DEEP SEQUENCING OF MODELS OF BREAST DUCTAL CARCINOMA IN SITU REVEALS ALDH5A1 AS A NOVEL POTENTIAL THERAPEUTIC TARGET

We attempted to identify alterations in gene expression that occur during the progression from normal breast to ductal carcinoma in situ (DCIS) with the aim to elucidate significant genes and pathways underlying the premalignant transformation. To determine the expression changes that are common to multiple DCIS models (MCF10.DCIS, SUM102 and SUM225) and normal mammary epithelial cells (MCF10A), we grew the cells in three dimensional overlay culture with reconstituted basement membrane and used the extracted RNA for 76 cycles of deep sequencing (mRNA-Seq) using Illumina Genome Analyzer GAIIx. Analysis of mRNA-Seq results showed 295 consistently differentially expressed transcripts in DCIS models as compared to MCF10A. These differentially expressed genes are associated with a number of signaling pathways such as integrin, fibroblast growth factor and TGFß signaling. Many differentially expressed transcripts in DCIS were found to be involved in cell-cell signaling, cell-cell adhesion and cell proliferation. We further investigated ALDH5A1 gene that encodes for the enzyme, aldehyde dehydrogenase 5A1, which is involved in glutamate metabolism. Further, inhibition of ALDH5A1 with different pharmacological drugs resulted in significant inhibition of cell growth and proliferation in the DCIS models. Overall design: Four cell lines examined: normal mammary epithelial cell line (one sample) and three ductal carcinoma in situ cell lines (three samples). Each sample has two duplicates

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Kaur H, Mao S, Li Q, Sameni M, Krawetz SA, Sloane BF, Mattingly RR