Total RNA was extracted using a miRNeasy Mini Kit (Qiagen – 217004), according to manufacturer's protocol. Quantity and quality of RNA were assessed using an Agilent 2100 Bioanalyzer and RNA 6000 Nano Kits (Agilent – 5067-1511) 500 ng total RNA per sample was used to prepare libraries using Illumina's TruSeq RNA Library kit, according to manufacturer's protocol.