Conventional anti-cancer drug screening is typically performed in the absence of accessory cells (e.g. stromal cells) of the tumor microenvironment, which can profoundly alter anti-tumor drug activity. To address this major limitation, we have developed assays (e.g. the tumor cell-specific in vitro bioluminescence imaging (CS-BLI) assay) to selectively quantify tumor cell viability, in presence vs. absence of non-malignant stromal cells or drug treatment. These assays have allowed us to identify that neoplastic cells from diverse malignancies exhibit stroma-induced resistance to different anti-tumor agents. In this analysis, we evaluated the molecular changes triggered in myeloma cells by their in vitro interaction with stromal cells. The transcriptional profile of 3 human multiple myeloma (MM) cell lines (MM.1S, MM.1R, INA-6) co-cultured with stromal cells vs. when cultured alone was characterized by oligonucleotide microarray analysis, using the human U133 plus 2.0 Affymetrix GeneChip.
Tumor cell-specific bioluminescence platform to identify stroma-induced changes to anticancer drug activity.
Cell line
View SamplesEstrogen signaling pathway is critical for breast cancer development and has remained the major adjuvant therapeutic target for this disease. Tamoxifen has been used in clinic for many years to treat ER-positive breast cancer. However a great many (30%) suffer relapse due to drug resistance. In this study, the bromodomain inhibitor JQ1 was found to down-regulate ERalpha gene expression and have anti-tumor effect in cultured tamoxifen-resisant breast cancer cells.
An epigenomic approach to therapy for tamoxifen-resistant breast cancer.
Cell line, Treatment
View SamplesThe androgen receptor (AR) is a key driver of prostate cancer (PC), even in the state of castration-resistant PC (CRPC), and frequently even after treatment with second-line hormonal therapies such as abiraterone and enzalutamide. The persistence of AR activity via both ligand-dependent and ligand-independent (including constitutively active AR splice variants) mechanisms highlights the unmet need for alternative approaches to block AR signaling in CRPC. We investigated the transcription factor GATA2 as a regulator of AR signaling and a novel therapeutic target in PC. We demonstrate that GATA2 directly promotes AR expression (both full-length and splice variant), resulting in a strong positive correlation between GATA2 and AR expression in PC (cell lines and patient specimens). Conversely, GATA2 expression is repressed by androgen and AR, suggesting a negative feedback regulatory loop that, upon androgen deprivation, derepresses GATA2 to contribute to AR overexpression in CRPC. Simultaneously, GATA2 is necessary for optimal transcriptional activity of AR (both full-length and splice variant). GATA2 co-localizes with AR and FOXA1 on chromatin to enhance recruitment of steroid receptor coactivators (SRCs) and formation of the transcriptional holocomplex. In agreement with these important functions, high GATA2 expression and transcriptional activity predicted for worse clinical outcome in PC patients. A GATA2 small molecule inhibitor suppressed the expression and transcriptional function of AR (both full-length and splice variant) and exerted potent anticancer activity against PC cell lines. We propose pharmacological inhibition of GATA2 as a first-in-field approach to target AR expression and function and improve outcomes in CRPC.
GATA2 facilitates steroid receptor coactivator recruitment to the androgen receptor complex.
Cell line
View SamplesHsp90 is critical for regulation of the phenotype and functional activity of human T lymphocytes and natural killer (NK) cells.
Heat shock protein 90 is critical for regulation of phenotype and functional activity of human T lymphocytes and NK cells.
Specimen part, Treatment
View SamplesIdentification of differentially expressed genes upon treatment with Eltrombopag in HL60 cells. HL60 cells were untreated, or treated with 3ug/ml of Eltrombopag for 36 hrs in RPMI with 10% FBS
Eltrombopag inhibits the proliferation of leukemia cells via reduction of intracellular iron and induction of differentiation.
Specimen part, Cell line
View SamplesApproximately 20% of early-stage breast cancers display amplification or overexpression of the ErbB2/HER2 oncogene, conferring poor prognosis and resistance to endocrine therapy. Targeting HER2+ tumors with trastuzumab or the receptor tyrosine kinase (RTK) inhibitor lapatinib significantly improves survival, yet tumor resistance and progression of metastatic disease can develop over time. While the mechanisms of cytosolic HER2 signaling are well studied, nuclear signaling components and gene regulatory networks that bestow therapeutic resistance and limitless proliferative potential are incompletely understood. Here, we use biochemical and bioinformatics approaches to identify effectors and targets of HER2 transcriptional signaling in human breast cancer. Phosphorylation and activity of the Steroid Receptor Coactivator-3 (SRC-3) is reduced upon HER2 inhibition, and recruitment of SRC-3 to regulatory elements of endogenous genes is altered. Transcripts regulated by HER2 signaling are highly enriched with E2F1 binding sites and define a gene signature associated with proliferative breast tumor subtypes, cell cycle progression, and G1 to S phase transition. We show that HER2 signaling drives proliferation in breast cancer cells through regulation of E2F1-driven DNA metabolism and replication genes together with phosphorylation and activity of the transcriptional coactivator SRC-3. Furthermore, our analyses identified a cyclin dependent kinase (CDK) signaling node that, when targeted using the CDK4/6 inhibitor Palbociclib, defines cooperative signaling pathways for expression of tumorigenic gene networks. Our findings suggest this proliferative gene signature is amendable to pharmacological targeting. These results have implications for rational discovery of pharmacological combinations in pre-clinical models of adjuvant treatment and therapeutic resistance
HER2 Signaling Drives DNA Anabolism and Proliferation through SRC-3 Phosphorylation and E2F1-Regulated Genes.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
H2.0-like homeobox regulates early hematopoiesis and promotes acute myeloid leukemia.
Specimen part, Cell line
View SamplesThe goal was to study the role of Hlx in hematopoiesis.
H2.0-like homeobox regulates early hematopoiesis and promotes acute myeloid leukemia.
Specimen part
View SamplesTo study the role of Hlx in hematopoietic differentiation and tumorigenesis, URE cells were infected with short-hairpin-containing pSIH1-H1-copGFP lentiviral vector (System Biosciences, Mountain View, CA) containing either nucleotide sequences targeting luciferase (shControl) or HLX (shHLX). After 24hrs incubation in Iscoves modified Dulbeccos medium (IMDM) containing FBS, mIL-3, mIL-6 and mSCF with lentiviral supernatants in the presence of 8ug/ml polybrene, cells were cultured in fresh medium for several days. Subsequently, GFP+ cells were sorted by FACS and RNA was prepared.
H2.0-like homeobox regulates early hematopoiesis and promotes acute myeloid leukemia.
Cell line
View SamplesThe transcriptional profile of the human multiple myeloma (MM) cell line MM.1S treated with MLN4924 vs control MM.1S cells was characterized by oligonucleotide microarray analysis, using the human U133 plus 2.0 Affymetrix GeneChip, according to previously described protocols for total RNA extraction and purification; cDNA synthesis; in vitro transcription reaction for production of biotin-labeled cRNA; hybridization of cRNA with U133plus2.0 Affymetrix gene chips; and scanning of image output files. Scanned image output files were analyzed using DNA-Chip Analyzer (dChip) (www.dchip.org), including conversion to DCP files, normalization and modeling. The gene expression profile of MM.1S cells for each time point of MLN4924 treatment was compared to the profile of control MM.1S cells.
Molecular and cellular effects of NEDD8-activating enzyme inhibition in myeloma.
Cell line, Time
View Samples