Unknown,Transcriptomics,Genomics,Proteomics

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Identification of KDM3A regulated genes in the ER positive breast cancer cell line MCF-7

ABSTRACT: Using a siRNA screen we identified the histone demethylase enzyme KDM3A as a potential positive regulator of ER signalling in breast cancer. To interrogate the full extent of KDM3A regulation on ER signalling we assessed basal and estrogen (E2)- stimulated global gene expression changes in KDM3A-depleted MCF-7 cells by microarray analysis using the Illumina Human HT12 Version 4 BeadChip array. We identified ER regulated genes affected by KDM3A knockdown and determined that KDM3A is required for ER recruitment to estrogen response elements in the promotors of ER regulated genes. We also identified that KDM3A regulates expression of a number of genes involved in proliferation and that knockdown of KDM3A inhibits ER positive breast cancer cell growth. MCF-7 cells were transfected with either a non-silencing scrambled control siRNA (siSCR) or a KDM3A targeting siRNA (siKDM3A-B) using Lipfectamine RNAiMAX (Invitrogen) to a final concentration of 25 nM in steroid depleted conditions. Cells were grown for 48 hours prior to treatment with vehicle or 10 nM E2 for 4 hours before RNA extraction using TRIzol (Ambion, Life Technologies) and hybridization of triplicate samples to an Illumine HT-12 v4 BeadChip array. One sample failed due to low amounts of cRNA and was therefore not included in the analysis (siKDM3A + E2 Replicate 3). The array for replicates 1 and 2 was performed in August 2013 (Array 1) and replicate 3 in August 2014 (Array 2). When processing the data Array 2 was normalized to Array 1.

ORGANISM(S): Homo sapiens

SUBMITTER: Mark Wade

PROVIDER: E-GEOD-68918 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Project description:Altered expression of microRNAs (miRNAs), an abundant class of small non-protein-coding RNAs that mostly function as negative regulators of protein-coding gene expression, is common in cancer. Here we analyze the regulation of miRNA expression in response to estrogen, a steroid hormone that is involved in the development and progression of breast carcinomas and that is acting via the estrogen receptors (ER) transcription factors. We set out to thoroughly describe miRNA expression, by using miRNA microarrays and real time RTPCR experiments, in various breast tumor cell lines in which estrogen signaling has been induced by 17β-estradiol (E2). We show that the expression of a broad set of miRNAs decreases following E2 treatment in an ER-dependent manner. We further show that enforced expression of several of the repressed miRNAs reduces E2-dependent cell growth, thus linking expression of specific miRNAs with estrogen-dependent cellular response. In addition, a transcriptome analysis revealed that the E2-repressed miR-26a and miR-181a regulate many genes associated with cell growth and proliferation, including the progesterone receptor gene, a key actor in estrogen signaling. Strikingly, miRNA expression is also regulated in breast cancers of women who had received antiestrogen neoadjuvant therapy thereby showing an estrogen-dependent in vivo regulation of miRNA expression. Overall, our data indicates that the extensive alterations in miRNA regulation upon estrogen signalling pathway plays a key role in estrogen-dependent functions and highlights the utility of considering miRNA expression in the understanding of antiestrogen resistance of breast cancer. 9 samples analyzed. Triplicates were done. MCF-7+miR26a+E2 (n=1 to 3) ; MCF7+miRctrl+E2 (n=1 to 3) ; MCF7+miRctrl+vehicle (n=1 to 3). We generated pairwise comparisons using EASANA from GenoSplice technology: MCF-7+miR26a+E2 versus MCF7+miRctrl+E2 and MCF-7+miRctrl+E2 versus MCF7+miRctrl+vehicle. Fold change ≥1.5 were selected.

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Identification of KDM3A regulated genes in the ER positive breast cancer cell line MCF-7

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