In some adenomas of the colon, intestinal crypt cells appear to have proliferated abnormally to form small tumors known as polyps. Studies on the familial type of such a disease led to the identification of a major signaling pathway (which was aberrant in the polyp cells) as being involved in the maintenance of the gut stem-cell compartment. What signaling pathway is this? Is it upregulated or downregulated in colon cancers?
A) MAPK pathway; up-regulated
B) MAPK pathway; down-regulated
C) Wnt pathway; up-regulated
D) Wnt pathway; down-regulated
E) Hedgehog pathway; down-regulated

Question

Quizplus · Accepted Answer

Inactivation of Apc, the product of which negatively regulates the Wnt signaling pathway, is found in many colon cancers. Wnt signaling is important in keeping the crypt cells in a proliferative state.

In Some Adenomas of the Colon, Intestinal Crypt Cells Appear