Rbpj conditional knockout reveals distinct functions of Notch4/Int3 in mammary gland development and tumorigenesis

A. Raafat, S. Lawson, S. Bargo, M. Klauzinska, L. Strizzi, A. S. Goldhar, K. Buono, D. Salomon, B. K. Vonderhaar, R. Callahan*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

48 Scopus citations


Transgenic mice expressing the Notch 4 intracellular domain (ICD) (Int3) in the mammary gland have two phenotypes: arrest of mammary alveolar/lobular development and mammary tumorigenesis. Notch4 signaling is mediated primarily through the interaction of Int3 with the transcription repressor/activator Rbpj. We have conditionally ablated the Rbpj gene in the mammary glands of mice expressing whey acidic protein (Wap)-Int3. Interestingly, Rbpj knockout mice (Wap-Cre+/Rbpj-/-/Wap-Int3) have normal mammary gland development, suggesting that the effect of endogenous Notch signaling on mammary gland development is complete by day 15 of pregnancy. RBP-J heterozygous (Wap-Cre+/Rbpj-/+/Wap-Int3) and Rbpj control (Rbpj flox/flox/Wap-Int3) mice are phenotypically the same as Wap-Int3 mice with respect to mammary gland development and tumorigenesis. In addition, the Wap-Cre+/Rbpj-/-/Wap-Int3-knockout mice also developed mammary tumors at a frequency similar to Rbpj heterozygous and Wap-Int3 control mice but with a slightly longer latency. Thus, the effect on mammary gland development is dependent on the interaction of the Notch ICD with the transcription repressor/activator Rbpj, and Notch-induced mammary tumor development is independent of this interaction.

Original languageEnglish (US)
Pages (from-to)219-230
Number of pages12
Issue number2
StatePublished - Jan 15 2009


  • Int3
  • RBP-J
  • Tumorigenesis

ASJC Scopus subject areas

  • Genetics
  • Molecular Biology
  • Cancer Research


Dive into the research topics of 'Rbpj conditional knockout reveals distinct functions of Notch4/Int3 in mammary gland development and tumorigenesis'. Together they form a unique fingerprint.

Cite this