Cell lines derived from tumor tissues have been used as a valuable system tostudy gene regulation and cancer development. Comprehensive characterization ofthe genetic background of cell lines could provide clues on novel genes responsiblefor carcinogenesis and help in choosing cell lines for particular studies. Here, we havecarried out whole exome and RNA sequencing of commonly used glioblastoma (GBM)cell lines (U87, T98G, LN229, U343, U373 and LN18) to unearth single nucleotidevariations (SNVs), indels, differential gene expression, gene fusions and RNA editingevents. We obtained an average of 41,071 SNVs out of which 1,594 (3.88%) werepotentially cancer-specific. The cell lines showed frequent SNVs and indels in someof the genes that are known to be altered in GBM- EGFR, TP53, PTEN, SPTA1 andNF1. Chromatin modifying genes- ATRX, MLL3, MLL4, SETD2 and SRCAP also showedalterations. While no cell line carried IDH1 mutations, five cell lines showed hTERTpromoter activating mutations with a concomitant increase in hTERT transcript levels.Five significant gene fusions were found of which NUP93-CYB5B was validated. Anaverage of 18,949 RNA editing events was also obtained. Thus we have generated acomprehensive catalogue of genetic alterations for six GBM cell lines.
Elucidating the cancer-specific genetic alteration spectrum of glioblastoma derived cell lines from whole exome and RNA sequencing.
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View SamplesAffymetrix HuGene ST 1.0 microarrays were used to study and compare gene expression in peripheral blood CD8+ T cells of human patients with Acute Infectious Mononucleosis (AIM; acute EBV infection) and during convalescence (CONV; 6-12 months after AIM visit). Blood samples were drawn from ten human patients with AIM and again during their covalescence (CONV). Peripheral blood mononuclear cells were isolated and cryopreserved. Paired AIM and CONV samples were thawed and CD8+ T cells purified with magnetic beads. RNA was isolated and processed for hybridization according to the Affymetrix protocol
A Gene Expression Signature That Correlates with CD8+ T Cell Expansion in Acute EBV Infection.
Specimen part, Disease stage
View SamplesUterine leiomyomata (UL), the most common neoplasm in reproductive-age women, have recurrent cytogenetic abnormalities including del(7)(q22q32). To develop a molecular signature, matched del(7q) and non-del(7q) tumors identified by FISH or karyotyping from 11 women were profiled with expression arrays. Our analysis using paired t-tests demonstrates this matched design is critical to eliminate confounding effects of genotype and environment that underlie patient variation. A gene list ordered by genome-wide significance showed enrichment for the 7q22 target region. Modification of the gene list by weighting each sample for percent of del(7q) cells to account for the mosaic nature of these tumors further enhanced the frequency of 7q22 genes. Pathway analysis revealed two of the 19 significant functional networks were associated with development and the most represented pathway was protein ubiquitination, which can influence tumor development by stabilizing oncoproteins and destabilizing tumor suppressor proteins. Array CGH (aCGH) studies determined the only consistent genomic imbalance was deletion of 9.5 megabases from 7q22-7q31.1. Combining the aCGH data with the del(7q) UL mosacism-weighted expression analysis resulted in a list of genes that are commonly deleted and whose copy number is correlated with significantly decreased expression. These genes include the proliferation inhibitor HPB1, the loss of expression of which has been associated with invasive breast cancer, as well as the mitosis integrity-maintenance tumor suppressor RINT1. This study provides a molecular signature of the del(7q) UL subgroup and will serve as a platform for future studies of tumor pathogenesis.
Identifying the molecular signature of the interstitial deletion 7q subgroup of uterine leiomyomata using a paired analysis.
Disease
View SamplesUterine leiomyomata (UL), the most common neoplasm in reproductive age women, have recurrent cytogenetic abnormalities including t(12;14). To develop a molecular signature, matched t(12;14) and non-t(12;14) tumors identified by FISH or karyotyping from each of 9 women were profiled using Affymetrix GeneChip U133 Plus 2.0 oligonucleotide arrays. Model analysis demonstrated the necessity for a matched design to eliminate the confounding effect of genotype and environment that underlay patient to patient variation.
Expression profiling of uterine leiomyomata cytogenetic subgroups reveals distinct signatures in matched myometrium: transcriptional profilingof the t(12;14) and evidence in support of predisposing genetic heterogeneity.
Sex, Specimen part
View SamplesEbf1 is a transcription factor with documented, and dose dependent, functions in both normal and malignant B-lymphocyte development. In order to understand more about the role of Ebf1 in malignant transformation, we have investigated the impact of reduced functional Ebf1 dose on early B-cell progenitors. Gene expression analysis in loss and gain of function analysis suggested that Ebf1 was involved in the regulation of genes of importance for DNA repair as well as cell survival. Investigation of the level of DNA damage in steady state as well as after induction of DNA damage by UV light supported that pro-B cells lacking one functional allele of Ebf1 display a reduced ability to repair DNA damage. This was correlated to a reduction in expression of Rad51 and combined analysis of published 4C and chromatin Immuno precipitation data suggested that this gene is a direct target for Ebf1. Even though the lack of one allele of Ebf1 did not result in any dramatic increase of tumor formation, we noted a dramatic increase in the formation of pro-B cell leukemia in mice carrying a combined heterozygote mutation in the Ebf1 and Pax5 genes. Even though the tumors were phenotypically similar and stable, we noted a large degree of molecular heterogeneity well in line with a mechanism involving impaired DNA repair. Our data support the idea that Ebf1 controls homologous DNA repair in a dose dependent manner and that this may explain the frequent involvement of Ebf1 in human leukemia
Ebf1 heterozygosity results in increased DNA damage in pro-B cells and their synergistic transformation by Pax5 haploinsufficiency.
Specimen part, Cell line, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Site-specific programming of the host epithelial transcriptome by the gut microbiota.
Sex, Specimen part
View SamplesDifferential expression of genes between Arabidopsis WRKY18/40 knock out and wild type plants, after 8 h post inoculation of powdery mildew pathogen.
Transcriptional reprogramming regulated by WRKY18 and WRKY40 facilitates powdery mildew infection of Arabidopsis.
Specimen part, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Frequent Derepression of the Mesenchymal Transcription Factor Gene FOXC1 in Acute Myeloid Leukemia.
Specimen part
View SamplesBone marrow samples from normal adult male donors were collected into EDTA. Red cells were removed by ammonium chloride lysis. Leukocytes were washed in SM buffer and CD34+ cells were separated from CD34- cells using an AutoMACS device and anti-CD34 immunomagnetic beads (Miltenyi Biotec), according to manufacturers instructions. For mature cell populations, CD34- cells were FACS purified according to the following immunophenotypes, with 7-AAD used to exclude dead cells: Neutrophils: side scatter high CD15+ CD16+. Monocytes: side scatter low-intermediate CD14+ CD16- CD15-. See also Huang et al., 2014.
Frequent Derepression of the Mesenchymal Transcription Factor Gene FOXC1 in Acute Myeloid Leukemia.
Specimen part
View SamplesGiven the importance of deregulated phosphoinositide (PI) signaling in leukemic hematopoiesis, genes coding for proteins that regulate PI metabolism may have significant and as yet unappreciated roles in leukemia. We performed a targeted knockdown screen of PI modulator genes in human AML cells and identified candidates required to sustain proliferation or prevent apoptosis. One of these, the lipid kinase phosphatidylinositol-5-phosphate 4-kinase, type II, alpha (PIP4K2A) regulates cellular levels of phosphatidylinositol-5-phosphate (PtsIns5P) and phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2). We found PIP4K2A to be essential for the clonogenic and leukemia-initiating potential of human AML cells, and for the clonogenic potential of murine MLL-AF9 AML cells. Importantly, PIP4K2A is also required for the clonogenic potential of primary human AML cells. Its knockdown results in accumulation of the cyclin-dependent kinase inhibitors CDKN1A and CDKN1B, G1 cell cycle arrest and apoptosis. Both CDKN1A accumulation and apoptosis were partially dependent upon activation of the mTOR pathway. Critically, however, PIP4K2A knockdown in normal hematopoietic stem and progenitor cells, both murine and human, did not adversely impact either clonogenic or multilineage differentiation potential, indicating a selective dependency which we suggest may be the consequence of the regulation of different transcriptional programmes in normal versus malignant cells. Thus, PIP4K2A is a novel candidate therapeutic target in myeloid malignancy.
A targeted knockdown screen of genes coding for phosphoinositide modulators identifies PIP4K2A as required for acute myeloid leukemia cell proliferation and survival.
Specimen part, Time
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