Differential expression of microRNA expression in tamoxifen-sensitive MCF-7 versus tamoxifen-resistant LY2 human breast cancer cells

Microarrays identified miRNAs differentially expressed and 4-hydroxytamoxifen (4-OHT) regulated in MCF-7 endocrine-sensitive versus resistant LY2 human breast cancer cells. 97 miRNAs were differentially expressed in MCF-7 versus LY2 cells. Opposite expression of miRs-10a, 21, 22, 29a, 93, 125b, 181, 200a, 200b, 200c, 205, and 222 was confirmed. Bioinformatic analyses to impute the biological significance of these miRNAs identified 36 predicted gene targets from those regulated by 4-OHT in MCF-7 cells. Agreement in the direction of anticipated regulation was detected for 12 putative targets. These miRNAs with opposite expression between the two cell lines may be involved in endocrine resistance.

► 97 miRNAs were differentially expressed in MCF-7 versus LY2 breast cancer cells.
► miRs-10a, 22, 29a, 125b, and 222 were higher in LY2 than MCF-7 cells.
► miRs-21, 200a, 200b, 200c, and 205 were higher in MCF-7 than LY2 cells.
► Identified control genes for miRNA QPCR for MCF-7 and LY2 cells treated with 4-OHT.
► Computationally identified miRNA target mRNA genes in 4-OHT-treated MCF-7 cells.