Transcriptomic analysis of gastric cancer cells in response to stable over-expression of circular RNA derived from CTNNB1 gene (circ-CTNNB1)

Circular RNAs (circRNAs), a subclass of noncoding RNAs characterized by covalently closed continuous loops, play emerging roles in tumorigenesis and aggressiveness. However, the functions and underlying mechanisms of circRNAs in regulating the Wnt/ß-catenin signaling and cancer progression still remain elusive. We identify one intronic circRNA derived from CTNNB1 (circ-CTNNB1) as a novel driver of cancer progression. To investigate the mechanisms underlying the oncogenic functions of circ-CTNNB1, we employed the Illumina HiSeq X Ten as a discovery platform to analyze the transcriptome profiling changes of human gastric cancer AGS cells in response to stable over-expression of circ-CTNNB1. The results showed that stable over-expression of circ-CTNNB1 led to altered expression of 2230 human mRNAs, including 1244 up-regulated genes and 986 down-regulated genes. Furthermore, we validated the RNA-seq results by real-time RT-PCR with high identity. Overall, our results provided fundamental information about the transcriptomic changes in response to circ-CTNNB1 over-expression in human cancer cells, and these findings will help us understand the pathogenesis of cancer progression. Overall design: Total RNA of cells stably transfected with empty vector or circ-CTNNB1 was extracted using the TRIzol® reagent according to the manufacturer's instructions. RNA concentration was measured using a Qubit® RNA Assay Kit with a Qubit® 2.0 Fluorometer (Life Technologies, Inc.), and integrity was assessed using the RNA Nano 6000 Assay Kit with a Bioanalyzer 2100 system (Agilent Technologies, CA). Library preparation and transcriptome sequencing on an Illumina HiSeq X Ten platform were performed by Novogene Bioinformatics Technology Co., Ltd. (Beijing, China), and 100 bp paired-end reads were generated. HTSeq v0.6.0 was used to count the reads numbers mapped to each gene.