Integrated Molecular Analysis of Tamoxifen-Resistant Invasive Lobular Breast Cancer Cells
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE96570 | GEO | 2018/03/05
REPOSITORIES: GEO
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Project description:One-third of all ER+ breast tumors treated with endocrine therapy fail to respond, and the remainder are likely to relapse in the future. Almost all data on endocrine resistance has been obtained in models of invasive ductal carcinoma (IDC). However, invasive lobular carcinomas (ILC) comprise up to 15% of newly diagnosed invasive breast cancers diagnosed each year and, while the incidence of IDC has remained relatively constant during the last 20 years, the prevalence of ILC continues to increase among postmenopausal women. We report a new model of Tamoxifen (TAM)-resistant invasive lobular breast carcinoma cells that provides novel insights into the molecular mechanisms of endocrine resistance. SUM44 cells express ER and are sensitive to the growth inhibitory effects of antiestrogens. Selection for resistance to 4-hydroxytamoxifen led to the development of the SUM44/LCCTam cell line, which exhibits decreased expression of estrogen receptor alpha (ERα) and increased expression of the estrogen-related receptor gamma (ERRγ). Knockdown of ERRγ in SUM44/LCCTam cells by siRNA restores TAM sensitivity, and overexpression of ERRγ blocks the growth-inhibitory effects of TAM in SUM44 and MDA-MB-134 VI lobular breast cancer cells. ERRγ-driven transcription is also increased in SUM44/LCCTam, and inhibition of activator protein 1 (AP1) can restore or enhance TAM sensitivity. These data support a role for ERRγ/AP1 signaling in the development of TAM resistance, and suggest that expression of ERRγ may be a marker of poor Tamoxifen response.
2008-11-01 | GSE12708 | GEO
Project description:One-third of all ER+ breast tumors treated with endocrine therapy fail to respond, and the remainder are likely to relapse in the future. Almost all data on endocrine resistance has been obtained in models of invasive ductal carcinoma (IDC). However, invasive lobular carcinomas (ILC) comprise up to 15% of newly diagnosed invasive breast cancers diagnosed each year and, while the incidence of IDC has remained relatively constant during the last 20 years, the prevalence of ILC continues to increase among postmenopausal women. We report a new model of Tamoxifen (TAM)-resistant invasive lobular breast carcinoma cells that provides novel insights into the molecular mechanisms of endocrine resistance. SUM44 cells express ER and are sensitive to the growth inhibitory effects of antiestrogens. Selection for resistance to 4-hydroxytamoxifen led to the development of the SUM44/LCCTam cell line, which exhibits decreased expression of estrogen receptor alpha (ERα) and increased expression of the estrogen-related receptor gamma (ERRγ). Knockdown of ERRγ in SUM44/LCCTam cells by siRNA restores TAM sensitivity, and overexpression of ERRγ blocks the growth-inhibitory effects of TAM in SUM44 and MDA-MB-134 VI lobular breast cancer cells. ERRγ-driven transcription is also increased in SUM44/LCCTam, and inhibition of activator protein 1 (AP1) can restore or enhance TAM sensitivity. These data support a role for ERRγ/AP1 signaling in the development of TAM resistance, and suggest that expression of ERRγ may be a marker of poor Tamoxifen response. Experiment Overall Design: Total RNA was extracted from sub-confluent T-25 cm^2 tissue culture flasks of SUM44 and LCCTam cells, then processed and arrayed. Microarray data quality was then assessed using several tools, including those recommended by Affymetrix and a series of additional QC measures. The Robust Multiple-Array Average (RMA) method was used to preprocess the raw gene expression data, as implemented in the Bioconductor project (http://bioconductor.org). We then isolated a reduced dimension dataset that included genes that exhibit â¥2 fold change, p<0.05 and genes with intensity â¥log2(10) in both SUM44 and SUM44/LCCTam groups. Data visualization before and after dimensionality reduction was facilitated by multidimensional scaling as estimated using Principal Component Analysis (PCA) and Discriminant Component Analysis (DCA), to ensure that the global structure of the data was not altered by dimensionality reduction procedures.
2008-11-13 | E-GEOD-12708 | biostudies-arrayexpress
Project description:The identification of lobular caricnoma in situ (LCIS) in a patient's specimen confers and appreciable increased risk of development of future invasive mammary carcinoma. However the study of LCIS presents a challenge as it is usually only recognized in fixed specimens and no good in vivo or in vitro models currently exist. Recent advances in high throughput genomics have made possible comprehensive copy number analysis of lesions such as this. We have characterized LCIS on microdissected cases of archival patient samples using aCGH. We used 4 cases of LCIS with adjacent ILC. Histological sections from 4 cases of LCIS and 4 cases of ILC microdissected, DNA extracted and subjected to whole genome amplification, and aCGH.
2010-12-31 | E-GEOD-20474 | biostudies-arrayexpress
Project description:Invasive lobular breast cancer (ILC) is the second most common histological sub-type of breast cancer. Although the majority of ILC are strongly hormone receptor positive and are of low-intermediate grade, they present a number of clinical challenges. These challenges include limitations in physical exam and breast imaging for early detection, decreased response to chemotherapy and prospective evidence for differences in the benefit from specific adjuvant endocrine treatment regimens when compared to invasive ductal cancer (IDC). In addition to loss of e-cadherin, ILCs possess genetic alterations that are suggestive of a unique estrogen receptor(ER) axis, including an increase in the frequency of FOXA1 mutations and decrease in GATA3 truncating mutations. We performed a randomized Phase II clinical trial, Palbociclib and Endocrine therapy for LObular breast cancer Preoperative Study (PELOP), in which patients were stratified by histological subtype and found that the magnitude of the difference between the benefit from letrozole compared tamoxifen is significantly higher in ILC versus IDC. To elucidate the mechanism underlying this divergent response we comprehensively studied the ER axis in experimental models of ILC and IDC and clinical samples and show that ILC harbors a unique ER transcriptional axis that stems from increased FOXA1 chromatin binding and an altered chromatin state. These findings provide insights to the unique pattern of response to endocrine treatment in ILC and mechanisms of resistance to endocrine treatment, and offer new treatment strategies to improve outcomes for patients with this breast cancer subtype."
2022-08-31 | GSE152361 | GEO
Project description:Invasive lobular breast cancer (ILC) is the second most common histological sub-type of breast cancer. Although the majority of ILC are strongly hormone receptor positive and are of low-intermediate grade, they present a number of clinical challenges. These challenges include limitations in physical exam and breast imaging for early detection, decreased response to chemotherapy and prospective evidence for differences in the benefit from specific adjuvant endocrine treatment regimens when compared to invasive ductal cancer (IDC). In addition to loss of e-cadherin, ILCs possess genetic alterations that are suggestive of a unique estrogen receptor(ER) axis, including an increase in the frequency of FOXA1 mutations and decrease in GATA3 truncating mutations. We performed a randomized Phase II clinical trial, Palbociclib and Endocrine therapy for LObular breast cancer Preoperative Study (PELOP), in which patients were stratified by histological subtype and found that the magnitude of the difference between the benefit from letrozole compared tamoxifen is significantly higher in ILC versus IDC. To elucidate the mechanism underlying this divergent response we comprehensively studied the ER axis in experimental models of ILC and IDC and clinical samples and show that ILC harbors a unique ER transcriptional axis that stems from increased FOXA1 chromatin binding and an altered chromatin state. These findings provide insights to the unique pattern of response to endocrine treatment in ILC and mechanisms of resistance to endocrine treatment, and offer new treatment strategies to improve outcomes for patients with this breast cancer subtype."
2022-08-31 | GSE152360 | GEO
Project description:Estrogen receptor-positive (ER+) invasive lobular breast cancer (ILC) comprises about ~15% of breast cancer. ILC’s unique genotypic (loss of wild type E-cadherin expression) and phenotypic (small individual round cancer cells that grow in discontinuous nests) are thought to contribute to a distinctive pattern of metastases to serosal membranes. Unlike invasive ductal carcinoma (IDC), ILC metastases often intercalate into the mesothelial layer of the peritoneum and other serosal surfaces. While ER activity is a known driver of ILC proliferation, very little is known about how additional nuclear receptors contribute to ILC’s distinctive biology. In ER+ IDC, we showed previously that glucocorticoid receptor (GR) activity inhibits pro-proliferative gene expression and cell proliferation. Here we examined ER+ ILC models and find that GR activation similarly reduces S-phase entry gene expression and ILC proliferation. While slowing tumor growth rate, our data also suggest that GR activation results in an enhanced metastatic phenotype through increasing integrin-encoding gene expression, extracellular matrix protein adhesion, and mesothelial cell clearance. Moreover, in an intraductal mouse mammary gland model of ILC, we found that GR expression is associated with increased metastases despite slowed primary mammary tumor growth. Taken together, our findings suggest GR-mediated gene expression may contribute to the unusual characteristics of ILC biology.
2023-09-04 | GSE241993 | GEO
Project description:Breast cancer is categorized by the molecular and histologic presentation of the tumor; with the major histologic subtypes observed in patients being No Special Type (NST; commonly known as Invasive Ductal Carcinoma, IDC) and Invasive Lobular Carcinoma (ILC). ILC are characterized by growth in a single file discohesive manner with stromal infiltration attributed to their hallmark loss of E-cadherin (CDH1). The Cancer Cell Line Encyclopedia (CCLE) currently only lists three ILC cell lines; emphasizing the need to expand the inventory of models available to researchers. Here we report the successful establishment and characterization of a novel ILC cell line, WCRC-25, from a metastatic pleural effusion from a postmenopausal Caucasian woman with metastatic ILC. WCRC-25 is an ER-negative luminal epithelial ILC cell line with both luminal and Her2-like features. It exhibits anchorage independent growth and haptotactic migration towards Collagen I. Sequencing revealed a CDH1 Q706* truncating mutation in WCRC-25, together with mutations in FOXA1, CTCF, BRCA2 and TP53 which were also seen in a series of metastatic lesions from the patient. Copy number analyses revealed amplification and deletion of genes frequently altered in ILC while optical gene mapping (Bionano) revealed novel structural rearrangements. RNA-seq analysis comparing the primary tumor, metastases and the cell line revealed signatures for cell cycle progression and receptor tyrosine kinase signaling. To assess targetability, we treated WCRC-25 with AZD5363 and Alpelisib confirming WCRC-25 as susceptible to PI3K/Akt signaling inhibition as predicted by our RNA sequencing analysis. In conclusion, we report WCRC-25 as a novel ILC cell line with much promise as a valuable research tool to advance our understanding of ILC and its therapeutic vulnerabilities.
2023-12-20 | GSE221512 | GEO
Project description:Estrogen receptor-positive (ER+) invasive lobular breast cancer (ILC) comprises about ~15% of breast cancer. ILC’s unique genotypic (loss of wild type E-cadherin expression) and phenotypic (small individual round cancer cells that grow in discontinuous nests) are thought to contribute to a distinctive pattern of metastases to serosal membranes. Unlike invasive ductal carcinoma (IDC), ILC metastases often intercalate into the mesothelial layer of the peritoneum and other serosal surfaces. While ER activity is a known driver of ILC proliferation, very little is known about how additional nuclear receptors contribute to ILC’s distinctive biology. In ER+ IDC, we showed previously that glucocorticoid receptor (GR) activity inhibits pro-proliferative gene expression and cell proliferation. Here we examined ER+ ILC models and find that GR activation similarly reduces S-phase entry gene expression and ILC proliferation. While slowing tumor growth rate, our data also suggest that GR activation results in an enhanced metastatic phenotype through increasing integrin-encoding gene expression, extracellular matrix protein adhesion, and mesothelial cell clearance. Moreover, in an intraductal mouse mammary gland model of ILC, we found that GR expression is associated with increased metastases despite slowed primary mammary tumor growth. Taken together, our findings suggest GR-mediated gene expression may contribute to the unusual characteristics of ILC biology.
2023-09-04 | GSE241992 | GEO
Project description:We identified MDC1 as a putative novel transcriptional co-regulator of estrogen receptor alpha (ER) in models of invasive lobular carcinoma. In this study, our goal was to define the contribution of MDC1 to regulation of the ER transcriptome in ILC cell lines versus invasive ductal carcinoma cells.
2021-05-13 | GSE171364 | GEO
Project description:Invasive lobular carcinoma (ILC) is a histological subtype of breast cancer that is frequently associated with favorable outcomes, as ~90% of ILC express the estrogen receptor (ER). However, recent retrospective analyses suggest that ILC patients receiving adjuvant endocrine therapy may not benefit from improved outcomes versus other breast cancer patients. Based on these observations, we characterized ER function and endocrine response in ILC models. The ER-positive ILC cell lines MDA MB 134VI (MM134) and SUM44PE were used to examine the ER-regulated transcriptome in vitro via gene expression microarray analyses and ER ChIP-Seq. In parallel, estrogen response was assessed in vivo in the patient-derived ILC xenograft HCI-013. Response to endocrine therapy was also examined in ILC cell lines. We identified 915 genes that were uniquely E2-regulated in ILC cell lines versus other breast cancer cell lines, and a subset of these genes were also regulated in vivo in HCI-013. We observed that MM134 were de novo tamoxifen resistant, and were induced to grow by 4-hydroxytamoxifen, as well as other anti-estrogens, as partial agonists. Growth was accompanied by agonist activity of tamoxifen on ER-mediated gene expression. Though tamoxifen induced cell growth, MM134 cells required FGFR1 signaling to maintain viability and were sensitive to combined endocrine therapy and FGFR1 inhibition. Our observation that ER drives a unique program of gene expression in ILC cells correlates with the ability of tamoxifen to induce growth in these cells. Targeting growth factors using FGFR1 inhibitors may block survival pathways required by ILC and reverse tamoxifen resistance. Cells were hormone deprived by replacing growth medium with IMEM+2% charcoal stripped serum for 3 days. Following deprivation, cells were treated for 3 or 24 hours with 1nM E2 or vehicle (0.01% EtOH) in biological quadruplicate. Following treatment, cells were lysed and RNA was harvested using the Illustra RNAspin Mini kit (GE Health). cRNA synthesis and labeling was performed using the Ambion MessageAmp Premier Kit (Life Technologies), and cRNA was hybridized to U133A 2.0 arrays (Affymetrix, Santa Clara, CA). cRNA synthesis and labeling, hybridization, and scanning were performed by the University of Pittsburgh Cancer Biomarkers Facility.
2014-01-16 | E-GEOD-50694 | biostudies-arrayexpress