Project description:MicroRNAs are noncoding, endogenous small RNAs that regulate target genes by cleavage of the targeted mRNA or translational repression. We investigated the microRNAome using 2-color microarrays in a highly invasive human breast cancer cell line, MDA-MB-231 (sub line 4175) and a non-invasive breast epithelial cell line, MCF10A. We found 13 miRNAs that were up-regulated and 9 were down-regulated significantly in 4175 cells (p <0.05, fold change >2) compared with MCF10A cells. We compared the highly metastatic human breast cell lines MDA-MB-231 (4175 subline) with non-metastatic MCF10A cell lines. Two 4175 sublines and two MCF10A cell lines, independently grown and harvested. Dye swap was performed.