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Title: Expression profile of etoposide-resistant MCF7 (MCF7VP) cells      
dateReleased:
04-08-2011
description:
The second leading cause of cancer death for women in the U.S. is breast cancer. Moreover, a significant number of patients with breast tumors acquire resistance to drugs during therapy. To develop targeted therapeutic strategies to combat drug resistance it is essential to understand the basic molecular mechanisms through which cancer cells control sensitivity to chemotherapeutics. To identify new candidate genes and facilitate the discovery of novel drug resistance pathways, we have generated a resistance profile or ‘resistome’ of etoposide resistant MCF7 breast cancer cells. Differential expression of over 5000 genes (fold change > 2, P value < 0.05) indicate that several drug resistance mechanisms may be operating in these cells, including up-regulation of ABC transporter genes, down-regulation of the drug target and down-regulation of apoptotic genes. Several transcription factors such as RUNX2, SOX9, ETS1 and SMAD3 were up-regulated in the drug resistant cells. Targeted RUNX2 knockdown in the resistant cells using siRNA increased sensitivity to etoposide and also upregulated expression of pro-apoptotic genes indicating that RUNX2 could be a molecular target against etoposide resistance. Differential miRNA (microRNA) expression was observed among the drug resistant and sensitive cells suggesting that miRNA may also play a role in regulation of drug resistance. Hsa-miR-218, which targets ABCC6, was down-regulated in the drug resistant cell line. Transfection of a miR-218 mimic could down-regulate the expression of the efflux pump ABCC6 by 65% in drug resistant cells suggesting that regulation of miRNA may play an important role in etoposide resistance. RNA from MCF7 and etoposide-resistant MCF7 (MCF7VP) cell lines were hybridized to Affymetrix microarrays. Both samples were run in triplicate
privacy:
not applicable
aggregation:
instance of dataset
ID:
E-GEOD-28413
refinement:
raw
alternateIdentifiers:
28413
keywords:
functional genomics
dateModified:
08-12-2015
availability:
available
types:
gene expression
name:
Homo sapiens
ID:
A-AFFY-44
name:
Affymetrix GeneChip Human Genome U133 Plus 2.0 [HG-U133_Plus_2]
accessURL: https://www.ebi.ac.uk/arrayexpress/files/E-GEOD-28413/E-GEOD-28413.raw.1.zip
storedIn:
ArrayExpress
qualifier:
gzip compressed
format:
TXT
accessType:
download
authentication:
none
authorization:
none
accessURL: https://www.ebi.ac.uk/arrayexpress/files/E-GEOD-28413/E-GEOD-28413.processed.1.zip
storedIn:
ArrayExpress
qualifier:
gzip compressed
format:
TXT
accessType:
download
authentication:
none
authorization:
none
accessURL: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE28413
storedIn:
Gene Expression Omnibus
qualifier:
not compressed
format:
HTML
accessType:
landing page
primary:
true
authentication:
none
authorization:
none
abbreviation:
EBI
homePage: http://www.ebi.ac.uk/
ID:
SCR:004727
name:
European Bioinformatics Institute
homePage: https://www.ebi.ac.uk/arrayexpress/
ID:
SCR:002964
name:
ArrayExpress

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