Authors: Liffers ST; Munding JB; Vogt M; Kuhlmann JD; Verdoodt B; Nambiar S; Maghnouj A; Mirmohammadsadegh A; Hahn SA; Tannapfel A
Abstract: MicroRNAs (miRNAs: short non-coding RNAs) are emerging as a class of potential novel tumor markers, as their dysregulation is being increasingly reported in various types of cancers. In the present study, we investigated the transcription status of miRNA-148a (miR-148a) in human pancreatic ductal adenocarcinoma (PDAC) and its role in the regulation of the dual specificity protein phosphatase CDC25B. We observed that miR-148a exhibited a significant 4-fold down-regulation in PDAC as opposed to normal pancreatic ductal cells. In addition, we observed that stable lentiviral-mediated overexpression of miR-148a in the pancreatic cancer cell line IMIM-PC2, inhibited tumor cell growth and colony formation. Furthermore, CDC25B was identified as a potential target of miR-148a by in silico analysis using PicTar, Targetscan and miRanda in conjunction with gene ontology analysis. The proposed interaction between miR-148a and the 3' untranslated region (UTR) of CDC25B was verified by in-vitro luciferase assays. We demonstrate that the activity of a luciferase reporter containing the 3'UTR of CDC25B was repressed in the presence of miR-148a mimics, confirming that miR-148a targets the 3'UTR of CDC25B. Finally, CDC25B was down-regulated at the protein level in miR-148a overexpressing IMIM-PC2-cells, and in transiently transfected pancreatic cell lines (as detected by Western blot analysis), as well as in patient tumor samples (as detected by immunohistochemistry). In summary, we identified CDC25B as a novel miR-148a target which may confer a proliferative advantage in PDAC.
Keywords: 3' Untranslated Regions; Carcinoma, Pancreatic Ductal/*metabolism/pathology/physiopathology; Cell Line, Tumor; Cell Proliferation; Cell Survival/*genetics; *Down-Regulation; Gene Expression Regulation; HEK293 Cells; Humans; MicroRNAs/*metabolism; Pancreatic Neoplasms/*metabolism/pathology/physiopathology; Transfection; Up-Regulation; cdc25 Phosphatases/genetics/metabolism|
Journal: Laboratory investigation; a journal of technical methods and pathology Volume: 91 Issue: 10 Pages: 1472-9 Date: June 29, 2011 PMID: 21709669 |
Liffers ST, Munding JB, Vogt M, Kuhlmann JD, Verdoodt B, Nambiar S, Maghnouj A, Mirmohammadsadegh A, Hahn SA, Tannapfel A (2011) MicroRNA-148a is down-regulated in human pancreatic ductal adenocarcinomas and regulates cell survival by targeting CDC25B. Laboratory investigation; a journal of technical methods and pathology 91: 1472-9.
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