Cyclin D1 is required for transformation by activated Neu and is induced through an E2F-dependent signaling pathway.
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.
Lee
R J
RJ
Department of Developmental Biology, The Albert Einstein Cancer Center, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Albanese
C
C
Fu
M
M
D'Amico
M
M
Lin
B
B
Watanabe
G
G
Haines
G K
GK
Siegel
P M
PM
Hung
M C
MC
Yarden
Y
Y
Horowitz
J M
JM
Muller
W J
WJ
Pestell
R G
RG
D000818:Animals; D001665:Binding Sites; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D019938:Cyclin D1 / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D020935:MAP Kinase Signaling System; D008321:Mammary Glands, Animal / Q000378:metabolism / Q000473:pathology; D051379:Mice; D008819:Mice, Nude; D008822:Mice, Transgenic; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D000090063:Proto-Oncogene Mas; D016372:RNA, Antisense / Q000235:genetics / Q000502:physiology; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D056465:Retinoblastoma-Binding Protein 1; D016329:Sp1 Transcription Factor / Q000378:metabolism; D051705:Sp3 Transcription Factor; D050680:Transcription Factor DP1; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation; D014407:Tumor Cells, Cultured
D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D019938:Cyclin D1; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D020559:Monomeric GTP-Binding Proteins; D000090063:Proto-Oncogene Mas; D016372:RNA, Antisense; D018719:Erb-b2 Receptor Tyrosine Kinases; D056465:Retinoblastoma-Binding Protein 1; D016329:Sp1 Transcription Factor; D051705:Sp3 Transcription Factor; D050680:Transcription Factor DP1; D014157:Transcription Factors; C533431:Arid4a protein, mouse; C493753:E2F1 protein, human; C493754:E2f1 protein, mouse; C000715470:MAS1 protein, human; C493735:TFDP1 protein, human; C493736:Tfdp1 protein, mouse