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GSE22865
Homo sapiens
11 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Extracellular, cancer-specific methylated DNA has been shown to be a prognostic marker when detected in serum or plasma. In this study we investigated the effect of treating cancer cells with differentially methylated CpG DNA. When breast cancer cell lines were treated with methylated CpG DNA, a consistent upregulation of CHAC1 mRNA expression was observed. CHAC1 was recently described to be a novel component of the unfolded protein response pathway. To elucidate the role of CHAC1 mRNA expression in cancer in more detail, we analyzed expression of this gene in breast (n=107) and ovarian cancer (n=107) and found a strong correlation with tumor differentiation. Poorly differentiated tumors exhibited higher CHAC1 expression levels (p=0.004 for breast and p=0.031 for ovarian cancer). Additionally, hormone receptor (HR)-negative breast cancers (p<0.001) and advanced stage disease ovarian cancers (p=0.026) also demonstrated high CHAC1 mRNA levels. mRNA expression analysis of the two known CHAC1 isoforms showed a strong association of expression above the median with poor outcome in breast cancer patients in a multivariate analysis (isoform a: relative risk (RR) of death 3.2 (95% CI 1.6-6.5; p<0.01); RR of relapse 3.9 (95% CI 1.6-9.8; p<0.01); isoform b: relative risk (RR) of death 3.5 (95% CI 1.6-7.3; p<0.01); RR of relapse 6.6 (95% CI 2.4-18.5; p<0.01)). Univariate analysis in ovarian cancer showed that CHAC1 mRNA expression above the median was associated with a poor relapse free survival (p=0.03). In younger ovarian cancer patients (age < median age), a high CHAC1 mRNA expression was associated with overall survival (p=0.007) and relapse free survival (p=0.015). Finally, we show that downregulation of CHAC1 by small interfering RNA suppressed breast cancer cell migration and proliferation, whereas overexpression resulted in an observed increase in these cellular behaviours. This is the first report demonstrating that a gene (CHAC1) whose expression is triggered by methylated, but not unmethylated DNA, is involved in tumour biology.
Publication Title
Elevated mRNA expression of CHAC1 splicing variants is associated with poor outcome for breast and ovarian cancer patients.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Mouse Clariom S Array (clariomsmouse)
Description
Tcl1 tg mice develop a chronic lymphocytic leukemia (CLL) -like disease. To investigate the contribution of the adhesion molecule CD44 to CLL pathophysiology, we developed a CD19Cre CD44flox/flox Tcl1 tg mouse with a B cell specific CD44 deficiency (CD44B Tcl1 tg).
Publication Title
Microenvironment-induced CD44v6 promotes early disease progression in chronic lymphocytic leukemia.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 22 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Protein kinase c-β-dependent activation of NF-κB in stromal cells is indispensable for the survival of chronic lymphocytic leukemia B cells in vivo.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 14 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Tumor cell survival critically depends on heterotypic communication with benign cells in the microenvironment. Here we describe a novel survival signaling pathway activated in stromal cells by contact to B-cells from chronic lymphocytic leukemia (CLL) patients. The expression of PKC-II and the subsequent activation of NF-B in bone marrow stromal cells is a prerequisite to support the survival of malignant B-cells. PKC- knockout mice are insusceptible to CLL-transplantations, underscoring the in vivo significance of the PKC-II- NF-B signaling pathway in the tumor microenvironment. Upregulated stromal PKC-II in biopsies from CLL, breast- and pancreatic- cancer patients suggest that this pathway may commonly be activated in a variety of malignancies.
Publication Title
Protein kinase c-β-dependent activation of NF-κB in stromal cells is indispensable for the survival of chronic lymphocytic leukemia B cells in vivo.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 8 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Tumor cell survival critically depends on heterotypic communication with benign cells in the microenvironment. Here we describe a novel survival signaling pathway activated in stromal cells by contact to B-cells from chronic lymphocytic leukemia (CLL) patients. The expression of PKC-II and the subsequent activation of NF-B in bone marrow stromal cells is a prerequisite to support the survival of malignant B-cells. PKC- knockout mice are insusceptible to CLL-transplantations, underscoring the in vivo significance of the PKC-II- NF-B signaling pathway in the tumor microenvironment. Upregulated stromal PKC-II in biopsies from CLL, breast- and pancreatic- cancer patients suggest that this pathway may commonly be activated in a variety of malignancies.
Publication Title
Protein kinase c-β-dependent activation of NF-κB in stromal cells is indispensable for the survival of chronic lymphocytic leukemia B cells in vivo.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 10 Downloadable Samples
Illumina Genome Analyzer II
Description
Specific mutations in the XPD subunit of transcription factor IIH result in combined xeroderma pigmentosum (XP)/Cockayne syndrome (CS), a severe DNA repair disorder characterized at the cellular level by a transcriptional arrest following UV irradiation. This transcriptional arrest has always been thought to be the result of faulty transcription-coupled repair. In the present study, we investigate the transcriptional dysregulation that follows UV irradiation in XP-D/CS compared with “pure” XP-D cells or WT cells. We also study how this process is affected by the inhibition of the histone deacetylase Sirt1.
Publication Title
Sirt1 suppresses RNA synthesis after UV irradiation in combined xeroderma pigmentosum group D/Cockayne syndrome (XP-D/CS) cells.
Sample Metadata Fields
No sample metadata fields
View Samples- Escherichia coli str. k-12 substr. mg1655
- 4 Downloadable Samples
- Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
Promoter recognition by bacterial RNA polymerase is mediated by subunits, which assemble transiently to RNA polymerase core enzyme (E) during transcription initiation. subunits drive transcription of specific sets of genes by allowing RNA polymerase to interact with different promoter sequences. However, 70, the housekeeping subunit, and S, an alternative subunit mainly active during slow growth and in response to cellular stresses, appear to recognize almost identical promoter sequences, raising the question of how promoter selectivity is achieved in the bacterial cell. To identify sequence determinants for selective promoter recognition, we performed a run-off/microarray experiment (ROMA): in vitro transcription experiments were carried out with RNA polymerase saturated either with 70 (E70) or with S (ES) using the whole Escherichia coli genome as DNA template, and transcript levels were determined by microarray analysis. We found that several genes associated with bacterial growth (e.g., ribosomal operons) were transcribed more efficiently by E70. In contrast, ES transcribed preferentially genes involved in stress responses, secondary metabolism, as well as regulatory RNAs and intergenic regions with yet unknown function. Genes preferentially recognized in vitro by ES showed reduced expression in ES -deficient mutant strain of E. coli. Sequence comparison of E70- versus ES dependent promoters confirms that the presence of a -35 sequence and the relative location of UP elements affect promoter interaction with either form of RNA polymerase, and suggests that a G/C bias in the -2/+1 nucleotides would favour efficient promoter recognition by E70.
Publication Title
In vitro transcription profiling of the σS subunit of bacterial RNA polymerase: re-definition of the σS regulon and identification of σS-specific promoter sequence elements.
Sample Metadata Fields
Disease
View Samples- Escherichia coli str. k-12 substr. mg1655
- 58 Downloadable Samples
- Affymetrix E. coli Genome 2.0 Array (ecoli2)
Description
The widespread use of electricity raises the question of whether or not 50 Hz (power line frequency in Europe) magnetic fields (MFs) affect organisms. We investigated the transcription of Escherichia coli K-12 MG1655 in response to extremely low-frequency (ELF) MFs. Fields generated by three signal types (sinusoidal continuous, sinusoidal intermittent, and power line intermittent; all at 50 Hz, 1 mT), were applied and gene expression was monitored at the transcript level using an Affymetrix whole-genome microarray. Bacterial cells were grown continuously in a chemostat (dilution rate D = 0.4 h-1) fed with glucose-limited minimal medium and exposed to 50 Hz MFs with a homogenous flux density of 1 mT. For all three types of MFs investigated, neither bacterial growth (determined using optical density) nor culturable counts were affected. Likewise, no statistically significant change (fold-change > 2, P 0.01) in the expression of 4,358 genes and 714 intergenic regions represented on the gene chip was detected after MF exposure for 2.5 h (1.4 generations) or 15 h (8.7 generations). Moreover, short-term exposure (8 min) to the sinusoidal continuous and power line intermittent signal neither affected bacterial growth nor showed evidence for reliable changes in transcription. In conclusion, our experiments did not indicate that the different tested MFs (50 Hz, 1 mT) affected the transcription of E. coli.
Publication Title
Genome-wide transcription analysis of Escherichia coli in response to extremely low-frequency magnetic fields.
Sample Metadata Fields
Treatment
View Samples- Homo sapiens
- 10 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Gene expression profile in CS1AN deficient and CSBwt restored cell lines after 24 hours of UV or alphe-amanitin treatment (only for restored). The comaprison of expression profile between 0 and 24 hours revealed
Publication Title
Regulatory interplay of Cockayne syndrome B ATPase and stress-response gene ATF3 following genotoxic stress.
Sample Metadata Fields
Specimen part, Treatment
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
The goal of this experiment was to compare gene expression after t-RA treatment in cells with or without the presence of the PolyADP ribose Glycohydrolase protein (PARG)
Publication Title
Poly (ADP-ribose) glycohydrolase regulates retinoic acid receptor-mediated gene expression.
Sample Metadata Fields
Cell line
View Samples