title: MicroRNA-148a is down-regulated in human pancreatic ductal adenocarcinomas and regulates cell survival by targeting CDC25B.
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.
authors.affiliation: Institute of Pathology, Ruhr-University Bochum, Bochum, Germany.
authors.forename: Sven-T
authors.initials: ST
authors.lastname: Liffers
authors.forename: Johanna B
authors.initials: JB
authors.lastname: Munding
authors.forename: Markus
authors.initials: M
authors.lastname: Vogt
authors.forename: Jan D
authors.initials: JD
authors.lastname: Kuhlmann
authors.forename: Berlinda
authors.initials: B
authors.lastname: Verdoodt
authors.forename: Sandeep
authors.initials: S
authors.lastname: Nambiar
authors.forename: Abdelouahid
authors.initials: A
authors.lastname: Maghnouj
authors.forename: Alireza
authors.initials: A
authors.lastname: Mirmohammadsadegh
authors.forename: Stephan A
authors.initials: SA
authors.lastname: Hahn
authors.forename: Andrea
authors.initials: A
authors.lastname: Tannapfel
mesh_terms: D020413:3' Untranslated Regions; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival / Q000235:genetics*; D015536:Down-Regulation; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology; D014162:Transfection; D015854:Up-Regulation; D020687:cdc25 Phosphatases / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; C550570:MIRN148 microRNA, human; D035683:MicroRNAs; C517008:CDC25B protein, human; D020687:cdc25 Phosphatases