[siRNA against Keap1 as a strategy to stimulate a cancer chemopreventive phenotype]
>>Published online before print May 9, 2005
Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0501475102
OPEN ACCESS ARTICLE
Medical Sciences
Utility of siRNA against Keap1 as a strategy to stimulate a cancer chemopreventive phenotype
( antioxidant | chemoprevention | glutathione | nuclear factor erythroid 2 p45-related factor 2 | aldo-keto reductase )
Tim W. P. Devling *, Christopher D. Lindsay , Lesley I. McLellan *, Michael McMahon *, and John D. Hayes *
*Biomedical Research Centre, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, Scotland, United Kingdom; and Biomedical Sciences Department, Defense Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, United Kingdom
Communicated by Paul Talalay, The Johns Hopkins University School of Medicine, Baltimore, MD, February 22, 2005 (received for review November 18, 2004)
A duplex 21 nucleotide small interfering RNA (siRNA) against human Keap1 is described that represents a unique class of cancer chemopreventive agent. This siRNA can knockdown Keap1 mRNA and thereby relieve negative regulation of nuclear factor erythroid 2 p45-related factor 2 (Nrf2)-mediated gene expression. The siRNA lowered endogenous Keap1 mRNA to <30% of control levels between 24 and 72 h after transfection in human HaCaT keratinocyte cells and was capable of blocking ectopic expression of FLAG-tagged human Keap1 protein but not that of ectopic V5-tagged mouse Keap1 protein. Transfection of human HaCaT cells with Keap1 siRNA markedly enhanced endogenous levels of nuclear factor erythroid 2 p45-related factor 2 (Nrf2) protein and increased transcription of an antioxidant response element-driven reporter gene by 2.3-fold. Furthermore, 48 h after transfection of these cells with Keap1 siRNA, expression of aldo-keto reductase 1C1/2 and the glutamate cysteine ligase catalytic and modifier subunits was elevated between 5- and 14-fold. A modest increase of 3-fold in NAD(P)H:quinone oxidoreductase 1 was also observed. The Keap1 siRNA produced a 1.75-fold increase in intracellular glutathione 48 h after transfection. Thus, antagonism of Keap1 by siRNA can be used to preadapt human cells to oxidative stress without the need to expose them to redox stressors.<<
This a full text freebie:
pnas.org
Looks interesting. Prevention . . .
Cheers, Tuck |
