Enhanced Rate of Acquisition of Point Mutations in Mouse Intestinal Adenomas Compared to Normal Tissue

Publication date: 13 June 2017
Source:Cell Reports, Volume 19, Issue 11
Author(s): Natalia Lugli, Vasilis S. Dionellis, Paloma Ordóñez-Morán, Irene Kamileri, Sotirios K. Sotiriou, Joerg Huelsken, Thanos D. Halazonetis
The most prevalent single-nucleotide substitution (SNS) found in cancers is a C-to-T substitution in the CpG motif. It has been proposed that many of these SNSs arise during organismal aging, prior to transformation of a normal cell into a precancerous/cancer cell. Here, we isolated single intestinal crypts derived from normal tissue or from adenomas of Apc^min/+ mice, expanded them minimally in vitro as organoids, and performed exome sequencing to identify point mutations that had been acquired in vivo at the single-cell level. SNSs, most of them being CpG-to-TpG substitutions, were at least ten times more frequent in adenoma than normal cells. Thus, contrary to the view that substitutions of this type are present due to normal-cell aging, the acquisition of point mutations increases upon transformation of a normal intestinal cell into a precancerous cell.

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By performing exome sequencing on organoids derived from single intestinal crypts from Apc^min/+ mice, Lugli et al. find that the rate of acquisition of point mutations in vivo increases upon transformation of normal cells to precancerous cells.


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