title: Progesterone induces BRCA1 mRNA decrease, cell cycle alterations and apoptosis in the MCF7 breast cancer cell line.
abstract: BACKGROUND
  Inherited mutations of the BRCA1 gene are responsible for hereditary breast and ovarian cancer syndrome. However, little is known of how disruption of BRCA1 functions preferentially increases cancer risk in hormone-dependent organs. We aimed to study whether BRCA1 was regulated by progesterone in the MCF7 breast cancer cell line.
  
  
  METHODS
  MCF7 breast cancer cells were incubated with 10(-4) or 10(-10) M progesterone for 24 or 48 hours. BRCA1 expression, proliferation and apoptosis were analysed.
  
  
  RESULTS
  10(-4) M progesterone decreased cell proliferation, cell cycle progression and induced apoptosis. In addition, BRCA1 and cyclin A mRNA decreased. In contrast, none of these effects were observed in MCF7 cells incubated with 10(-10) M progesterone.
  
  
  CONCLUSIONS
  The down-regulation of BRCA1 in MCF7 cells incubated with 10(-4) M progesterone seems to be a consequence of cell cycle alterations rather than a direct effect of the hormone on BRCA1.
authors.affiliation: INSERM U 481, Faculté de Médecine Xavier Bichat, 75018 Paris, France. yan.ansquer@lmr.ap-hop-paris.fr
authors.forename: Yan
authors.initials: Y
authors.lastname: Ansquer
authors.forename: Agnès
authors.initials: A
authors.lastname: Legrand
authors.forename: Annie-France
authors.initials: AF
authors.lastname: Bringuier
authors.forename: Nathalie
authors.initials: N
authors.lastname: Vadrot
authors.forename: Bernard
authors.initials: B
authors.lastname: Lardeux
authors.forename: Laurent
authors.initials: L
authors.lastname: Mandelbrot
authors.forename: Gérard
authors.initials: G
authors.lastname: Feldmann
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D019313:BRCA1 Protein / Q000096:biosynthesis / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D016213:Cyclins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D011374:Progesterone / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011960:Receptors, Estrogen / Q000096:biosynthesis; D011980:Receptors, Progesterone / Q000096:biosynthesis
chemical_list: D019313:BRCA1 Protein; D016213:Cyclins; D012333:RNA, Messenger; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; D011374:Progesterone