MiRNA-205 modulates cellular invasion and migration via regulating zinc finger E-box binding homeobox 2 expression in esophageal squamous cell carcinoma cells

Background: Esophageal squamous cell carcinoma (ESCC) is often diagnosed at later stages until they are incurable. MicroRNA (miR) is a small, non-coding RNA that negatively regulates gene expression mainly via translational repression. Accumulating evidence indicates that deregulation of miR is associated with human malignancies including ESCC. The aim of this study was to identify miR that could be specifically expressed and exert distinct biological actions in ESCC. Methods: Total RNA was extracted from ESCC cell lines, OE21 and TE10, and a non-malignant human esophageal squamous cell line, Het-1A, and subjected to microarray analysis. Expression levels of miR that showed significant differences between the 2 ESCC and Het-1A cells based on the comprehensive analysis were analyzed by the quantitative reverse transcriptase (RT)-PCR method. Then, functional analyses, including cellular proliferation, apoptosis and Matrigel invasion and the wound healing assay, for the specific miR were conducted. Using ESCC tumor samples and paired surrounding non-cancerous tissue obtained endoscopically, the association with histopathological differentiation was examined with quantitative RT-PCR. Results: Based on the miR microarray analysis, there were 14 miRs that showed significant differences (more than 2-fold) in expression between the 2 ESCC cells and non-malignant Het-1A. Among the significantly altered miRs, miR-205 expression levels were exclusively higher in 5 ESCC cell lines examined than any other types of malignant cell lines and Het-1A. Thus, miR-205 could be a specific miR in ESCC. Modulation of miR-205 expression by transfection with its precursor or anti-miR-205 inhibitor did not affect ESCC cell proliferation and apoptosis, but miR-205 was found to be involved in cell invasion and migration. Western blot revealed that knockdown of miR-205 expression in ESCC cells substantially enhanced expression of zinc finger E-box binding homeobox 2, accompanied by reduction of E-cadherin, a regulator of epithelial mesenchymal transition. The miR-205 expression levels were not associated with histological differentiation of human ESCC. Conclusions: These results imply that miR-205 is an ESCC-specific miR that exerts tumor-suppressive activities with EMT inhibition by targeting ZEB2.Kayoko Matsushima... Gregory J Goodall... et al

Tecnologies lingüístiques per a llengües minoritzades el cas de l'alguerès

La tecnologia pot jugar un rol decisiu en els processos de normalització lingüística. La creació de recursos lingüístics -amb el potencial formatiu o de disseminació que comporten, especialment en llengües en procés d'estandardització- és una possibilitat que cal tenir present en dissenyar estratègies per a la normalització. Aquest article se proposa contribuir al procés de normalització de l'alguerès, varietat parlada a l'Alguer (Sardenya) per unes dotze mil persones, mitjançant una anàlisi de les obres de consulta digitals i dels recursos lingüístics existents. En la primera part se proporcionen dades sobre el context sociolingüístic i se fa un estat de la qüestió sobre el procés d'estandardització de l'alguerès. La segona part mira d'identificar, amb referències a altres comunitats lingüístiques en situacions similars, accions en l'àmbit tecnològic que podrien dur-se a terme en paral·lel al procés d'estandardització de l'alguerès.Technology can play a decisive role in linguistic normalisation processes. The creation of linguistic resources (with the potential they have for education or to encourage the spread of languages, especially those in the process of standardisation) is a possibility that should be taken into account in designing normalisation strategies. This article proposes contributing to the process of normalising Algherese, a variety spoken in Alghero (Sardinia) by around twelve thousand people, through an analysis of digital reference works and existing linguistic resources. The first part provides data about the sociolinguistic context and establishes the current situation regarding the process of standardising Algherese. The second part seeks to identify, with references to other language communities in similar situations, actions in the technological sphere that could be carried out in parallel with the process of standardising Algheres

Isocitrate Dehydrogenase Mutations Promote a ZEB1/mir-200-dependent Epithelial Mesenchymal Transition

Mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) occur in a variety of tumor types, and these mutations result in production of the oncometabolite, 2-hydroxyglutarate (2-HG). However it is not clear how mutant IDH and 2-HG alter signaling to promote cancer.To address this question, we created a panel of isogenic IDH1/2 wild-type and mutant colon carcinoma and mammary epithelial cell lines. From this, differences were noted in the ability of different IDH2 mutations to cause robust 2-HG accumulation. We find that IDH1/2 mutants producing high levels of intracellular 2-HG cause an epithelial mesenchymal transition (EMT)-like phenotype, characterized by changes in EMT-related gene expression as well as changes in cellular morphology. Addition of exogenous 2-HG to an IDH wild-type cell line is sufficient on its own to induce an EMT-like phenotype. The mutant IDH-induced EMT is dependent on upregulation of the transcription factor ZEB1 and downregulation of the mir-200 family of micro RNA’s. Knockdown of IDH1 in IDH1 R132H mutant cells is sufficient to reverse the EMT-like phenotype, demonstrating the necessity for continued expression of mutant IDH and 2-HG to maintain this phenotype. These results suggest mutant IDH proteins reversibly deregulate discreet signaling pathways that contribute to tumorigenesis

An F876l mutation in androgen receptor confers genetic and phenotypic resistance to MDV3100 (Enzalutamide)

Castration-resistant prostate cancer (CRPC) is the most aggressive, incurable form of prostate cancer. MDV3100 (enzalutamide), an antagonist of the androgen receptor (AR), was approved for clinical use in men with metastatic CRPC. Although this compound showed clinical efficacy, many initial responders later developed resistance. To uncover relevant resistant mechanisms, we developed a model of spontaneous resistance to MDV3100 in LNCaP prostate cancer cells. Detailed characterization revealed that emergence of an F876L mutation in AR correlated with blunted AR response to MDV3100 and sustained proliferation during treatment. Functional studies confirmed that ARF876L confers an antagonist-to-agonist switch that drives phenotypic resistance. Finally, treatment with distinct antiandrogens orcyclin-dependent kinase (CDK)4/6 inhibitors effectively antagonized ARF876L function. Together, these findings suggest that emergence of F876L may (i) serve as a novel biomarker for prediction of drug sensitivity, (ii) predict a "withdrawal" response to MDV3100, and (iii) be suitably targeted with other antiandrogens or CDK4/6 inhibitors. SIGNIFICANCE: We uncovered an F876L agonist-switch mutation in AR that confers genetic and phenotypic resistance to the antiandrogen drug MDV3100. On the basis of this finding, we propose new therapeutic strategies to treat patients with prostate cancer presenting with this AR mutation. © 2013 American Association for Cancer Research

The miR-200 Family Inhibits Epithelial-Mesenchymal Transition and Cancer Cell Migration by Direct Targeting of E-cadherin Transcriptional Repressors ZEB1 and ZEB2*

MicroRNAs are small non-coding RNA molecules that can regulate gene expression by interacting with multiple mRNAs and inducing either translation suppression or degradation of mRNA. Recently, several miRNAs were identified as either promoters or suppressors of metastasis. However, it is unclear in which step(s) of the multistep metastatic cascade these miRNAs play a defined functional role. To study the functional importance of miRNAs in epithelial-mesenchymal transition (EMT), a process thought to initiate metastasis by enhancing the motility of tumor cells, we used a well established in vitro EMT assay: transforming growth factor-β-induced EMT in NMuMG murine mammary epithelial cells. We found that members of the miR-200 family, organized as two clusters in the genome, were repressed during EMT. Overexpression of each miRNA individually or as clusters in NMuMG cells hindered EMT by enhancing E-cadherin expression through direct targeting of ZEB1 and ZEB2, which encode transcriptional repressors of E-cadherin. In the 4TO7 mouse carcinoma cell line, which expresses low levels of endogenous E-cadherin and displays a mesenchymal phenotype, ectopic expression of the miR-200 family miRNAs significantly increased E-cadherin expression and altered cell morphology to an epithelial phenotype. Furthermore, ectopic expression of each miR-200 miRNA cluster significantly reduced the in vitro motility of 4TO7 cells in migration assays. These results suggested that loss of expression of the miR-200 family members may play a critical role in the repression of E-cadherin by ZEB1 and ZEB2 during EMT, thereby enhancing migration and invasion during cancer progression