T47D cell line transfected with various ESR1 fusion genes (or with estrogen treatment), vs. YFP transfection alone
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: Charles Perou
PROVIDER: E-GEOD-69774 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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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: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:For the largest class of human tumors, those of epithelial origin, little is known about their initiating genetic hits or cells of origin. Whether tissue stem cells or more committed progenitors are targets for transformation is also uncertain. Experience in hematopoietic malignancies and sarcomas teaches that recurrent chromosomal translocations represent initiating oncogenic events. To develop a system in which epithelial tumorigenesis can be assessed from the initial event to frank malignancy, we have generated mice that conditionally express the Etv6-NTRK3 (EN) fusion oncoprotein, the product of the t(12;15)(p13;q25) translocation characteristic of one form of human breast cancer. Activation of EN expression in mammary tissues by Whey acidic protein (Wap) promoter-driven Cre leads to fully penetrant, multifocal malignant breast cancer with short latency. We provide genetic evidence that committed, bipotent or CD61+ luminal alveolar progenitors, can be targets of tumorigenesis. Furthermore, EN transforms these otherwise transient progenitors through the AP1 complex. Our model supports the existence of an epithelial cell hierarchy in both normal mammary glands and malignancy. To our knowledge, this is the first murine model of human epithelial cancer based on a recurrent chromosomal translocation. Given increasing relevance of chromosomal translocations in epithelial cancers, such mice serve as a paradigm for the study of their genetic pathogenesis and cellular origins, and generation of novel preclinical models. Experiment Overall Design: Reference X Sample
2008-06-16 | E-GEOD-9343 | biostudies-arrayexpress
Project description:Anti-cancer drug testing is challenging, but genetically engineered mouse models (GEMMs) and orthotopic, syngeneic transplants (OSTs) may offer advantages for pre-clinical testing including an intact microenvironment. We examined the efficacy of six chemotherapeutic or targeted anti-cancer drugs, alone and in combination, using over 500 GEMMs/OSTs representing three distinct breast cancer subtypes: Basal-like (C3(1)-T-antigen GEMM), Luminal B (MMTV-Neu GEMM), and Claudin-low (T11/TP53-/- OST). While a few single agents offered exceptional efficacy like lapatinib in the Neu/ERBB2 driven model, combination therapies tended to be more active and life prolonging. Using expression profiling of chemotherapy treated murine tumors, we identified an expression signature that was able to predict pathological complete response to neoadjuvant anthracycline-taxane treated human breast cancer patients, even after accounting for the common clinical variables and other genomic signatures. These results show that credentialed murine models can predict the efficacy of would-be anti-cancer compounds in humans, and that GEMMs can be used to develop new biomarkers of therapeutic responsiveness in humans. control X treatment
2014-01-01 | E-GEOD-37915 | biostudies-arrayexpress
Project description:The ability to predict metastatic potential is of clinical and biological importance. Numerous metastasis/relapse predictors exist for breast cancer patients; however, what is less well established is whether predicting metastasis to specific organs sites is feasible. In this study we sought to determine: 1) the degree to which gene signatures vary across tumors and their metastases, 2) if genomic intrinsic subtypes associate with particular organs of relapse, and 3) if other genomic signatures can predict spread to specific organs. Using a gene expression microarray data set of >1000 breast tumors and metastases, we observed that >90% of 298 gene signatures were similarly expressed between matched pairs of breast tumors and metastases; those most altered were reflective of cell types including fibroblasts and immune cells. Significant associations were identified between tumor subtypes and organ of first relapse. Among these, HER2-enriched tumors were significantly associated with liver, and Basal-like and Claudin-low tumors with brain and lung. Correspondingly, previously published brain and lung metastasis signatures, along with embryonic stem cell and tumor initiating cell signatures, were also associated with Basal-like and Claudin-low subtypes. These signatures strongly correlated with low Differentiation Scores (DS) and, to a lesser extent, high proliferation. Interestingly, within Basal-like and Claudin-low tumors, low DS further predicted for brain and lung metastases. In total, intrinsic subtype and DS provide clinically useful information that identifies the distant organ sites that should be most closely monitored for signs of disease recurrence. 414 samples profiled on Agilent microarrays.
2011-06-20 | E-GEOD-26338 | biostudies-arrayexpress
Project description:The tumor suppressor p53 is the most frequently mutated gene in human cancers, mutated in 25-30% of breast cancers. However, mutation rates differ according to breast cancer subtype, being more prevalent in aggressive estrogen receptor (ER) negative tumors, basal-like and HER2 amplified subtypes. This heterogeneity suggests that p53 may function differently across breast cancer subtypes. We used RNAi-mediated p53 knockdown (KD) and antagomir-mediated KD of microRNAs to study how gene expression and cellular response to p53 loss differ in luminal vs. basal-like breast cancer. As expected, p53 loss caused down regulation of established p53 targets (e.g. p21 and miR-34 family) and increased proliferation in both luminal and basal-like cell lines. However, some p53-dependent changes were subtype-specific, including expression of miR-134, miR-146a, and miR-181b. To study the cellular response to miR-146a upregulation in p53-impaired basal-like lines, antagomir knockdown of miR-146a was performed. KD of miR-146a caused decreased proliferation and increased apoptosis, effectively ablating the effects of p53 loss. Furthermore, we found that miR-146a upregulation decreased NF-kB expression and downregulated the NF-kB-dependent extrinsic apoptotic pathway (including TNF, FADD, and TRADD) and antagomir-mediated miR-146a KD restored expression of these components, suggesting a plausible mechanism for miR-146a-dependent cellular responses. These findings are relevant to human basal-like tumor progression in vivo, since miR-146a is highly expressed in p53-mutant basal-like breast cancers. These findings suggest that targeting miR-146a expression may have value for altering the aggressiveness of p53 mutant basal-like tumors. reference x sample
2014-06-30 | E-GEOD-52783 | biostudies-arrayexpress
Project description:The fibroblast growth factor pathway is known to cooperate with the highly oncogenic Wnt/ï¢-catenin pathway in mouse models of breast cancer. To investigate the mechanisms involved in this cooperativity, we utilized MMTV-driven transgenic mouse lines expressing a drug-inducible model for FGF Receptor signaling (iFGFR) crossed with the previously characterized MMTV-Wnt-1 mouse model. In these bigenic mice, both iFGFR1 and iFGFR2 activation resulted in a dramatic enhancement of mammary tumorigenesis. Tumor microarray analysis identified no transcriptional enhancement of Wnt/ï¢-catenin targets, however, identified a protein translational gene signature that also correlated with elevated FGFR1 and FGFR2 expression in several human breast cancer data sets. Additionally, iFGFR1 activation resulted in enhanced polysome recruitment and a marked increase in protein expression of several different Wnt/ï¢-catenin target oncogenes. Rapid FGFR-induced ERK activation and phosphorylation of key translation regulators was observed both in vivo in the transgenic mouse model, and in human breast cancer cell lines treated with exogenous FGF. These studies suggest that translational regulation is a key rate-limiting step required for oncogenic cooperativity between the Wnt and FGF pathways. reference X sample
2010-03-09 | E-GEOD-17916 | 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:Introduction: Over the past several years, we have been interested in understanding the mechanisms by which hormone-dependent (HD) mammary carcinomas grow in the absence of the stimulatory hormone. We have hypothesized that the stromal compartment plays a pivotal role in the acquisition of the hormone-independent (HI) phenotype by providing stimulatory factors that replace the proliferative effects of the hormone. Methods: We used DNA microarrays to compare the gene expression profiles of tumors from the MPA mouse breast cancer model, one hormone-dependent (C4-HD) and one hormone-independent (C4-HI), using whole tumor samples or laser-captured purified stromal and epithelial cells obtained from the same tumors. The expression of selected genes was validated by immunohistochemistry and immunofluorescence assays. Results: We identified 413 genes that were expressed in tumor stroma but not in epithelial cells. Eighty-five percent of these genes were upregulated, whereas the remaining 15% were downregulated in C4-HI tumors relative to their expression in the C4-HD tumor stroma. Several matrix metallopeptidases, including Mmp13, Mmp3, Mmp10 and Mmp9, were overexpressed in the C4-HI tumor microenvironment. On the other hand, 1100 genes were specifically expressed in the tumor parenchyma. Among them, the 29% were upregulated, whereas the remaining 71% were downregulated, in C4-HI relative to C4-HD tumor epithelium. Steap, Pdgfc, Runx2, Cxcl9 and Sdf2 were among the genes with high expression in the C4-HI tumor parenchyma. Interestingly, we found that Fgf2 was one of the few genes upregulated by MPA in C4-HD tumors, confirming its pivotal role in regulating tumor growth in this model. Conclusions: We demonstrate a gene expression profile that distinguishes epithelial from stromal cells in mammary tumors with different hormone dependence. Our results support the hypothesis that the tumor-associated stroma may contribute to hormone-independent tumor growth. The fact that Fgf2 was one of these few stimulatory genes is worth investigating. reference X sample
2011-01-22 | E-GEOD-23214 | biostudies-arrayexpress
Project description:Purpose:The identification of biomarkers predictive of neoadjuvant chemotherapy response in breast cancer patients would be an important advancement in personalized cancer therapy. We hypothesized that due to similarities between radiation and chemotherapy induced cellular response mechanisms, radiation responsive genes may be useful in predicting response to neoadjuvant chemotherapy. Materials and Methods: Murine p53 null breast cancer cell lines representative of the luminal, basal-like and claudin-low human breast cancer subtypes were irradiated to identify radiation responsive genes. These murine radiation induced genes were then converted to their human orthologs. These genes were then used to develop a predictor of pathologic complete response (pCR) that was validated on two independent published neoadjuvant chemotherapy data sets of genomic data with response. Results: A radiation induced gene signature consisting of 30 genes was identified on a training set of 337 human primary breast cancer tumor samples that was prognostic for survival. Mean expression of this signature was calculated for individual samples in two independent published datasets and was found to be significantly predictive of pathologic complete response. Multivariate logistic regression analysis in both independent datasets showed that this 30 gene signature added significant predictive information independent of that provided by standard clinical predictors and other gene expression based predictors of pathologic complete response. Conclusion: This study provides new biologic information regarding response to neoadjuvant chemotherapy and a means of possibly improving the prediction of pathologic complete response. reference x sample
2015-01-21 | E-GEOD-48073 | biostudies-arrayexpress