The expression of oncogenic K-rasG12D in enterocytes leads to the development of serrated hyperplasia in the colonic epithelium in the mouse. Tumor progression is inhibited due to an Erk1/2 dependent induction of oncogene induced senescence, which is accompanied by an upregulation of p16Ink4a. The activation of K-rasG12D in enterocytes in combination with the deletion of the Ink4a/Arf locus leads to the formation of invasive carcinomas in the proximal colon. At the molecular and histological level, these tumors closely resemble human serrated adenomas and comprise a distinct tumor entity. Carcinogenesis in these mice is independent of the activation of the Wnt pathway, which is commonly found in classical colon tumors.
These findings introduce the K-rasG12D mouse as a novel model for serrated tumorigenesis and suggest Ras-Raf-Mek-Erk signalling as the initiator in the alternative route to colorectal cancer.
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The expression of oncogenic K-rasG12D in enterocytes leads to the development of serrated hyperplasia in the colonic epithelium in the mouse. Tumor progression is inhibited due to an Erk1/2 dependent induction of oncogene induced senescence, which is accompanied by an upregulation of p16Ink4a. The activation of K-rasG12D in enterocytes in combination with the deletion of the Ink4a/Arf locus leads to the formation of invasive carcinomas in the proximal colon. At the molecular and histological lev...
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