Cyclin D1 is required for transformation by activated Neu and is induced through an E2F-dependent signaling pathway

Mol Cell Biol. 2000 Jan;20(2):672-83. doi: 10.1128/mcb.20.2.672-683.2000.


The neu (c-erbB-2) proto-oncogene encodes a tyrosine kinase receptor that is overexpressed in 20 to 30% of human breast tumors. Herein, cyclin D1 protein levels were increased in mammary tumors induced by overexpression of wild-type Neu or activating mutants of Neu in transgenic mice and in MCF7 cells overexpressing transforming Neu. Analyses of 12 Neu mutants in MCF7 cells indicated important roles for specific C-terminal autophosphorylation sites and the extracellular domain in cyclin D1 promoter activation. Induction of cyclin D1 by NeuT involved Ras, Rac, Rho, extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38, but not phosphatidylinositol 3-kinase. NeuT induction of the cyclin D1 promoter required the E2F and Sp1 DNA binding sites and was inhibited by dominant negative E2F-1 or DP-1. Neu-induced transformation was inhibited by a cyclin D1 antisense or dominant negative E2F-1 construct in Rat-1 cells. Growth of NeuT-transformed mammary adenocarcinoma cells in nude mice was blocked by the cyclin D1 antisense construct. These results demonstrate that E2F-1 mediates a Neu-signaling cascade to cyclin D1 and identify cyclin D1 as a critical downstream target of neu-induced transformation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Binding Sites
  • Carrier Proteins*
  • Cell Cycle Proteins*
  • Cell Transformation, Neoplastic / pathology*
  • Cyclin D1 / antagonists & inhibitors
  • Cyclin D1 / genetics
  • Cyclin D1 / metabolism*
  • DNA-Binding Proteins / metabolism
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • Humans
  • JNK Mitogen-Activated Protein Kinases
  • MAP Kinase Signaling System*
  • Mammary Glands, Animal / metabolism
  • Mammary Glands, Animal / pathology
  • Mice
  • Mice, Nude
  • Mice, Transgenic
  • Mitogen-Activated Protein Kinases / antagonists & inhibitors
  • Mitogen-Activated Protein Kinases / metabolism
  • Monomeric GTP-Binding Proteins / genetics
  • Monomeric GTP-Binding Proteins / metabolism
  • Mutation / genetics
  • Promoter Regions, Genetic / genetics
  • RNA, Antisense / genetics
  • RNA, Antisense / physiology
  • Receptor, ErbB-2 / antagonists & inhibitors
  • Receptor, ErbB-2 / genetics
  • Receptor, ErbB-2 / metabolism*
  • Retinoblastoma-Binding Protein 1
  • Sp1 Transcription Factor / metabolism
  • Sp3 Transcription Factor
  • Transcription Factor DP1
  • Transcription Factors / metabolism*
  • Transcriptional Activation
  • Tumor Cells, Cultured


  • Arid4a protein, mouse
  • Carrier Proteins
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • E2F1 protein, human
  • E2f1 protein, mouse
  • RNA, Antisense
  • Retinoblastoma-Binding Protein 1
  • Sp1 Transcription Factor
  • TFDP1 protein, human
  • Tfdp1 protein, mouse
  • Transcription Factor DP1
  • Transcription Factors
  • Cyclin D1
  • Sp3 Transcription Factor
  • Receptor, ErbB-2
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinases
  • Monomeric GTP-Binding Proteins