Total RNA extraction and RT-qPCR analysis
Total RNA was extracted using the TRIzol Reagent (CoWin Biosciences, Jiangsu, China) according to the manufacturer’s instructions. The extracted RNA was reverse-transcribed into cDNA using Super Script III Reverse Transcriptase (Vazyme Biotech Co., Ltd., Nanjing, China). ABCB1 mRNA expression was evaluated through a relative quantitative method. The formula, 2-△△CT, was used to calculate the quantity of DNA amplified. The sequencing primers used for amplification, which were provided by Tsingke Biotechnology Co., Ltd., were;
ABCB1-F: 5′-TTGCTGCTTACATTCAGGTTTCA-3′,
ABCB1-R: 5′-AGCCTATCTCCTGTCGCATTA-3′,
GAPDH-F: 5′-GCACCGTCAAGGCTGAGAAC-3′,
GAPDH-R: 5′-TGGTGAAGACGCCAGTGGA-3′.