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.
No associated publication
Specimen part, Cell line, Time
View SamplesMolecular 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.
Molecular signature of cell cycle exit induced in human T lymphoblasts by IL-2 withdrawal.
No sample metadata fields
View SamplesDifferential 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.
No associated publication
Sex, Age, Disease
View SamplesPilocytic 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.
Transcriptional profiles of pilocytic astrocytoma are related to their three different locations, but not to radiological tumor features.
Sex, Age, Specimen part, Disease
View SamplesGenomic hallmarks of homologous recombination deficiency in invasive breast carcinomas to appear in Internationa Journal of Cancer
No associated publication
Sex, Specimen part
View SamplesDifferentially expressed genes between 171 human soft tissue sarcomas with complex genomics
From PTEN loss of expression to RICTOR role in smooth muscle differentiation: complex involvement of the mTOR pathway in leiomyosarcomas and pleomorphic sarcomas.
Sex, Specimen part, Cell line
View SamplesUp to now the role of tumor-specific pTregs and anergic cells during tumor development is not fully understood. Here we used a genetically-induced tumor expressing a MHC-II restricted DBY model antigen to characterize the tumor-induced pTregs and anergic cells that arise early during tumor development.
Induction of anergic or regulatory tumor-specific CD4<sup>+</sup> T cells in the tumor-draining lymph node.
Time
View SamplesUp to know CD4 T cell antitumor responses have been mostly studied in transplanted tumor models. However, although they are valuable tools, they are not suitable to study the long term interactions between tumors and the immune system
Induction of anergic or regulatory tumor-specific CD4<sup>+</sup> T cells in the tumor-draining lymph node.
Time
View SamplesCD4+ T cells as mediators of antitumor responses are beginning to be appreciated. Our team demonstrated that chronically activated CD4+ T cells (chCD4+ T cells) were expanded in the blood of cancer patients and their expansion is correlated with tumor regression.
Induction of anergic or regulatory tumor-specific CD4<sup>+</sup> T cells in the tumor-draining lymph node.
Disease
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
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