title: Post-transcriptional regulation by microrna-21 and let-7a microRNA in paediatric cholesteatoma.
abstract: This study investigated the role of microRNA-21 (miR-21) and let-7a microRNA in paediatric and adult cholesteatoma. Total RNA and protein were isolated from the cholesteatoma specimens and normal skin of 10 adults and 10 children. Levels of miR-21 and let-7a microRNA were  assessed by real-time reverse transcription-polymerase chain reaction, and levels of phosphatase and tensin homologue (PTEN), programmed cell death 4 (PDCD4) and high mobility group AT-hook 2 (HMGA2) protein were assessed by Western blot analysis. Levels of miR-21 and let-7a microRNA  were significantly higher in cholesteatoma tissue compared with normal skin, especially in paediatric patients. PTEN, PDCD4 and HMGA2 protein levels were significantly lower in paediatric versus adult cholesteatoma patients. It is possible that upregulation of miR-21 leads to higher tumour  cell proliferation and invasion of cholesteatoma in children than adults, and the benign nature of cholesteatoma may be due to a balance between let-7a microRNA and miR-21. These data may help to identify targets for miRNA- and protein-based therapeutic interventions for the non-surgical  or adjunctive treatment of cholesteatoma.
authors.affiliation: Department of Otolaryngology, Institute of Clinical Medicine, The First Affiliated Hospital of Zhengzhou University, 1 JianShe East Road, ZhengZhou, Henan 450052, China. chenxiaohua617@hotmail.com
authors.forename: X
authors.initials: X
authors.lastname: Chen
authors.forename: Z
authors.initials: Z
authors.lastname: Qin
mesh_terms: D000293:Adolescent; D000328:Adult; D015153:Blotting, Western; D002648:Child; D002675:Child, Preschool; D002781:Cholesteatoma / Q000235:genetics*; D005786:Gene Expression Regulation; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: C524940:MIRN21 microRNA, human; D035683:MicroRNAs; C487931:mirnlet7 microRNA, human