Overcoming cellular growth restriction, including the evasion of cellular senescence, is a hallmark of cancer. We report that PAK4 is overexpressed in all human breast cancer subtypes and associated with poor patient outcome. In mice, MMTV-PAK4 overexpression promotes spontaneous mammary cancer, while PAK4 gene depletion delays MMTV-PyMT driven tumors. Importantly, PAK4 prevents senescence-like growth arrest in breast cancer cells in vitro, in vivo and ex vivo, but is not needed in non-immortalized cells, while PAK4 overexpression in untransformed human mammary epithelial cells abrogates H-Ras-V12-induced senescence. Mechanistically, a PAK4 – RELB - C/EBPa axis controls the senescence-like growth arrest and a PAK4 phosphorylation residue (RELB-Se151) is critical for RELB-DNA interaction, transcriptional activity and expression of the senescence regulator C/EBPa. These findings establish PAK4 as a promoter of breast cancer that can overcome oncogene-induced senescence and reveal a selective vulnerability of cancer to PAK4 inhibition. Overall design: We quantify transcription via high-throughput RNA sequencing in two human breast cancer cell lines (BT-549 and Hs578T) 72hrs after transient transfection with control (siControl) or PAK4-targetting siRNA.
PAK4 suppresses RELB to prevent senescence-like growth arrest in breast cancer.
Specimen part, Cell line, Subject
View SamplesDensely ionizing radiation is a major component of the space radiation environment and has potentially greater carcinogenic effect compared to sparsely ionizing radiation that is prevalent in the terrestrial environment. It is unknown to what extent the irradiated microenvironment contributes to the differential carcinogenic potential of densely ionizing radiation. To address this gap, 10-week old BALB/c mice were irradiated with 100 cGy sparsely ionizing g-radiation or 10, 30, or 80 cGy of densely ionizing, 350 MeV/amu Si particles and transplanted 3 days later with syngeneic Trp53 null mammary fragments. Tumor appearance was monitored for 600 days. Tumors arising in Si-particle irradiated mice had a shorter median time to appearance, grew faster and were more likely to metastasize. Most tumors arising in sham-irradiated mice were ER-positive, pseudo-glandular and contained both basal keratin 14 and luminal keratin 8/18 cells (designated K14/18), while most tumors arising in irradiated hosts were K8/18 positive (designated K18) and ER negative. Comparison of K18 vs K14/18 tumor expression profiles showed that genes increased in K18 tumors were associated with ERBB2 and KRAS while decreased genes overlapped with those down regulated in metastasis and by loss of E-cadherin. Consistent with this, K18 tumors grew faster than K14/18 tumors and more mice with K18 tumors developed lung metastases compared to mice with K14/18 tumors. However, K18 tumors arising in Si-particle irradiated mice grew even faster and were more metastatic compared to control mice. A K18 Si-irradiated host profile was enriched in genes involved in mammary stem cells, stroma, and Notch signaling. Thus systemic responses to densely ionizing radiation enriches for a ER-negative, K18-positive tumor, whose biology is more aggressive compared to similar tumors arising in non-irradiated hosts.
Densely ionizing radiation acts via the microenvironment to promote aggressive Trp53-null mammary carcinomas.
No sample metadata fields
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 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 SamplesTrypanosoma cruzi is an obligate intracellular protozoan parasite that causes human Chagas disease, a leading cause of heart failure in Latin America. Using Affymetrix oligonucleotide arrays we screened phenotypically diverse human cells (foreskin fibroblasts, microvascular endothelial cells and vascular smooth muscle cells) for a common transcriptional response signature to T. cruzi. A common feature was a prominent type I interferon response, indicative of a secondary response to secreted cytokines. Using transwell plates to distinguish cytokine-dependent and -independent gene expression profiles in T. cruzi-infected cells, a core cytokine-independent response was identified in fibroblasts and endothelial cells that featured metabolic and signaling pathways involved in cell proliferation, amino acid catabolism and response to wounding. Significant downregulation of genes involved in mitotic cell cycle and cell division predicted that T. cruzi infection impedes cell cycle progression in the host cell.
Cytokine-dependent and-independent gene expression changes and cell cycle block revealed in Trypanosoma cruzi-infected host cells by comparative mRNA profiling.
No sample metadata fields
View SamplesThe intracellular pathogen Trypanosoma cruzi secretes an activity that blocks TGF--dependent induction of connective tissue growth factor (CTGF/CCN2). Here, we address the mechanistic basis for T. cruzi-mediated interference of
A soluble factor from Trypanosoma cruzi inhibits transforming growth factor-ß-induced MAP kinase activation and gene expression in dermal fibroblasts.
Specimen part
View SamplesBefore and after anaerobic Fe(II) shocked WT and ?bqsR of late stationary phase P. aeruginosa PA14 strains Associated publication: Kreamer NN, Costa F, Newman DK. 2015. The ferrous iron-responsive BqsRS two-component system activates genes that promote cationic stress tolerance. mBio 6(1):e02549-14. doi:10.1128/mBio.02549-14. Overall design: Expression profiles of rRNA-depleted total RNA from WT and ?bqsR Fe(II)-shocked (before and after 30 min incubation with 200 µM ferrous ammonium sulfate ) cultures grown anaerobically to deep stationary phase (A500 = 0.8) in Fe-limited (1 µM ferrous ammonium sulfate) MOPS minimal medium containing succinate as the carbon source, in triplicate
The ferrous iron-responsive BqsRS two-component system activates genes that promote cationic stress tolerance.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Mice without macroH2A histone variants.
Sex, Specimen part
View SamplesMacroH2As core histone variants have a unique structure that includes C-terminal nonhistone domain. MacroH2As are highly conserved in vertebrates, and are thought to regulate gene expression. However the nature of genes regulated by macroH2As and the biological significance of macroH2As for the organism remain unclear. Here we examine macroH2A function in vivo by knocking out both macroH2A1 and macroH2A2 in the mouse.
Mice without macroH2A histone variants.
Sex, Specimen part
View SamplesMacroH2As core histone variants have a unique structure that includes C-terminal nonhistone domain. MacroH2As are highly conserved in vertebrates, and are thought to regulate gene expression. However the nature of genes regulated by macroH2As and the biological significance of macroH2As for the organism remain unclear. Here we examine macroH2A function in vivo by knocking out both macroH2A1 and macroH2A2 in the mouse.
Mice without macroH2A histone variants.
Sex, Specimen part
View Samples