Knockdown of ZEB2-AS1 inhibits cell invasion and induces apoptosis in colorectal cancer

Purpose: To uncover the potential function of long non-coding RNA (lncRNA) ZEB2-AS1 in the progression of colorectal cancer (CRC), and its underlying mechanism. Methods: Relative level of ZEB2-AS1 in CRC tissues and matched normal ones was determined by quantitative real-time polymerase chain reaction (qRT-PCR). Correlation between ZEB2-AS1 level and survival of CRC patients was analyzed by Kaplan-Meier method. Regulatory effects of ZEB2-AS1 on cellular behaviors of CRC cells were evaluated. The interactions between ZEB2-AS1 with LSD1 and EZH2 were explored by RNA immunoprecipitation (RIP) assay. 5-Ethynyl-2'-deoxyuridine (EdU) assay was performed to elucidate the roles of ZEB2-AS1, LSD1 and EZH2 on the proliferative ability of CRC cells. Finally, Spearman's correlation analysis was performed to analyze the relationship between ZEB2-AS1 level and expressions of proliferation-and invasion-related genes. Results: ZEB2-AS1 was upregulated in CRC tissues relative to matched controls. Its level remained higher in CRC patients with >= 6 cm in tumor size, nodal metastasis and stage III-IV. CRC patients with low-level ZEB2-AS1 presented worse survival compared with those with high-level ZEB2-AS1. QRT-PCR data showed higher abundance of ZEB2-AS1 in CRC cell lines than colonic epithelial cell line. Knockdown of ZEB2-AS1 attenuated the proliferative, migratory and invasive abilities, but induced apoptosis of DLD1 and SW620 cells. RIP assay demonstrated the interaction between ZEB2-AS1 and LSD1, EZH2. Moreover, EdU assay revealed that transfection of sh-ZEB2-AS1 attenuated the proliferative ability, which was further reduced after co-transfection of sh-LSD1 or sh-EZH2. Finally, correlation analysis showed that mRNA level of ZEB2-AS1 was positively correlated to those of LSD1, EZH2, MMP9, MMP12 and KRAS, but negatively correlated to KLF2. Conclusions: LncRNA ZEB2-AS1 is upregulated in CRC. It accelerates CRC cells to proliferate via interacting with EZH2 and LSD1, thus promoting the progression of CRC.