title: Cooperative Effect of miR-141-3p and miR-145-5p in the Regulation of Targets in Clear Cell Renal Cell Carcinoma.
abstract: BACKGROUND
  Due to the poor prognosis for advanced renal cell carcinoma (RCC), there is an urgent need for new therapeutic targets and for prognostic markers to identify high risk tumors. MicroRNAs (miRNAs) are frequently dysregulated in tumors, play a crucial role during carcinogenesis and therefore might be promising new biomarkers. In previous studies, we identified miR-141-3p and miR-145-5p to be downregulated in clear cell RCC (ccRCC). Our objective was to investigate the functional association of these miRNAs, focusing on the cooperative regulation of new specific targets and their role in ccRCC progression.
  
  
  METHODS
  The effect of miR-141-3p and miR-145-5p on cell migration was examined by overexpression in 786-O cells. New targets of both miRNAs were identified by miRWalk, validated in 786-O and ACHN cells and additionally characterized in ccRCC tissue on mRNA and protein level.
  
  
  RESULTS
  In functional analysis, a tumor suppressive effect of miR-141-3p and miR-145-5p by decreasing migration and invasion of RCC cells could be shown. Furthermore, co-overexpression of the miRNAs seemed to result in an increased inhibition of cell migration. Both miRNAs were recognized as post-transcriptional regulators of the targets EAPP, HS6ST2, LOX, TGFB2 and VRK2. Additionally, they showed a cooperative effect again as demonstrated by a significantly increased inhibition of HS6ST2 and LOX expression after simultaneous overexpression of both miRNAs. In ccRCC tissue, LOX mRNA expression was strongly increased compared to normal tissue, allowing also to distinguish between non-metastatic and already metastasized primary tumors. Finally, in subsequent tissue microarray analysis LOX protein expression showed a prognostic relevance for the overall survival of ccRCC patients.
  
  
  CONCLUSIONS
  These results illustrate a jointly strengthening effect of the dysregulated miR-141-3p and miR-145-5p in various tumor associated processes. Focusing on the cooperative effect of miRNAs provides new opportunities for the development of therapeutic strategies and offers novel prognostic and diagnostic capabilities.
authors.affiliation: Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany.|Berlin Institute for Urologic Research, Berlin, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Liep
authors.affiliation: Institute of Pathology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Ergin
authors.initials: E
authors.lastname: Kilic
authors.affiliation: Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Hellmuth A
authors.initials: HA
authors.lastname: Meyer
authors.affiliation: Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
authors.forename: Jonas
authors.initials: J
authors.lastname: Busch
authors.affiliation: Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany.|Berlin Institute for Urologic Research, Berlin, Germany.
authors.forename: Klaus
authors.initials: K
authors.lastname: Jung
authors.affiliation: Department of Urology, Charité - Universitätsmedizin Berlin, Berlin, Germany.|Berlin Institute for Urologic Research, Berlin, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Rabien
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D053208:Kaplan-Meier Estimate; D007680:Kidney Neoplasms / Q000175:diagnosis / Q000235:genetics* / Q000401:mortality; D008297:Male; D035683:MicroRNAs / Q000235:genetics*; D008875:Middle Aged; D060787:Neoplasm Grading; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics*
chemical_list: C533895:MIRN141 microRNA, human; C541010:MIRN145 microRNA, human; D035683:MicroRNAs; D012333:RNA, Messenger