Long Non-coding RNA Facilitates Colorectal Cancer Development Through EZH2/DNMT1-Induced miR-133b Suppression.

This study aimed to identify the roles of the long non-coding RNA in colorectal cancer (CRC) development. The expression levels of and miR-133b in CRC were determined by reverse transcription (RT)-polymerase chain reaction (PCR) and the functions of in CRC were evaluated and . Methylation-specific PCR assay was performed to detect the miR-133b promoter methylation in CRC cells. Bioinformatics analysis, RNA immunoprecipitation, dual luciferase assay, RNA pull-down, co-immunoprecipitation (IP), and chromatin IP (ChIP) assays were used to elucidate whether could recruit EZH2/DNMT1 and bind to the miR-133b promoter region, leading to dysregulated methylation and the depression of miR-133b. The expression levels of DNA methyltransferases (DNMTs), EZH2, and nucleoporin 214(NUP214) were analyzed by western blotting. Data showed that was highly expressed, whereas miR-133b was downregulated in the CRC tissues and cells. , silencing inhibited cell proliferation and impeded cell cycle at the G1/S phase by upregulating miR-133b. knockdown reduced tumor growth. Further analysis showed that the methylation in miR-133b promoter region was increased in the CRC and silencing increased miR-133b expression through depressing methylation of its promoter region. ChIP-PCR experiments demonstrated that EZH2 and DNMT1 could bind to the miR-133b promoter region and it was abolished by knockdown. sh-EZH2 reversed the overexpression of DNMTs and CRC cell cycle progression induced by the upregulation. LINC00114 could regulate the NUP214 protein expression by sponging miR-133b. These results demonstrated that suppressed miR-133b expression via EZH2/DNMT1-mediated methylation of its promoter region, indicating that might be a potential novel target for CRC diagnosis and treatment.