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GSE75034
Homo sapiens
166 Downloadable Samples
Illumina HumanWG-6 v3.0 expression beadchip
Description
The present work aimed to identify reference genes for RT-qPCR studies of hypoxia in cervical cancer. From 422 candidate reference genes selected from the literature, we used Illumina array-based expression profiles to identify 182 genes not affected by hypoxia treatment in eight cervical cancer cell lines or correlated with the hypoxia-associated dynamic contrast-enhanced magnetic resonance imaging parameter ABrix in 42 patients. Among these genes, we selected nine candidates (CHCHD1, GNB2L1, IPO8, LASP1, RPL27A, RPS12, SOD1, SRSF9, TMBIM6) that were not associated with tumor volume, stage, lymph node involvement or disease progression in array data of 150 patients, for further testing by RT-qPCR. geNorm and NormFinder analyses of RT-qPCR data of 74 patients identified CHCHD1, SRSF9 and TMBIM6 as the most suitable set of reference genes, with stable expression both overall and across patient subgroups with different hypoxia status (ABrix) and clinical parameters. The suitability of the three candidates as reference genes were validated in studies of the hypoxia-induced genes DDIT3, ERO1A, and STC2. After normalizing with CHCHD1, SRSF9 and TMBIM6, the RT-qPCR data of these genes showed a significant correlation with Illumina expression (P<0.001, n=74) and ABrix (P<0.05, n=32), and the STC2 data were associated with clinical outcome, in accordance with the Illumina data. Thus, CHCHD1, SRSF9 and TMBIM6 seem to be suitable reference genes for studying hypoxia-related gene expression in cervical cancer samples by RT-qPCR. STC2 might be a useful prognostic hypoxia biomarker in cervical cancer that warrants further investigation.
Publication Title
Identification and Validation of Reference Genes for RT-qPCR Studies of Hypoxia in Squamous Cervical Cancer Patients.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 22 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Purpose: Resistance to endocrine therapy in estrogen receptor-positive (ER+) breast cancer remains a major clinical problem. Recently, the CDK4/6 inhibitor palbociclib combined with letrozole was approved for treatment of ER+ advanced breast cancer, and other CDK4/6 inhibitors are being investigated in combination with different endocrine treatments. However, the role of CDK4/6 in endocrine resistance and their potential as predictive biomarkers of endocrine treatment response remains undefined.
Publication Title
High CDK6 Protects Cells from Fulvestrant-Mediated Apoptosis and is a Predictor of Resistance to Fulvestrant in Estrogen Receptor-Positive Metastatic Breast Cancer.
Sample Metadata Fields
Specimen part
View Samples- Arabidopsis thaliana
- 12 Downloadable Samples
- Affymetrix Arabidopsis ATH1 Genome Array (ath1121501)
Description
Arabidopsis is a non-host to the biotrophic fungus Blumeria graminis f.sp. hordei (Bgh), effectively hindering Bgh ingress to the epidermal cells by deposition of callosic papillae formations, i.e. penetration resistance. To better understand the transcriptional changes in Arabidopsis towards Bgh, we compared un-inoculated and inoculated wild-type Arabidopsis samples, with those an ATAF1 mutant allele, compromised in penetration resistance. The experiment included sampling of 8 rosettes for each replicate sample from 6-weeks old plants, 12 hrs after inoculation. A total of 12 biolocigal replicates were sampled with three replicates from each of the four blocks (Wild-type, ataf1-1, Bgh, control). ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Michael Krogh Jensen. The equivalent experiment is AT31 at PLEXdb.]
Publication Title
Transcriptional regulation by an NAC (NAM-ATAF1,2-CUC2) transcription factor attenuates ABA signalling for efficient basal defence towards Blumeria graminis f. sp. hordei in Arabidopsis.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 80 Downloadable Samples
- Illumina HumanWG-6 v3.0 expression beadchip
Description
Emerging biomarkers based on medical images and molecular characterization of tumor biopsies open up for combining the two disciplines and exploiting their synergy in treatment planning. We compared pretreatment classification of cervical cancer patients by two previously validated imaging- and gene-based hypoxia biomarkers, evaluated the influence of intratumor heterogeneity, and investigated the benefit of combining them in prediction of treatment failure. The imaging-based biomarker was hypoxic fraction, determined from diagnostic dynamic contrast enhanced (DCE)-MR images. The gene-based biomarker was a hypoxia gene expression signature determined from tumor biopsies. Paired data were available for 118 patients. Intratumor heterogeneity was assessed by variance analysis of MR images and multiple biopsies from the same tumor. The two biomarkers were combined using a dimension-reduction procedure. The biomarkers classified 75% of the tumors with the same hypoxia status. Both intratumor heterogeneity and distribution pattern of hypoxia from imaging were unrelated to inconsistent classification by the two biomarkers, and the hypoxia status of the slice covering the biopsy region was representative of the whole tumor. Hypoxia by genes was independent on tumor cell fraction and showed minor heterogeneity across multiple biopsies in 9 tumors. This suggested that the two biomarkers could contain complementary biological information. Combination of the biomarkers into a composite score led to improved prediction of treatment failure (HR:7.3) compared to imaging (HR:3.8) and genes (HR:3.0) and prognostic impact in multivariate analysis with clinical variables. In conclusion, combining imaging- and gene-based biomarkers enables more precise and informative assessment of hypoxia-related treatment resistance in cervical cancer, independent of intratumor heterogeneity.
Publication Title
Combining imaging- and gene-based hypoxia biomarkers in cervical cancer improves prediction of chemoradiotherapy failure independent of intratumour heterogeneity.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 2 Downloadable Samples
- Illumina HumanWG-6 v3.0 expression beadchip
Description
Hypoxia promotes an aggressive tumor phenotype with increased genomic instability, partially due to downregulation of DNA repair pathways. However, in addition to DNA repair, genome stability is also controlled by cell cycle checkpoints. An important issue is therefore whether hypoxia also can alter the DNA damage cell cycle checkpoints. Here, we show that hypoxia (24h 0.2% O2) alters the expression of several G2 checkpoint regulators, as examined by microarray gene expression analysis and immunoblotting of U2OS cells. While some of the changes reflected hypoxia-induced inhibition of cell cycle progression, flow cytometric bar-coding analysis of individual cells showed that the levels of several G2 checkpoint regulators were reduced in G2 phase cells after hypoxic exposure, in particular cyclin B1. These effects were accompanied by decreased Cyclin dependent kinase (CDK) activity in G2 phase cells after hypoxia. Furthermore, cells pre-exposed to hypoxia showed a longer G2 checkpoint arrest upon treatment with ionizing radiation. Similar results were found following other hypoxic conditions (~0.03 % O2 20h and 0.2% O2 72h). These results demonstrate that the DNA damage G2 checkpoint can be altered as a consequence of hypoxia, and we propose that such alterations may influence the genome stability of hypoxic tumors.
Publication Title
Hypoxia-induced alterations of G2 checkpoint regulators.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 166 Downloadable Samples
- Illumina HumanWG-6 v3.0 expression beadchip
Description
We have previously identified a prognostic 31-gene expression signature in locally advanced cervical cancer that is associated with tumor hypoxia and reflected by the dynamic contrast enhanced magnetic resonance (DCE-MR) image parameter ABrix. To bring the signature closer to clinical use, we here aimed to construct a classifier with key signature genes that retained an association to ABrix and separated the patients into groups with different hypoxia status and chemoradiotherapy outcome.
Publication Title
Integrative Analysis of DCE-MRI and Gene Expression Profiles in Construction of a Gene Classifier for Assessment of Hypoxia-Related Risk of Chemoradiotherapy Failure in Cervical Cancer.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 151 Downloadable Samples
- Illumina HumanWG-6 v3.0 expression beadchip
Description
We compared the prognostic significance of ectodomain isoforms of the epidermal growth factor receptor (EGFR), which lack the tyrosine kinase (TK) domain, with that of the full length receptor and its autophosphorylation status in cervical cancers treated with conventional chemoradiotherapy.
Publication Title
Membranous expression of ectodomain isoforms of the epidermal growth factor receptor predicts outcome after chemoradiotherapy of lymph node-negative cervical cancer.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 54 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
We aimed to investigate the transcriptional program associated with pimonidazole staining in prostate cancer.
Publication Title
The tumour hypoxia marker pimonidazole reflects a transcriptional programme associated with aggressive prostate cancer.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Homo sapiens
- 158 Downloadable Samples
- Illumina HumanWG-6 v3.0 expression beadchip
Description
We explored the prognostic impact of the dynamic contrast enhanced MR imaging (DCE-MRI) parameter ABrix in cervical cancer combined with global gene expression data to reveal the underlying molecular phenotype of the parameter and construct a gene signature that reflected ABrix. Based on 78 cervical cancer patients subjected to curative chemoradiotherapy, we identified a prognostic ABrix parameter by pharmacokinetic analysis of DCE-MR images based on the Brix model, where tumors with low ABrix appeared to be most aggressive. Gene set enrichment analysis of 46 tumors with pairwise DCE-MRI and gene expression data showed a significant correlation between ABrix and the hypoxia gene sets, whereas gene sets related to proliferation, radioresistance, and wound healing were not significant. Hypoxia gene sets specific for cervical cancer created in cell culture experiments, including targets of the hypoxia inducible factor (HIF1) and the unfolded protein response (UPR), were the most significant. In the remaining 32 tumors, low ABrix was associated with upregulation of HIF1 protein expression, as assessed by immunohistochemistry, consistent with increased hypoxia. Based on the hypoxia gene sets, a signature of 31 genes that were upregulated in tumors with low ABrix was constructed. This DCE-MRI hypoxia gene signature showed prognostic impact in an independent validation cohort of 109 patients.
Publication Title
Hypoxia-induced gene expression in chemoradioresistant cervical cancer revealed by dynamic contrast-enhanced MRI.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Homo sapiens
- 36 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip
Description
We aimed to investigate gene expression associated with radiosensitisation of normoxic and hypoxic prostate cancer cells by the class I/II histone deacetylase inhibitor (HDACi) vorinostat.
Publication Title
Hypoxia-independent gene expression signature associated with radiosensitisation of prostate cancer cell lines by histone deacetylase inhibition.
Sample Metadata Fields
Cell line, Treatment
View Samples