and Aδ fibres. These alterations contribute to a hypoalgesic phenotype in inflammatory but not in neuropathic pain in these Zeb2(+/-) mice.

CONCLUSIONS

Our data suggest that the under-reaction to pain observed in MWS patients results from a reduced responsivity to nociceptive stimulation rather than an inability to communicate discomfort.

Zeb2 is a homeodomain transcription factor that plays pleiotropic functions during embryogenesis, but its role for midbrain dopaminergic (mDA) neuron development is unknown. Here we report that Zeb2 is highly expressed in progenitor cells in the ventricular zone of the midbrain floor plate and downregulated in postmitotic neuroblasts. Functional experiments show that Zeb2 expression in the embryonic ventral midbrain is dynamically regulated by a negative feedback loop that involves miR-200c. We also find that Zeb2 overexpression reduces the levels of CXCR4, NR4A2, and PITX3 in the developing ventral midbrain in vivo, resulting in migration and mDA differentiation defects. This phenotype was recapitulated by miR-200c knockdown, suggesting that the Zeb2-miR-200c loop prevents the premature differentiation of mDA progenitors into postmitotic cells and their migration. Together, our study establishes Zeb2 and miR-200c as critical regulators that maintain the balance between mDA progenitor proliferation and neurogenesis.

Breast cancer is the most common cancer in women worldwide and can be classified into multiple subtypes, including triple-negative breast cancer (TNBC). TNBC is more aggressive than other types of breast cancer and has a poor prognosis. However, excluding chemotherapy, the treatment of TNBC does not involve targeted therapy. The dysregulated expression of lncRNAs plays a vital role in the development of numerous cancers. Thus, the aim of this meta-analysis is to determine the functional roles of lncRNAs in TNBC. We performed a systematic search for articles related to TNBC using multiple online databases, including PubMed, EMBASE, Web of Science, and Science-Direct. We collated pooled hazard ratios with 95% confidence interval to estimate the prognostic value of lncRNAs. We assessed the quality of studies using the Newcastle-Ottawa scale. Data were collected from cohort studies that compared overall survival, disease-free survival, and relapse-free survival between patients with high and patients with low expression of lncRNAs. Using 2,192 samples from 21 studies, we observed a correlation between poor prognosis and the upregulation of 14 lncRNAs (LINC00173, HUMT, HOTAIR, LUCAT1, HIF1A-AS2, ZEB2-AS1, NAMPT-AS, DANCR, LINC01638, ZNF469-3, AFAP1-AS1, ANRIL, MALAT1, and HULC) and downregulation of four lncRNAs (MIR503HG, NEF, TC0NS_12_00002973, and GAS5). The pooled hazard ratios for the correlation between differentially expressed lncRNAs and overall, disease-free, and relapse-free survival were 2.38 (2.03-2.78), 2.19 (1.51-3.16), and 3.19 (0.81-12.53), respectively. This meta-analysis shows that the expression of candidate lncRNAs may reliably predict the prognosis of patients with TNBC.

A model of K-Ras-initiated lung cancer was used to follow the transition of precancerous adenoma to adenocarcinoma. In hypoxic, Tgf-β1-rich interiors of adenomas, we show that adenoma cells divide asymmetrically to produce cancer-generating cells highlighted by epithelial mesenchymal transition and a CD44/Zeb1 loop. In these cells, Zeb1 represses the Smad inhibitor Zeb2/Sip1, causing Pten loss and launching Tgf-β1 signaling that drives nuclear translocation of Yap1. Surprisingly, the nuclear polarization of transcription factors during mitosis establishes parent and daughter fates prior to cytokinesis in sequential asymmetric divisions that generate cancer cells from precancerous lesions. Mutation or knockdown of Zeb1 in the lung blocked the production of CD44hi, Zeb1hi cancer-generating cells from adenoma cells. A CD44/Zeb1 loop then initiates two-step transition of precancerous cells to cancer cells via a stable intermediate population of cancer-generating cells. We show these initial cancer-generating cells are independent of cancer stem cells generated in tumors by p53-regulated reprogramming of existing cancer cells.

Members of microRNA-200 (miRNA-200) family have a regulatory role in epithelial to mesenchymal transition (EMT) by suppressing Zeb1 and Zeb2 expression. Consistent with its role in suppressing EMT, Hsa-miR-200c-3p (miR-200c), a member of miR-200 family is poorly expressed in mesenchymal-like triple-negative breast cancer (TNBC) cells and ectopic miR-200c expression suppresses cell migration. In this study, we demonstrated that miR-200c potently inhibited TNBC cell growth and tumor development in a mechanism distinct from its ability to downregulate Zeb1 and Zeb2 expression, because silencing them only marginally affected TNBC cell growth. We identified phosphodiesterase 7B (PDE7B) as a bona fide miR-200c target. Importantly, miR-200c-led inhibition in cell growth and tumor development was prevented by forcing PDE7B transgene expression, while knockdown of PDE7B effectively inhibited cell growth. These results suggest that miR-200c inhibits cell growth by targeting PDE7B mRNA. To elucidate mechanism underlying miR-200c/PDE7B regulation of TNBC cell growth, we showed that cAMP concentration was lower in TNBC cells compared with estrogen receptor-positive (ER + ) cells, and that both miR-200c and PDE7B siRNAs were able to increase cAMP concentration in TNBC cells. High level of cellular cAMP has been shown to induce cell cycle arrest and apoptosis in TNBC cells. Our observation that ectopic expression of miR-200c triggered apoptosis indicates that it does so by elevating level of cellular cAMP. Analysis of breast tumor gene expression datasets revealed an inverse association between miR-200c and PDE7B expression. Especially, both low miR-200c and high PDE7B expression were correlated with poor survival of breast cancer patients. Our study supports a critical role of miR-200c/PDE7B relationship in TNBC tumorigenesis.

Breast cancer is the most common invasive cancer in women with the highest number of related deaths which is caused by distal metastasis. Recently, integrated analysis of gene expression profile suggested widespread gene dysregulation in various types of cancer. Research in the past decade has focused on long non‑coding RNAs (lncRNAs), particularly in cell proliferation, tumor progression and metastasis. OPA‑interacting protein 5 antisense transcript 1 (OIP5‑AS1) is an evolutionarily conserved long non‑coding RNA that has been linked to oncogenesis in multiple cancers. In breast cancer, dysregulation of OIP5‑AS1 was reported but the precise role in cancer development and progression remains unclear. In the present study, using small interfering RNA (siRNA) targeting OIP5‑AS1, it was shown that knockdown of OIP5‑AS1 was associated with alteration of EMT markers and suppressed migration and invasion of breast cancer cells. Among the EMT‑related transcription factors, ZEB1 and ZEB2 were significantly downregulated with OIP5‑AS1 knockdown. Computational analysis and a dual‑luciferase reporter system identified miR‑340‑5p was the target gene for OIP5‑AS1. Further experiments verified the function of OIP5‑AS1 in cell invasion was dependent on miR‑340a‑5p through regulating target gene ZEB2. In vivo study demonstrated that overexpressing OIP5‑AS1 in breast cancer cells promoted lung metastasis in nude mice. The findings of the present study revealed the mechanism of OIP5‑AS1 in breast cancer metastasis. Overall, our study may provide a potential therapeutic target for breast cancer metastasis.

Alterations in gene expression are key events in disease etiology and risk. Poor reproducibility in detecting differentially expressed genes across studies suggests individual genes may not be sufficiently informative for complex diseases, such as myocardial infarction (MI). Rather, dysregulation of the 'molecular network' may be critical for pathogenic processes. Such a dynamic network can be built from pairwise non-linear interactions.

We investigate non-linear interactions represented in mRNA expression profiles that integrate genetic background and environmental factors. Using logistic regression, we test the association of individual GWAS-based candidate genes and non-linear interaction terms (between these mRNA expression levels) with MI. Based on microarray data in CATHGEN (CATHeterization in GENetics) and FHS (Framingham Heart Study), we find individual genes and pairs of mRNAs, encoded by 41 MI candidate genes, with significant interaction terms in the logistic regression model. Two pairs replicate between CATHGEN and FHS (CNNM2|GUCY1A3 and CNNM2|ZEB2). Analysis of RNAseq data from GTEx (Genotype-Tissue Expression) shows that 20 % of these disease-associated RNA pairs are co-expressed, further prioritizing significant interactions. Because edges in sparse co-expression networks formed solely by the 41 candidate genes are unlikely to represent direct physical interactions, we identify additional RNAs as links between network pairs of candidate genes. This approach reveals additional mRNAs and interaction terms significant in the context of MI, for example, the path CNNM2|ACSL5|SCARF1|GUCY1A3, characterized by the common themes of magnesium and lipid processing.

The results of this study support a role for non-linear interactions between genes in MI and provide a basis for further study of MI systems biology. mRNA expression profiles encoded by a limited number of candidate genes yield sparse networks of MI-relevant interactions that can be expanded to include additional candidates by co-expression analysis. The non-linear interactions observed here inform our understanding of the clinical relevance of gene-gene interactions in the pathophysiology of MI, while providing a new strategy in developing clinical biomarker panels.

As a transcription factor, zinc finger E-box binding homeobox 2 (ZEB2) includes multiple functional domains which interact with kinds of transcriptional co-effectors. It has been reported that ZEB2 was involved in signal transduction and multiple cellular functions. However, the functional role of ZEB2 in inflammation is still obscure. The aim of the current study is to explore the function of ZEB2 in inflammation cytokine secretion and the role of the nuclear factor-κB (NF-κB) signaling pathway in lipopolysaccharide (LPS)-induced human proximal tubule cell line (HK-2) cells. Our result demonstrated that expression of ZEB2 was significantly downregulated and expression of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) was upregulated in response to LPS. Meanwhile, knockdown of ZEB2 by transfecting siRNA increased TNF-α and IL-6 secretion. Overexpression of ZEB2 resulted in a decrease of TNF-α and IL-6 secretion in HK-2 cells. Additionally, Western blot analysis indicated that ZEB2 suppressed the activation of the NF-κB signaling pathway via downregulating the levels of phosphorylated p65 and IκBα compared with LPS stimulation. Collectively, our data demonstrated that ZEB2 attenuated LPS-induced inflammation cytokine secretion possibly through suppressing the NF-κB signaling pathway.

ZEB1 and ZEB2 are zinc-finger E homeobox-binding transcription factors best known for their role in driving epithelial to mesenchymal transition. However, in recent years our understanding of these two transcription factors has broadened, and it is now clear that they are expressed by a variety of immune cells of both myeloid and lymphoid lineages, including dendritic cells, macrophages, monocytes, B, T, and NK cells. In these cells, ZEBs function to regulate important transcriptional networks necessary for cell differentiation, maintenance, and function. Here, we review the current understanding of ZEB regulation across immune cell lineages, particularly in mice, highlighting present gaps in our knowledge. We also speculate on important questions for the future.

Colon cancer is among the most commonly diagnosed cancers in the United States with an estimated 97220 new cases expected by the end of 2018. It affects 1.2 million people around the world and is responsible for about 0.6 million deaths every year. Despite decline in overall incidence and mortality over the past 30 years, there continues to be an alarming rise in early-onset colon cancer cases (< 50 years). Patients are often diagnosed at late stages of the disease and tend to have poor survival. We previously showed that the WNT "gatekeeper" gene, secreted frizzled-related protein 4 (SFRP4), is over-expressed in early-onset colon cancer. SFRP4 is speculated to play an essential role in cancer by inhibiting the epithelial mesenchymal transition (EMT).

To investigate the correlation between SFRP4 expression and EMT-linked genes in colon cancer and how it affects patient survival.

SFRP4 expression relative to that of EMT-linked genes and survival analysis were performed using the University of California Santa Cruz Cancer Browser interface.

SFRP4 was found to be co-expressed with the EMT-linked markers CDH2, FN1, VIM, TWIST1, TWIST2, SNAI1, SNAI2, ZEB1, ZEB2, POSTN, MMP2, MMP7, MMP9, and COL1A1. SFRP4 expression negatively correlated with the EMT-linked suppressors CLDN4, CLDN7, TJP3, MUC1, and CDH1. The expression of SFRP4 and the EMT-linked markers was higher in mesenchymal-like samples compared to epithelial-like samples which potentially implicates SFRP4-EMT mechanism in colon cancer. Additionally, patients overexpressing SFRP4 presented with poor overall survival (P = 0.0293).

Considering the implication of SFRP4 in early-onset colon cancer, particularly in the context of EMT, tumor metastasis, and invasion, and the effect of increased expression on colon cancer patient survival, SFRP4 might be a potential biomarker for early-onset colon cancer that could be targeted for diagnosis and/or disease therapy.

The molecular mechanisms underlying the pathogenesis of diffuse-type gastric cancer (DGC) have not been adequately explored due to a scarcity of appropriate animal models. A recently developed tool well suited for this line of investigation is the Pdx-1-Cre;Cdh1F/+ ;Trp53F/F ;Smad4F/F (pChe PS) mouse model that spontaneously develops metastatic DGC showing nearly complete E-cadherin loss. Here, we performed a proteogenomic analysis to uncover the molecular changes induced by the concurrent targeting of E-cadherin, p53, and Smad4 loss. The gene expression profiles of mouse DGCs and in vivo gastric phenotypes from various combinations of gene knockout demonstrated that these mutations collaborate to activate cancer-associated pathways to generate aggressive DGC. Of note, WNT-mediated epithelial-to-mesenchymal transition (EMT) and extracellular matrix (ECM)-cytokine receptor interactions were prominently featured. In particular, the WNT target gene osteopontin (OPN) that functions as an ECM cytokine is highly upregulated. In validation experiments, OPN contributed to DGC stemness by promoting cancer stem cell (CSC) survival and chemoresistance. It was further found that Bcl-xL acts as a targetable downstream effector of OPN in DGC CSC survival. In addition, Zeb2 and thymosin-β4 (Tβ4) were identified as prime candidates as suppressors of E-cadherin expression from the remaining Cdh1 allele during DGC development. Specifically, Tβ4 suppressed E-cadherin expression and anoikis while promoting cancer cell growth and migration. Collectively, these proteogenomic analyses broaden and deepen our understanding of the contribution of key driver mutations in the stepwise carcinogenesis of DGC through novel effectors, namely OPN and Tβ4.

The epithelial-mesenchymal transition (EMT) is the crucial step that cancer cells must pass before they can undergo metastasis. The transition requires the activity of complex functional networks that downregulate properties of the epithelial phenotype and upregulate characteristics of the mesenchymal phenotype. The networks frequently include reciprocal repressions between transcription factors (TFs) driving the EMT and microRNAs (miRs) inducing the reverse process, termed mesenchymal-epithelial transition (MET). In this work we develop four kinetic models that are based on experimental data and hypotheses describing how autocrine transforming growth factor-β (TGF-β) signal transduction induces and maintains an EMT by upregulating the TFs ZEB1 and ZEB2 which repress the expression of the miR-200b/c family members. After successful model calibration we validate our models by predicting requirements for the maintenance of the mesenchymal steady state which agree with experimental data. Finally, we apply our validated kinetic models for the design of experiments in cancer therapy. We demonstrate how steady state properties of the kinetic models, combined with data from tumor-derived cell lines of individual patients, can predict the minimal amount of an inhibitor to induce a MET.

Infection with herpes simplex virus-1 (HSV-1) brings numerous changes in cellular gene expression. Levels of most host mRNAs are reduced, limiting synthesis of host proteins, especially those involved in antiviral defenses. The impact of HSV-1 on host microRNAs (miRNAs), an extensive network of short non-coding RNAs that regulate mRNA stability/translation, remains largely unexplored. Here we show that transcription of the miR-183 cluster (miR-183, miR-96, and miR-182) is selectively induced by HSV-1 during productive infection of primary fibroblasts and neurons. ICP0, a viral E3 ubiquitin ligase expressed as an immediate-early protein, is both necessary and sufficient for this induction. Nuclear exclusion of ICP0 or removal of the RING (really interesting new gene) finger domain that is required for E3 ligase activity prevents induction. ICP0 promotes the degradation of numerous host proteins and for the most part, the downstream consequences are unknown. Induction of the miR-183 cluster can be mimicked by depletion of host transcriptional repressors zinc finger E-box binding homeobox 1 (ZEB1)/-crystallin enhancer binding factor 1 (δEF1) and zinc finger E-box binding homeobox 2 (ZEB2)/Smad-interacting protein 1 (SIP1), which we establish as new substrates for ICP0-mediated degradation. Thus, HSV-1 selectively stimulates expression of the miR-183 cluster by ICP0-mediated degradation of ZEB transcriptional repressors.

Immature neurons generated by the subpallial MGE tangentially migrate to the cortex where they become parvalbumin-expressing (PV+) and somatostatin (SST+) interneurons. Here, we show that the Sp9 transcription factor controls the development of MGE-derived cortical interneurons. SP9 is expressed in the MGE subventricular zone and in MGE-derived migrating interneurons. Sp9 null and conditional mutant mice have approximately 50% reduction of MGE-derived cortical interneurons, an ectopic aggregation of MGE-derived neurons in the embryonic ventral telencephalon, and an increased ratio of SST+/PV+ cortical interneurons. RNA-Seq and SP9 ChIP-Seq reveal that SP9 regulates MGE-derived cortical interneuron development through controlling the expression of key transcription factors Arx, Lhx6, Lhx8, Nkx2-1, and Zeb2 involved in interneuron development, as well as genes implicated in regulating interneuron migration Ackr3, Epha3, and St18. Thus, Sp9 has a central transcriptional role in MGE-derived cortical interneuron development.

Several subtypes of high-grade endometrial carcinomas (ECs) contain an undifferentiated component of non-epithelial morphology, including undifferentiated and dedifferentiated carcinomas and carcinosarcomas (CSs). The mechanism by which an EC undergoes dedifferentiation has been the subject of much debate. The epithelial-mesenchymal transition (EMT) is one of the mechanisms implicated in the transdifferentiation of high-grade carcinomas. To improve our understanding of the role of EMT in these tumors, we studied a series of 89 carcinomas including 14 undifferentiated/dedifferentiated endometrial carcinomas (UECs/DECs), 49 CSs (21 endometrial, 29 tubo-ovarian and peritoneal), 17 endometrioid carcinomas (grade 1-3), and 9 high-grade serous carcinomas of the uterus, using a panel of antibodies targeting known epithelial markers (Pan-Keratin AE1/AE3 and E-cadherin), mesenchymal markers (N-cadherin), EMT transcription factors (TFs) (ZEB1, ZEB2, TWIST1), PAX8, estrogen receptors (ER), progesterone receptors (PR), and the p53 protein. At least one of the three EMT markers (more frequently ZEB1) was positive in the sarcomatous component of 98% (n = 48/49) of CSs and 98% (n = 13/14) of the undifferentiated component of UEC/DEC. In addition, 86% of sarcomatous areas of CSs and 79% of the undifferentiated component of UEC/DEC expressed all three EMT-TFs. The expression of these markers was associated with the loss of or reduction in epithelial markers (Pan-keratin, E-cadherin), PAX8, and hormone receptors. In contrast, none of the endometrioid and serous endometrial carcinomas expressed ZEB1, while 6% and 36% of endometrioid and 11% and 25% of serous carcinomas focally expressed ZEB2 and TWIST1, respectively. Although morphologically different, EMT appears to be implicated in the dedifferentiation in both CSs and UEC/DEC. Indeed, we speculate that the occurrence of EMT in a well differentiated endometrioid carcinoma may consecutively lead to a dedifferentiated and undifferentiated carcinoma, while in a type II carcinoma, it may result in a CS.

The specific function of microRNA-545 (miR-545) has been reported to regulate the development of human cancers. However, the effect of miR-545 is still unclear in non-small cell lung cancer (NSCLC). Hence, this study explored the molecular mechanism of miR-545 in NSCLC. The expression levels of miR-545 and ZEB2 were measured through reverse transcription-quantitative polymerase chain reaction (RT-qPCR) assay. The protein expression was detected by western blotting. Dual luciferase assay was applied to evaluate the relationship between miR-545 and zinc finger E-box-binding homeobox 2 (ZEB2). MTT and Transwell assays were used to investigate the function of miR-545 in NSCLC. The expression of miR-545 was decreased in NSCLC tissues. The overexpression of miR-545 suppressed the migration, invasion and proliferation of NSCLC cells. Furthermore, ZEB2 was a direct target gene of miR-545. The knockout of ZEB2 suppressed the development of NSCLC. miR-545 inhibited the progression of NSCLC through targeting ZEB2. Moreover, miR-545 repressed the development of NSCLC via blocking EMT and Wnt/β-catenin pathway. In conclusion, miR-545 inhibited the progression of NSCLC through targeting ZEB2 and blocking EMT and Wnt/β-catenin pathway.