title: miRConnect 2.0: identification of oncogenic, antagonistic miRNA families in three human cancers.
abstract: BACKGROUND
  Based on their function in cancer micro(mi)RNAs are often grouped as either tumor suppressors or oncogenes. However, miRNAs regulate multiple tumor relevant signaling pathways raising the question whether two oncogenic miRNAs could be functional antagonists by promoting different steps in tumor progression. We recently developed a method to connect miRNAs to biological function by comparing miRNA and gene array expression data from the NCI60 cell lines without using miRNA target predictions (miRConnect).
  
  
  RESULTS
  We have now extended this analysis to three primary human cancers (ovarian cancer, glioblastoma multiforme, and kidney renal clear cell carcinoma) available at the Cancer Genome Atlas (TCGA), and have correlated the expression of the clustered miRNAs with 158 oncogenic signatures (miRConnect 2.0). We have identified functionally antagonistic groups of miRNAs. One group (the agonists), which contains many of the members of the miR-17 family, correlated with c-Myc induced genes and E2F gene signatures. A group that was directly antagonistic to the agonists in all three primary cancers contains miR-221 and miR-222. Since both miR-17 ~ 92 and miR-221/222 are considered to be oncogenic this points to a functional antagonism of different oncogenic miRNAs. Analysis of patient data revealed that in certain patients agonistic miRNAs predominated, whereas in other patients antagonists predominated. In glioblastoma a high ratio of miR-17 to miR-221/222 was predictive of better overall survival suggesting that high miR-221/222 expression is more adverse for patients than high miR-17 expression.
  
  
  CONCLUSIONS
  miRConnect 2.0 is useful for identifying activities of miRNAs that are relevant to primary cancers. The new correlation data on miRNAs and mRNAs deregulated in three primary cancers are available at miRConnect.org.
authors.affiliation: Feinberg School of Medicine, Division Hematology/Oncology, Northwestern University, Chicago, IL 60611, USA.
authors.forename: Youjia
authors.initials: Y
authors.lastname: Hua
authors.forename: Niels
authors.initials: N
authors.lastname: Larsen
authors.forename: Shanker
authors.initials: S
authors.lastname: Kalyana-Sundaram
authors.forename: Jørgen
authors.initials: J
authors.lastname: Kjems
authors.forename: Arul M
authors.initials: AM
authors.lastname: Chinnaiyan
authors.forename: Marcus E
authors.initials: ME
authors.lastname: Peter
mesh_terms: D002292:Carcinoma, Renal Cell / Q000235:genetics* / Q000503:physiopathology; D045744:Cell Line, Tumor; D016000:Cluster Analysis; D058750:Epithelial-Mesenchymal Transition / Q000235:genetics; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D005909:Glioblastoma / Q000235:genetics* / Q000503:physiopathology; D006801:Humans; D007680:Kidney Neoplasms / Q000235:genetics* / Q000503:physiopathology; D035683:MicroRNAs / Q000235:genetics* / Q000502:physiology; D009369:Neoplasms / Q000235:genetics; D009857:Oncogenes / Q000502:physiology; D010051:Ovarian Neoplasms / Q000235:genetics* / Q000503:physiopathology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger; C524941:MIRN17 microRNA, human; C525709:MIR221, human; C525710:MIR222, human