miRNA expression in breast cancer cell lines

We analyzed the miRNA expression in 6 breast cancer cell lines from young (HCC1500, HCC1937) and old (MCF-7, MDA-MB-231, HCC1806 and MDA-MB-468) patients with breast cancer using the GeneChip® miRNA 2.0 Array (Affymetrix, Santa Clara, CA, USA). Total RNA from BC cell lines was isolated in passage 4 using High Pure RNA Isolation Kit from Roche following the manufacturer’s protocol. RNA concentration was measured using a NanoDrop ND 2000-UV-vis Spectrophotometer (Thermo Fisher Scientific Inc., Wilmington DE, USA). RNA integrity determined by RIN (RNA integrity number) value was assessed with the Agilent 2100 Bioanalyzer using RNA 6000 Nano Assay (Agilent Technologies Inc., Santa Clara, CA, USA). Microarray expression profiling was performed using GeneChip® miRNA 2.0 Array (Affymetrix, Santa Clara, CA, USA).