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Systematic identification of genes with coding microsatellites mutated in DNA mismatch repair-deficient cancer cells

Item Type:Article
Title:Systematic identification of genes with coding microsatellites mutated in DNA mismatch repair-deficient cancer cells
Creators Name:Woerner, S.M. and Gebert, J. and Yuan, Y.P. and Sutter, C. and Ridder, R. and Bork, P. and von Knebel-Doeberitz, M.
Abstract:Microsatellite instability (MSI) caused by deficient DNA mismatch-repair functions is a hallmark of cancers associated with the hereditary nonpolyposis colorectal cancer (HNPCC) syndrome but is also found in about 15% of all sporadic tumors. Most affected microsatellites reside in untranslated intergenic or intronic sequences. However, recently few genes with coding microsatellites were also shown to be mutational targets in MSI-positive cancers and might represent important mutation targets in their pathogenesis. The systematic identification of such genes and the analysis of their mutation frequency in MSI-positive cancers might thus reveal major clues to their functional role in MSI-associated carcinogenesis. We therefore initiated a systematic database search in 33,595 distinctly annotated human genes and identified 17,654 potentially coding mononucleotide repeats (cMNRs) and 2,028 coding dinucleotide repeats (cDNRs), which consist of n ≥ 6 and n ≥ 4 repeat units, respectively. Expression pattern and mutation frequency of 19 of these genes with the longest repeats were compared between DNA mismatch repair-deficient (MSI+) and proficient (MSS) cancer cells. Instability frequencies in these coding microsatellite genes ranged from 10% to 100% in MSI-H tumor cells, whereas MSS cancer cells did not show mutations. RT-PCR analysis further showed that most of the affected genes (10/15) were highly expressed in tumor cells. The approach outlined here identified a new set of genes frequently affected by mutations in MSI-positive tumor cells. It will lead to novel and highly specific diagnostic and therapeutic targets for microsatellite unstable cancers.
Keywords:Coding Microsatellites, Colorectal Cancer, Microsatellite Instability, Mismatch Repair
Source:International Journal of Cancer
Page Range:12-19
Date:1 January 2001
Official Publication:https://doi.org/10.1002/ijc.1299
PubMed:View item in PubMed

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