title: Low expression of secreted frizzled-related protein 4 in aggressive pituitary adenoma.
abstract: OBJECTIVE
  The secreted frizzled-related proteins (sFRPs) are reported to be antagonists of a number of tumors. This study was designed to investigate the relationship of sFRP4 with aggressiveness of pituitary adenomas.
  
  
  METHODS
  Specimens were classified into three groups: normal control (n = 10), non-aggressive group (n = 42) and aggressive group (n = 26) according to preoperative magnetic resonance imaging (MRI)/computed tomography. sFRP4 were investigated by PCR, Western blotting, and immunohistochemistry (IHC). The methylation status of the sFRP4 promoter region was observed by MassArray. Cell culture and 5-aza-2-deoxycytidine treatment was performed to observe the relationship of downregulation of sFRP4 with methylation of the sFRP4 gene.
  
  
  RESULTS
  PCR and Western blot results showed that sFRP4 expression was downregulated in aggressive pituitary adenomas, which was confirmed by IHC. Methylation of the sFRP4 promoter was increased in aggressive pituitary adenomas. And methylation of the sFRP4 promoter lead to downregulation of sFRP4 expression.
  
  
  CONCLUSIONS
  sFRP4 expression is inversely related to the aggressiveness of pituitary adenomas, and act as a tumor suppressor.
authors.affiliation: Beijing Neurosurgical Institute, Capital Medical University, 6 Tiantan Xili, Dongcheng District, Beijing, 100050, People's Republic of China.
authors.forename: Youtu
authors.initials: Y
authors.lastname: Wu
authors.forename: Jiwei
authors.initials: J
authors.lastname: Bai
authors.forename: Zhenye
authors.initials: Z
authors.lastname: Li
authors.forename: Fei
authors.initials: F
authors.lastname: Wang
authors.forename: Lei
authors.initials: L
authors.lastname: Cao
authors.forename: Chunhui
authors.initials: C
authors.lastname: Liu
authors.forename: Shengyuan
authors.initials: S
authors.lastname: Yu
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Yu
authors.forename: Yazhuo
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D000236:Adenoma / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D016022:Case-Control Studies; D002460:Cell Line; D018899:CpG Islands; D019175:DNA Methylation; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D014057:Tomography, X-Ray Computed; D014162:Transfection; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*; D055815:Young Adult; D000094742:Secreted Frizzled-Related Proteins
chemical_list: D014408:Biomarkers, Tumor; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D025521:Tumor Suppressor Proteins; C118723:SFRP4 protein, human; D000094742:Secreted Frizzled-Related Proteins