Determination of trastuzumab responsive microRNAs in SKBR3 and BT474 cells.

To develop gene-miRNA and pathway-miRNA networks in trastuzumab treatment, we performed a recent miRNA microarray profiling in trastuzumab treated/untreated SKBR3 and BT474 cell lines. The cells were plated at a starting density of 2 millions in 100 mm cell culture dishes and then, they were treated with 6 ug/mL trastuzumab and PBS in two replicates. Total RNA was isolated with the TRIzol reagent (Invitrogen) according to the manufacturer's instructions. RNA samples were isolated after 144h trastuzumab treatment. A total of 4 samples from BT474 cells (2 from trastuzumab treated and 2 from PBS treated) and 4 samples from SKBR3 cells (2 from trastuzumab treated and 2 from PBS treated) were analyzed.