miRNA Expression Validation via Northern Blotting

To validate the expression of miRNAs, northern blotting was performed according to the methods described in previous studies^{58 (link)}. In briefly, 20 μg of total RNA from each sample was separated on a 15% polyacrylamide gel and transferred to an Immobilon-Ny+ membrane (Merck Millipore, http://www.merckmillipore.com). Subsequently, the membrane was hybridized with probes labelled with c32P-ATP at 37 °C overnight in Hybridization Solution (TOYOBO, http://www.toyobo-global.com). Finally, the membrane was washed several times with low- (19 SSC, 0.5% SDS) and high-stringency (0.29 SSC, 0.2% SDS) buffer at 37 °C and exposed using a phosphorimager. The probe sequences are listed in Table S9.