The tyrosine kinase ErbB2 positive breast tumors have more aggressive tumor growth, poorer clinical outcome, and more resistance to radiotherapy, chemotherapy and hormone therapy. A humanized anti-ErbB2 monoclonal antibody Herceptin and a small molecules inhibitor Lapatinib were developed and approved by FDA to treat patients with ErbB2 amplification and overexpression. Unfortunately, most ErbB2+ breast cancers do not respond to Herceptin and Lapatinib, and the majority of responders become resistant within 12 months of initial therapy (defined as secondary drug resistance). Such differences in response to Lapatinib treatment is contributed by substantial heterogeneity within ErbB2+ breast cancers. To address this possibility, we carried out transcriptomic analysis of mammary tumors from genetically diverse MMTV-ErbB2 mice. This will help us to have a better understanding of the heterogeneous response to ErbB2 targeted therapy and permit us to design better and more individualized (personalized) treatment strategies for human ErbB2 positive breast cancer.
Unraveling heterogeneous susceptibility and the evolution of breast cancer using a systems biology approach.
Specimen part
View SamplesWe developed a mouse model that captures radiation effects on host biology by transplanting unirradiated Trp53 null mammary tissue to sham or irradiated hosts. Gene expression profiles of tumors that arose in irradiated mice are distinct from those that arose in nave hosts.
Murine microenvironment metaprofiles associate with human cancer etiology and intrinsic subtypes.
Specimen part
View SamplesThis study investigates three radiation exposure scenarios in BALB/c and C57BL/6 mice: (1) low dose (LD) group -- four weekly doses of 7.5 cGy, (2) high dose (HD) group -- four weekly doses of 1.8 Gy, (3) unexposed group -- four weekly sham exposures. We then used comparative expression profiles of the mouse mammary gland and cardiac blood to build a model of candidate tissue functions associated with LD cancer susceptibility in these strains and murine and human knowledgebases to characterize these tissue functions and their relevance to breast cancer.
Genetic differences in transcript responses to low-dose ionizing radiation identify tissue functions associated with breast cancer susceptibility.
Sex, Age, Specimen part
View SamplesTranscriptional profiling of mammary tissue irradiated at 10 weeks of age with either 100 cGy sparsely ionizing gamma-rays, or 10 cGy or 30 cGy densely ionizing radiation (350 MeV/amu Si). Mammary tissue was collected 1 weeks, 4 weeks, and 12 weeks post-irradiation.
Irradiation of juvenile, but not adult, mammary gland increases stem cell self-renewal and estrogen receptor negative tumors.
Sex, Specimen part, Time
View SamplesThe purpose of this experiment is to elucidate temporal activities and biological processes that can be inferred in response to a 200cGy challenging dose with or without a 10 cGy priming dose in embryonic human fibroblasts
No associated publication
Age, Specimen part, Cell line
View SamplesWe have reported more than a dozen microenvironmental factors whose signaling must be integrated in order to effect an organized, functional tissue morphology. In order to identify underlying commonalities in gene transcription associated with the phenotype, we compared the gene expression of organized and disorganized epithelial cells of the HMT-3522 breast cancer progression series: the non-malignant S1 cells that form polarized spheres (acini), the malignant T4-2 cells that form large tumor-like clusters, and the phenotypically reverted T4-2 cells that polarize as a result of correction of the microenvironmental signaling.
Inhibitors of Rho kinase (ROCK) signaling revert the malignant phenotype of breast cancer cells in 3D context.
Specimen part, Treatment
View SamplesTransforming growth factor beta-1 (TGFbeta) is a tumor suppressor during the initial stage of tumorigenesis, but it can switch to a tumor promoter during neoplastic progression. Ionizing radiation (IR), both a carcinogen and a therapeutic agent, induces TGFbeta activation in vivo. We now show that IR sensitizes human mammary epithelial cells (HMEC) to undergo TGFbeta-mediated epithelial to mesenchymal transition (EMT). Non-malignant HMEC (MCF10A, HMT3522 S1 and 184v) were irradiated with 2 Gy shortly after attachment in monolayer culture, or treated with a low concentration of TGFbeta (0.4 ng/ml), or double-treated. All double-treated (IR+TGFbeta) HMEC underwent a morphological shift from cuboidal to spindle-shaped. This phenotype was accompanied by decreased expression of epithelial markers E-cadherin, beta-catenin and ZO-1, remodeling of the actin cytoskeleton, and increased expression of mesenchymal markers N-cadherin, fibronectin and vimentin. Furthermore, double-treatment increased cell motility, promoted invasion and disrupted acinar morphogenesis of cells subsequently plated in Matrigel. Neither radiation nor TGFbeta alone elicited EMT, even though IR increased chronic TGFbeta signaling and activity. Gene expression profiling revealed that double treated cells exhibit a specific 10-gene signature associated with Erk/MAPK signaling. We hypothesized that IR-induced MAPK activation primes non-malignant HMEC to undergo TGFbeta-mediated EMT. Consistent with this, Erk phosphorylation were transiently induced by irradiation, persisted in irradiated cells treated with TGFbeta, and treatment with U0126, a Mek inhibitor, blocked the EMT phenotype. Together, these data demonstrate that the interactions between radiation-induced signaling pathways elicit heritable phenotypes that could contribute to neoplastic progression.
Ionizing radiation predisposes nonmalignant human mammary epithelial cells to undergo transforming growth factor beta induced epithelial to mesenchymal transition.
No sample metadata fields
View SamplesGene expression in murine ES cells
Modeling insertional mutagenesis using gene length and expression in murine embryonic stem cells.
No sample metadata fields
View SamplesAffymetrix MOE430A arrays. Mouse embryonic fibroblasts (MEFs) from E11 passaged through crisis. Starved in 0.5% FBS for 16 h then stimulated by 20% serum final concentration for 30 minutes. The purpose was to identify genes affected by the loss of MED23 protein (subunit of the mediator complex). Samples were assayed in duplicate (Set 1 and Set 2) for starved state and serum state cells.
No associated publication
No sample metadata fields
View SamplesDetailed information about stage-specific changes in gene expression is crucial for understanding the gene regulatory networks underlying development and the various signal transduction pathways contributing to morphogenesis. Here, we describe the global gene expression dynamics during early murine limb development, when cartilage, tendons, muscle, joints, vasculature, and nerves are specified and the musculoskeletal system of the limbs is established. We used whole-genome microarrays to identify genes with differential expression at 5 stages of limb development (E9.5 to 13.5), during fore-limb and hind-limb patterning. We found that the onset of limb formation is characterized by an up-regulation of transcription factors, which is followed by a massive activation of genes during E10.5 and E11.5 which tampers off at later time points. Among 3520 genes identified as significantly up-regulated in the limb, we find ~30% to be novel, dramatically expanding the repertoire of candidate genes likely to function in the limb. Hierarchical and stage-specific clustering identified expression profiles that correlate with functional programs during limb development and are likely to provide new insights into specific tissue patterning processes. Here we provide for the first time, a comprehensve analysis of developmentally regulated genes during murine limb development, and provide some novel insights into the expression dynamics governing limb morphogenesis.
Global gene expression analysis of murine limb development.
Specimen part
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