Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Taxane-selected ovarian cancer cell lines

ABSTRACT: Each of the six ovarian carcinoma cell lines was exposed to docetaxel or paclitaxel at IC50 levels (the concentration required to kill 50% of the population). After several passages at this initial concentration of taxanes, drug concentrations were escalated, and this process was repeated until variants displayed at least a 10-fold resistance to the selecting agents. mRNA and genomic DNA were isolated from the parental and resistant variants, and hybridized onto Stanford human cDNA microarrays containing about 42000 elements. We analyzed the gene expression profiles and copy number alterations, and identified a cluster of genes co-activated with MDR1 on chromosome arm 7q21. In six of these variants, regional activation was driven by gene copy number alterations, with low-level gains or high-level amplifications spanning the involved region. However, three variants displayed a regional increases in gene expression even without concomitant gene copy number changes. These results suggest that regional gene activation may be a fundamental mechanism for acquired drug resistance, with or without changes in gene dosage. In addition to numerical and structural chromosomal changes driven by genome instability in cancer cells, other mechanisms might be involved in MDR1 regional activation, such as chromatin remodeling and DNA or histone modifications of the 7q21 region. A compound treatment design type is where the response to administration of a compound or chemical (including biological compounds such as hormones) is assayed. Computed

ORGANISM(S): Homo sapiens

SUBMITTER: Yan Wang

PROVIDER: E-GEOD-4173 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

Regional activation of chromosomal arm 7q with and without gene amplification in taxane-selected human ovarian cancer cell lines.

Wang Yan C YC Juric Dejan D Francisco Brian B Yu Ron X RX Duran George E GE Chen Kevin G KG Chen Xin X Sikic Branimir I BI

Genes, chromosomes & cancer 20060401 4

Taxanes are important drugs in the treatment of ovarian and other cancers, but their efficacy is limited by intrinsic and acquired drug resistance. Expression of the multidrug transporter P-glycoprotein, encoded by the MDR1 (ABCB1) gene, is one of the causes of clinical drug resistance to taxanes. To study the mechanisms of MDR1 activation related to taxanes, we established 11 multidrug-resistant variants from six ovarian cancer cell lines by continuous exposure to either paclitaxel or docetaxel ...[more]

PMID: 16382445

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Project description:Summary: Breast cancer cell lines have been used widely to investigate breast cancer pathobiology and new therapies. Breast cancer is a molecularly heterogeneous disease, and it is important to understand how well and which cell lines best model that diversity. In particular, microarray studies have identified molecular subtypes (luminal A, luminal B, ERBB2-associated, basal-like and normal-like) with characteristic gene-expression patterns and underlying DNA copy number alterations (CNAs). Here, we studied a collection of breast cancer cell lines to catalog molecular profiles and to assess their relation to breast cancer subtypes. Whole-genome DNA microarrays were used to profile gene expression and CNAs in a collection of 52 widely-used breast cancer cell lines, and comparisons were made to existing profiles of primary breast tumors. Hierarchical clustering was used to identify gene-expression subtypes, and Gene Set Enrichment Analysis (GSEA) to discover biological features of those subtypes. Genomic and transcriptional profiles were integrated to discover within high-amplitude CNAs candidate cancer genes with coordinately altered gene copy number and expression. Transcriptional profiling of breast cancer cell lines identified one luminal and two basal-like (A and B) subtypes. Luminal lines displayed an estrogen receptor (ER) signature and resembled luminal-A/B tumors, basal-A lines were associated with ETS-pathway and BRCA1 signatures and resembled basal-like tumors, and basal-B lines displayed mesenchymal and stem-cell characteristics. Compared to tumors, cell lines exhibited similar patterns of CNA, but an overall higher complexity of CNA (genetically simple luminal-A tumors were not represented), and only partial conservation of subtype-specific CNAs. We identified 80 high-level DNA amplifications and 13 presumptive homozygous deletions, and the resident genes with concomitantly altered gene-expression, highlighting known and novel candidate breast cancer genes. Overall, breast cancer cell lines were genetically more complex than tumors, but retained expression patterns with relevance to the luminal-basal subtype distinction. The compendium of molecular profiles defines cell lines suitable for investigations of subtype-specific pathobiology, biomarkers and therapies, and provides a resource for discovery of new breast cancer genes. HEEBO oligonucleotide microarrays from the Stanford Functional Genomics Facility were used to perform gene expression profiling of 50 human breast epithelial cell lines, in comparison to a universal RNA reference. Expression data were analyzed by hierarchical clustering to identify subgroups, and gene set enrichment analysis to identify subgroup-specific gene pathways.

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Dataset Information

Taxane-selected ovarian cancer cell lines

Publications

Regional activation of chromosomal arm 7q with and without gene amplification in taxane-selected human ovarian cancer cell lines.

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