Dataset Information

Whole-Exome Sequencing Reveals High Mutational Concordance between Primary and Matched Recurrent Triple-Negative Breast Cancers.

ABSTRACT:

Purpose

Triple-negative breast cancer (TNBC) is a molecularly complex and heterogeneous breast cancer subtype with distinct biological features and clinical behavior. Although TNBC is associated with an increased risk of metastasis and recurrence, the molecular mechanisms underlying TNBC metastasis remain unclear. We performed whole-exome sequencing (WES) analysis of primary TNBC and paired recurrent tumors to investigate the genetic profile of TNBC.

Methods

Genomic DNA extracted from 35 formalin-fixed paraffin-embedded tissue samples from 26 TNBC patients was subjected to WES. Of these, 15 were primary tumors that did not have recurrence, and 11 were primary tumors that had recurrence (nine paired primary and recurrent tumors). Tumors were analyzed for single-nucleotide variants and insertions/deletions.

Results

The tumor mutational burden (TMB) was 7.6 variants/megabase in primary tumors that recurred (n = 9); 8.2 variants/megabase in corresponding recurrent tumors (n = 9); and 7.3 variants/megabase in primary tumors that did not recur (n = 15). MUC3A was the most frequently mutated gene in all groups. Mutations in MAP3K1 and MUC16 were more common in our dataset. No alterations in PI3KCA were detected in our dataset.

Conclusions

We found similar mutational profiles between primary and paired recurrent tumors, suggesting that genomic features may be retained during local recurrence.

SUBMITTER: Kaur J

PROVIDER: S-EPMC10531222 | biostudies-literature | 2023 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Whole-Exome Sequencing Reveals High Mutational Concordance between Primary and Matched Recurrent Triple-Negative Breast Cancers.

Kaur Jaspreet J Chandrashekar Darshan S DS Varga Zsuzsanna Z Sobottka Bettina B Janssen Emiel E Gandhi Khanjan K Kowalski Jeanne J Kiraz Umay U Varambally Sooryanarayana S Aneja Ritu R

Genes 20230825 9

<h4>Purpose</h4>Triple-negative breast cancer (TNBC) is a molecularly complex and heterogeneous breast cancer subtype with distinct biological features and clinical behavior. Although TNBC is associated with an increased risk of metastasis and recurrence, the molecular mechanisms underlying TNBC metastasis remain unclear. We performed whole-exome sequencing (WES) analysis of primary TNBC and paired recurrent tumors to investigate the genetic profile of TNBC.<h4>Methods</h4>Genomic DNA extracted ...[more]

PMID: 37761830

Similar Datasets

Project description:1. The application of massively parallel sequencing has led to the identification of aberrant druggable pathways and somatic mutations within therapeutically relevant genes in gastro-oesophageal cancer. Given the widespread use of formalin-fixed paraffin-embedded (FFPE) samples in the study of this disease, it would be beneficial, especially for the purposes of biomarker evaluation, to assess the concordance between comprehensive exome-wide sequencing data from archival FFPE samples originating from a prospective clinical study and those derived from fresh-frozen material. 2. We analysed whole-exome sequencing data to define the mutational concordance of 16 matched fresh-frozen and FFPE gastro-oesophageal tumours (N = 32) from a prospective clinical study. We assessed DNA integrity prior to sequencing and then identified coding mutations in genes that have previously been implicated in other cancers. In addition, we calculated the mutant-allele heterogeneity (MATH) for these samples. 3. Although there was increased degradation of DNA in FFPE samples compared with frozen samples, sequencing data from only two FFPE samples failed to reach an adequate mapping quality threshold. Using a filtering threshold of mutant read counts of at least ten and a minimum of 5% variant allele frequency (VAF) we found that there was a high median mutational concordance of 97% (range 80.1-98.68%) between fresh-frozen and FFPE gastro-oesophageal tumour-derived exomes. However, the majority of FFPE tumours had higher mutant-allele heterogeneity (MATH) scores when compared with corresponding frozen tumours (p < 0.001), suggesting that FFPE-based exome sequencing is likely to over-represent tumour heterogeneity in FFPE samples compared to fresh-frozen samples. Furthermore, we identified coding mutations in 120 cancer-related genes, including those associated with chromatin remodelling and Wnt/β-catenin and Receptor Tyrosine Kinase signalling. 4. These data suggest that comprehensive genomic data can be generated from exome sequencing of selected DNA samples extracted from archival FFPE gastro-oesophageal tumour tissues within the context of prospective clinical trials.

Project description:Study hypothesisExome sequencing can identify genetic causes of idiopathic recurrent pregnancy loss (RPL).Study findingWe identified compound heterozygous deleterious mutations affecting DYNC2H1 and ALOX15 in two out of four families with RPL. Both genes have a role in early development. Bioinformatics analysis of all genes with rare and putatively pathogenic mutations in miscarriages and couples showed enrichment in pathways relevant to pregnancy loss, including the complement and coagulation cascades pathways.What is known alreadyNext generation sequencing (NGS) is increasingly being used to identify known and novel gene mutations in children with developmental delay and in fetuses with ultrasound-detected anomalies. In contrast, NGS is rarely used to study pregnancy loss. Chromosome microarray analysis detects putatively causative DNA copy number variants (CNVs) in ∼2% of miscarriages and CNVs of unknown significance (predominantly parental in origin) in up to 40% of miscarriages. Therefore, a large number of miscarriages still have an unknown cause.Study design, samples/materials, methodsWhole exome sequencing (WES) was performed using Illumina HiSeq 2000 platform on seven euploid miscarriages from four families with RPL. Golden Helix SVS v8.1.5 was used for data assessment and inheritance analysis for deleterious DNA variants predicted to severely disrupt protein-coding genes by introducing a frameshift, loss of the stop codon, gain of the stop codon, changes in splicing or the initial codon. Webgestalt (http://bioinfo.vanderbilt.edu/webgestalt/) was used for pathway and disease association enrichment analysis of a gene pool containing putatively pathogenic variants in miscarriages and couples in comparison to control gene pools.Main results and the role of chanceCompound heterozygous mutations in DYNC2H1 and ALOX15 were identified in miscarriages from two families with RPL. DYNC2H1 is involved in cilia biogenesis and has been associated with fetal lethality in humans. ALOX15 is expressed in placenta and its dysregulation has been associated with inflammation, placental, dysfunction, abnormal oxidative stress response and angiogenesis. The pool of putatively pathogenic single nucleotide variants (SNVs) and small insertions and deletions (indels) detected in the miscarriages showed enrichment in 'complement and coagulation cascades pathway', and 'ciliary motility disorders'. We conclude that CNVs, individual SNVs and pool of deleterious gene mutations identified by exome sequencing could contribute to RPL.Limitations, reasons for cautionThe size of our sample cohort is small. The functional effect of candidate mutations should be evaluated to determine whether the mutations are causative.Wider implications of the findingsThis is the first study to assess whether SNVs may contribute to the pathogenesis of miscarriage. Furthermore, our findings suggest that collective effect of mutations in relevant biological pathways could be implicated in RPL.Study funding and competing interestsThe study was funded by Canadian Institutes of Health Research (grant MOP 106467) and Michael Smith Foundation of Health Research Career Scholar salary award to ERS.

Dataset Information

Whole-Exome Sequencing Reveals High Mutational Concordance between Primary and Matched Recurrent Triple-Negative Breast Cancers.

Purpose

Methods

Results

Conclusions

Publications

Whole-Exome Sequencing Reveals High Mutational Concordance between Primary and Matched Recurrent Triple-Negative Breast Cancers.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets