2.5. RNA Isolation and qRT-PCR

Total RNA was extracted by TRIzol reagent (Invitrogen, Carlsbad, CA, USA) according to the manufacturer's protocol. RNAs in the cytoplasm and nucleus were extracted by the Cytoplasmic & Nuclear RNA Purification Kit (Norgen, Belmont, CA, USA). The RNA was reverse-converted into cDNA in accordance with instructions using the reverse transcription kit (RiboBio, Guangzhou, China). qRT-PCR was performed with SYBR Green master mix (Takara, Japan), and then the relative level of RNA was detected by the Applied Biosystems StepOnePlus Real-Time PCR System (Applied Biosystems, Singapore). The primer sequences are listed in Table 3.

Primers' sequence.

β-Actin was used as total and cytoplasmic controls, and U6 was used as nuclear control, respectively.