ShRNA profiling of human normal breast and breast cancer cell lines to identify genes regulated by YAP
Ontology highlight
ABSTRACT: Frequent loss of heterozygosity (LOH) at 11q22-23 in breast cancer strongly suggests that this region contains a tumor suppressor gene, yet to be identified. We and others have shown Yes-associated protein (YAP), which is located at 11q22.2, transactivates the p53 family member p73 upon DNA damage, suggesting a tumor suppressive function for YAP. Our analysis of breast tumor tissues by immunohistochemistry (IHC) showed loss of YAP protein expression in great portion of breast cancers. We used microarray to look at the targte genes regulated by YAP in normal breast luminal cell and breast cancer cell lines. Experiment Overall Design: We generated stable cell lines by introducing control vector(pRS-IRES-GFP/pmig) or YAP shRNA(pRS-IRES-GFP-YAP/pmig-YAP) in a normal breast luminal cell line 1089 luminal and breast cancer cell lines MDA MB231. RAN was extracted and hybridized on Affymetrix microarrays.We looked for new target genes regulated by YAP in normal breast luminal cell and breast cancer cell lines.
Project description:Indole-3-carbinol (I3C) is a natural anti-carcinogenic compound found at high concentrations in Brassica vegetables. ER-positive cell lines demonstrated the greatest sensitivity to the anti-tumor effects of I3C compared to ER-negative breast cancer cell lines. Gene expression analysis was performed to identify genes and pathways that accounted for sensitivity to I3C. Microarray analysis performed using Illumina HT-12 v4 expression arrays A total of 36 samples were analyzed with six breast cancer cell lines treated with either the vehicle control or the drug Indole-3-carbinol in triplicate. The cell lines were: MCF-7, T47D, ZR751(sensitive to the drug, apoptosis/growth arrest) and MDA-MB-231, MDA-MB-157, and MDA-MB-436 (insensitive to the drug). Sensitive cell lines are of the luminal subtype and insensitive cell lines are of the basal subtype.
Project description:Background Estrogen and progesterone are potent breast mitogens. In addition to steroid hormones, multiple signaling pathways input to estrogen receptor (ER) and progesterone receptor (PR) actions via posttranslational events. Protein kinases commonly activated in breast cancers phosphorylate steroid hormone receptors (SRs) and profoundly impact their activities. Methods To better understand the role of modified PRs in breast cancer, we measured total and phospho-Ser294 PRs in 209 human breast tumors represented on 2754 individual tissue spots within a tissue microarray and assayed the regulation of this site in human tumor explants cultured ex vivo. To complement this analysis, we assayed PR target gene regulation in T47D luminal breast cancer models following treatment with progestin (promegestone; R5020) and antiprogestins (mifepristone, onapristone, or aglepristone) in conditions under which the receptor is regulated by Lys388 SUMOylation (K388 intact) or is SUMO-deficient (via K388R mutation to mimic persistent Ser294 phosphorylation). Selected phospho-PR-driven target genes were validated by qRT-PCR and following RUNX2 shRNA knockdown in breast cancer cell lines. Primary and secondary mammosphere assays were performed to implicate phospho-Ser294 PRs, epidermal growth factor signaling, and RUNX2 in breast cancer stem cell biology. Results Phospho-Ser294 PR species were abundant in a majority (54%) of luminal breast tumors, and PR promoter selectivity was exquisitely sensitive to posttranslational modifications. Phospho-PR expression and target gene programs were significantly associated with invasive lobular carcinoma (ILC). Consistent with our finding that activated phospho-PRs undergo rapid ligand-dependent turnover, unique phospho-PR gene signatures were most prevalent in breast tumors clinically designated as PR-low to PR-null (luminal B) and included gene sets associated with cancer stem cell biology (HER2, PAX2, AHR, AR, RUNX). Validation studies demonstrated a requirement for RUNX2 in the regulation of selected phospho-PR target genes (SLC37A2). In vitro mammosphere formation assays support a role for phospho-Ser294-PRs via growth factor (EGF) signaling as well as RUNX2 as potent drivers of breast cancer stem cell fate. Conclusions We conclude that PR Ser294 phosphorylation is a common event in breast cancer progression that is required to maintain breast cancer stem cell fate, in part via cooperation with growth factor-initiated signaling pathways and key phospho-PR target genes including SLC37A2 and RUNX2. Clinical measurement of phosphorylated PRs should be considered a useful marker of breast tumor stem cell potential. Alternatively, unique phospho-PR target gene sets may provide useful tools with which to identify patients likely to respond to selective PR modulators that block PR Ser294 phosphorylation as part of rational combination (i.e., with antiestrogens) endocrine therapies designed to durably block breast cancer recurrence.
Project description:Frequent loss of heterozygosity (LOH) at 11q22-23 in breast cancer strongly suggests that this region contains a tumor suppressor gene, yet to be identified. We and others have shown Yes-associated protein (YAP), which is located at 11q22.2, transactivates the p53 family member p73 upon DNA damage, suggesting a tumor suppressive function for YAP. Our analysis of breast tumor tissues by immunohistochemistry (IHC) showed loss of YAP protein expression in great portion of breast cancers. We used microarray to look at the targte genes regulated by YAP in normal breast luminal cell and breast cancer cell lines. Keywords: gene knock down
Project description:The primary cause of mortality in breast cancer is metastasis, a process which is still poorly understood. To study the process of breast cancer metastasis, we isolated focal hyperplasias from the MMTV-PyMT transgenic breast cancer model and transplanted to syngeneic hosts. The transplants underwent stereotyped progression to adenoma, early carcinoma, and late carcinoma at 5, 8 and 18 weeks post-transplant, respectively. We compared the gene expression profiles of adenomas and late carcinomas by microarray. Analysis of the data revealed that the most differentially expressed gene family between adenomas and late carcinomas were luminal differentiation genes, among them GATA-3. Adenomas were uniformly immunopositive for GATA-3, whereas early carcinomas displayed partial loss of GATA-3. Disseminated tumour cells and 18-week late carcinomas were invariably GATA-3 negative. We found that re-introduction of GATA-3 in late carcinomas induced markers of luminal differentiation and inhibited tumour dissemination to distant sites. Keywords: spotted oligonucleotide Full length GATA-3 was cloned into the PMIG retroviral vector, which contains an IRES-GFP cassette. Primary cultures of non-fluorescent MMTV-PyMT carcinomas were infected with the GATA-3 and control retroviruses and transplanted back into the cleared mammary fat pads of wild-type mice. After six weeks of growths, tumors were isolated and total RNA harvested by the Trizol method. Total RNA from GATA-3 infected tumor outgrowths were compared to empty vector infected tumor outgrowths.
Project description:One of the major hurdles for the early detection of cancer is our poor understanding of tumour initiating events. Historically, cancer research has focused on histological and molecular characterisation of established tumours which has led to the identification of hundreds of putative driver mutations. It is currently unclear how these genetic aberrations impact the cell state of nascent tumour cells and their microenvironment. BRCA1 driven triple negative breast cancer (TNBC) for example has been shown to arise from luminal progenitor cells yet little is known about how BRCA1 loss-of-function (LOF) and concomitant mutations affect the luminal progenitor cell state. This repository contains ATAC-sequencing dataset of luminal progenitors isolated from 6-months old Brca1/p53 and wild-type mice. This data was used to show that the perturbation of Brca1/p53in luminal progenitors induces an aberrant alveolar differentiation pre-malignancy. Unlike alveolar differentiation occurring during gestation, this process is cell autonomous and characterised by the dysregulation of transcription factors driving alveologenesis. The ATAC-sequencing data supports a model where transcriptional and epigenetic changes driven by Brca1/p53 inadvertently promote a differentiation program hardwired in luminal progenitors, highlighting the deterministic role of the cell of origin and offering a potential explanation for the tissue specificity of BRCA1 tumours.
Project description:Introduction: Breast radiotherapy is currently â??one size fits allâ?? regardless of breast cancer subtype (eg. luminal, basal). However, recent clinical data suggests that radiation response may vary significantly among subtypes. Therefore, current practice leads to over- or under-treatment of women whose tumors are more or less radiation responsive. We hypothesized that this clinical variability may be due, in part, to differences in cellular radiation response. Methods: We exposed 16 biologically-diverse breast tumor cell lines to 0 or 5GY radiation. Microarray analysis was performed on RNA harvested from those cell lines. Samples were run in triplicate. Following quality assessment, differential gene expression analysis was performed using a two-way multiplicative linear mixed-effects model. A candidate radiation response biomarkers with biologically plausible role in radiation response, were identified and confirmed at the RNA and protein level with qPCR and Western blotting assays. Induction in human breast tumors was confirmed in 32 patients with paired pre- and post-radiation tumor samples using IHC and microarray analysis. Quantification of protein was performed in a blinded manner and included positive and negative controls. The objective of our study was to identify genomic determinants of radiation sensitivity using clinical samples as well as breast tumor cell lines. In order to identify differences in the radiation response gene expression profiles of specific breast cancer subtypes, we exposed 16 biologically-diverse breast tumor cell lines to 0 or 5GY radiation. Microarray analysis was performed on RNA harvested from those cell lines. Samples were run in triplicate. Following quality assessment, differential gene expression analysis was performed using a two-way multiplicative linear mixed-effects model. Candidate radiation response biomarker with a biologically plausible role in radiation response, were identified and confirmed at the RNA and protein level with qPCR and Western blotting assays. Induction of the genes of interest were further evaluated and confirmed in human breast tumors in 32 breast cancer patients with paired pre- and post-radiation tumor samples using IHC and microarray analysis assays.
Project description:Exposure to progesterone is a recognized risk factor for breast cancer, and PGR polymorphisms are associated with various malignancies. The two progesterone receptor (PR) isoforms, full length PR-B and truncated PR-A, are expressed from the PGR gene in breast tissue and play crucial roles in normal physiology and breast cancer progression. An imbalance in the expression ratio of these isoforms, favoring increased levels of PR-A, is common in breast cancer and is associated with resistance to tamoxifen in Luminal A-type tumors. Notably, PRs have recently been implicated in promoting endocrine resistance and driving the expansion of cancer stem-like cell (CSC) populations. Despite this insight, the isoform-specific molecular and epigenetic mechanisms underlying PR action in ER+ breast cancers remain understudied. Phenotypic studies of T47D cell lines that express exclusively PR-A or PR-B showed that PR isoforms regulate divergent cell fates. PR-B expressing cells have a higher proliferation rate, while PR-A expressing cells produce more mammospheres. We profiled progesterone-driven gene expression in cells grown in both adherent (2D) and mammosphere (3D) growth conditions and found differential gene regulation by PR-A and PR-B that is consistent with the observed divergent phenotypes. We then performed CUT&RUN to identify the genomic binding patterns unique to each PR isoform and their suite of target genes. Our findings indicate that PR-A acts as a regulator of the cell cycle and senescence, while PR-B plays a pivotal role in metabolism and intracellular signaling. Our genomic profiling of PRs in this model system has unveiled novel isoform-specific functions of PR. This work has shifted our prior understanding of the role of PRs in gene regulation, offering potential insights for therapeutic interventions in ER+ breast cancer.
Project description:Exposure to progesterone is a recognized risk factor for breast cancer, and PGR polymorphisms are associated with various malignancies. The two progesterone receptor (PR) isoforms, full length PR-B and truncated PR-A, are expressed from the PGR gene in breast tissue and play crucial roles in normal physiology and breast cancer progression. An imbalance in the expression ratio of these isoforms, favoring increased levels of PR-A, is common in breast cancer and is associated with resistance to tamoxifen in Luminal A-type tumors. Notably, PRs have recently been implicated in promoting endocrine resistance and driving the expansion of cancer stem-like cell (CSC) populations. Despite this insight, the isoform-specific molecular and epigenetic mechanisms underlying PR action in ER+ breast cancers remain understudied. Phenotypic studies of T47D cell lines that express exclusively PR-A or PR-B showed that PR isoforms regulate divergent cell fates. PR-B expressing cells have a higher proliferation rate, while PR-A expressing cells produce more mammospheres. We profiled progesterone-driven gene expression in cells grown in both adherent (2D) and mammosphere (3D) growth conditions and found differential gene regulation by PR-A and PR-B that is consistent with the observed divergent phenotypes. We then performed CUT&RUN to identify the genomic binding patterns unique to each PR isoform and their suite of target genes. Our findings indicate that PR-A acts as a regulator of the cell cycle and senescence, while PR-B plays a pivotal role in metabolism and intracellular signaling. Our genomic profiling of PRs in this model system has unveiled novel isoform-specific functions of PR. This work has shifted our prior understanding of the role of PRs in gene regulation, offering potential insights for therapeutic interventions in ER+ breast cancer.
Project description:This is a dynamic pathway model capturing ERBB receptor signaling as well as downstream MAPK and PI3K signaling pathways. The effect of different growth factors and drugs on the formation of active receptor dimers is explicitly included. The model was established and calibrated on time-resolved data of the luminal breast cancer cell lines MCF7 and T47D across an array of four ligands and five drugs. For the description of the full modeling project including condition-specific parameters, observables, measurement data and experimental conditions the model is provided in PEtab format in addition to the classical SBML version.
Project description:RUNX1 encodes a RUNX family transcription factor (TF) and was recently identified as a novel mutated gene in human luminal breast cancers. We found that Runx1 is expressed in all subpopulations of murine mammary epithelial cells (MECs) except the secretory alveolar luminal cells. Conditional knockout of Runx1 in MECs by MMTV-Cre led to a decrease in luminal MECs, largely due to a profound reduction in the estrogen receptor (ER)-positive mature luminal subpopulation, a phenotype that could be rescued by loss of either Trp53 or Rb1. Mechanistically RUNX1 represses Elf5, a master regulatory TF gene for alveolar cells, and activates Foxa1, a key mature luminal TF gene involved in the ER program. Collectively, our data identified a key regulator of the ER+ luminal lineage whose disruption may contribute to development of ER+ luminal breast cancer when under the background of either TP53 or RB1 loss. Thoracic and inguinal mammary glands from 3 MMTV-Cre;Runx1L/L;R26Y and 3 MMTV-Cre;Runx1+/+;R26Y adult virgin females were dissected out, minced and digested to single cell suspension. Runx1L is the floxed conditional knockout allele of Runx1. R26Y is a conditional YFP reporter that would be turned on upon Cre-mediated recombination. FACSaria machine was used to sort out the YFP-marked luminal epithelial cell population of each of these 6 mice. Total RNA was isolated with Qiagen RNeasy kit and subsequently amplified by Nugen V2 and applied to Affymetrix mouse genome 430 2.0 arrays.