The NSCLC cell line A549 was cultured in RPMI 1640 medium (Corning) containing 10% fetal bovine serum (Gibco, USA) and 100 units per ml penicillin-streptomycin solution at 37℃ in a 5% CO2 atmosphere. The collected samples were put in liquid nitrogen quickly and preserved in low temperature environment. TRIzol (Thermo Fisher Scientific, Waltham, MA, USA) was used to isolate total RNA from tissue samples following the manufacturer'sprotocol. The dsDNA was fragmented to ∼200–500 bp with the time Fragmentase (Thermo). The 3'terminal fragments were released from magnetic beads by restriction endonuclease GsuI (Thermo) digestion, and ligated with Illumina P5/P7 sequencing adapters.
Experimental Factor: stimulus
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