Age-associated gene expression in normal breast tissue mirrors qualitative age-at-incidence patterns for breast cancer
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ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Melissa Troester
PROVIDER: E-GEOD-43973 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Breast cancer is no longer viewed as a homogenous disease, but rather a compilation of several distinct subtypes as defined by microarray or other large scale genomic analyses. Based on prior reports, we hypothesized that younger women’s breast tumors would be enriched for more aggressive subtypes (i.e. Basal-like) and higher grade, and that age-specific gene expression differences may be highly dependent on subtype classification and/or grade. Using two independent datasets, our current analysis shows that breast tumors arising in women aged = 45 years are enriched for the Basal-like subtype (and higher grade) while those aged = 65 years are enriched for Luminal tumors. Moreover, when evaluating gene expression differences between age-defined groups, sizable gene lists were identified which diminished to few, if any, age-specific genes when statistically correcting for significant clinical factors (i.e. subtype, grade, etc). Keywords: reference x sample 344 breast tumor samples hybridized with Stratagene common reference and profiled on Agilent microarrays.
2010-08-31 | E-GEOD-20624 | biostudies-arrayexpress
Project description:Introduction: Overall survival of early-stage breast cancer (BC) patients is similar for those who undergo breast conserving therapy (BCT) and mastectomy, however, 10-15% of women undergoing BCT suffer ipsilateral breast tumor recurrence. The risk of recurrence may vary with age or breast cancer subtype. Understanding the gene expression of the cancer-adjacent tissue and/or stromal response to specific tumor subtypes is important for developing clinical strategies to reduce recurrence risk. Methods: We studied gene expression data in cancer-adjacent tissue from 158 BC patients. Complementary in vitro cocultures were used to study cell-cell communication between fibroblasts and specific breast cancer subtypes. Results: Our results suggest that intrinsic tumor subtypes are reflected in histologically normal cancer-adjacent tissue. Gene expression of cancer-adjacent tissues shows that triple negative (Claudin-low or Basal-like tumors) exhibit increased expression of genes involved in inflammation and immune response. While such changes could reflect distinct immune populations present in the microenvironment of different breast cancer subtypes, altered immune response gene expression was also observed in cocultures in the absence of immune cell infiltrates, emphasizing that these inflammatory mediators are secreted by breast-specific cells. In addition, while triple negative BCs are associated with upregulated immune response genes, Luminal breast cancers are more commonly associated with estrogen-response in adjacent tissues. Conclusions: Specific characteristics of BCs are reflected in the surrounding benign tissue. This commonality between tumor and surrounding tissue may underlie second primaries and local recurrences. Biomarkers derived from cancer-adjacent tissue may be helpful in defining personalized surgical strategies or in predicting recurrence risk. reference x sample
2014-04-30 | E-GEOD-50939 | biostudies-arrayexpress
Project description:Purpose: Previous studies of breast tissue gene expression have demonstrated that the extratumoral microenvironment has substantial variability across individuals, some of which can be attributed to epidemiologic factors. To evaluate how mammographic density (MD) and breast tissue composition relate to extratumoral microenvironment gene expression, we used data on 121 breast cancer patients from the population-based Polish Women’s Breast Cancer Study.Design: Breast cancer cases were classified based on a previously reported, biologically-defined extratumoral gene expression signature with two subtypes: an Active subtype, which is associated with high expression of genes related to fibrosis and wound response, and an Inactive subtype, which has high expression of cellular adhesion genes. MD of the contralateral breast was assessed using pre-treatment mammograms and a quantitative, reliable computer-assisted thresholding method. Breast tissue composition was evaluated based on digital image analysis of tissue sections. Results:The Inactive extratumoral subtype was associated with significantly higher percentage mammographic density (PD) and dense area (DA) in univariate analysis (PD: p=0.001; DA: p=0.049) and in multivariable analyses adjusted for age and body mass index (PD: p=0.004; DA: p=0.049). Inactive/higher MD tissue was characterized by a significantly higher percentage of stroma and a significantly lower percentage of adipose tissue, with no significant change in epithelial content. Analysis of published gene expression signatures suggested that Inactive/higher MD tissue expressed increased estrogen response and decreased TGF-ß signaling. Conclusions:By linking novel molecular phenotypes with MD, our results indicate that MD reflects broad transcriptional changes, including changes in both epithelia- and stroma-derived signaling. reference x sample
2013-10-21 | E-GEOD-49175 | biostudies-arrayexpress
Project description:Basal-like breast cancer (BBC) is an aggressive subtype of breast cancer that has no biologically targeted therapy. The interactions of BBCs with stromal cells are important determinants of tumor biology, with inflammatory cells playing well-recognized roles in cancer progression. Despite the fact that macrophage–BBC communication is bidirectional, important questions remain about how BBCs affect adjacent immune cells. This study investigated monocyte-to-macrophage differentiation and polarization and gene expression in response to coculture with basal like versus luminal breast cancer cells. Changes induced by coculture were compared with changes observed under classical differentiation and polarization conditions. Monocytes (THP-1 cells) exposed to BBC cells in coculture had altered gene expression with upregulation of both M1 and M2 macrophage markers. Two sets of M1 and M2 markers were selected from the PCR profiles and used for dual immunofluorescent staining of BBC versus luminal cocultured THP-1s, and cancer-adjacent, benign tissue sections from patients diagnosed with BBCs or luminal breast cancer, confirming the differential expression patterns. Relative to luminal breast cancers, BBCs also increased differentiation of monocytes to macrophages and stimulated macrophage migration. Consistent with these changes in cellular phenotype, a distinct pattern of cytokine secretion was evident in macrophage–BBC cocultures, including upregulation of NAP-2, osteoprotegerin, MIG, MCP-1, MCP-3, and interleukin (IL)-1b. Application of IL-1 receptor antagonist (IL-1RA) to cocultures attenuated BBC-induced macrophage migration. These data contribute to an understanding of the BBC-mediated activation of the stromal immune response, implicating specific cytokines that are differentially expressed in basal-like microenvironments and suggesting plausible targets for modulating immune responses to BBCs.Introduction: Overall survival of early-stage breast cancer (BC) patients is similar for those who undergo breast conserving therapy (BCT) and mastectomy, however, 10-15% of women undergoing BCT suffer ipsilateral breast tumor recurrence. The risk of recurrence may vary with age or breast cancer subtype. Understanding the gene expression of the cancer-adjacent tissue and/or stromal response to specific tumor subtypes is important for developing clinical strategies to reduce recurrence risk. Methods: We studied gene expression data in cancer-adjacent tissue from 158 BC patients. Complementary in vitro cocultures were used to study cell-cell communication between fibroblasts and specific breast cancer subtypes. Results: Our results suggest that intrinsic tumor subtypes are reflected in histologically normal cancer-adjacent tissue. Gene expression of cancer-adjacent tissues shows that triple negative (Claudin-low or Basal-like tumors) exhibit increased expression of genes involved in inflammation and immune response. While such changes could reflect distinct immune populations present in the microenvironment of different breast cancer subtypes, altered immune response gene expression was also observed in cocultures in the absence of immune cell infiltrates, emphasizing that these inflammatory mediators are secreted by breast-specific cells. In addition, while triple negative BCs are associated with upregulated immune response genes, Luminal breast cancers are more commonly associated with estrogen-response in adjacent tissues. Conclusions: Specific characteristics of BCs are reflected in the surrounding benign tissue. This commonality between tumor and surrounding tissue may underlie second primaries and local recurrences. Biomarkers derived from cancer-adjacent tissue may be helpful in defining personalized surgical strategies or in predicting recurrence risk. reference x sample
2013-11-15 | E-GEOD-52292 | biostudies-arrayexpress
Project description:Introduction: In breast cancers, the basal-like subtype has high levels of genomic instability relative to other breast cancer subtypes with many basal-like-specific regions of aberration. There is evidence that this genomic instability extends to smaller scale genomic aberrations as well, as shown by a previously described micro-event in the PTEN gene in the Basal-like SUM149 breast cancer cell line. Methods: We sought to identify if small regions of genomic change exist by using a high density, gene centric Comparative Genomic Hybridizations (CGH) array on both cell lines and primary tumors. A custom Agilent tiling array for CGH (244,000 probes, 200bp tiling resolution) was created to identify small regions of genomic change and was focused on previously identified basal-like-specific, and general cancer genes. Tumor genomic DNA from 94 patients and 2 breast cancer cell lines was labeled and hybridized to these arrays. Aberrations were called using SWITCHdna and the smallest 25% of SWITCHdna-defined genomic segments being called micro-aberrations (<64 contiguous probes, ~ <15kb). Results: Our data showed that primary tumor breast cancer genomes frequently contained areas of small-scale copy number gains and losses, termed micro-aberrations, which are undetectable using lower-density genome-wide platforms. The basal-like subtype exhibited the highest incidence of these events. These micro-aberrations sometimes altered expression of the involved gene as suggested by data from microarray and mRNA-seq studies. We confirmed the presence of the PTEN micro-amplification in SUM149 and by mRNA-seq showed that this resulted in loss of expression of all exons downstream of this event. Micro-aberrations disproportionately affected the 5’ regions of the affected genes, including the promoter region, and a high frequency of micro-aberrations was associated with poor survival outcomes. Conclusion: Using a high probe density, gene-centric aCGH microarray, we present evidence of small-scale genomic aberrations that contribute to gene inactivation, and thus, genomic instability and tumor formation through a mechanism not detected using conventional copy number analyses. reference x sample
2013-04-22 | E-GEOD-36889 | biostudies-arrayexpress
Project description:Interactions of cancer cells with the vasculature are essential for tumor growth and likely promote metastatic progression. Endothelial cell content and lympho-vascular invasion are generally associated with tumor aggressiveness, however, these features are generally not employed in the clinic. We aimed to determine if endothelial cell gene expression signatures could be utilized to better characterize breast tumor biology, and to establish if vascular cell-derived signatures could provide information to predict tumors likely to metastasize. Here we report on the identification of a gene signature for vascular endothelial cells, and a second for cancer-activated vasculature. Both signatures independently identify subsets of aggressive breast cancers. Interestingly, the vascular content signature and a previously identified hypoxia signature both provide prognostic information beyond currently utilized clinical parameters and intrinsic subtype classifications. In these studies, we also examined the relationship that the breast cancer subtypes have with vascular gene expression profiles, and found that claudin-low tumors and cell lines express vascular gene expression profiles and displayed endothelial-like tube formation when grown in three-dimensions. These findings are directly applicable to clinical care and therapeutic treatment design as they identify highly aggressive subsets of tumors with genetic and morphologic vascular properties. reference x sample
2014-01-01 | E-GEOD-37145 | biostudies-arrayexpress
Project description:Triple-negative (TN) and Basal-like (BL) breast cancer definitions have been used interchangeably to identify breast cancers that lack expression of the hormonal receptors (HR) and overexpression and/or amplification of HER2. However, both classifications when compared to each other, show substantial discordance rates. Here, we molecularly characterize TN tumors, and Basal-like tumors, and compare and contrast the results in terms of common patterns and distinct patterns for each. In total, when testing 412 TN and 473 Basal-like tumors, 21.4% and 31.5% were identified as non-Basal-like and non-TN, respectively. TN tumors identified as Luminal or HER2-enriched showed undistinguishable overall gene expression profiles when compared versus Luminal or HER2-enriched tumors that were not TN. Similar findings were observed within Basal-like tumors regardless of the TN status. Interestingly, most TN tumors identified as HER2-enriched showed low HER2 expression and lack of HER2 amplification despite the similar overall gene expression profiles to HER2-E tumors that were not TN. Lastly, additional genomic classifications are examined within TN and Basal-like cancers, most of which are largely concordant with tumor intrinsic subtype. These results suggest that future clinical trials focused on TN disease should consider stratifying patients based on Basal-like versus non-Basal-like gene expression profiles as this appears to be the main biological difference seen within TN breast cancer patients. reference x sample
2014-07-29 | E-GEOD-41119 | biostudies-arrayexpress
Project description:End-stage breast cancers are clonally heterogeneous and harbor many poorly-understood treatment resistance mechanisms. We therefore established multiple Patient-Derived-Xenograft (PDX) models to study genomic events driving advanced disease. Comparative whole-genome sequencing of paired primary tumors and their PDX models demonstrated that PDX retain the vast majority of the structural variations and copy number aberrations seen within the originating tumor, and with high fidelity. Variant allele fractions (VAF) were preserved, even for rare mutations. Clonal representation is therefore a transplantable phenotype, indicating that genomic heterogeneity can be regulated in a tumor-autonomous mechanism, indifferent to host immune status. Mutations and gene rearrangements were documented in the ESR1 gene in three of five sequenced luminal PDX/progenitor tumor pairs (amplification, point mutation and translocation), and were associated with clinical endocrine response phenotypes, differential PDX estradiol responsiveness and all induced estradiol-independent growth in standard cell lines. PDX models are therefore a significant new tool for fundamental studies on the molecular basis for resistance to endocrine treatment in advanced breast cancer. reference x sample
2013-12-22 | E-GEOD-46604 | biostudies-arrayexpress
Project description:Chemotherapy resistance frequently drives tumor progression. However, the underlying molecular mechanisms are poorly characterized. Epithelial-to-mesenchymal transition (EMT) has been shown to correlate with therapy resistance, but the functional link and signaling pathways remain to be elucidated. We report here that miR-30c, a human breast tumor prognostic marker, plays a pivotal role in chemo-resistance by a direct targeting of the actin-transporter TWF1, which promotes EMT. An IL-6 family member, IL-11 was identified as a secondary target of TWF1 in the miR-30c signaling pathway. Expression of miR-30c inversely correlated with IL-11 expression in clinical tumors and IL-11 correlated with relapse-free survival in breast cancer patients. Identification of a novel miRNA-mediated pathway that regulates chemo-resistance in breast cancer will facilitate the development of new management strategies. reference x sample
2013-01-18 | E-GEOD-22049 | biostudies-arrayexpress
Project description:Basal-like breast tumors are aggressive cancers associated with high proliferation and metastasis. Currently basal-like breast cancer patients can only be treated with chemotherapy options. However, resistance to chemotherapy often occurs, resulting in recurrence and patient death. Some extremely aggressive basal-like breast cancers are also associated with hypoxia, inflammation and high leukocyte infiltration. Herein we discovered that the neural-specific transcription factor Engrailed 1 (EN1) is exclusively overexpressed in basal-like breast cancers. ShRNA-mediated knockdown of EN1 in basal-like breast cancer cells triggered potent and selective cell death. In contrast, ectopic overexpression of EN1 in normal cells activated survival pathways and conferred resistance to chemotherapeutic agents. Exogenous expression of EN1 cDNA reprogrammed the breast epithelial cells towards a long-lived, neural-like phenotype displaying dopaminergic markers. Gene expression microarrays demonstrated that the EN1 cDNA altered transcription of a high number of inflammatory molecules, notably chemokines and chemokine receptors, which could mediate pro-survival pathways. To block EN1 function, we engineered synthetic interference peptides (iPeps) comprising the EN1-specific sequences mediating essential protein-protein interactions necessary for EN1 function and an N-terminal cell-penetrating peptide/nuclear localization sequence. These EN1-iPeps rapidly mediated a strong apoptotic response in tumor cells overexpressing EN1, with no toxicity to normal or non EN1-expressing cells. Delivery of EN1-iPeps into basal-like cancer cells significantly decreased the IC50 of chemotherapeutic drugs routinely used to treat breast cancer. Lastly, MALDI-TOF mass spectrometry and immunoprecipitation assays demonstrated that EN1-iPeps captured targets involved in transcriptional and post-transcriptional regulation. Importantly, the EN1-iPeps bound the Glutamyl-prolyl tRNA synthetase (EPRS) target, which has been associated with the transcript-specific translational control of inflammatory proteins and activation of amino acid stress pathways. These studies show that EN1 activates intrinsic inflammatory pathways associated with pro-survival in basal-like breast cancer and that peptides targeting EN1 function could potentially be used to combat these lethal forms of breast cancer. reference x sample
2013-12-31 | E-GEOD-47358 | biostudies-arrayexpress