The second leading cause of cancer death for women in the U.S. is breast cancer. Moreover, a significant number of patients with breast tumors acquire resistance to drugs during therapy. To develop targeted therapeutic strategies to combat drug resistance it is essential to understand the basic molecular mechanisms through which cancer cells control sensitivity to chemotherapeutics. To identify new candidate genes and facilitate the discovery of novel drug resistance pathways, we have generated a resistance profile or ?resistome? of etoposide resistant MCF7 breast cancer cells. Differential expression of over 5000 genes (fold change > 2, P value < 0.05) indicate that several drug resistance mechanisms may be operating in these cells, including up-regulation of ABC transporter genes, down-regulation of the drug target and down-regulation of apoptotic genes. Several transcription factors such as RUNX2, SOX9, ETS1 and SMAD3 were up-regulated in the drug resistant cells. Targeted RUNX2 knockdown in the resistant cells using siRNA increased sensitivity to etoposide and also upregulated expression of pro-apoptotic genes indicating that RUNX2 could be a molecular target against etoposide resistance. Differential miRNA (microRNA) expression was observed among the drug resistant and sensitive cells suggesting that miRNA may also play a role in regulation of drug resistance. Hsa-miR-218, which targets ABCC6, was down-regulated in the drug resistant cell line. Transfection of a miR-218 mimic could down-regulate the expression of the efflux pump ABCC6 by 65% in drug resistant cells suggesting that regulation of miRNA may play an important role in etoposide resistance.
No associated publication
Specimen part, Cell line
View SamplesThe second leading cause of cancer death for women in the U.S. is breast cancer. Moreover, a significant number of patients with breast tumors acquire resistance to drugs during therapy. To develop targeted therapeutic strategies to combat drug resistance it is essential to understand the basic molecular mechanisms through which cancer cells control sensitivity to chemotherapeutics. To identify new candidate genes and facilitate the discovery of novel drug resistance pathways, we have generated a resistance profile or resistome of etoposide resistant MCF7 breast cancer cells. Differential expression of over 5000 genes (fold change > 2, P value < 0.05) indicate that several drug resistance mechanisms may be operating in these cells, including up-regulation of ABC transporter genes, down-regulation of the drug target and down-regulation of apoptotic genes. Several transcription factors such as RUNX2, SOX9, ETS1 and SMAD3 were up-regulated in the drug resistant cells. Targeted RUNX2 knockdown in the resistant cells using siRNA increased sensitivity to etoposide and also upregulated expression of pro-apoptotic genes indicating that RUNX2 could be a molecular target against etoposide resistance. Differential miRNA (microRNA) expression was observed among the drug resistant and sensitive cells suggesting that miRNA may also play a role in regulation of drug resistance. Hsa-miR-218, which targets ABCC6, was down-regulated in the drug resistant cell line. Transfection of a miR-218 mimic could down-regulate the expression of the efflux pump ABCC6 by 65% in drug resistant cells suggesting that regulation of miRNA may play an important role in etoposide resistance.
No associated publication
Specimen part, Cell line
View SamplesThe second leading cause of cancer death for women in the U.S. is breast cancer, moreover, a significant number of patients with breast tumors acquire resistance to drugs during therapy. To develop targeted therapeutic strategies to combat drug resistance it is essential to understand the basic molecular mechanisms through which cancer cells control sensitivity to chemotherapeutics. To identify new candidate genes and facilitate the discovery of novel drug resistance pathways, we have generated a resistance profile or resistome of etoposide resitant MCF7 breast cancer cells. Differential expression of over 5000 genes (fold change > 2, P value < 0.05) indicate that several drug resistance mechanisms may be operating in these cells, including up-regulation of ABC transporter genes, down-regulation of the drug target and down-regulation of apoptotic genes. Several transcription factors such as RUNX2, SOX9, ETS1 and SMAD3 were up-regulated in the drug resistant cells. Targeted RUNX2 knockdown in the resistant cells using siRNA increased sensitivity to etoposide and also upregulated expression of pro-apoptotic genes indicating that RUNX2 could be a molecular target against etoposide resistance. Differential miRNA (microRNA) expression was observed among the drug resistant and sensitive cells suggesting that miRNA may also play a role in regulation of drug resistance. Hsa-miR-218, which targets ABCC6, was down-regulated in the drug resistant cell line. Transfection of a miR-218 mimic could down-regulate the expression of the efflux pump ABCC6 by 65% in drug resistant cells suggesting that regulation of miRNA may play an important role in etoposide resistance.
No associated publication
Specimen part, Cell line
View SamplesDuring mammalian gastrulation, pluripotent epiblast stem cells migrate through the primitive streak to form the multipotent progenitors of the mesoderm and endoderm germ layers. Msgn1 is a bHLH transcription factor and is a direct target gene of the Wnt/bcatenin signaling pathway. Msgn1 is expressed in the mesodermal compartment of the primitive streak and is necessary for the proper development of the mesoderm. Msgn1 mutants show defects in somitogenesis leading to a lack of trunk skeletal muscles, vertebra and ribs.
The Wnt3a/β-catenin target gene Mesogenin1 controls the segmentation clock by activating a Notch signalling program.
Specimen part, Treatment
View SamplesThe goal of this project was to elucidate the target genes and transcriptional networks activated by Wnt3a during gastrulation, a complex morphogenetic process in which the embryonic germ layers are formed and the vertebrate body plan is established.
The Wnt3a/β-catenin target gene Mesogenin1 controls the segmentation clock by activating a Notch signalling program.
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View SamplesTranscriptome analysis of control and MALAT1 lncRNA-depleted RNA samples from human diploid lung fibroblasts [WI38]
Long noncoding RNA MALAT1 controls cell cycle progression by regulating the expression of oncogenic transcription factor B-MYB.
Specimen part, Cell line
View SamplesWe previously generated genetically engineered mouse (GEM) models based on perturbation of Tp53, Rb with or without Brca1 or Brca2 that develop serous epithelial ovarian cancer (SEOC) closely resembling the human disease on histologic and molecular levels. We have adapted these GEM models to orthotopic allografts that uniformly develop tumors with short latency in immunocompetent recipients and are ideally suited for routine preclinical studies. To monitor passaged tumors at the molecular level, we analyzed transcriptional profiles of a set of primary SEOC and matching derived passaged tumors. We have merged this dataset with previously published ( doi: 10.1158/0008-5472.CAN-11-3834; PMID 22617326) dataset of murine primary ovarian tumors from our GEM models (GSE46169) and merged and compared them to expression profiles of human dataset published previously (doi: 10.1038/nature10166).
Pathway-specific engineered mouse allograft models functionally recapitulate human serous epithelial ovarian cancer.
Specimen part
View SamplesWe have developed mouse models for serous epithelial ovarian cancer (SEOC) based on conditional inactivation of p53 and Rb tumor suppression (RB-TS) in combination with or without Brca1/2 following injection of adenovirus expressing Cre recombinase into the ovarian bursa. These models develop metastatic (Stage IV) disease with key histopathological features resembling human SEOC.To determine whether these mouse tumors resemble human SEOC at the molecular level, we conducted global gene expression analysis on 27 ovarian carcinomas and 3 pooled normal ovarian surface epithelium samples (single epithelial layer isolated from ovarian surface by laser capture).
Perturbation of Rb, p53, and Brca1 or Brca2 cooperate in inducing metastatic serous epithelial ovarian cancer.
Specimen part
View SamplesTo identify genes involved in survival to prolonged hypoxia we exposed HCT116 to hypoxia for 3 days. Control cells were exposed to normoxic conditions.
Autocrine production of IL-11 mediates tumorigenicity in hypoxic cancer cells.
Disease, Disease stage, Cell line, Treatment
View SamplesTo identify patterns of drug-induced gene modulation that occur across different cell types, we measured gene expression changes across NCI-60 cell lines after exposure to 15 anticancer agents. The results were integrated into a database and set of interactive analysis tools, the NCI Transcriptional Pharmacodynamics Workbench (NCI TPW), intended to allow exploration of gene expression modulation, including by molecular pathway, drug target, and association with drug sensitivity. We identified common transcriptional responses across drugs and cell types and uncovered cell signaling pathway–specific gene expression changes associated with drug sensitivity. We also demonstrated the value of this tool for investigating clinically relevant molecular hypotheses, utilizing the NCI TPW to assess drug-induced expression changes in genes associated with immune function and epithelial-mesenchymal transition, and to identify candidate biomarkers for drug activity. The NCI TPW provides a comprehensive resource to facilitate understanding of tumor cell characteristics that define sensitivity to anticancer drugs.
The NCI Transcriptional Pharmacodynamics Workbench: A Tool to Examine Dynamic Expression Profiling of Therapeutic Response in the NCI-60 Cell Line Panel.
Specimen part
View Samples