Estrogen stimulates transcription of c-jun protooncogene

Mol Endocrinol. 1990 Jul;4(7):1041-50. doi: 10.1210/mend-4-7-1041.


Estrogen is a mitogen for the rat uterus, where it induces transient activation of c-fos and c-myc protooncogene expression, followed by increases in DNA synthesis and cell proliferation. JUN-C, the product of the c-jun protooncogene, is a nuclear protein that can interact with FOS to modulate the activity of AP-1-responsive promoters. To test whether c-jun is a target for estrogen regulation, we measured the effects of 17 beta-estradiol on the expression of this gene in rat uterus. A human c-jun cDNA probe detects in rat uterus two mRNA species of 2.5 and 3.2 kilobases. Treatment of the animals with estrogen results in a rapid transient increase in the concentrations of these mRNAs; a 4- to 5-fold increase over the prestimulation level was detected starting 30 min after estrogen injection and lasting for 2 h, with a return to the prestimulation level after 4 h. In accordance with the results obtained by analysis of the mRNA, we found that estrogen increases 3- to 4-fold c-jun gene transcription in the uterus, at the same time it induces its mRNA accumulation. The ability of estrogen to induce c-jun gene expression was not abolished by the protein synthesis inhibitor cycloheximide, suggesting that transcriptional activation of this protooncogene is a primary response to the hormone. Furthermore, we found that in the estrogen-responsive MCF-7 human mammary carcinoma cells, estrogen stimulates transcription of a reporter gene containing four copies of a jun/AP-1 response element. These data demonstrate that c-jun gene expression is regulated by estrogen and suggest that JUN-C could play a role in the activation of cell proliferation by estrogen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Chloramphenicol O-Acetyltransferase / genetics
  • DNA-Binding Proteins / genetics*
  • Drug Resistance
  • Enhancer Elements, Genetic
  • Estrogens / pharmacology*
  • Female
  • HeLa Cells
  • Humans
  • Molecular Sequence Data
  • Proto-Oncogene Proteins c-jun
  • Proto-Oncogenes / drug effects*
  • RNA, Messenger / metabolism*
  • Rats
  • Rats, Inbred Strains
  • Transcription Factors / genetics*
  • Transcription, Genetic / drug effects
  • Uterus / drug effects
  • Uterus / metabolism*


  • DNA-Binding Proteins
  • Estrogens
  • Proto-Oncogene Proteins c-jun
  • RNA, Messenger
  • Transcription Factors
  • Chloramphenicol O-Acetyltransferase