Long non-coding RNA 91H regulates IGF2 expression by interacting with IGF2BP2 and promotes tumorigenesis in colorectal cancer.

91H, a long non-coding antisense transcripts located on the position of the H19/IGF2 locus had been suggested to play a critical role in tumour development. However, little study had proved the mechanism in colorectal cancer (CRC). Hence, we performed this study to deeply explore the mechanism of lncRNA 91H in tumour progression. The expression of lncRNA 91H was first detected in CRC tissues and cells which was higher in vitro and in vivo than normal cells or tissues and CRC patients with high lncRNA 91H expression usually had a high risk in tumour metastasis (p < .05). Then, monodansylcadaverine (MDC) staining, scratch wound, migration and invasion assays were conducted which showed to that reduced lncRNA 91H would greatly affect tumour migration, invasion and autophagy. Finally, by RNA pull down and RNA-binding protein immunoprecipitation (RIP) assay, a significant interaction was found between lncRNA 91H and IGF2BP2 which was proved to play an important role in CRC IGF2 expression. All these results suggested lncRNA 91H promotes IGF2 expression by interacting with IGF2BP2 which would provide a new strategy in finding potential CRC diagnostic biomarkers and therapeutic targets.