Several chemicals that can accumulate to high levels in our body
(for example BPA and some pesticides) have been recently linked
to an increased risk of cancer and/or impaired responsiveness to
anticancer drugs. A team of researchers, led by Sridhar Mani, at
Albert Einstein College of Medicine, New York, has now
identified a potential mechanistic link between environmental
exposure to these foreign chemicals (xenogens) and cancer drug
therapy response and survival. PXR is one protein by which cells
(including tumor cells) can sense xenogens. In their study, Mani
and colleagues determined that activation of PXR was sufficient
to enhance the cancerous characteristics of human colon tumor
cell lines and primary human colon cancer tissue xenografted
into immune system–deficient mice. Further analysis indicated
FXR activation leads to colon cancer growth through the
induction of the growth factor FGF19. The authors therefore
suggest that it will be important to investigate further the
extent to which the environme