I predict that this report from the Thomas Jefferson University Hospital News will spread much happiness amongst investors in Sirtris Pharma: "We've shown that by making a prostate cancer with cells overexpressing a mutation for the androgen receptor, which is resistant to current forms of therapy, we can almost completely block the growth of these cells with SIRT1 ... We systematically tested each androgen receptor mutation. These mutant receptors are resistant to current therapies and are all blocked by expression of SIRT1 ... This study shows that there is potentially new opportunity for these cancer patients with drugs that regulate SIRT1." Here we have one potential mechanism by which calorie restriction - and thus calorie restriction mimetic drugs - holds back one type of cancer. I'm sure there are others relating to the process and downstream effects of metabolism; I am surprised by the direct nature of this connection.

Link: http://www.jeffersonhospital.org/news/2006/article13110.html