Oxygen-regulated expression of the Wilms' tumor suppressor Wt1 involves hypoxia-inducible factor-1 (HIF-1).

نویسندگان

  • Kay-Dietrich Wagner
  • Nicole Wagner
  • Sven Wellmann
  • Gunnar Schley
  • Anja Bondke
  • Heinz Theres
  • Holger Scholz
چکیده

The Wilms' tumor gene Wt1 is unique among tumor suppressors because of its requirement for the development of certain organs. We recently described de novo expression of Wt1 in myocardial blood vessels of ischemic rat hearts. The purpose of this study was to analyze the mechanism(s) of hypoxic/ischemic induction of Wt1. We show here that Wt1 mRNA and protein is up-regulated in the heart and kidneys of rats exposed to normobaric hypoxia (8% O2). Ectopic Wt1 immunoreactivity was detected in renal tubules of hypoxic rats, which also expressed the antiapoptotic protein Bcl-2 and contained significantly fewer TUNEL-positive cells than in normoxic kidneys. Wt1 expression was enhanced in the osteosarcoma line U-2OS and in Reh lymphoblast cells that were grown either at 1% O2 or in the presence of CoCl2 and desferrioxamine, respectively. The promoter of the Wt1 gene was capable of mediating expression of a luciferase reporter in response to hypoxia. We identified a hypoxia-responsive element in the Wt1 sequence that bound to hypoxia-inducible factor-1 (HIF-1) and was required for activation of the Wt1 promoter by CoCl2 and HIF-1. These findings demonstrate that Wt1 expression can be stimulated by hypoxia, which involves activation of the Wt1 promoter by HIF-1.

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عنوان ژورنال:
  • FASEB journal : official publication of the Federation of American Societies for Experimental Biology

دوره 17 10  شماره 

صفحات  -

تاریخ انتشار 2003