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.
Global gene expression profiling in three tumor cell lines subjected to experimental cycling and chronic hypoxia.
Specimen part, Cell line
View SamplesThree 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).
Liposome-based DNA carriers may induce cellular stress response and change gene expression pattern in transfected cells.
Specimen part, Cell line, Treatment
View SamplesWe 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.
BRCA1-related gene signature in breast cancer: the role of ER status and molecular type.
Age
View SamplesThe expression was designed to determine whether exposure to CSF1-Fc has any effect on liver-specific gene expression in pigs.
Macrophage colony-stimulating factor (CSF1) controls monocyte production and maturation and the steady-state size of the liver in pigs.
Specimen part
View SamplesThe 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.
Gene expression analysis in ovarian cancer - faults and hints from DNA microarray study.
No sample metadata fields
View SamplesWe used microarray to examine changes in gene expression in the absence of Csf1r in the brain and spleen.
Pleiotropic Impacts of Macrophage and Microglial Deficiency on Development in Rats with Targeted Mutation of the <i>Csf1r</i> Locus.
Sex
View SamplesGlobal gene expression patterns associated with early stage endometrial cancer have been reported, but changes in molecular expression associated with tumor grade, depth of myometrial invasion, and non-endometrioid histology have not been previously elucidated. Our group hypothesized there are unique genetic events underlying early endometrial carcinogenesis. Ninety-two samples of pathologically reviewed stage I endometrial cancers (80 endometrioid and 12 serous) with a heterogeneous distribution of grade and depth of myometrial invasion (i.e. 9 IAG1, 14 IAG2, 7 IAG3, 14 IBG1, 12 IBG2, 13 IBG3, 7 ICG1, 10 ICG2, and 6 ICG3) were examined in relation to 12 samples of atrophic endometrium from postmenopausal women. Specimens were analyzed using oligonucleotide microarray analysis and a subset of the differentially expressed transcripts was validated using quantitative PCR. Comparison of early stage cancers with normal endometrium samples by the univariate t-test with 10,000 permutations identified 900 genes that were differentially regulated by at least 4-fold at a p value of <0.001. Unsupervised analysis revealed that when compared to normal endometrium, serous and endometrioid stage I cancers appeared to have similar expression patterns. However, when compared in the absence of normal controls, they were distinct. Differential expression analysis revealed a number of transcripts that were common as well as unique to both histologic types. This data uncovers previously unrecognized, novel pathways involved in early stage endometrial cancers and identifys targets for prevention strategies that are inclusive of both endometrioid and serous histologic subtypes.
Identifier mapping performance for integrating transcriptomics and proteomics experimental results.
Age, Disease stage, Race
View SamplesHydrogen peroxide is known to promote skin keratinocyte migration, although the mechanism of action is unclear. In an attempt to identify signaling pathways regulated by hydrogen peroxide in the skin, 3 day post fertilized (dpf) zebrafish larvae (nacre strain) were treated with 3mM hydrogen peroxide for 2 hours and subjected to RNA-seq analyses. Pools of about 1000 embryos for each of three biological replicates were derived from 5 independent mating pairs and raised to larval stages until 3 dpf. All larvae were subsequently homogenized in Trizol and total RNA was extracted using a chloroform extraction protocol treated with DNAse. Messenger RNA (mRNA) was subsequently purified from total RNA using biotin-tagged poly dT oligonucleotides and streptavidin-coated magnetic beads, followed by quality control using an Agilent Technologies 2100 Bioanalyzer (values >7 were used for sequencing). The poly(A)-tailed mRNA samples were fragmented and double-stranded cDNA generated by random priming for deep sequencing studies. Overall design: 6 samples total were analyzed. 3 untreated, and 3 hydrogen peroxide treated (3mM, 2hr)
Comparative transcriptomic profiling of hydrogen peroxide signaling networks in zebrafish and human keratinocytes: Implications toward conservation, migration and wound healing.
No sample metadata fields
View SamplesBackground: Cystic fibrosis (CF) is caused by mutations in the CFTR gene that impair function of this cAMP-regulated Cl- channel. In the small intestine, loss of CFTR function creates a dehydrated, acidic luminal environment which is believed to cause an accumulation of mucus, a phenotype characteristic of CF. CF mice have an innate immune response and impaired intestinal transit as well. We investigated whether lubiprostone, which activates the CLC2 Cl- channel, would improve the CF intestinal phenotype.
Lubiprostone ameliorates the cystic fibrosis mouse intestinal phenotype.
Specimen part, Treatment
View SamplesThe expansion, trafficking and functional effectiveness of adoptively transferred CD8+ T-cells play a critical role in mediating effective anti-tumor immunity. However, the mechanisms which program the highly proliferative and functional state of CD8+ T-cells are not completely understood. We hypothesized that IL-12, a cytokine commonly induced by TLR activation, could enhance T-cell priming by altering responsiveness to antigen and cytokines. Priming of tumor specific CD8+ T-cells in the presence of IL-12 induced the acquisition of a 'polyfunctional' effector response and increased the generation of memory cells. Moreover, IL-12 priming also promoted high levels of the IL-2 receptor alpha-chain (CD25) and robust IL-2 mediated activation of STAT5. This sensitivity to IL-2 translated into enhanced in vivo proliferation of adoptively transferred CD8+ T-cells. Furthermore, real-time, in vivo imaging of T-cell trafficking confirmed the ability of IL-12 priming to drive in vivo proliferation. IL-12 priming enhanced the anti-tumor function of adoptively transferred cells by reducing established subcutaneous tumor burden, and significantly increasing survival in an established intracranial tumor model. Finally, IL-12 priming of human PBMCs generates tumor specific T-cells phenotypically and functionally similar to IL-12 primed Pmel-1 T-cells. These results highlight IL-12 as an important mediator of CD8+ T-cell effector function and anti-tumor immunity.
Enhanced sensitivity to IL-2 signaling regulates the clinical responsiveness of IL-12-primed CD8(+) T cells in a melanoma model.
Sex, Specimen part, Treatment
View Samples