A combined miRNApiRNA signature
The small RNA library construction was performed according to the protocol previously described by Fehlmann et al (Fehlmann et al., 2016). Briefly, sRNA fragments with 18-30 nt in length were separated and recycled by 15% urea-PAGE gel electrophoresis. sRNAs were ligated with a 5-adenylated, 3-blocked single-stranded DNA adapter. After RT primer hybridization, the 5 adaptor was linked and the first strand cDNA was synthesized by a reverse transcription reaction. After several rounds of PCR amplification,100-120 bp products were purified and obtained for BGISEQ-500 sequencing (BGI, Inc.; Shenzhen, China).