Endocrine therapies targeting the proliferative effect of 17-estradiol (17E2) through estrogen receptor (ER) are the most effective systemic treatment of ER-positive breast cancer. However, most breast tumors initially responsive to these therapies develop resistance through a molecular mechanism that is not yet fully understood. The long-term estrogen-deprived (LTED) MCF7 cell model has been proposed to recapitulate acquired resistance to aromatase inhibitors (AIs) in postmenopausal women. To elucidate this resistance, genomic, transcriptomic and molecular data were integrated into the time course of MCF7-LTED adaptation. Dynamic and widespread genomic changes were observed, including amplification of the ESR1 locus consequently linked to an increase in ER. Dynamic transcriptomic profiles were also observed that correlated significantly with genomic changes and were influenced by transcription factors known to be involved in acquired resistance or cell proliferation (e.g. IRF1 and E2F1, respectively) but, notably, not by canonical ER transcriptional function. Consistently, at the molecular level, activation of growth factor signaling pathways by EGFR/ERBB/AKT and a switch from phospho-Ser118 (pS118)- to pS167-ER were observed during MCF7-LTED adaptation. Evaluation of relevant clinical settings identified significant associations between MCF7-LTED and breast tumor transcriptome profiles that characterize ER-negative status, early response to letrozole and recurrence after tamoxifen treatment. This study proposes a mechanism for acquired resistance to estrogen deprivation that is coordinated across biological levels and independent of canonical ER function.
Biological reprogramming in acquired resistance to endocrine therapy of breast cancer.
Specimen part, Cell line
View SamplesSince the discovery of induced pluripotent stem cells there has been intense interest in understanding the mechanisms that allow a somatic cell to be reprogrammed back to a pluripotent state. Several groups have studied the alterations in gene expression that occur as somatic cells modify their genome to that of an embryonic stem cell. Underpinning many of the gene expression changes are modifications to the epigenetic profile of the associated chromatin. We have used a large-scale shRNA screen to identify epigenetic modifiers that act as barriers to reprogramming. We have uncovered an important role for TRIM28 in cells resisting transition between somatic and pluripotent states. TRIM28 achieves this by maintaining the H3K9me3 repressed state and keeping endogenous retroviruses silenced. We propose that knockdown of TRIM28 during reprogramming results in more plastic H3K9me3 domains, dysregulation of genes nearby H3K9me3 marks, and up regulation of endogenous retroviruses, thus facilitating the transition through reprogramming. Overall design: Gene expression profiling using high through put sequencing at day 7 of Oct4, Sox2, Klf4 and cMyc (OSKM) expression in mouse embryonic fibroblasts with or without Trim28 / Setdb1 knockdown
TRIM28 is an Epigenetic Barrier to Induced Pluripotent Stem Cell Reprogramming.
Specimen part, Cell line, Treatment, Subject
View SamplesWe wanted to understand the consequences of GSK126-mediated Ezh2 inhibition in an orthotopic model of Kras-driven non-small cell lung cancer (NSCLC). We injected the NSCLC cells with above-mentioned genotype into Nude mice and treated them with GSK126 50mg/kg (daily) or vehicle. As additional control for Ezh2 specificity we treated one tumor with doxycycline that induces shRNA-mediated Ezh2 protein downregulation in those cells. Purified tumour cells were obtained by dissection and FACS sorting based of GFP expression. This experiment contributes the genome-wide response of NSCLC cells to Ezh2 inhibition in vivo. Overall design: We generated mRNA profiles of tumor cells tail vein injected into the lungs of Nude mice by deep sequencing. After FACS purification, RNA extraction and Bioanalyzer analysis, we processed only samples with high quality cellular and RNA profiles. Overall, we compared 10-day GSK126 treated cells (n=4) and up to 30 days GSK126 treated cells (n=3) to Captisol-treated samples (vehicle, n=2), using Illumina Hiseq2000. FACS sorted cells from individual animals were obtained by GFP expression. For H3K27ac and H2AK5ac profiling, we used KP primary tumors generated by injection of NSCLC into the tail vein of nude mice. Mice were sacrificed on the onset of shortness of breath and tissues were resuspended in ChIP lysis buffer.
Ezh2 inhibition in Kras-driven lung cancer amplifies inflammation and associated vulnerabilities.
No sample metadata fields
View SamplesWe have identified ZNF423 (also known as Ebfaz, OAZ or Zfp423) as a component critically required for retinoic acid (RA)-induced differentiation. ZNF423 associates with the RAR/RXR nuclear receptor complex and is essential for transactivation in response to retinoids. Down-regulation of ZNF423 expression by RNA interference in neuroblastoma cells results in a growth advantage and resistance to RA-induced differentiation, whereas overexpression of ZNF423 leads to growth inhibition and enhanced differentiation. Futhermore, we show that low ZNF423 expression is associated with poor disease outcome of neuroblastoma patients. To identify the other key pathways regulated by ZNF423 in human neuroblastoma, we expressed elevated levels of ZNF423 in SH-SY5Y cells and performed full genome gene expression analysis in these cells.
ZNF423 is critically required for retinoic acid-induced differentiation and is a marker of neuroblastoma outcome.
Specimen part
View SamplesTo study the senescence gene signatures in the cells, which were genetic SMARCB1 depleted or treated with aurora kinase inhibitors or etoposide, we performed next generation RNA sequencing on these cell, and ''FRIDMAN_SENESCENCE_UP'' geneset was used to determine the enrichment of senescence-related genes. The RNA sequencing results include (1) A375 cells and SMARCB1 depleted counterparts. (2) A549 cells and aurora kinase inhibitor (Alisertib, barasertib or tozasertib) or etoposide treated counterparts. Overall design: RNA seq data of A375_gSMARCB1 + A549_etoposide, Aurora kinases inhibitors treated, to check senescence gene expression signature one replicate of A375 cells parental V.S SMARCB1 KO (by CRISPR) + duplicates of A549 parental V.S etoposide, or 3 indepdent aurora kinase inhibitors (MLN8237/Alisertib, VX680/Tozasertib, AZD1132/Barasertib)
High-Throughput Functional Genetic and Compound Screens Identify Targets for Senescence Induction in Cancer.
Disease, Disease stage, Cell line, Subject
View SamplesDespite intense investigation of intrinsic and extrinsic factors that regulate pluripotency, the process of initial fate commitment of embryonic stem (ES) cells is still poorly understood. Here, we used a genome wide shRNA screen in mouse ES cells to identify genes that are essential for initiation of differentiation. Knockdown of the scaffolding protein Mek binding protein 1 (Mp1, also known as Lamtor3, Map2k1ip1) stimulated self-renewal of ES cells, blocked differentiation and promoted proliferation. Fibroblast growth factor 4 (FGF4) signaling is required for initial fate commitment of ES cells. Knockdown of Mp1 inhibited FGF4-induced differentiation but did not alter FGF4 driven proliferation. This uncoupling of differentiation and proliferation was also observed when oncogenic Ras isoforms were over expressed in ES cells. Knockdown of Mp1 redirected FGF4 signaling from differentiation towards pluripotency and upregulated the pluripotency-related genes Esrrb, Rex1, Tcl1 and Sox2.
A genome-wide RNAi screen in mouse embryonic stem cells identifies Mp1 as a key mediator of differentiation.
Specimen part, Cell line
View SamplesUsing a chromatin regulator-focused shRNA library, we found that suppression of sex determining region Y-box 10 (SOX10) in melanoma causes resistance to BRAF and MEK inhibitors. To investigate how SOX10 loss leads to drug resistance, we performed transcriptome sequencing (RNAseq) of both parental A375 (Ctrl. PLKO) and A375-SOX10KD (shSOX10-1, shSOX10-2) cells. To ask directly whether SOX10 is involved indrug resistance in BRAF(V600E) melanoma patients, we isolated RNA from paired biopsies from melanoma patients (pre- and post- treatment) , that had gained BRAF or MEK inhibitor resistance . We performed RNAseq analysis to determine changes in transcriptome upon drug resistance. Overall design: Investigate genes regulated by SOX10 and differntial gene expression between pre- and post-treatment biopsies. We use short hairpin RNA to suppression SOX10 in A375 cells and cells were harvested with trizol reagent for RNA isolation. For paired biopsies (patient samples) we collected the first biopsy before the initiation of treatment and the second biopsy after drug resistance developed. RNA was isolated from FFPE samples and subjected for RNA sequencing.
Reversible and adaptive resistance to BRAF(V600E) inhibition in melanoma.
Sex, Age, Specimen part, Cell line, Subject
View SamplesHep3B and Huh7 cells pre-treated with XL413 for 10 days to induce senescence prior to sertraline treatment for 24 hours. For RNA sequencing, the library was prepared using TruSeq RNA sample prep kit according to the manufacturer's protocol (Illumina). Gene set enrichment analysis was performed using gene set enrichment analysis software. Overall design: RNA seq data of Hep3B-control, Hep3B-sertraline, Hep3B-XL413, Hep3B-XL413-sertraline, Huh7-control, Huh7-sertraline, Huh7-XL413, Huh7-XL413-sertraline cells, to check gene expression signatures
Inducing and exploiting vulnerabilities for the treatment of liver cancer.
Specimen part, Cell line, Treatment, Subject
View SamplesPurpose: to check senescence gene expression signature in XL413 treated liver cancer cells. Methods: Hep3B and Huh7 cells are treated with XL413 for 4 days. For RNA sequencing, the library was prepared using TruSeq RNA sample prep kit according to the manufacturer's protocol (Illumina). Gene set enrichment analysis was performed using gene set enrichment analysis software. The FRIDMAN_SENESCENCE_UP gene set was used to assess the enrichment of senescence-associated genes in the XL413-treated versus control cells. Overall design: RNA seq data of Hep3B-control, Hep3B-XL413, Huh7-control, and Huh7-XL413 cells, to check senescence gene expression signature
Inducing and exploiting vulnerabilities for the treatment of liver cancer.
Specimen part, Cell line, Treatment, Subject
View SamplesTo identify novel therapeutic opportunities for patients with acquired resistance to endocrine treatments in breast cancer, we applied a high-throughput drug screen. The IC50 values were determined for MCF7 and MCF7-LTED cells.
VAV3 mediates resistance to breast cancer endocrine therapy.
Cell line
View Samples