Newly identified intestinal stem cells give clues to colon cancer

Researchers at the Vanderbilt-Ingram Cancer Center have identified a new population of intestinal stem cells that provide additional clues to colon cancer. With the 2007 discovery of intestinal stem cells (marked by the molecule Lgr5) that were highly proliferative, scientists began to question whether quiescent cells even existed. This new stem cell population, however, appears to be relatively inactive and is marked by a protein, Lrig1, that possibly inhibits cell growth and proliferation. Colon cancer tumors are believed to result from a series of mutations in intestinal stem cells, which are self-renewing cells that give rise to all cell types in the intestinal tract. Lrig1 also acts as a tumor suppressor, inhibiting cell proliferation that can lead to cancer.