Chromosomal Instability in BRAF Mutant, Microsatellite Stable Colorectal Cancers

The BRAF oncogene is mutated in 15% of sporadic colorectal cancers. Approximately half of these BRAF mutant cancers demonstrate frequent frameshift mutations termed microsatellite instability (MSI), but are diploid and chromosomally stable. BRAF wild type cancers are typically microsatellite stable...

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Main Authors: Bond, Catherine E., Umapathy, Aarti, Buttenshaw, Ron L., Wockner, Leesa, Leggett, Barbara A., Whitehall, Vicki L. J.
Format: Online
Language:English
Published: Public Library of Science 2012
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3478278/
id pubmed-3478278
recordtype oai_dc
spelling pubmed-34782782012-10-29 Chromosomal Instability in BRAF Mutant, Microsatellite Stable Colorectal Cancers Bond, Catherine E. Umapathy, Aarti Buttenshaw, Ron L. Wockner, Leesa Leggett, Barbara A. Whitehall, Vicki L. J. Research Article The BRAF oncogene is mutated in 15% of sporadic colorectal cancers. Approximately half of these BRAF mutant cancers demonstrate frequent frameshift mutations termed microsatellite instability (MSI), but are diploid and chromosomally stable. BRAF wild type cancers are typically microsatellite stable (MSS) and instead acquire chromosomal instability (CIN). In these cancers, CIN is associated with a poor outcome. BRAF mutant cancers that are MSS, typically present at an advanced stage and have a particularly poor prognosis. We have previously demonstrated clinical and molecular similarities between MSS cancers with or without a BRAF mutation, and therefore hypothesised that CIN may also be frequent in BRAF mutant/MSS cancers. BRAF mutant/MSS (n = 60), and BRAF wild type/MSS CRCs (n = 90) were investigated for CIN using loss of heterozygosity analysis over twelve loci encompassing chromosomal regions 5q, 8p, 17p and 18q. CIN was frequent in BRAF mutant/MSS cancers (41/57, 72%), which was comparable to the rate found in BRAF wild type/MSS cancers (74/90, 82%). The greatest loss in BRAF mutant/MSS cancers occurred at 8p (26/44, 59%), and the least at 5q (19/49, 39%). CIN in BRAF mutant/MSS cancers correlated with advanced stage (AJCC III/IV: 15/17, 88%; p = 0.02); showed high rates of co-occurrence with the CpG Island Methylator Phenotype (17/23, 74%); and CIN at 18q and 8p associated with worse survival (p = 0.02, p<0.05). This study demonstrates that CIN commonly occurs in advanced BRAF mutant/MSS colorectal cancers where it may contribute to poorer survival, and further highlights molecular similarities occurring between these and BRAF wild type cancers. Public Library of Science 2012-10-22 /pmc/articles/PMC3478278/ /pubmed/23110075 http://dx.doi.org/10.1371/journal.pone.0047483 Text en © 2012 Bond et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
repository_type Open Access Journal
institution_category Foreign Institution
institution US National Center for Biotechnology Information
building NCBI PubMed
collection Online Access
language English
format Online
author Bond, Catherine E.
Umapathy, Aarti
Buttenshaw, Ron L.
Wockner, Leesa
Leggett, Barbara A.
Whitehall, Vicki L. J.
spellingShingle Bond, Catherine E.
Umapathy, Aarti
Buttenshaw, Ron L.
Wockner, Leesa
Leggett, Barbara A.
Whitehall, Vicki L. J.
Chromosomal Instability in BRAF Mutant, Microsatellite Stable Colorectal Cancers
author_facet Bond, Catherine E.
Umapathy, Aarti
Buttenshaw, Ron L.
Wockner, Leesa
Leggett, Barbara A.
Whitehall, Vicki L. J.
author_sort Bond, Catherine E.
title Chromosomal Instability in BRAF Mutant, Microsatellite Stable Colorectal Cancers
title_short Chromosomal Instability in BRAF Mutant, Microsatellite Stable Colorectal Cancers
title_full Chromosomal Instability in BRAF Mutant, Microsatellite Stable Colorectal Cancers
title_fullStr Chromosomal Instability in BRAF Mutant, Microsatellite Stable Colorectal Cancers
title_full_unstemmed Chromosomal Instability in BRAF Mutant, Microsatellite Stable Colorectal Cancers
title_sort chromosomal instability in braf mutant, microsatellite stable colorectal cancers
description The BRAF oncogene is mutated in 15% of sporadic colorectal cancers. Approximately half of these BRAF mutant cancers demonstrate frequent frameshift mutations termed microsatellite instability (MSI), but are diploid and chromosomally stable. BRAF wild type cancers are typically microsatellite stable (MSS) and instead acquire chromosomal instability (CIN). In these cancers, CIN is associated with a poor outcome. BRAF mutant cancers that are MSS, typically present at an advanced stage and have a particularly poor prognosis. We have previously demonstrated clinical and molecular similarities between MSS cancers with or without a BRAF mutation, and therefore hypothesised that CIN may also be frequent in BRAF mutant/MSS cancers. BRAF mutant/MSS (n = 60), and BRAF wild type/MSS CRCs (n = 90) were investigated for CIN using loss of heterozygosity analysis over twelve loci encompassing chromosomal regions 5q, 8p, 17p and 18q. CIN was frequent in BRAF mutant/MSS cancers (41/57, 72%), which was comparable to the rate found in BRAF wild type/MSS cancers (74/90, 82%). The greatest loss in BRAF mutant/MSS cancers occurred at 8p (26/44, 59%), and the least at 5q (19/49, 39%). CIN in BRAF mutant/MSS cancers correlated with advanced stage (AJCC III/IV: 15/17, 88%; p = 0.02); showed high rates of co-occurrence with the CpG Island Methylator Phenotype (17/23, 74%); and CIN at 18q and 8p associated with worse survival (p = 0.02, p<0.05). This study demonstrates that CIN commonly occurs in advanced BRAF mutant/MSS colorectal cancers where it may contribute to poorer survival, and further highlights molecular similarities occurring between these and BRAF wild type cancers.
publisher Public Library of Science
publishDate 2012
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3478278/
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