title: MicroRNA and histopathological characterization of pure mucinous breast carcinoma.
abstract: OBJECTIVE
  Pure mucinous breast carcinoma (PMBC) is an uncommon histological type of breast cancer characterized by a large amount of mucin production. MicroRNA (miRNA) is a large class of small noncoding RNA of about 22 nt involved in the regulation of various biological processes. This study aims to identify the miRNA expression profile in PMBC.
  
  
  METHODS
  MiRNA expression profiles in 11 PMBCs were analyzed by miRNA-microarray and real-time polymerase chain reaction (PCR). Thirty-one PMBCs and 27 invasive ductal carcinoma of no special types (IDC-NSTs) were assessed by immunohistochemistry using antibodies against ER, PR-progesterone receptor, HER2, Ki-67, Bcl-2, p53, PCNA, and CK5 and 6.
  
  
  RESULTS
  We analyzed the miRNA expression in 11 PMBCs and corresponding normal tissues using miRNA-microarray and real-time PCR, and found that miR-143 and miR-224-5p were significantly downregulated in mucinous carcinoma tissue. Compared with IDC-NSTs, PMBC showed a significantly higher ER positive rate, lower HER-2 positive rate, and lower cell proliferation rates.
  
  
  CONCLUSIONS
  To our knowledge, this is the first study to demonstrate the miRNA expression profile of PMBC, and our findings may lead to further understanding of this type of breast cancer.
authors.affiliation: Departments of Breast Oncology/Surgery, Tianjin Medical University Cancer Institute and Hospital; Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education; Key Laboratory of Cancer Prevention and Therapy, Tianjin; State Key Laboratory of Breast Cancer Research, Tianjin 300060, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Zhou
authors.forename: Shuai
authors.initials: S
authors.lastname: Li
authors.forename: Hui-Min
authors.initials: HM
authors.lastname: Meng
authors.forename: Li-Qiang
authors.initials: LQ
authors.lastname: Qi
authors.forename: Lin
authors.initials: L
authors.lastname: Gu
keywords: Pure mucinous breast carcinoma; microRNA; real-time PCR