Cancer and SRT1: Elixir Versus Sirtris??

Based on seemingly conflicting statements from competing biotechnology companies, it appears that Sirtris Pharmaceuticals and Elixir Pharmaceuticals have conflicting views on the mechanism of how the modulation of SIRT1 expression may one day be used as a cancer treatment. Judge for yourself:

Excpert from Sirtris press release dated April 16, 2008 :

Sirtris Pharmaceuticals, Inc. (NASDAQ: SIRT), a biopharmaceutical company
focused on discovering and developing small molecule drugs to treat diseases of
aging, announced that a research team led by the company's two Scientific
Advisory Board co-chairs has demonstrated that overexpression of the
SIRT1 enzyme can suppress tumor formation and growth in a preclinical
mouse model of colon cancer, providing the first in-vivo data that SIRT1 can
suppress tumor cell development. The paper, titled SIRT1 Deacetylase Suppresses
Intestinal Tumorigenesis and Colon Cancer Growth, appears in today's issue of
the scientific journal PLoS One.

Excerpt from Elixir website:

Conversely, blocking the amount or activity of SIRT1 has recently been
shown to reverse "epigenetic silencing," a phenomenon that decreases the
expression of important tumor suppressor genes. The implication of these
findings is that blocking SIRT1 could be important in combating several types of cancer. These observations highlight the large potential, and explain the recent interest, in the discovery and development of compounds which could either
increase or decrease the enzymes of this important class of SIRT targets.

If anyone with technical knowledge of this topic has a logical explanation for this seemingly conflicting information, please post a comment to explain.