title: Wnt1 is epistatic to Id2 in inducing mammary hyperplasia, ductal side-branching, and tumors in the mouse.
abstract: BACKGROUND
  During pregnancy, the mammary glands from Id2 mutant animals are deficient in lobulo-alveolar development. This failure of development is believed to be due to a proliferation defect.
  
  
  METHODS
  We have asked whether functional Id2 expression is necessary for Wnt induced mammary hyperplasia, side branching, and cancer, by generating mice expressing a Wnt1 transgene in an Id2 mutant background.
  
  
  RESULTS
  We show in this work that forced expression of Wnt1 in the mammary gland is capable of overcoming the block to proliferation caused by the absence of Id2. We also show that Wnt1 expression is able to cause mammary tumors in an Id2 mutant background.
  
  
  CONCLUSIONS
  We conclude that functional Id2 expression is not required for Wnt1 to induce mammary hyperplasia and mammary tumors.
authors.affiliation: Department of Developmental Biology, Howard Hughes Medical Institute, Beckman Center, Stanford University Medical School Stanford, CA 94305, USA. smarino@cmgm.stanford.edu
authors.forename: Susan
authors.initials: S
authors.lastname: Marino
authors.forename: Claire
authors.initials: C
authors.lastname: Romelfanger
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Yokota
authors.forename: Roel
authors.initials: R
authors.lastname: Nusse
mesh_terms: D000818:Animals; D004268:DNA-Binding Proteins / Q000235:genetics*; D004843:Epistasis, Genetic; D005260:Female; D015870:Gene Expression; D006965:Hyperplasia / Q000235:genetics / Q000473:pathology; D051797:Inhibitor of Differentiation Protein 2; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D008321:Mammary Glands, Animal / Q000473:pathology*; D015674:Mammary Neoplasms, Animal / Q000235:genetics* / Q000473:pathology; D051379:Mice; D008822:Mice, Transgenic; D011247:Pregnancy; D012097:Repressor Proteins / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D051153:Wnt Proteins; D051155:Wnt1 Protein
chemical_list: D004268:DNA-Binding Proteins; C497452:Idb2 protein, mouse; D051797:Inhibitor of Differentiation Protein 2; D036341:Intercellular Signaling Peptides and Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; D051153:Wnt Proteins; D051155:Wnt1 Protein; C495246:Wnt1 protein, mouse