Novel role of Engrailed 1 as pro-survival transcription factor in basal-like breast cancer and engineering of interference peptides to block its oncogenic function
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
SUBMITTER: PILAR BLANCAFORT
PROVIDER: E-GEOD-47358 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
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:Basal-like breast cancers have several well-characterized distinguishing molecular features, but most of these are features of the cancer cells themselves. The unique stromal-epithelial interactions, and more generally, microenvironmental features of basal-like breast cancers, have not been well characterized. To identify characteristic microenvironment features of basal-like breast cancer, we performed cocultures of several basal-like breast cancer cell lines with fibroblasts (reduction mammoplasty-derived fibroblast line; RMF) and compared these to cocultures of luminal breast cancer cell lines with fibroblasts. Interactions between basal-like cancer cells and fibroblasts induced expression of numerous interleukins and chemokines, including IL-6, IL-8, CXCL1, CXCL3, and TGFbeta. Under the influence of fibroblasts, basal-like breast cancer cell lines also showed increased migration in vitro. Migration was less pronounced for luminal lines, but these lines were more likely to have altered proliferation. These differences were relevant to tumor biology in vivo, as the gene set that distinguished luminal and basal-like stromal interactions in coculture also distinguishes basal-like from luminal tumors with 98% accuracy in 10-fold CV and 100% accuracy in an independent test set. However, comparisons between cocultures where cells were in direct contact and cocultures where interaction was solely through soluble factors suggest that there is an important impact of direct cell-to-cell contact. The phenotypes and gene expression changes invoked by cancer cell interactions with fibroblasts support the microenvironment and cell-cell interactions as intrinsic features of breast cancer subtypes. 99 samples were hybridized with Stratagene common reference and profiled on Agilent microarrays.
2011-05-26 | E-GEOD-26411 | biostudies-arrayexpress
Project description:SUMMARY: Basal breast cancer has been associated with mutations in a number of specific tumor suppressor genes, however, the mechanism by which these tumors express a basal lineage remains unknown. Notch signaling suppresses mammary stem cell (MaSC) self-renewal, while promoting luminal cell fate specification. Here we show that Lfng, a sugar transferase that facilitates Notch activation, suppresses mammary stem/bipotent progenitor cell proliferation. Targeted deletion of Lfng in mammary epithelium induces basal tumors with reduced expression of Notch targets, amplification of the Met/Caveolin gene locus, and elevated Met and Igf-1R signaling. Human basal breast cancer, a disease associated with elevated MET receptor signaling and Caveolin protein, express low levels of LFNG. Thus, reduced LFNG expression cooperates with a Met/ Caveolin amplicon to promote basal breast disease. SIGNIFICANCE: Anti-Notch therapy is currently being tested for efficacy against basal-like breast cancer in humans. Here we report that LFNG, which controls Notch receptor activation, is consistently expressed at a low level in basal tumors and that deletion of this gene in the mouse mammary gland reduces Notch signaling, increases proliferation and induces basal mammary tumors in cooperation with amplification of the Met/Caveolin gene locus. These mutations interact to promote basal gene expression by decreasing Notch pathway activation, as well as to enhance Met and Igf-1R signaling. These pathways can be targeted at multiple levels in humans harboring basal breast cancer with amplification of MET and CAV1/2 32 array samples
2012-05-29 | E-GEOD-28712 | 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: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 basal-like breast cancer subtype portends a poor clinical prognosis, and a defining feature of this subtype is the high expression of genes in the âproliferation signatureâ. B-Myb, a member of the MYB protein family of transcription factors, is highly expressed in the proliferation signature and is amplified and overexpressed in a variety of tumor types, including breast. In this report we demonstrated that B-Myb is highly expressed in basal-like breast cancer relative to the other subtypes, and B-Myb expression alone is prognostic. We also identified an association between a nonsynonymous B-Myb germline variant (S427G, rs2070235) and an increased risk of having a basal-like breast cancer among patients with breast cancer. The expression of B-Myb, or the S427G variant, was manipulated in vitro and we observed that in hTERT-immortalized normal Human Mammary Epithelial Cells, but not basal-like tumor-derived lines, cells ectopically expressing B-Myb showed increased sensitivity to DNA topoisomerase II inhibitors, but not other chemotherapeutics; in addition, microarray analyses of B-Myb overexpressing cells identified many G2/M targets as being preferentially induced. These results again suggest that B-Myb is involved in G2/M cell cycle control and that dysregulation of B-Myb may contribute to an increased sensitivity to a specific class of chemotherapeutic agents in vitro, and potentially in vivo. These data provide insight into the influence of B-Myb in human breast cancer, which is of potential clinical importance for determining disease risk and for guiding treatment. Experiment Overall Design: Reference VS. Samples
2009-01-18 | E-GEOD-11429 | biostudies-arrayexpress
Project description:ABSTRACT: Introduction: Basal-like and luminal breast cancers have distinct stromal-epithelial interactions, which likely play a role in progression to invasive cancer. However, little is known about how stromal-epithelial interactions evolve in benign and pre-invasive lesions.Methods: To study epithelial-stroma interactions in basal-like breast cancer progression, we cocultured reduction mammoplasty fibroblasts with the isogenic MCF10 series of cell lines (representing benign/normal, atypical hyperplasia, and ductal carcinoma in situ). We used gene expression microarrays to identify pathways induced by coculture in premalignant cells (MCF10DCIS) compared to normal and benign (MCF10A and MCF10AT1). Relevant pathways were then (1) targeted in vitro and effects on morphogenesis were evaluated and (2) evaluated in vivo for associations with basal-like subtype. Results: Our results show that premalignant MCF10DCIS cells express characteristic gene expression patterns of invasive basal-like microenvironments. Furthermore, while HGF secretion is upregulated (relative to normal, MCF10A levels) when fibroblasts are cocultured with either atypical (MCF10AT cells) or premalignant (MCF10DCIS) cells, only MCF10DCIS cells upregulate the HGF receptor, MET. In 3-dimensional cultures, upregulation of HGF/MET in MCF10DCIS cells induced morphological changes suggestive of invasive potential, and these changes were reversed by antibody-based blocking of HGF signaling. These results are relevant to in vivo progression because high expression of a novel MCF10DCIS-derived HGF signature was correlated with basal-like subtype among invasive cancers, with approximately 86% of basal-like cancers highly expressing the HGF signature. Conclusions: In this study we document coordinated and complementary changes in HGF secretion and MET expression in epithelium and stroma in pre-invasive lesions. These results suggest that targeting stroma-derived HGF signaling in early carcinogenesis may block progression of basal-like precursor lesions.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
2013-07-12 | E-GEOD-43467 | 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:Metaplastic breast cancers (MBC) are aggressive, chemoresistant tumors characterized by lineage plasticity. To advance understanding of their pathogenesis and relatedness to other breast cancer subtypes, 28 MBCs were compared with common breast cancers using comparative genomic hybridization, transcriptional profiling, and reverse-phase protein arrays and by sequencing for common breast cancer mutations. MBCs showed unique DNA copy number aberrations compared with common breast cancers. PIK3CA mutations were detected in 9 of 19 MBCs (47.4%) versus 80 of 232 hormone receptor-positive cancers (34.5%; P = 0.32), 17 of 75 HER-2-positive samples (22.7%; P = 0.04), 20 of 240 basal-like cancers (8.3%; P < 0.0001), and 0 of 14 claudin-low tumors (P = 0.004). Of 7 phosphatidylinositol 3-kinase/AKT pathway phosphorylation sites, 6 were more highly phosphorylated in MBCs than in other breast tumor subtypes. The majority of MBCs displayed mRNA profiles different from those of the most common, including basal-like cancers. By transcriptional profiling, MBCs and the recently identified claudin-low breast cancer subset constitute related receptor-negative subgroups characterized by low expression of GATA3-regulated genes and of genes responsible for cell-cell adhesion with enrichment for markers linked to stem cell function and epithelial-to-mesenchymal transition (EMT). In contrast to other breast cancers, claudin-low tumors and most MBCs showed a significant similarity to a "tumorigenic" signature defined using CD44(+)/CD24(-) breast tumor-initiating stem cell-like cells. MBCs and claudin-low tumors are thus enriched in EMT and stem cell-like features, and may arise from an earlier, more chemoresistant breast epithelial precursor than basal-like or luminal cancers. PIK3CA mutations, EMT, and stem cell-like characteristics likely contribute to the poor outcomes of MBC and suggest novel therapeutic targets. Comparison of reference samples against treatment
2009-04-01 | E-GEOD-10885 | biostudies-arrayexpress
Project description:The study of breast cancer pathogenesis relies heavily on the use of established cell lines often derived from metastatic lesions, which while having significantly contributed to the knowledge of breast cancer biology may inadvertently limit the understanding of the mechanisms governing the metastatic process. Our goal was to establish primary cultures from dissociation of breast tumors in order to provide cellular models that may better recapitulate breast cancer pathogenesis and the metastatic process. These cellular models differ from recently developed patient derived xenograft models (PDX) in that they can be used for both in vitro and in vivo studies. Here we report the characterization of six cellular models derived from the dissociation of primary breast tumor specimens, referred to as “dissociated tumor (DT) cells”. Among the DT cells are those that are tumorigenic and metastatic in immunosuppressed mice, and a group of cancer-associated fibroblasts (CAFs). In vitro, DT cells were characterized by proliferation assays, colony formation assays, protein and gene expression profiling, including PAM50 predictor analysis. The latter showed DT cultures similar to their paired primary tumor and as belonging to the basal and Her2-enriched subtypes, offering novel cellular models of these ER-negative breast cancer subtypes. In vivo, three DT cultures are tumorigenic in NOD/SCID and NSG mice, and one of these is metastatic to lymph nodes and lung after orthotopic inoculation into the mammary fat pad, without excision of the primary tumor. DT cultures comprised of CAFs were isolated from luminal-A, Her2-enriched and basal primary tumors, providing subtype-specific components of the tumor microenvironment. Altogether, these DT cultures provide closer-to-primary cellular models for the study of breast cancer pathogenesis, metastasis and tumor microenvironment. reference x sample
2014-08-22 | E-GEOD-55070 | biostudies-arrayexpress