ChIP was performed the same way as ChIP assay, except that DNA was recovered from the protein G complex using elution buffer (10 mM Tris at pH 8.0, 10 mM EDTA at pH 8.0, 1% SDS, 150 mM NaCL, 5 mM DTT). DNA was subsequently purified using Qiagen Mini Elute PCR purification kit. Total RNA was extracted using the miRNeasy Mini Kit (Qiagen #217004). The ChIP DNA libraries were prepared with the Ovation Ultralow DR Multiplex system (NuGEN). RNA-seq libraries were prepared with ovation RNA-seq system v2 kit (NuGEN).