library_construction_protocol: PrEC and C4-2 cells were treated with transcription inhibitor actinomycin D (ActD, Sigma) at a concentration of 5 μg/ml for 0, 15 minutes, 1 hour and 2 hours. RNA samples were then isolated using RNeasy Plus Mini Kit (Qiagen) and sent to BGI for library preparation and follow-up sequencing. Samples were sent to BGI for library preparation and follow-up sequencing