In utero-initiated cancer: the role of reactive oxygen species.

It is becoming more evident that not only can drugs and environmental chemicals interfere with normal fetal development by causing structural malformations, such as limb defects, but that xenobiotic exposure during development can also cause biochemical and functional abnormalities that may ultimately lead to cancer later on in life. Fetal toxicity may be partly mediated by the embryonic bioactivation of xenobiotics to free radical intermediates that can lead to oxidative stress and potentially lead, in some cases, to carcinogenesis. Using a number of examples, this review will focus on the role of reactive oxygen species (ROS) in the mechanisms pertaining to in utero initiated cancers. Copyright (c) 2007 Wiley-Liss, Inc.