title: MicroRNA-93 promotes ovarian granulosa cells proliferation through targeting CDKN1A in polycystic ovarian syndrome.
abstract: BACKGROUND
  MicroRNAs (miRNAs) are small, noncoding RNAs that negatively regulate gene expression post-transcriptionally. Whether differently expressed miRNAs contribute to promoting granulosa cell proliferation in polycystic ovarian syndrome disease (PCOS) remains unknown.
  
  
  OBJECTIVE
  We explored whether certain miRNAs are involved in the ovarian dysfunction of PCOS and the mechanism of increased granulosa cells proliferation. Patients and Cells: miRNA expression was analyzed in excised ovarian cortexes from 16 women with PCOS and 8 non-PCOS. An immortalized human granulosa (KGN) cell was used for the mechanism study.
  
  
  METHODS
  Expressions of miRNAs in ovarian cortexes were measured using qRT-PCR and KGN granulosa cells were cultured for proliferation assays after overexpression or inhibition of miR-93 or after insulin treatment. Bioinformatics were used to identify the potential miRNA targets. Protein expression analysis, luciferase assays, and rescue assays were used to confirm the substrate of miR-93.
  
  
  RESULTS
  MiR-93 expression was higher in PCOS ovarian cortex and its identified target, CDKN1A, was downregulated. MiR-93 overexpression promoted cell proliferation and G1 to S transition. Knocking down CDKN1A promoted cell growth and cell cycle progression in granulosa cells, and CDKN1A re-introduction reversed the promotional role of miR-93. High concentrations of insulin induced upregulation of miR-93, stimulated KGN cells proliferation and reduced CDKN1A expression.
  
  
  CONCLUSIONS
  miR-93 was increased in PCOS granulosa cells and targeted CDKN1A to promote proliferation and cell cycle progression. Insulin could upregulate the expression of miR-93 and stimulate cell proliferation. This might provide a new insight into the dysfunction of granulosa cells in PCOS.
authors.affiliation: Department of Obstetrics and Gynecology (L.J., J.H., L.L., Y.C., X.C., X.Z., D.Y.), Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120 China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Jiang
authors.forename: Jia
authors.initials: J
authors.lastname: Huang
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.forename: Yaxiao
authors.initials: Y
authors.lastname: Chen
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Chen
authors.forename: Xiaomiao
authors.initials: X
authors.lastname: Zhao
authors.forename: Dongzi
authors.initials: D
authors.lastname: Yang
mesh_terms: D002453:Cell Cycle / Q000235:genetics; D002460:Cell Line; D049109:Cell Proliferation / Q000235:genetics*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism*; D015536:Down-Regulation; D005260:Female; D006107:Granulosa Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D011085:Polycystic Ovary Syndrome / Q000235:genetics / Q000378:metabolism*
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; C543350:MIRN93 microRNA, human; D035683:MicroRNAs