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Sequencing of candidate chromosome instability genes in endometrial cancers reveals somatic mutations in ESCO1, CHTF18, and MRE11A.

ABSTRACT: Most endometrial cancers can be classified histologically as endometrioid, serous, or clear cell. Non-endometrioid endometrial cancers (NEECs; serous and clear cell) are the most clinically aggressive of the three major histotypes and are characterized by aneuploidy, a feature of chromosome instability. The genetic alterations that underlie chromosome instability in endometrial cancer are poorly understood. In the present study, we used Sanger sequencing to search for nucleotide variants in the coding exons and splice junctions of 21 candidate chromosome instability genes, including 19 genes implicated in sister chromatid cohesion, from 24 primary, microsatellite-stable NEECs. Somatic mutations were verified by sequencing matched normal DNAs. We subsequently resequenced mutated genes from 41 additional NEECs as well as 42 endometrioid ECs (EECs). We uncovered nonsynonymous somatic mutations in ESCO1, CHTF18, and MRE11A in, respectively, 3.7% (4 of 107), 1.9% (2 of 107), and 1.9% (2 of 107) of endometrial tumors. Overall, 7.7% (5 of 65) of NEECs and 2.4% (1 of 42) of EECs had somatically mutated one or more of the three genes. A subset of mutations are predicted to impact protein function. The co-occurrence of somatic mutations in ESCO1 and CHTF18 was statistically significant (P = 0.0011, two-tailed Fisher's exact test). This is the first report of somatic mutations within ESCO1 and CHTF18 in endometrial tumors and of MRE11A mutations in microsatellite-stable endometrial tumors. Our findings warrant future studies to determine whether these mutations are driver events that contribute to the pathogenesis of endometrial cancer.

SUBMITTER: Price JC

PROVIDER: S-EPMC3670891 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature

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Sequencing of candidate chromosome instability genes in endometrial cancers reveals somatic mutations in ESCO1, CHTF18, and MRE11A.

Price Jessica C JC Pollock Lana M LM Rudd Meghan L ML Fogoros Sarah K SK Mohamed Hassan H Hanigan Christin L CL Le Gallo Matthieu M Zhang Suiyuan S Cruz Pedro P Cherukuri Praveen F PF Hansen Nancy F NF McManus Kirk J KJ Godwin Andrew K AK Sgroi Dennis C DC Mullikin James C JC Merino Maria J MJ Hieter Philip P Bell Daphne W DW

PloS one 20130603 6

Most endometrial cancers can be classified histologically as endometrioid, serous, or clear cell. Non-endometrioid endometrial cancers (NEECs; serous and clear cell) are the most clinically aggressive of the three major histotypes and are characterized by aneuploidy, a feature of chromosome instability. The genetic alterations that underlie chromosome instability in endometrial cancer are poorly understood. In the present study, we used Sanger sequencing to search for nucleotide variants in the ...[more]

PMID: 23755103

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Project description:Pathogenic somatic missense mutations within the DNA polymerase epsilon (POLE) exonuclease domain define the important subtype of ultramutated tumours ('POLE-ultramutated') within the novel molecular classification of endometrial carcinoma (EC). However, clinical implementation of this classifier requires systematic evaluation of the pathogenicity of POLE mutations. To address this, we examined base changes, tumour mutational burden (TMB), DNA microsatellite instability (MSI) status, POLE variant frequency, and the results from six in silico tools on 82 ECs with whole-exome sequencing from The Cancer Genome Atlas (TCGA). Of these, 41 had one of five known pathogenic POLE exonuclease domain mutations (EDM) and showed characteristic genomic alterations: C>A substitution >?20%, T>G substitutions >?4%, C>G substitutions <?0.6%, indels <?5%, TMB?>?100?mut/Mb. A scoring system to assess these alterations (POLE-score) was developed; based on their scores, 7/18 (39%) additional tumours with EDM were classified as POLE-ultramutated ECs, and the six POLE mutations present in these tumours were considered pathogenic. Only 1/23 (4%) tumours with non-EDM showed these genomic alterations, indicating that a large majority of mutations outside the exonuclease domain are not pathogenic. The infrequent combination of MSI-H with POLE EDM led us to investigate the clinical significance of this association. Tumours with pathogenic POLE EDM co-existent with MSI-H showed genomic alterations characteristic of POLE-ultramutated ECs. In a pooled analysis of 3361 ECs, 13 ECs with DNA mismatch repair deficiency (MMRd)/MSI-H and a pathogenic POLE EDM had a 5-year recurrence-free survival (RFS) of 92.3%, comparable to previously reported POLE-ultramutated ECs. Additionally, 14 cases with non-pathogenic POLE EDM and MMRd/MSI-H had a 5-year RFS of 76.2%, similar to MMRd/MSI-H, POLE wild-type ECs, suggesting that these should be categorised as MMRd, rather than POLE-ultramutated ECs for prognostication. This work provides guidance on classification of ECs with POLE mutations, facilitating implementation of POLE testing in routine clinical care. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

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Dataset Information

Sequencing of candidate chromosome instability genes in endometrial cancers reveals somatic mutations in ESCO1, CHTF18, and MRE11A.

Publications

Sequencing of candidate chromosome instability genes in endometrial cancers reveals somatic mutations in ESCO1, CHTF18, and MRE11A.

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