29
May 2003
Gene expression: Dioxin mimicry of oestrogens
The industrial by-product dioxin is one of the most toxic environmental contaminants known. It has been linked to human cancers and is toxic to the reproductive, immune and endocrine systems. Dioxin is thought to modulate oestrogen signalling, but the mechanism of action is not known. Using a combination of biochemical, molecular biological and transgenic tools, Ohtake et al. have now established that the activated dioxin receptor interacts directly with the unliganded oestrogen receptors, prompting the expression of oestrogen-regulated target genes. The implication is that the many compounds that interact with the dioxin or aryl hydrocarbon receptor (AhR), a transcription factor for which the endogenous ligand is not yet known, could potentially cause oestrogen-signalled events in the absence of any circulating 17-oestradiol.
Modulation of oestrogen receptor signalling by association
with the activated dioxin receptor
FUMIAKI OHTAKE,
KEN-ICHI TAKEYAMA, TAKAHIRO MATSUMOTO, HIROCHIKA KITAGAWA, YASUJI YAMAMOTO, KEIKO
NOHARA, CHIHARU TOHYAMA, ANDREE KRUST, JUNSEI MIMURA, PIERRE CHAMBON, JUNN YANAGISAWA,
YOSHIAKI FUJII-KURIYAMA & SHIGEAKI KATO
Nature 423, 545–550
(2003); doi:10.1038/nature01606
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Gene expression: Oestrogen receptor hijacked
JAN J. BROSENS & MALCOLM G. PARKER
Widespread pollution
of the environment by dioxins poses a risk to human health. The mechanism used
by these chemicals to alter the body's responses to oestrogens is now being unveiled.
Nature 423, 487–488 (2003); doi:10.1038/423487a
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