cir-ITCH Plays an Inhibitory Role in Colorectal Cancer by Regulating the Wnt/β-Catenin Pathway

Noncoding RNAs (ncRNAs) are the dominant product of eukaryotic transcription. These products range from short microRNAs (miRNAs) to long intergenic noncoding RNAs (lincRNAs). Circular RNAs composed of exonic sequences represent an understudied form of ncRNA that was discovered more than 20 years ago. Using a TaqMan-based reverse transcriptase polymerase chain reaction assay, we analyzed the relationship between cir-ITCH expression and colorectal cancer (CRC) in a total of 45 CRCs and paired adjacent non-tumor tissue samples. We found that cir-ITCH expression was typically down-regulated in CRC compared to the peritumoral tissue. This result, as well as several follow-up experiments, showed that cir-ITCH could increase the level of ITCH, which is involved in the inhibition of the Wnt/β-catenin pathway. Therefore, our results showed that cir-ITCH plays a role in CRC by regulating the Wnt/β-catenin pathway.