title: Analysis of MiR-195 and MiR-497 expression, regulation and role in breast cancer.
abstract: OBJECTIVE
  To investigate expression, regulation, potential role and targets of miR-195 and miR-497 in breast cancer.
  
  
  METHODS
  The expression patterns of miR-195 and miR-497 were initially examined in breast cancer tissues and cell lines by Northern blotting and quantitative real-time PCR. Combined bisulfite restriction analysis and bisulfite sequencing were carried out to study the DNA methylation status of miR-195 and miR-497 genes. Breast cancer cells stably expressing miR-195 and miR-497 were established to study their role and targets. Finally, normal, fibroadenoma and breast cancer tissues were employed to analyze the correlation between miR-195/497 levels and malignant stages of breast tumor tissues.
  
  
  RESULTS
  MiR-195 and miR-497 were significantly downregulated in breast cancer. The methylation state of CpG islands upstream of the miR-195/497 gene was found to be responsible for the downregulation of both miRNAs. Forced expression of miR-195 or miR-497 suppressed breast cancer cell proliferation and invasion. Raf-1 and Ccnd1 were identified as novel direct targets of miR-195 and miR-497. miR-195/497 expression levels in clinical specimens were found to be correlated inversely with malignancy of breast cancer.
  
  
  CONCLUSIONS
  Our data imply that both miR-195 and miR-497 play important inhibitory roles in breast cancer malignancy and may be the potential therapeutic and diagnostic targets.
authors.affiliation: Institute of Molecular and Chemical Biology, East China Normal University, Shanghai, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.forename: Yulan
authors.initials: Y
authors.lastname: Zhao
authors.forename: Changxing
authors.initials: C
authors.lastname: Liu
authors.forename: Xiaona
authors.initials: X
authors.lastname: Chen
authors.forename: Yanting
authors.initials: Y
authors.lastname: Qi
authors.forename: Yue
authors.initials: Y
authors.lastname: Jiang
authors.forename: Chao
authors.initials: C
authors.lastname: Zou
authors.forename: Xiaolong
authors.initials: X
authors.lastname: Zhang
authors.forename: Shunying
authors.initials: S
authors.lastname: Liu
authors.forename: Xuejing
authors.initials: X
authors.lastname: Wang
authors.forename: Dan
authors.initials: D
authors.lastname: Zhao
authors.forename: Qiang
authors.initials: Q
authors.lastname: Sun
authors.forename: Zhenbing
authors.initials: Z
authors.lastname: Zeng
authors.forename: Andreas
authors.initials: A
authors.lastname: Dress
authors.forename: Marie C
authors.initials: MC
authors.lastname: Lin
authors.forename: Hsiang-Fu
authors.initials: HF
authors.lastname: Kung
authors.forename: Hallgeir
authors.initials: H
authors.lastname: Rui
authors.forename: Ling-Zhi
authors.initials: LZ
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Mao
authors.forename: Bing-Hua
authors.initials: BH
authors.lastname: Jiang
authors.forename: Lihui
authors.initials: L
authors.lastname: Lai
mesh_terms: D020413:3' Untranslated Regions; D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D002465:Cell Movement; D049109:Cell Proliferation; D018899:CpG Islands; D019938:Cyclin D1 / Q000378:metabolism; D019175:DNA Methylation; D015536:Down-Regulation; D005260:Female; D020868:Gene Silencing; D017930:Genes, Reporter; D006801:Humans; D049410:Luciferases, Renilla / Q000096:biosynthesis / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D009361:Neoplasm Invasiveness; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D015183:Restriction Mapping
chemical_list: D020413:3' Untranslated Regions; C530104:CCND1 protein, human; C552722:MIRN195 microRNA, human; C559640:MIRN497 microRNA, human; D035683:MicroRNAs; D019938:Cyclin D1; D049410:Luciferases, Renilla; D019908:Proto-Oncogene Proteins c-raf