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GSE63885
Homo sapiens
99 Downloadable Samples
Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
The introduction of microarray techniques to cancer research brought great expectations for finding biomarkers that would improve patients treatment; however, the results of such studies are poorly reproducible and critical analyses of these methods are rare. In this study, we examined global gene expression in 97 ovarian cancer samples. Also, validation of results by quantitative RT-PCR was performed on 30 additional ovarian cancer samples. We carried out a number of systematic analyses in relation to several defined clinicopathological features. The main goal of our study was to delineate the molecular background of ovarian cancer chemoresistance and find biomarkers suitable for prediction of patients prognosis. We found that histological tumor type was the major source of variability in genes expression, except for serous and undifferentiated tumors that showed nearly identical profiles. Analysis of clinical endpoints [tumor response to chemotherapy, overall survival, disease-free survival (DFS)] brought results that were not confirmed by validation either on the same group or on the independent group of patients. CLASP1 was the only gene that was found to be important for DFS in the independent group, whereas in the preceding experiments it showed associations with other clinical endpoints and with BRCA1 gene mutation; thus, it may be worthy of further testing. Our results confirm that histological tumor type may be a strong confounding factor and we conclude that gene expression studies of ovarian carcinomas should be performed on histologically homogeneous groups. Among the reasons of poor reproducibility of statistical results may be the fact that despite relatively large patients group, in some analyses one has to compare small and unequal classes of samples. In addition, arbitrarily performed division of samples into classes compared may not always reflect their true biological diversity. And finally, we think that clinical endpoints of the tumor probably depend on subtle changes in many and, possibly, alternative molecular pathways, and such changes may be difficult to demonstrate.
Publication Title
Gene expression analysis in ovarian cancer - faults and hints from DNA microarray study.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 41 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
We have analyzed, using DNA microarrays, putative differences in gene-expression level between hereditary BRCA1 mutation-linked and sporadic breast cancer. Our results show that a previously reported marked difference between BRCA1-mutation linked and sporadic breast cancer was probably due to uneven stratification of samples with different ER status and basal-like versus luminal-like subtype. We observed that apparent difference between BRCA1-linked and other types of breast cancer found in univariate analysis was diminished when data were corrected for ER status and molecular subtype in multivariate analyses. In fact, the difference in gene expression pattern of BRCA1-mutated and sporadic cancer is very discrete. These conclusions were supported by the results of Q-PCR validation. We also found that BRCA1 gene inactivation due to promoter hypermethylation had similar effect on general gene expression profile as mutation-induced protein truncation. This suggests that in the molecular studies of hereditary breast cancer, BRCA1 gene methylation should be recognized and considered together with gene mutation.
Publication Title
BRCA1-related gene signature in breast cancer: the role of ER status and molecular type.
Sample Metadata Fields
Age
View Samples- Mus musculus
- 14 Downloadable Samples
- Affymetrix Mouse Expression 430A Array (moe430a)
Description
Three types of stimuli -- heat shock, Lipofectamine 2000 and benzyl alcohol -- induce activity of some stress genes (hsp) in mouse B16-F10 cells. Besides hsp genes induction, each stimulus causes gene expression changes of different sets of genes. We used microarrays to analyze global gene expression changes in mouse B16-F10 cells treated with elevated temperature (heat shock, HS), with Lipofectamine 2000 (LA) or with 40mM benzyl alcohol (BA).
Publication Title
Liposome-based DNA carriers may induce cellular stress response and change gene expression pattern in transfected cells.
Sample Metadata Fields
Specimen part, Cell line, Treatment
View Samples- Homo sapiens
- 52 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Differential diagnosis between malignant follicular thyroid cancer (FTC) and benign follicular thyroid adenoma (FTA) is a great challenge for even an experienced pathologist and requires special effort. Molecular markers may potentially support a differential diagnosis between FTC and FTA in postoperative specimens. The purpose of this study was to derive molecular support for the differential diagnosis, in the form of a simple multigene mRNA-based classifier that would differentiate between FTC and FTA tissue samples.
Publication Title
No associated publication
Sample Metadata Fields
Sex, Age, Disease
View Samples- Homo sapiens
- 35 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Pilocytic astrocytoma is the most common type of brain tumor in pediatric population, generally connected with favorable prognosis, although recurrences or dissemination sometimes are also observed. For tumors originating in supra- or infratentorial location different molecular background was suggested but plausible correlations between transcriptional profile and radiological features and/or clinical course are still undefined. The purpose of this study was to identify gene expression profiles related to the most frequent locations of this tumor, subtypes based on various radiological features and clinical pattern of the disease. According to the radiological features presented on MRI, all cases were divided into four subtypes: solid or mainly solid, cystic with an enhancing cyst wall, cystic with a non-enhancing cyst wall and solid with central necrosis. Bioinformatic analyses showed that gene expression profile of pilocytic astrocytoma highly depends on the tumor location. Most prominent differences were noted for IRX2, PAX3, CXCL14, LHX2, SIX6, CNTN1 and SIX1 genes expression which could distinguish pilocytic astrocytomas of different location even within supratentorial region. Analysis of the genes potentially associated between radiological features showed much weaker transcriptome differences. Single genes showed association with the tendency to progression. Here we showed that pilocytic astrocytomas of three different locations could be precisely differentiated on the basis of gene expression level but their transcriptional profiles did not strongly reflect the radiological appearance of the tumor or the course of the disease.
Publication Title
Transcriptional profiles of pilocytic astrocytoma are related to their three different locations, but not to radiological tumor features.
Sample Metadata Fields
Sex, Age, Specimen part, Disease
View Samples- Homo sapiens
- 26 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
One of the most important features of tumor microenvironment, imposing adverse effect on patient prognosis, is low oxygen tension. There are two types of hypoxia that may occur within tumor mass: chronic and cycling. Preliminary studies point at cycling hypoxia as being more relevant in induction of aggressive phenotype of tumor cells and radioresistance though little is known about the molecular mechanism of this phenomenon. Analysis of gene expression profile of human prostate (PC-3), ovarian (SK-OV-3) and melanoma (WM793B) cancer cells to expermental cycling (interchanging conditions of 1% and 21% oxygen) or chronic (1% oxygen) for 72 hours. Gene expression profiles were analyzed using U133 Plus 2.0 Array (Affymetrix) oligonucleotide microarrays. Data analysis revealed that globally gene expression profiles induced by the two types of hypoxia are similar and they strongly depend on the cell type.However, cycling hypoxia changes expression of lower number of genes in comparison to chronic one ( 3767 vs. 5954 probesets (p<0.001)) and to lower extent (lower fold changes). Analysis of hypoxia-regulated gene lists obtained using Random Variance Model t-test identified 253 probe sets (FC>2, p<0.001) common to all three cell lines, though no universal (changed throughout all analyzed cell lines) genes specifically influanced only by cycling hypoxia was selected. On the other hand, we identified such genes within particular one or two cell lines. Among them those related with EGF pathway seemed to be overrepresented (i.e. EPHA2, AREG, and HBEGF) and together with PLAU and IL-8 were mostly validated by Q-PCR.
Publication Title
Global gene expression profiling in three tumor cell lines subjected to experimental cycling and chronic hypoxia.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Homo sapiens
- 17 Downloadable Samples
- Affymetrix Human Genome U133 Plus 2.0 Array (hgu133plus2)
Description
Molecular mechanisms of cell cycle exit are poorly understood. A group of genes required for cell cycle exit and maintenance of cell quiescence in human fibroblasts following serum deprivation has been recently identified. Studies on lymphocytes following growth factor deprivation-induced cell cycle exit have predominantly focused on the initiation of apoptosis. A set of genes involved in lymphocyte quiescence have also been identified among genes highly expressed in resting lymphocytes and down-regulated after cell activation. In our study, proliferating IL-2-dependent human T cells were forced to exit cell cycle by growth factor withdrawal, and their gene expression profiles were examined.
Publication Title
Molecular signature of cell cycle exit induced in human T lymphoblasts by IL-2 withdrawal.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
The objective of the experiment was to compare changes in the transcriptome induced by direct X-irradiation of cells and by factors released by irradiated cells into the culture medium (irradiation conditioned medium, ICM), using the K562 human erythroleukemic cell line. Two culture flasks with K562 cells (5 x 105 cells/ml) were irradiated with X-rays at the dose of 4 Gy and in both the culture medium was changed immediately after irradiation, after 1 hour of recovery in fresh medium in standard growth conditions medium containing factors released by irradiated cells was collected from one flask, filtered from cell debris and untreated control K 562 cells were grown in this medium in standard conditions for 36h. The irradiated cells of the second flask were incubated for 36 hours in parallel and RNA was isolated from both irradiated and Irradiation Conditioned Medium-exposed samples. The transcript levels were measured in these RNA samples using Affymetrix HGU 133A microarrays and compared to the levels in RNA from control cells grown for 36h or control cells collected after 1h after change of medium. Experiments were repeated twice.
Publication Title
No associated publication
Sample Metadata Fields
Specimen part, Cell line, Time
View Samples- Homo sapiens
- 6 Downloadable Samples
Illumina HiSeq 2500
Description
The impact of the transcriptome-wide alternative splicing on proteomic-wide protein subcellular localization was investigated by analyzing RNA-Seq data.
Publication Title
No associated publication
Sample Metadata Fields
Sex, Specimen part, Disease, Cell line
View Samples- Homo sapiens
- 158 Downloadable Samples
- Affymetrix Human Genome U133A Array (hgu133a)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Subtype-specific genomic alterations define new targets for soft-tissue sarcoma therapy.
Sample Metadata Fields
Specimen part, Disease, Cell line
View Samples