title: The microRNA-processing enzymes: Drosha and Dicer can predict prognosis of nasopharyngeal carcinoma.
abstract: OBJECTIVE
  Dysregulation of microRNA (miRNA) metabolism has been observed in a variety of human cancers, but the expression patterns of the enzymes responsible for generating miRNAs remain largely unexplored. In this study, we investigated the expression profiles of the two most important enzymes of the miRNA machinery, Drosha and Dicer, which were closely correlated with nasopharyngeal carcinoma (NPC) and patient survival.
  
  
  METHODS
  Dicer and Drosha mRNA levels were detected by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) using 24 NPC tissues, 7 normal nasopharyngeal epithelium samples (NPE) and NPC cell lines. In addition, protein levels were detected by immunohistochemistry (IHC) using an NPC tissue microarray (TMA), which include 251 NPC and 105 NPE cases. For some NPC patients can not be contacted, the survival data were available only for 146 patients. Kaplan-Meier analysis was performed, and the chi-square and log-rank tests were used to detect significance levels using SPSS 15.0 software.
  
  
  RESULTS
  The mean level of Dicer and Drosha mRNA were significantly down-regulated in NPC tissue specimens and cell lines when compared with controls. The low levels of Dicer and Drosha protein were frequently seen in NPC, and the low expression of Dicer and Drosha protein was significantly correlated with shorter progression-free survival (PFS) and overall survival (OS) of NPC patients.
  
  
  CONCLUSIONS
  We observed that Drosha and Dicer expression was dysregulation in NPC compared with healthy control samples and was significantly correlated with shorter PFS and OS of NPC patients. Therefore, we hypothesise that the expression levels of Dicer and Drosha could be used as potential prognostic biomarkers for NPC.
authors.affiliation: Cancer Research Institute, Central South University, 110 Xiang-Ya Road, Changsha, 410078, Hunan, People's Republic of China.
authors.forename: Xiaofang
authors.initials: X
authors.lastname: Guo
authors.forename: Qianjin
authors.initials: Q
authors.lastname: Liao
authors.forename: Pan
authors.initials: P
authors.lastname: Chen
authors.forename: Xiayu
authors.initials: X
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Xiong
authors.forename: Jian
authors.initials: J
authors.lastname: Ma
authors.forename: Xiaoling
authors.initials: X
authors.lastname: Li
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Luo
authors.forename: Hailin
authors.initials: H
authors.lastname: Tang
authors.forename: Min
authors.initials: M
authors.lastname: Deng
authors.forename: Yin
authors.initials: Y
authors.lastname: Zheng
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.forename: Wenling
authors.initials: W
authors.lastname: Zhang
authors.forename: Guiyuan
authors.initials: G
authors.lastname: Li
mesh_terms: D002277:Carcinoma; D045744:Cell Line, Tumor; D053487:DEAD-box RNA Helicases / Q000096:biosynthesis* / Q000235:genetics; D018572:Disease-Free Survival; D015536:Down-Regulation; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000201:enzymology* / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D043244:Ribonuclease III / Q000096:biosynthesis* / Q000235:genetics; D015996:Survival Rate
chemical_list: D035683:MicroRNAs; D012333:RNA, Messenger; C408087:DICER1 protein, human; C517918:DROSHA protein, human; D043244:Ribonuclease III; D053487:DEAD-box RNA Helicases