title: Promoter methylation assay of SASH1 gene in breast cancer.
abstract: OBJECTIVE
  To analyze the relationship between the expression of SASH1 and its methylation level of SASH1 gene promoter in human breast cancer.
  
  
  METHODS
  Expression levels of SASH1 were examined in breast cancer tissues and adjacent normal tissues with immunohistochemistry and with real time PCR (RT-PCR) methylation analysis was performed with MassArray.
  
  
  RESULTS
  Immunohistochemistry showed that SASH1 expression was strongly reduced in breast cancer compared with adjacent normal tissues. Quantitative methylation analysis by MassArray revealed that CpG sites in SASH1 promoter shared similar methylation pattern in tumor tissue and adjacent normal tissue. The CpG sites with significant difference in methylation level were CpG_26.27 and CpG_54.55. Moreover, 5-aza-2'-deoxycytidine (5-Aza-dc) treatment of tumor cell line MDA-MB-231 caused significant elevation of SASH1 mRNA.
  
  
  CONCLUSIONS
  Based on these data, we propose that increase of DNA methylation level in the promoter region of gene SASH1, particularly CpG_26.27 or CpG_54.55 sites, possibly repressed SASH1 expression in breast cancer.
authors.affiliation: Children's Hospital and Institutes of Biomedical Sciences, Fudan University, Shanghai.
authors.forename: Lin
authors.initials: L
authors.lastname: Sheyu
authors.forename: Liu
authors.initials: L
authors.lastname: Hui
authors.forename: Zhang
authors.initials: Z
authors.lastname: Junyu
authors.forename: Xu
authors.initials: X
authors.lastname: Jiawei
authors.forename: Wang
authors.initials: W
authors.lastname: Honglian
authors.forename: Sang
authors.initials: S
authors.lastname: Qing
authors.forename: Zhang
authors.initials: Z
authors.lastname: Hengwei
authors.forename: Guo
authors.initials: G
authors.lastname: Xuhui
authors.forename: Xing
authors.initials: X
authors.lastname: Qinghe
authors.forename: He
authors.initials: H
authors.lastname: Lin
mesh_terms: D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D014408:Biomarkers, Tumor / Q000235:genetics* / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism; D045744:Cell Line, Tumor; D018899:CpG Islands; D019175:DNA Methylation / Q000187:drug effects; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000077209:Decitabine; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; C474743:SASH1 protein, human; D025521:Tumor Suppressor Proteins; D000077209:Decitabine; D015254:DNA Modification Methylases; D001374:Azacitidine