To identify metastasis suppressor genes, which are functionally compromised in late-stage breast cancer, we compared the gene expression profiles of an established breast cancer progression cell line model and leveraged large amounts of publically available data by applying multiple bioinformatics filters. Here we report the identification of serum deprivation response (SDPR, also known as cavin-2) as a bona fide metastasis suppressor, capable of impairing the metastatic growth of cancer cells while having no effect on the growth of primary tumors.
SDPR functions as a metastasis suppressor in breast cancer by promoting apoptosis.
Disease, Disease stage, Cell line
View SamplesBasal-like breast cancer (BLBC) cells share phenotypic similarities with cancer stem cells (CSCs) but the underlying molecular basis for this connection remains elusive. We hypothesized that BLBC cells are able to establish a niche permissive to the maintenance of CSCs and found that tumor cell-derived periostin (POSTN), a component of the extracellular matrix, as well as a corresponding cognate receptor, integrin v3, are highly expressed in a subset of BLBC cell lines as well as in cancer stem cell-enriched populations. Furthermore, we demonstrated that an intact periostin-integrin 3 signaling axis is required for the maintenance of breast CSCs. POSTN activates the ERK signaling pathway and regulates NF-B-mediated transcription of key cytokines, namely IL6 and IL8, which in turn mediate downstream activation of STAT3. In summary, these findings suggest that BLBC cells have an innate ability to establish a microenvironmental niche supportive of CSCs.
Tumor Cell-Derived Periostin Regulates Cytokines That Maintain Breast Cancer Stem Cells.
Cell line
View SamplesIn this study, we took advantage of a previously established breast cancer progression cell line model system, which consists of a parental MCF10A (MI) spontaneously immortalized mammary epithelial cell line and two of its derivatives: 1) MCF10ATk.cl2 (MII), a MCF10A H-Ras transformed cell line and 3) MCF10CA1h (MIII), derived from a xenograft of the MII cells in nude mice that progressed to carcinoma (1, 2). These cell lines were previously reported to exhibit distinct tumorigenic properties when re-implanted in nude mice; MI is non-tumorigenic, MII forms benign hyperplastic lesions and MIII forms low-grade, well differentiated carcinomas (2, 3). The advantage of this system is that these cell lines were derived from a common genetic background (MCF10A) and accumulated distinct genetic/epigenetic alterations in vivo enabling them to acquire a range of non-tumorigenic to carcinogenic properties. Our initial studies showed that MIII cells, but not MI or MII, exhibit an EMT phenotype, promoter DNA hypermethylation of epithelial genes and highly invasive properties in vitro.
Smad signaling is required to maintain epigenetic silencing during breast cancer progression.
Cell line
View SamplesLuminal breast cancers express estrogen (ER) and progesterone (PR) receptors, and respond to endocrine therapies. However, some ER+PR+ tumors display intrinsic or acquired resistance, possibly related to PR. Two PR isoforms, PR-A and PR-B, regulate distinct gene subsets that may differentially influence tumor fate. A high PR-A:PR-B ratio is associated with poor prognosis and tamoxifen resistance. We speculate that excessive PR-A marks tumors that will relapse early. Here we address mechanisms by which PR-A regulate transcription, focusing on SUMOylation. We use receptor mutants and synthetic promoter/reporters to show that SUMOylation deficiency or the deSUMOylase SENP1 enhance transcription by PR-A, independent of the receptors dimerization interface or DNA binding domain. De-SUMOylation exposes the agonist properties of the antiprogestin RU486. Thus, on synthetic promoters, SUMOylation functions as an independent brake on transcription by PR-A. What about PR-A SUMOylation of endogenous human breast cancer genes? To study these, we used gene expression profiling. Surprisingly, PR-A SUMOylation influences progestin target genes differentially, with some upregulated, others downregulated, and others unaffected. Hormone-independent gene regulation is also PR-A SUMOylation dependent. Several SUMOylated genes were analyzed in clinical breast cancer database. In sum, we show that SUMOylation does not simply repress PR-A. Rather, it regulates PR-A activity in a target selective manner including genes associated with poor prognosis, shortened survival, and metastasis.
SUMOylation Regulates Transcription by the Progesterone Receptor A Isoform in a Target Gene Selective Manner.
Specimen part, Treatment
View SamplesPsychological, psychosocial and physical stress are major risk factors, which enhance the development of sporadic late-onset Alzheimer`s disease. The chronic unpredictable mild stress model mimics those risk factors and triggers signs of neurodegeneration and neuropathological features of sporadic AD such as tau hyperphosphorylation and enhanced amyloid beta generation. The study investigated the impact of chronic unpredictable mild stress on signs of neurodegeneration by analyzing hippocampal gene expression with whole genome microarray gene expression profiling.
Inhibition of ACE Retards Tau Hyperphosphorylation and Signs of Neuronal Degeneration in Aged Rats Subjected to Chronic Mild Stress.
Sex, Age, Specimen part
View SamplesTo test whether a genomic classifier (GC) predicts development of metastatic disease in patients treated with salvage radiation therapy (SRT) after radical prostatectomy (RP).
Utilization of a Genomic Classifier for Prediction of Metastasis Following Salvage Radiation Therapy after Radical Prostatectomy.
Specimen part
View SamplesSteroid hormones regulate essential physiological processes and inadequate levels are associated with various pathological conditions. In testosterone-producing Leydig cells, steroidogenesis is strongly stimulated by LH via its receptor leading to increased cAMP production and expression of the steroidogenic acute regulatory (STAR) protein, which is essential for the initiation of steroidogenesis. Leydig cell steroidogenesis then passively decreases following the rapid degradation of cAMP into AMP by phosphodiesterases. In this study, we show that AMP-activated protein kinase (AMPK) is activated following cAMP breakdown in MA-10 and MLTC-1 Leydig cells. Activated AMPK then actively inhibits cAMP-induced steroidogenesis by repressing the expression of key regulators of steroidogenesis including Star and Nr4a1. Similar results were obtained in Y-1 adrenal cells and in the constitutive steroidogenic cell line R2C. Our data identify AMPK as an active repressor of steroid hormone biosynthesis in steroidogenic cells that is essential to preserve cellular energy and prevent excess steroid production.
A cell-autonomous molecular cascade initiated by AMP-activated protein kinase represses steroidogenesis.
Specimen part, Treatment
View SamplesPowdery mildew, caused by the fungus Blumeria graminis (DC) Speer, is one of the most important foliar diseases of cereals worldwide. It is an obligate biotrophic parasite, colonising leaf epidermal cells to obtain nutrients from the plant cells without killing them. Syringolin A (sylA), a circular peptide secreted by the phytopathogenic bacterium Pseudomonas syringae pv. syringae, triggers a hypersensitive cell death reaction (HR) at infection sites when sprayed onto powdery mildew infected wheat which essentially eradicates the fungus. The rational was to identify genes whose expression was specifically regulated during HR, i.e. genes that might be involved in the switch of compatibility to incompatibility.<br></br>Powdery mildew-infected or uninfected plants were treated with syringolin two days after infection and plant material for RNA extraction was collected at 0.5, 1, 2, 4, 8, 12 hours after treatment (hat), resulting in an early (2 and 4 hat) and late pool (8 and 12 hat). Plant material that was uninfected prior to syringolin treatment was collected 8 and 12 hat (late pool of uninfected plant material), and 1 hat, respectively.
Transcriptional changes in powdery mildew infected wheat and Arabidopsis leaves undergoing syringolin-triggered hypersensitive cell death at infection sites.
Compound, Time
View SamplesThe initial segment of the epididymis is vital for male fertility, therefore, it is important to understand the mechanisms that regulate this important region. Deprival of testicular luminal fluid factors/lumicrine factors from epididymis, a subset of cells within the initial segment undergo apoptosis. In this study, microarray analyses was used to examine early changes in the downstream signal transduction pathways following the loss of lumicrine factors, and we discovered the following cascade of events leading to loss of protection and eventual apoptosis. First, mRNA expression of several key components of ERK pathway decreased sharply after 6 hours of loss protection from testicular lumicrine factors. After 12 hours, the levels of mRNA expression of STAT and NF-B pathways components increased, mRNA expression of genes encoding cell cycle inhibitors increased. After 18 hours of loss protection from testicular lumicrine factors, apoptosis was observed in the initial segment. In conclusion, testicular lumicrine factors protect the cells of the initial segment by activating ERK pathway, repressing STAT and NF-B pathways, and preventing a cascade of reactions leading to apoptosis.
Testicular lumicrine factors regulate ERK, STAT, and NFKB pathways in the initial segment of the rat epididymis to prevent apoptosis.
Sex, Specimen part, Time
View SamplesAbstract: Cellular senescence, an integral component of aging and cancer, arises in response to diverse triggers, including telomere attrition, macromolecular damage, and signaling from activated oncogenes. At present, senescent cells are identified by the combined presence of multiple traits, such as senescence-associated protein expression and secretion, DNA damage, and ß-galactosidase activity; unfortunately, these traits are neither exclusively nor universally present in senescent cells. To identify robust shared markers of senescence, we have performed RNA-sequencing analysis across 8 diverse models of senescence triggered in human diploid fibroblasts (WI-38, IMR-90) and endothelial cells (HUVEC, HAEC) by replicative exhaustion, exposure to ionizing radiation or doxorubicin, and expression of the oncogene HRASG12V. The intersection of the altered transcriptomes revealed 47 RNAs consistently elevated and 26 RNAs consistently reduced across all senescence models, including many protein-coding mRNAs and some long noncoding RNAs. We propose that these shared transcriptome profiles will enable the identification of senescent cells in vivo, the investigation of their roles in aging and malignancy, and the development of strategies to target senescent cells therapeutically. Overall design: Transcriptomic analysis of various cell line models of senescence and their respective controls
Transcriptome signature of cellular senescence.
Specimen part, Cell line, Treatment, Subject
View Samples