Somatic pathogenic variants in the normal mammary gland of sporadic breast cancer patients.
Ontology highlight
ABSTRACT:
PROVIDER: EGAC00001002391 | EGA |
REPOSITORIES: EGA
Similar Datasets
Project description:The mammary gland undergoes hormonally stimulated cycles of proliferation, lactation, and involution. We hypothesized that these factors increase the mutational burden in glandular tissue and may explain high cancer incidence rate in the general population, and recurrent disease. Hence, we investigated the DNA sequence variants in the normal mammary gland, tumor, and peripheral blood from 52 reportedly sporadic breast cancer patients. Targeted resequencing of 542 cancer-associated genes revealed subclonal somatic pathogenic variants of: PIK3CA, TP53, AKT1, MAP3K1, CDH1, RB1, NCOR1, MED12, CBFB, TBX3, and TSHR in the normal mammary gland at considerable allelic frequencies (9 × 10-2- 5.2 × 10-1), indicating clonal expansion. Further evaluation of the frequently damaged PIK3CA and TP53 genes by ultra-sensitive duplex sequencing demonstrated a diversified picture of multiple low-level subclonal (in 10-2-10-4 alleles) hotspot pathogenic variants. Our results raise a question about the oncogenic potential in non-tumorous mammary gland tissue of breast-conserving surgery patients.
| S-EPMC9243094 | biostudies-literature
Project description:The mammary gland undergoes hormonally stimulated cycles of proliferation, lactation and involution. We hypothesized that these factors increase the mutational burden in glandular tissue and may explain high cancer incidence rate in the general population and recurrent disease. Hence, we investigated the DNA sequence variants in the normal mammary gland, tumor and peripheral blood from 52 reportedly sporadic breast cancer patients, including breast-conserving surgery cases. Targeted resequencing of 542 cancer associated genes revealed mosaic somatic pathogenic variants of: PIK3CA, TP53, AKT1, MAP3K1, CDH1, RB1, NCOR1, MED12, CBFB, TBX3 and TSHR in the normal mammary gland, at considerable allelic frequencies (9x10-2 to 5.2x10-1) indicating clonal expansion. Further evaluation of the frequently damaged PIK3CA and TP53 genes by ultra-sensitive duplex sequencing demonstrated a diversified picture of multiple low level-mosaic (in 10-2 to 10-4 alleles) hotspot pathogenic variants. Our results raise a question about the oncogenic potential in non-tumor mammary gland tissue of breast-conserving surgery patients.
| EGAS00001005698 | EGA
Project description: Not available
| S-EPMC10666181 | biostudies-literature
Project description:The receptor tyrosine kinase AXL is associated with epithelial plasticity in several solid tumors including breast cancer and AXL-targeting agents are currently in clinical trials. We hypothesized that AXL is a driver of stemness traits in cancer by co-option of a regulatory function normally reserved for stem cells. AXL-expressing cells in human mammary epithelial ducts co-expressed markers associated with multipotency, and AXL inhibition abolished colony formation and self-maintenance activities while promoting terminal differentiation in vitro. Axl-null mice did not exhibit a strong developmental phenotype, but enrichment of Axl + cells was required for mouse mammary gland reconstitution upon transplantation, and Axl-null mice had reduced incidence of Wnt1-driven mammary tumors. An AXL-dependent gene signature is a feature of transcriptomes in basal breast cancers and reduced patient survival irrespective of subtype. Our interpretation is that AXL regulates access to epithelial plasticity programs in MaSCs and, when co-opted, maintains acquired stemness in breast cancer cells.
| S-EPMC7578759 | biostudies-literature
Project description:Women in North America have a one in eight lifetime risk of developing breast cancer (BC), and a significant proportion of these individuals will develop recurrent BC and will eventually succumb to the disease. Metastatic, therapy-resistant BC cells are refractory to cell death induced by multiple stresses. Here, we document that the vitamin D receptor (VDR) acts as a master transcriptional regulator of autophagy. Activation of the VDR by vitamin D induces autophagy and an autophagic transcriptional signature in BC cells that correlates with increased survival in patients; strikingly, this signature is present in the normal mammary gland and is progressively lost in patients with metastatic BC. A number of epidemiological studies have shown that sufficient vitamin D serum levels might be protective against BC. We observed that dietary vitamin D supplementation in mice increases basal levels of autophagy in the normal mammary gland, highlighting the potential of vitamin D as a cancer-preventive agent. These findings point to a role of vitamin D and the VDR in modulating autophagy and cell death in both the normal mammary gland and BC cells.
| S-EPMC5358377 | biostudies-literature
Project description:This study demonstrates a liquid-liquid extraction for the sequential tandem mass spectrometry (LC-MS/MS) analysis of non-polar lipids, polar metabolites, proteins and phosphorylation sites from a single piece of tissue. Extraction of 10 mg BRCA-/-, p53-/- breast tumor tissue or normal mammary gland tissue with methyl-tert-butyl ether (MTBE) results in three phases: an upper non-polar phase containing 1,382 lipids, a lower polar phase with 805 metabolites and a precipitated protein pellet with 4,792 proteins with 1,072 phosphorylation sites. Comparative analysis revealed an activated AKT-mTOR pathway in tumors. Tumors also showed a reduction of phosphorylation sites involved in transcription and RNA splicing and decreased abundance of enzymes in lipid synthesis. Analysis of polar metabolites revealed a reduction in glycolysis, pentose phosphate pathway, polyamines and nucleotides, but an increase in TCA and urea cycle intermediates. Analysis of lipids revealed a shift from high triglycerides in mammary gland to high phospholipid levels in tumors. The data were integrated into a model showing breast tumors exhibit features on the proteomic, lipidomic and metabolomic level that are distinct from normal breast tissue. Our integrative technique lends itself to samples such as tumor biopsies, dried blood spots and fluids including urine and CSF to develop biomarkers of disease.
| S-EPMC5674068 | biostudies-literature
Project description:Genetic analyses were conducted on tumor samples from 88 patients with uveal melanoma (UM), 6 of whom carry pathogenic germline variants in BAP1. We assessed the frequency, pattern, and prognostic significance of somatic aberrations, and investigated differences between germline BAP1 variant carriers compared to sporadic cases. The frequency of the main oncogenic driver mutations was not significantly different between these groups. Patients with germline BAP1 variants did not have significantly different overall survival compared to the wildtype or somatic BAP1 mutation groups. Patients with a somatic BAP1 mutation (n = 24) had a significantly worse prognosis compared to wildtype (n = 58). All patients with stage III tumors and a somatic BAP1 mutation (n = 7) developed metastasis, however four of 28 stage I-II tumors without metastasis had somatic BAP1 mutations, with observation time >5 years. The tumor from one germline BAP1 carrier (stage IIIC) with a somatic EIF1AX splice variant, has not developed metastasis within a 22-year observation time.
| S-EPMC11460691 | biostudies-literature
Project description:BackgroundBreast cancers (BCs) that arise in individuals heterozygous for a germline pathogenic variant in a susceptibility gene, such as BRCA1 and BRCA2, PALB2, and RAD51C, have been shown to exhibit biallelic loss in the respective genes and be associated with triple-negative breast cancer (TNBC) and distinctive somatic mutational signatures. Tumor sequencing thus presents an orthogonal approach to assess the role of candidate genes in BC development.MethodsExome sequencing was performed on paired normal-breast tumor DNA from 124 carriers of germline loss-of-function (LoF) or missense variant carriers in 15 known and candidate BC predisposition genes identified in the BEACCON case-control study. Biallelic inactivation and association with tumor genome features including mutational signatures and homologous recombination deficiency (HRD) score were investigated.ResultsBARD1-carrying TNBC (4 of 5) displayed biallelic loss and associated high HRD scores and mutational signature 3, as did a RAD51D-carrying TNBC and ovarian cancer. Biallelic loss was less frequent in BRIP1 BCs (4 of 13) and had low HRD scores. In contrast to other established BC genes, BCs from carriers of CHEK2 LoF (6 of 17) or missense (2 of 20) variant had low rates of biallelic loss. Exploratory analysis of BC from carriers of LoF variants in candidate genes such as BLM, FANCM, PARP2, and RAD50 found little evidence of biallelic inactivation.ConclusionsBARD1 and RAD51D behave as classic BRCA-like predisposition genes with biallelic inactivation, but this was not observed for any of the candidate genes. However, as demonstrated for CHEK2, the absence of biallelic inactivation does not provide definitive evidence against the gene's involvement in BC predisposition.
| S-EPMC9905963 | biostudies-literature
Project description:ImportanceMetaplastic breast cancer (MpBC) is a rare, heterogeneous disease often associated with inferior outcomes. A growing body of literature describes the clinical and molecular features of MpBC, yet limited data describe the pathogenic germline variants (PGVs) in breast cancer susceptibility genes among affected individuals.ObjectiveTo examine the frequency and types of PGVs in breast cancer genes among patients with MpBC.Design, setting, and participantsThis is a descriptive retrospective cohort study of patients who received a diagnosis of MpBC at the University of Pennsylvania between January 2010 and May 2023. Electronic medical records were reviewed for demographic, clinicopathologic, and germline genetic testing information. Germline variant status was independently confirmed by a licensed genetic counselor and a physician with expertise in genetics. MpBC diagnosis and subtype were confirmed by a breast pathologist. Participants were identified via query of an institutional pathology database for reports signed between January 2010 and May 2023 including the term metaplastic. Among 320 initially obtained reports, 272 individuals had confirmed MpBC and were included in the study.ExposureGermline genetic testing to investigate the presence of PGVs in breast cancer susceptibility genes.Main outcomes and measuresThe primary outcome measurement was the prevalence of PGVs in breast cancer susceptibility genes among participants. The hypothesis that individuals with MpBC have an enrichment of PGVs in genes associated with inherited breast cancer risk was formulated before data collection.ResultsThe total sample size was 272 women, and the median age at diagnosis was 58 years (range, 20-102 years); all were biological female patients; 143 of 272 (52.6%) had documentation of germline genetic testing; and participants with testing were significantly younger than those without (median age, 53 years [range, 20-79 years] vs 63 years [range, 29-102 years]; P < .001). Of the 143 patients, 24 (16.8%) had a PGV in a breast cancer susceptibility gene (BRCA1, n = 17; BRCA2, n = 5; PALB2, n = 1; CHEK2, n = 1). Patients with PGV-associated MpBC received a diagnosis at a younger age than those with sporadic disease, but there were no significant differences in hormone receptor positivity, ERBB2 status, or metaplastic subtype.Conclusions and relevanceIn this cohort study of patients with MpBC, a substantial proportion of clinically tested patients had a PGV in a breast cancer susceptibility gene, most commonly BRCA1. Germline testing was high yield in patients with MpBC, many of whom would be included in current germline testing eligibility criteria.
| S-EPMC11836754 | biostudies-literature
Project description: Not available
| S-EPMC6802240 | biostudies-literature