Homo sapiens
Ontology highlight
ABSTRACT:
PROVIDER: PRJNA99573 | ENA |
REPOSITORIES: ENA
Similar Datasets
Project description:We investigated the influence of genome position on propensity to amplify. First, we integrated a mutant form of DHFR into different positions in the human genome, challenged cells with methotrexate and then studied the genomic alterations arising in drug resistant cells. We observed site specific differences in methotrexate sensitivity, organization of amplicons and amplification frequency. One site was uniquely associated with a significantly enhanced propensity to amplify and recurrent amplicon boundaries, possibly implicating a rare folate sensitive fragile site in initiating amplification. Hierarchical clustering of gene expression patterns and subsequent gene enrichment analysis revealed two clusters differing significantly in expression of MYC target genes independent of integration site. We introduced a mutant form of DHFR (L22F), which confers greater resistance to methotrexate than the wild type (endogenous) gene into HCT116+chr3 cells and isolated independent clones containing DHFR* at different positions in the genome and identified genome sequences flanking the integration site of DHFR* using inverse PCR. For further analysis, we selected only clones, which were considered to have a single insertion of DHFR* by inverse PCR (13 independent insertion sites). The individual insertion site clones were further characterized with respect to genome copy number profiles. To select methotrexate resistant colonies, we exposed cells to a concentration of methotrexate that was three to four times the IC-50 for each integration site. Genomic copy number profiles were obtained for isolated resistant colonies (GSE6262) by using UCSF HumArray platform (GPL4421). Twelve methotrexate resistant colonies (four different integration sites) were selected for microarray analysis of gene expression at the mRNA level. The untreated integration site clone was used as the reference (Cy5 labeled cDNA) for each of the hybridizations with its respective resistant colonies (Cy3 labeled cDNA). Hybridizations were carried out on arrays of printed long oligonucleotides (70mers) containing 21,000 elements (Operon V2.0, printed in J. David Gladstone Institutes, Genomics Core Laboratory).
2007-10-08 | E-GEOD-6361 | biostudies-arrayexpress
Project description:We investigated the influence of genome position on propensity to amplify. First, we integrated a mutant form of DHFR into different positions in the human genome, challenged cells with methotrexate and then studied the genomic alterations arising in drug resistant cells. We observed site specific differences in methotrexate sensitivity, organization of amplicons and amplification frequency. One site was uniquely associated with a significantly enhanced propensity to amplify and recurrent amplicon boundaries, possibly implicating a rare folate sensitive fragile site in initiating amplification. Hierarchical clustering of gene expression patterns and subsequent gene enrichment analysis revealed two clusters differing significantly in expression of MYC target genes independent of integration site. Keywords: Gene amplification, array CGH, chromosomal fragile sites
2007-10-08 | GSE6361 | GEO
Project description:We investigated the influence of genome position on propensity to amplify. First, we integrated a mutant form of DHFR into different positions in the human genome, challenged cells with methotrexate and then studied the genomic alterations arising in drug resistant cells. We observed site specific differences in methotrexate sensitivity, organization of amplicons and amplification frequency. One site was uniquely associated with a significantly enhanced propensity to amplify and recurrent amplicon boundaries, possibly implicating a rare folate sensitive fragile site in initiating amplification. Hierarchical clustering of gene expression patterns and subsequent gene enrichment analysis revealed two clusters differing significantly in expression of MYC target genes independent of integration site. Keywords: Gene amplification, array CGH, chromosomal fragile sites
2007-10-08 | GSE6360 | GEO
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
2010-09-25 | GSE24338 | GEO
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
2011-02-19 | GSE20463 | GEO
Project description:Gene methylation profiling of immortalized human mesenchymal stem cells comparing HPV E6/E7-transfected MSCs cells with human telomerase reverse transcriptase (hTERT)- and HPV E6/E7-transfected MSCs. hTERT may increase gene methylation in MSCs. Goal was to determine the effects of different transfected genes on global gene methylation in MSCs.
2011-08-25 | GSE23936 | GEO
Project description:Genome position and gene amplification - higher resolution mapping of amplicons
| PRJNA99571 | ENA
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs. One-condition experment, gene expression of 3A6
2010-09-25 | E-GEOD-24338 | biostudies-arrayexpress
Project description:Amplifications, regions of focal high level copy number change, lead to overexpression of oncogenes or drug resistance genes in tumors. Their presence is often associated with poor prognosis; however the use of amplification as a mechanism for overexpression of a particular gene in tumors varies. To investigate the influence of genome position on propensity to amplify, we integrated a mutant form of DHFR into different positions in the human genome, challenged cells with methotrexate and then studied the genomic alterations arising in drug resistant cells. We observed site specific differences in methotrexate sensitivity, organization of amplicons and amplification frequency. One site was uniquely associated with a significantly enhanced propensity to amplify and recurrent amplicon boundaries, possibly implicating a rare folate sensitive fragile site in initiating amplification. Hierarchical clustering of gene expression patterns and subsequent gene enrichment analysis revealed two clusters differing significantly in expression of MYC target genes independent of integration site. These studies suggest that genome context together with the particular challenges to genome stability experienced during the progression to cancer contribute to the propensity to amplify a specific oncogene or drug resistance gene, whereas the overall functional response to drug (or other) challenge may be independent of the genomic location of an oncogene. Keywords: Gene amplification, array CGH, chromosomal fragile sites
2007-10-08 | GSE6262 | GEO