12 research outputs found
ERG Induces Epigenetic Activation of Tudor Domain-Containing Protein 1 (TDRD1) in ERG Rearrangement-Positive Prostate Cancer
Background Overexpression of ERG transcription factor due to genomic ERG-
rearrangements defines a separate molecular subtype of prostate tumors. One of
the consequences of ERG accumulation is modulation of the cellâs gene
expression profile. Tudor domain-containing protein 1 gene (TDRD1) was
reported to be differentially expressed between TMPRSS2:ERG-negative and
TMPRSS2:ERG-positive prostate cancer. The aim of our study was to provide a
mechanistic explanation for the transcriptional activation of TDRD1 in ERG
rearrangement-positive prostate tumors. Methodology/Principal Findings Gene
expression measurements by real-time quantitative PCR revealed a remarkable
co-expression of TDRD1 and ERG (r2 = 0.77) but not ETV1 (r2<0.01) in human
prostate cancer in vivo. DNA methylation analysis by MeDIP-Seq and bisulfite
sequencing showed that TDRD1 expression is inversely correlated with DNA
methylation at the TDRD1 promoter in vitro and in vivo (Ď = â0.57).
Accordingly, demethylation of the TDRD1 promoter in TMPRSS2:ERG-negative
prostate cancer cells by DNA methyltransferase inhibitors resulted in TDRD1
induction. By manipulation of ERG dosage through gene silencing and forced
expression we show that ERG governs loss of DNA methylation at the TDRD1
promoter-associated CpG island, leading to TDRD1 overexpression.
Conclusions/Significance We demonstrate that ERG is capable of disrupting a
tissue-specific DNA methylation pattern at the TDRD1 promoter. As a result,
TDRD1 becomes transcriptionally activated in TMPRSS2:ERG-positive prostate
cancer. Given the prevalence of ERG fusions, TDRD1 overexpression is a common
alteration in human prostate cancer which may be exploited for diagnostic or
therapeutic procedures
Histidine-Rich Glycoprotein Protects from Systemic Candida Infection
Fungi, such as Candida spp., are commonly found on the skin and at mucosal surfaces. Yet, they rarely cause invasive infections in immunocompetent individuals, an observation reflecting the ability of our innate immune system to control potentially invasive microbes found at biological boundaries. Antimicrobial proteins and peptides are becoming increasingly recognized as important effectors of innate immunity. This is illustrated further by the present investigation, demonstrating a novel antifungal role of histidine-rich glycoprotein (HRG), an abundant and multimodular plasma protein. HRG bound to Candida cells, and induced breaks in the cell walls of the organisms. Correspondingly, HRG preferentially lysed ergosterol-containing liposomes but not cholesterol-containing ones, indicating a specificity for fungal versus other types of eukaryotic membranes. Both antifungal and membrane-rupturing activities of HRG were enhanced at low pH, and mapped to the histidine-rich region of the protein. Ex vivo, HRG-containing plasma as well as fibrin clots exerted antifungal effects. In vivo, Hrgâ/â mice were susceptible to infection by C. albicans, in contrast to wild-type mice, which were highly resistant to infection. The results demonstrate a key and previously unknown antifungal role of HRG in innate immunity
TMPRSS2-ERG -specific transcriptional modulation is associated with prostate cancer biomarkers and TGF-β signaling
<p>Abstract</p> <p>Background</p> <p><it>TMPRSS2-ERG </it>gene fusions occur in about 50% of all prostate cancer cases and represent promising markers for molecular subtyping. Although <it>TMPRSS2-ERG </it>fusion seems to be a critical event in prostate cancer, the precise functional role in cancer development and progression is still unclear.</p> <p>Methods</p> <p>We studied large-scale gene expression profiles in 47 prostate tumor tissue samples and in 48 normal prostate tissue samples taken from the non-suspect area of clinical low-risk tumors using Affymetrix GeneChip Exon 1.0 ST microarrays.</p> <p>Results</p> <p>Comparison of gene expression levels among <it>TMPRSS2-ERG </it>fusion-positive and negative tumors as well as benign samples demonstrated a distinct transcriptional program induced by the gene fusion event. Well-known biomarkers for prostate cancer detection like <it>CRISP3 </it>were found to be associated with the gene fusion status. WNT and TGF-β/BMP signaling pathways were significantly associated with genes upregulated in <it>TMPRSS2-ERG </it>fusion-positive tumors.</p> <p>Conclusions</p> <p>The <it>TMPRSS2-ERG </it>gene fusion results in the modulation of transcriptional patterns and cellular pathways with potential consequences for prostate cancer progression. Well-known biomarkers for prostate cancer detection were found to be associated with the gene fusion. Our results suggest that the fusion status should be considered in retrospective and future studies to assess biomarkers for prostate cancer detection, progression and targeted therapy.</p
Matrix-Dependent Regulation of AKT in Hepsin-Overexpressing PC3 Prostate Cancer Cells12
The serine-protease hepsin is one of the most prominently overexpressed genes in human prostate carcinoma. Forced expression of the enzyme in mice prostates is associated with matrix degradation, invasive growth, and prostate cancer progression. Conversely, hepsin overexpression in metastatic prostate cancer cell lines was reported to induce cell cycle arrest and reduction of invasive growth in vitro. We used a system for doxycycline (dox)-inducible target gene expression in metastasis-derived PC3 cells to analyze the effects of hepsin in a quantitative manner. Loss of viability and adhesion correlated with hepsin expression levels during anchorage-dependent but not anchorage-independent growth. Full expression of hepsin led to cell death and detachment and was specifically associated with reduced phosphorylation of AKT at Ser473, which was restored by growth on matrix derived from RWPE1 normal prostatic epithelial cells. In the chorioallantoic membrane xenograft model, hepsin overexpression in PC3 cells reduced the viability of tumors but did not suppress invasive growth. The data presented here provide evidence that elevated levels of hepsin interfere with cell adhesion and viability in the background of prostate cancer as well as other tissue types, the details of which depend on the microenvironment provided. Our findings suggest that overexpression of the enzyme in prostate carcinogenesis must be spatially and temporally restricted for the efficient development of tumors and metastases
<i>TDRD1</i> is co-expressed with <i>ERG</i> but not with <i>ETV1</i> in prostate cancer.
<p>(A) Correlation analysis of mRNA levels measured by qRT-PCR in <i>TMPRSS2:ERG</i>-negative (ERG-, nâ=â30) and <i>TMPRSS2:ERG</i>-positive (ERG+, nâ=â17) prostate cancers as well as adjacent benign prostate tissue (nâ=â46). Pearson correlation coefficient is shown. (B) Analysis of mRNA expression in prostate cell lines by qRT-PCR. Two independent experiments were performed in triplicate. Human testis RNA was used as positive control for <i>TDRD1</i> expression. (C) Analysis of protein expression in prostate cell lines by western blotting. (D) Analysis of mRNA expression in hematopoietic cancer cell lines by qRT-PCR. Two independent experiments were performed in triplicate.</p
ERG transcription factor is required to maintain high <i>TDRD1</i> expression.
<p>(A) <i>ERG</i> and <i>TDRD1</i> mRNA expression levels in VCaP cells measured 72 h after gene silencing with siRNAs. Three independent experiments were performed in triplicate. (B) ERG and TDRD1 protein expression in VCaP cells 72 h after gene silencing with siRNAs.</p
ERG-induced loss of epigenetic repression at the <i>TDRD1</i> promoter is a major mechanism of <i>TDRD1</i> overexpression.
<p>(A) DNA methylation analysis of the <i>TDRD1</i> promoter-associated CpG island in prostate cell lines by bisulfite sequencing. Average methylation level of the whole CpG island calculated from five sequenced colonies is shown (%). (B) Analysis of mRNA expression in LNCaP cells after treatment with the demethylating agent 5-aza-2â˛-deoxycytidine. Insert: analysis of protein expression in LNCaP cells after treatment with 5-aza-2â˛-deoxycytidine. 75Âľg of protein lysate from LNCaP cells was used per lane. (C) Analysis of mRNA expression in stable LNCaP clones overexpressing <i>ERG</i>. Two independent experiments were performed in triplicate. Insert: ERG expression analysis at 48 h in LNCaP clones by western blotting. (D) Bisulfite sequencing of the <i>TDRD1</i> promoter-associated CpG island in LNCaP cells 48 h after induction of ERG expression with doxycycline. (E) Bisulfite sequencing of the <i>TDRD1</i> promoter-associated CpG island 96 h after silencing of <i>ERG</i> in VCaP cells. The data shown in (D) and (E) are mean % of methylation of the entire CpG island calculated from 11â12 sequenced clones.</p
<i>TDRD1</i> does not control LINE1 activity in <i>TMPRSS2:ERG</i>-positive VCaP cells.
<p>(A) mRNA expression analysis of <i>PIWIL</i> genes in prostate cell lines by qRT-PCR. Testis RNA was used as a positive control. (B) mRNA expression analysis of LINE1 ORF2 in VCaP cells following 5 days of treatment with 5-aza-2â˛-deoxycytidine. (C) mRNA expression analysis of LINE1 ORF2 in VCaP cells following prolonged (8 days) <i>ERG</i> or <i>TDRD1</i> silencing. (D) Metabolic viability assay of VCaP cells treated with siRNAs. One (B), two (A) or three (C, D) independent experiments were performed in triplicate.</p
<i>TDRD1</i> promoter associated CpG island is hypomethylated in <i>TMPRSS2:ERG</i>-positive prostate cancer.
<p>(A) Analysis of <i>TDRD1</i> promoter methylation in prostate tumors by MeDIP-Seq. The values represent the average degree of DNA methylation of the 500-bp bins. (B) Correlation analysis of <i>TDRD1</i> promoter methylation and <i>TDRD1</i> mRNA expression in prostate cancer. The Spearman correlation coefficient is shown.</p