title: [BRCA1 regulates progesterone receptors A and B protein expressions in breast cancer cells in vitro].
abstract: OBJECTIVE
  To study the regulatory role of BRCA1 in the expression of progesterone receptors A and B (PRA and PRB) in breast cancer cells.
  
  
  METHODS
  Breast cancer MCF-7 cells were transfected with pFlag-CMV2-BRCA1 wt plasmid containing a full-length BRCA1 cDNA or with BRCA1-specific siRNA via lipofectamine 2000 to induce overexpression or suppressed expression of BRCA1, respectively. Twenty-four hours after the transfection, the cells were incubated in fresh culture medium containing 100 nmol/L progesterone for 24 h. The total RNA extract or whole cell lysate was prepared for detecting BRCA1, PRA and PRB expressions using RT-PCR and Western blotting.
  
  
  RESULTS
  The protein expressions of PRA and PRB were significantly decreased whereas their mRNA expressions remained unchanged in MCF-7 cells overexpressing BRCA1. In MCF-7 cells with BRCA1 knock-down, in contrast, the PRA and PRB protein expressions were markedly increased.
  
  
  CONCLUSIONS
  In breast cancer cells, exogenous and endogenous BRCA1 can both down-regulate the expressions of PRA and PRB at the protein level.
authors.affiliation: Department of Cell Biology, Southern Medical University, Guangzhou 510515, China. guo81929@126.com
authors.forename: Yin-xia
authors.initials: YX
authors.lastname: Guo
authors.forename: Wei-sen
authors.initials: WS
authors.lastname: Zeng
authors.forename: Ya-wei
authors.initials: YW
authors.lastname: Liu
authors.forename: Yu-sheng
authors.initials: YS
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Lin
authors.forename: Jing-bo
authors.initials: JB
authors.lastname: Xiong
authors.forename: Shen-qiu
authors.initials: SQ
authors.lastname: Luo
mesh_terms: D019313:BRCA1 Protein / Q000096:biosynthesis / Q000235:genetics*; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics*; D011980:Receptors, Progesterone / Q000096:biosynthesis / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
chemical_list: D019313:BRCA1 Protein; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D011980:Receptors, Progesterone