Search bioRxiv⌕ Search

Biology subjects

Storniolo, A. M.

Publications and source records attributed to Storniolo, A. M..

7 recordsLinked to original sources

Systematic dissection of epigenetic age acceleration in normal breast tissue reveals its link to estrogen signaling and cancer risk

Breast aging encompasses intricate molecular and cellular changes that elevate cancer risk. Our study profiled DNA methylation and gene expression of 181 normal breast samples and systematically evaluated eight epigenetic clocks. We found that clocks trained using breast tissues demonstrate improved age prediction in normal breast tissue, and bias universally exists in epigenetic clocks, necessitating a proper definition of age acceleration. Cell composition analysis revealed significant age-related alterations and highlighted its distinct associations with age acceleration, including increased luminal epithelial and myoepithelial cells and reduced adipocytes and immune cells, connecting age acceleration to carcinogenesis from a cell compositional perspective. Additionally, CpG sites associated with age acceleration were enriched for estrogen receptor binding sites, providing a mechanistic link between estrogen exposure, accelerated aging, and cancer. These findings highlight the importance of cellular heterogeneity in epigenetic age estimates and the potential of age acceleration to guide for risk stratification and prevention strategies.

bioinformatics↗

Single nuclei chromatin accessibility and transcriptomic map of breast tissues of women of diverse genetic ancestry

Single nuclei analysis is allowing robust classification of cell types in an organ that helps to establish relationships between cell-type specific gene expression and chromatin accessibility status of gene regulatory regions. Using breast tissues of 92 healthy donors of various genetic ancestry, we have developed a comprehensive chromatin accessibility and gene expression atlas of human breast tissues. Integrated analysis revealed 10 distinct cell types in the healthy breast, which included three major epithelial cell subtypes (luminal hormone sensing, luminal adaptive secretory precursor, and basal-myoepithelial cells), two endothelial subtypes, two adipocyte subtypes, fibroblasts, T-cells, and macrophages. By integrating gene expression signatures derived from epithelial cell subtypes with spatial transcriptomics, we identify specific gene expression differences between lobular and ductal epithelial cells and age-associated changes in epithelial cell gene expression patterns and signaling networks. Among various cell types, luminal adaptive secretory cells and fibroblasts showed genetic ancestry dependent variability. A subpopulation of luminal adaptive secretory cells with alveolar progenitor (AP) cell state were enriched in Indigenous American (IA) ancestry and fibroblast populations were distinct in African ancestry. ESR1 expression pattern was distinctly different in cells from IA compared to the rest, with a high level of ESR1 expression extending to AP cells and crosstalk between growth factors and Estrogen Receptor signaling being evident in these AP cells. In general, cell subtype-specific gene expression did not uniformly correlate with cell-specific chromatin accessibility, suggesting that transcriptional regulation independent of chromatin accessibility governs cell type-specific gene expression in the breast.

cancer biology↗

BRCA1 and BRCA2 germline mutations driven signaling pathway alterations are sufficient to initiate breast tumorigenesis by the PIK3CAH1047R oncogene.

Single cell transcriptomics studies have begun to identify breast epithelial cell and stromal cell specific transcriptome differences between BRCA1/2 mutation carriers and non-carriers. We generated a single cell transcriptome atlas of breast tissues from BRCA1, BRCA2 mutation carriers and compared this single cell atlas of mutation carriers with our previously described single cell breast atlas of healthy non-carriers. We observed that BRCA1 but not BRCA2 mutations altered the ratio between basal, luminal progenitor and mature luminal cells in breast tissues. A unique subcluster of cells within luminal progenitors is underrepresented in case of BRCA1 and BRCA2 mutation carriers compared to non-carriers. Both BRCA1 and BRCA2 mutations specifically altered transcriptomes in epithelial cells which are an integral part of NF-{kappa}B, LARP1, and MYC signaling. Reduction of MYC signaling and translational machinery in BRCA1/2 mutant epithelial cells is reminiscent of embryonic diapause-like adaptation that occurs in drug tolerant populations of cells. Signaling pathway alterations in epithelial cells unique to BRCA1 mutations included STAT3, BRD4, SMARCA4, HIF2A/EPAS1, and Inhibin-A signaling. BRCA2 mutations were associated with upregulation of IL-6, PDK1, FOXO3, and TNFSF11 signaling. These signaling pathway alterations are sufficient to alter sensitivity of BRCA1/BRCA2-mutant breast epithelial cells to transformation as epithelial cells from BRCA1 mutation carriers overexpressing hTERT + PIK3CAH1047R generated adenocarcinomas, whereas similarly modified mutant BRCA2 cells generated basal carcinomas in NSG mice. Thus, our studies provide a high-resolution transcriptome atlas of breast epithelial cells of BRCA1 and BRCA2 mutation carriers and reveal their susceptibility to PIK3CA mutation-driven transformation. Statement of SignificanceThis study provides a single cell atlas of breast tissues of BRCA1/2 mutation carriers and demonstrates that aberrant signaling due to BRCA1/2 mutations sufficient to initiate breast cancer by mutant PIK3CA.

cancer biology↗

Influence of genetic ancestry on breast stromal cells provides biologic basis for increased incidence of metaplastic breast cancer in women of African descent

The biologic basis of genetic ancestry-dependent variability in disease incidence and outcome is just beginning to be explored. We recently reported enrichment of a population of ZEB1-expressing cells located adjacent to the ductal epithelial cells in the normal breast of women of African Ancestry (AA) compared to European Ancestry (EA). By establishing and characterizing cell lines corresponding to these cells and validating in vitro findings with tissue microarrays of healthy breast tissue from AA, EA and Latina Ancestry (LA) women, we demonstrate that these cells have the properties of fibroadipogenic/mesenchymal stromal cells that express PROCR and PDGFR. PROCR+/ZEB1+/PDGFR+ cells, hence renamed as PZP cells, are enriched in the normal breast tissues of AA compared to EA or LA women. In vitro, PZP cells trans-differentiated into adipocytes or osteocytes. In co-culture conditions, PZP:epithelial cell communication resulted in luminal epithelial cells acquiring basal/stem cell characteristics and increased expression of IL-6 suggesting the impact of this communication on breast epithelial hierarchy and the microenvironment. Consistent with this possibility, the level of phospho-STAT3, which is a downstream target of IL-6, was higher in the normal and cancerous breast tissues of AA compared to EA women. PZP cells transformed with HRasG12V {+/-} SV40-T/t antigens generated metaplastic carcinoma in NSG mice suggesting that these cells could be the cell-of-origin of metaplastic breast cancers. Collectively, these results identify a stromal cell component that could influence the biology of breast cancer in AA women.

cancer biology↗

Aberrant epigenetic and transcriptional events associated with breast cancer risk

BackgroundGenome-wide association studies have identified several breast cancer susceptibility loci. However, biomarkers for risk assessment are still missing. Here, we investigated cancer-related molecular changes detected in tissues from women at high risk for breast cancer prior to disease manifestation. Disease-free breast tissue cores donated by healthy women (N=146, median age=39 years) were processed for both methylome (MethylCap) and transcriptome (Illuminas HiSeq4000) sequencing. Analysis of tissue microarray and primary breast epithelial cells was used to confirm gene expression dysregulation. ResultsTranscriptomic analysis identified 69 differentially expressed genes between women at either high and those at average risk of breast cancer (Tyrer-Cuzick model) at FDR<0.05 and fold change[&ge;]2. The majority of the identified genes were involved in DNA damage checkpoint, cell cycle, and cell adhesion. Two genes, FAM83A and NEK2, were overexpressed in tissue sections (FDR<0.01) and primary epithelial cells (p<0.05) from high-risk breasts. Moreover, 1698 DNA methylation aberrations were identified in high-risk breast tissues (FDR<0.05), partially overlapped with cancer-related signatures and correlated with transcriptional changes (p<0.05, r[&le;]0.5). Finally, among the participants, 35 women donated breast biopsies at two time points, and age-related molecular alterations enhanced in high-risk subjects were identified. ConclusionsNormal breast tissue from women at high risk of breast cancer bears molecular aberrations that may contribute to breast cancer susceptibility. This study is the first molecular characterization of the true normal breast tissues and provides an opportunity to investigate molecular markers of breast cancer risk, which may lead to new preventive approaches.

cancer biology↗

The Human Tumor Atlas Network (HTAN) Breast PreCancer Atlas: A multi-omic integrative analysis of ductal carcinoma in situ with clinical outcomes

Ductal carcinoma in situ (DCIS) is the most common precursor of invasive breast cancer (IBC), with variable propensity for progression. We have performed the first multiscale, integrated profiling of DCIS with clinical outcomes by analyzing 677 DCIS samples from 481 patients with 7.1 years median follow-up from the Translational Breast Cancer Research Consortium (TBCRC) 038 study and the Resource of Archival Breast Tissue (RAHBT) cohorts. We identified 812 genes associated with ipsilateral recurrence within 5 years from treatment and developed a classifier that was predictive of DCIS or IBC recurrence in both cohorts. Pathways associated with recurrence include proliferation, immune response, and metabolism. Distinct stromal expression patterns and immune cell compositions were identified. Our multiscale approach employed in situ methods to generate a spatially resolved atlas of breast precancers, where complementary modalities can be directly compared and correlated with conventional pathology findings, disease states, and clinical outcome. HIGHLIGHTS Development of a new classifier for DCIS recurrence or progression Outcome associated pathways identified across multiple data types and compartments Four stroma-specific signatures identified CNAs characterize DCIS subgroups associated with high risk invasive cancers

cancer biology↗

A single cell atlas of the healthy breast tissues reveal clinically relevant clusters of breast epithelial cells

SummarySingle cell RNA sequencing is an evolving field to elucidate cellular architecture of adult organs. Using normal breast tissues from healthy volunteers and a rapid procurement/processing/sequencing protocol, 13 breast epithelial cell clusters were identified. Approximately 90% of breast cancers were enriched for cell-of-origin signatures derived from differentiated luminal clusters and two minor luminal progenitor clusters. Expression of cell cycle and chromosome segregation-related genes were higher in one of the minor clusters and breast tumors with this cluster signature displayed the highest mutation rate and poor outcome. We identified TBX3 and PDK4 as genes co-expressed with estrogen receptor (ER) in the normal breasts and their expression analyses in >550 breast cancers enabled prognostically relevant cell-of-origin based subclassification of ER+ breast cancers.Significance This study elucidates different epithelial cell types of the normal breasts and identifies a minor subpopulation of cells from which the majority of breast cancers may originate. This observation should help to develop methods to characterize breast tumors based on cell-of-origin. Although it was suggested that intrinsic subtypes of breast cancers have distinct cells of origins, this study suggests multiple cell-of-origin for an intrinsic subtype of breast cancer, including for hormone responsive breast cancers. Cell-of-origin signatures allowed survival-associated subclassification of intrinsic subtypes. Critically, this normal breast cell atlas would allow for the classification of genes differentially expressed in a breast tumor compared to normal breast due to the cell-of-origin of tumor and those that are acquired due to genomic aberrations.Competing Interest StatementThe authors have declared no competing interest.View Full Text

cancer biology↗