1. MAPing the Role of Kras Mutations in Hyperplastic Polyps
Terrence Barrett 
Gastroenterology 
Volume 141, Issue 3, Pages (September 2011)
DOI: /j.gastro
Copyright © 2011 AGA Institute Terms and Conditions

2. Figure 1
Algorithm for polyp formation from KrasG12D and APC mutations. (A) KrasG12D mutation activates MEK signaling that upregulates cyclin E and suppresses cyclin dependent kinases (CDKs) p21, p57, and p19, resulting in expansion of the transit amplifying (TA) but not stem cell zone. Kras signaling can also activate Notch pathway via MEK which may account for the loss of Paneth cells. A novel MEK-induced increase in goblet cells was also observed. (B) APC mutation increases β-catenin activation in tubular adenomas and adenocarcinomas if other mutations are accumulated. Consequent to APC mutations, the pool of intestinal stem cells (ISCs) extend into upper crypt regions.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2011 AGA Institute Terms and Conditions