Total RNA and miRNA in treated cells were isolated using TRIzol reagent (Invitrogen) according to the manufacturer's instructions. The stem-loop reverse-transcription (RT) primers were designed as follows: miR-200b, 5′-GTCGTATCCAGTGCAGGGTCCGAGGTATTCGCACTGGATACGACTCATCAT-3′, and U6, 5′-CGCTTCACGAATTTGCGTGTCA-3.′ Reverse transcription was performed using a DNA synthesis kit (RevertAidTM First Strand cDNA Synthesis Kit; Fermentas, Ottawa, Canada) following the manufacturer's instructions. The random RT primer 5′- (dN) 9-3′ was used for the p27/kip1, RND3, and GAPDH genes. The polymerase chain reaction (PCR) primers were designed as follows: miR-200b sense, 5′-GCGGCTAATACTGCCTGGTAA-3′, reverse, 5′-GTGCAGGGTCCGAGGT-3′; U6 sense, 5′-CGCTTCGGCAGCACATATACTA-3′, reverse, 5′-CGCTTCACGAATTTGCGTGTCA-3′; P27 sense, 5′-TAATTGGGGCTCCGGCTAACT-3′, reverse, 5′-TTGCAGGTCGCTTCCTTATTC-3′; RND3 sense, 5′-ATAGAGTTGAGCCTGTGGGACAC-3′, reverse, 5′-AGGGTCTCTGGTCTACTGATGTC-3′; GAPDH sense, 5′-TGCACCACCAACTGCTTAGC-3′, reverse, 5′-GGCATGGACTGTGGTCATGAG-3′ using an master mix (SABI SYBR Green Master Mix; Invitrogen) according to the manufacturer's protocol. All mRNA quantification data were normalized to human GAPDH, and U6 snRNA was used as an endogenous control for the miRNA detection. The data were processed using 2-ΔΔCt methods.