Real time quantitative reverse transcription-PCR (qRT-PCR)

TRIzol (Life Technologies, Grand Island, NY, USA) regant was used to isolate total RNA from tissues and cells according to the instructions. To determine the expression levels of miR-381, SOX4 mRNA and lncRNA-TUG1, a quantitative one-step Perfect Real Time RT-qPCR (SYBR-Green I) kit (Takara Biotechnology Co., Ltd., Dalian, China) was used to synthetize cDNA and amplify target genes. MiR-381 and RNU6 Bulge-Loop™ primers were purchased from RiboBio Co., Ltd. (Guangzhou, China). SOX4, lncRNA-TUG1 and GAPDH primers were synthetized by Sangon Co., Ltd. (Shanghai, China). Sequences of these primers were shown as follow. SOX4 primers: 5′-AGCGACAAGATCCCTTTCATTC-3′ (forward) and 5′-CGTTGCCGGACTTCACCTT-3′ (reverse); lncRNA-TUG1: 5′-TAGCAGTTCCCCAATCCTTG3-3′ (forward) and 5′-CACAAATTCCCATCATTCCC-3′ (reverse); GAPDH: 5′-CGGAGTCAACGGATTTGGTCGTAT-3′ (forward) and 5′-AGCCTTCTCCATGGTGGTGAAGAC-3′ (reverse). GAPDH was used as an endogenous control for SOX4 and lncRNA-TUG1. RNU6 served as an endogenous control for miR-381.