miRNA expression profiles of estrogen-dependent and estrogen deprivation-resistant MCF-7 breast cancer cell lines

A series of MCF-7 variants were previously developed that are estrogen-dependent for growth (MCF-7:WS8 cells), or resistant to estrogen deprivation/vulnerable to fast (MCF-7:5C) and delayed (MCF-7:2A) E2-inducible apoptosis. To identify miRNAs associated with aromatase inhibitor (AI)-resistance and vulnerability to E2-induced apoptosis, estrogen deprivation-resistant 5C and 2A cells were compared to estrogen-dependent WS8 cells and among each other. Total RNA from MCF-7:WS8, MCF-7:2A and MCF-7:5C cells was extracted. Three biological replicates per cell line derivative were performed. The profiling series included a total of 12 samples, preprocessed data from 9 samples (triplicates for WS8, 2A and 5C) were extracted for this study. Hybridization of biotin-labelled RNA was performed on Affymetrix GeneChip miRNA_2.0 Arrays.