Zinc (Zn) is a major elemental component of respirable ambient particulate matter (PM) detected often at alarming levels in urban air. Exposure to PM has been widely associated with increased cardiovascular morbidity and mortality, however, it is not known what components or sources of PM are causative. We recently demonstrated that long-term episodic inhalation of combustion PM, having similar amount of Zn found in urban PM, caused myocardial lesions in rats. We further demonstrated that a single pulmonary exposure to Zn at high concentration is associated with disturbances in cardiac mitochondrial function, ion channel regulation, calcium homeostasis, and cell signaling. Therefore, in this study we investigated the role of PM-associated Zn in cardiac injury using multiple exposure scenarios. Male Wistar-Kyoto (WKY) rats of 12-14 wks age were intratracheally exposed (once per wk x 8 or16 wks) to either (1) saline (control); (2) PM having no soluble Zn; (3) combustion PM suspension containing 14.5 ug/mg water-soluble Zn at high and (4) low dose levels, (5) the aqueous fraction of this suspension devoid of solid insoluble particulate fraction (14.5 ug/mg soluble Zn), or (6) Zn sulfate. Zn concentrations were identical in groups 3, 5 and 6. Pulmonary toxicity was apparent in all exposure groups when compared to saline as determined by recovery of cells in bronchoalveolar lavage fluid. Long-term exposure to PM with or without soluble Zn, or Zn sulfate caused distinct myocardial lesions characterized by subepicardial and randomly distributed myocardial inflammation, degeneration, and fibrosis. The lesion severity was higher in those groups receiving Zn PM. Because cardiac mitochondria are likely the primary target of inhaled metal or other absorbed PM components, we analyzed mitochondrial DNA damage using QPCR and found that all exposure groups except those exposed to PM without Zn caused variable degree of damage. Aconitase activity, sensitive to inhibition by oxidative stress was inhibited slightly but significantly in rats receiving zinc sulfate. Although modest, microarray (Affymetrix) analysis revealed expression changes in the heart reflective of effects on cell signaling, inflammation/oxidative stress, mitochondrial fatty acid metabolisms and cell cycle regulation in rats exposed to zinc sulfate. However, these changes were minimal following exposure to PM devoid of soluble metals. We demonstrate that episodic subchronic pulmonary exposure to zinc sulfate causes cardiac injury and mitochondrial DNA damage. Thus, water-soluble PM-associated zinc may be one of the PM components responsible for cardiovascular morbidity.
The role of particulate matter-associated zinc in cardiac injury in rats.
No sample metadata fields
View SamplesCancer cell motility and invasiveness are fundamental characteristics of the malignant phenotype and are regulated through diverse signaling networks involving kinases and transcription factors. In this study, we identify a nuclear hormone receptor (ER)-protein kinase (ERK5)-cofilin (CFL1) network that specifies the degree of breast cancer cell aggressiveness through coupling of actin reorganization and hormone receptor-mediated transcription. Using dominant negative and constitutively active forms, as well as small molecule inhibitors of ERK5 and MEK5, we show that hormone activation of estrogen receptor- determines the nuclear versus cytoplasmic localization of the MAPK family member ERK5, which functions as a coregulator of ER-gene transcription.
Novel roles for ERK5 and cofilin as critical mediators linking ERα-driven transcription, actin reorganization, and invasiveness in breast cancer.
Specimen part
View SamplesThe nuclear hormone receptor, estrogen receptor-alpha (ER), and MAP kinases both play key roles in hormone-dependent cancers, yet their interplay and the integration of their signaling inputs remain poorly understood. In these studies, we document that estrogen-occupied ER activates and interacts with ERK2, a downstream effector in the MAPK pathway, resulting in ERK2 and ER colocalization at chromatin binding sites across the genome of breast cancer cells.
Genomic collaboration of estrogen receptor alpha and extracellular signal-regulated kinase 2 in regulating gene and proliferation programs.
Disease, Disease stage, Cell line, Time
View SamplesExposure to ultraviolet (UV) irradiation is the major cause of nonmelanoma skin cancer, the most common form of cancer in the United States. UV irradiation has a variety of effects on the skin associated with carcinogenesis, including DNA damage and effects on signal transduction. The alterations in signaling caused by UV regulate inflammation, cell proliferation, and apoptosis. UV also activates the orphan receptor tyrosine kinase and proto-oncogene Erbb2 (HER2/neu). In this study, we demonstrate that the UV-induced activation of Erbb2 regulates the response of the skin to UV. Inhibition or knockdown of Erbb2 before UV irradiation suppressed cell proliferation, cell survival, and inflammation after UV. In addition, Erbb2 was necessary for the UV-induced expression of numerous proinflammatory genes that are regulated by the transcription factors nuclear factor-kappaB and Comp1, including interleukin-1beta, prostaglandin-endoperoxidase synthase 2 (Cyclooxygenase-2), and multiple chemokines. These results reveal the influence of Erbb2 on the UV response and suggest a role for Erbb2 in UV-induced pathologies such as skin cancer.
Erbb2 regulates inflammation and proliferation in the skin after ultraviolet irradiation.
No sample metadata fields
View SamplesThe transcription factor FOXM1 coordinates the expression of cell cycle-related genes and plays a pivotal role in tumorigenesis and cancer progression. We have previously shown that FOXM1 acts downstream of 14-3-3 signaling, which correlates with a more aggressive tumor phenotype. However, the role that FOXM1 might play in engendering the resistance to endocrine treatments in estrogen receptor-positive (ER+) patients when tumor FOXM1 is high, has not been clearly defined.
The forkhead transcription factor FOXM1 promotes endocrine resistance and invasiveness in estrogen receptor-positive breast cancer by expansion of stem-like cancer cells.
Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrative genomics of gene and metabolic regulation by estrogen receptors α and β, and their coregulators.
Specimen part, Cell line
View SamplesAndrogen receptor (AR) is the major therapeutic target in aggressive prostate cancer. However, targeting AR alone can result in drug resistance and disease recurrence. Therefore, simultaneous targeting of multiple pathways could in principle be an effective new approach to treating prostate cancer. Here we provide proof-of-concept that a small molecule inhibitor of nuclear ß-catenin activity (called C3) can inhibit both the AR and ß-catenin signaling pathways that are often misregulated in prostate cancer. Treatment with C3 ablated prostate cancer cell growth by disruption of both ß-catenin/TCF and ß-catenin/AR protein interaction, reflecting the fact that TCF and AR have overlapping binding sites on ß-catenin. Given that AR interacts with, and is transcriptionally regulated by ß-catenin, C3 treatment also resulted in decreased occupancy of ß-catenin on the AR promoter and diminished AR and AR/ß-catenin target gene expression. Interestingly, C3 treatment resulted in decreased AR binding to target genes accompanied by decreased recruitment of an AR and ß-catenin cofactor, CARM1, providing new insight into the unrecognized function of ß-catenin in prostate cancer. Importantly, C3 inhibited tumor growth in an in vivo xenograft model, and blocked renewal of bicalutamide-resistant sphere forming cells, indicating the therapeutic potential of this approach. Overall design: Compare and contrast the expression profile of prostate cancer cells treated with a Wnt inhibitor (C3) with respect to ß-catenin and AR knockdown (all samples in duplicates).
Inhibition of androgen receptor and β-catenin activity in prostate cancer.
Disease, Subject
View SamplesThe closely related transcription factors (TFs), estrogen receptors ER and ER, regulate divergent gene expression programs and proliferative outcomes in breast cancer. Utilizing MCF-7 breast cancer cells with ER, ER, or both receptors as a model system to define the basis of differing response specification by related TFs, we show that these TFs and their key coregulators, SRC3 and RIP140, generate overlapping as well as unique chromatin-binding and transcription-regulating modules.
Integrative genomics of gene and metabolic regulation by estrogen receptors α and β, and their coregulators.
Specimen part, Cell line
View SamplesBackground: The KRAS gene is mutated in about 40% of colorectal cancer (CRC) cases, which has been clinically validated as a predictive mutational marker of intrinsic resistatnce to anti-EGFR inhibitor (EGFRi) therapy. Since nearly 60% of patients with a wild type KRAS fail to respond to EGFRi treatment, there is a need to develop more reliable molecular signatures to better predict response. Here we address the challenge of adapting a gene expression signature predictive of RAS pathway activation, created using fresh frozen (FF) tissues, for use with more widely available formalin fixed paraffin-embedded (FFPE) tissues. Methods: In this study, we evaluated the translation of an 18-gene RAS pathway signature score from FF to FFPE in 54 CRC cases, using a head-to-head comparison of five technology platforms. FFPE-based technologies included the Affymetrix GeneChip (Affy), NanoString nCounter(NanoS), Illumina whole genome RNASeq (RNA-Acc), Illumina targeted RNASeq(t-RNA), and Illumina stranded Total RNA-rRNA-depletion (rRNA). Results: Using Affy_FF as the "gold" standard, initial analysis of the 18-gene RAS scores on all 54 samples shows varying pairwise Spearman correlations, with (1) Affy_FFPE(r=0.233, p=0.090); (2) NanoS_FFPE(r=0.608, p<0.0001); (3) RNA-Acc_FFPE(r=0.175, p=0.21); (4) t-RNA_FFPE (r=-0.237, p=0.085); and (5) t-RNA (r=-0.012, p=0.93). These results suggest that only NanoString has successful FF to FFPE translation. The subsequent removal of identified "problematic" samples (n=15) and gene (n=2) further improves the correlations of Affy_FF with three of the five technologies: Affy_FFPE (r=0.672, p<0.0001); NanoS_FFPE (r=0.738, p<0.0001); and RNA-Acc_FFPE (r=0.483, p=0.002). Conclusions: Of the five technology platforms tested, NanoString technology provides a more faithful translation of the RAS pathway gene expression signature from FF to FFPE than the Affymetrix GeneChip and multiple RNASeq technologies. Moreover, NanoString was the most forgiving technology in the analysis of samples with presumably poor RNA quality. Using this approach, the RAS signature score may now be reasonably applied to FFPE clinical samples. Overall design: Fifty-four (54) FFPE evaluable tumor specimens were selected from a larger multi-center cohort of 468 well-characterized colorectal adenocarcinoma patients whose tissues were obtained between October 2006 and September 2010 at the University of South Florida. The sample cohort was composed of tumor samples that were available as matched fresh-frozen (FF) and formalin-fixed paraffin-embedded (FFPE) pairs.
Adaptation of a RAS pathway activation signature from FF to FFPE tissues in colorectal cancer.
Specimen part, Subject
View SamplesThe MCF-7 were infected with either control adenovirus expressing B-galactosidase (Ad) or adenovirus expressing ERB (AdERbeta) for 72 h. For knockdown of the endogenous ERa in MCF-7 cells, cells were treated with siRNA for 24h (AdERbeta+SiERalpha). Then cells were treated with Veh (0.1% EtOH), 10 nM E2 or 1 uM BEs (botanical extracts) for 24h. Overall design: Duplicate samples run; treatment after knockdown included a control treatment (V), estradiol (E2) or botanical extracts; genistein (Gen), S-equol, liquiritigenin (Liq)
Transcriptomic analysis identifies gene networks regulated by estrogen receptor α (ERα) and ERβ that control distinct effects of different botanical estrogens.
No sample metadata fields
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