Abstract: Objective To explore the effect of circUBE2D2 on the proliferation, migration and invasion of SW620 colorectal cancer cells and its underlying mechanism. Methods The cancer tissues and the corresponding para-cancerous tissues from 45 patients with colorectal cancer admitted to our hospital from January 2020 to May 2020 were collected. The expression levels of circUBE2D2 and miR-376a-3p were detected by qRT-PCR. Human colorectal cancer cell line SW620 was used in this research and were divided into groups as follows: si-NC group, si-circUBE2D2 group, miR-NC group, miR-376a-3p group, si-circUBE2D2 + anti-miR-NC group, and si-circUBE2D2 + anti-miR-376a-3p group. The CCK-8 and plate colony formation assay were used to measure the proliferation and colony formation of cells. The migration and invasion of cells were determined by the wound healing assay and the transwell assay. The dual luciferase reporter experiment was used to assay the effect of miR-376a-3p overexpression on the luciferase activity of the wild-type vector WT-circUBE2D2. The expression levels of E-cadherin and N-cadherin proteins were detected by Western blotting. Results The expression level of circUBE2D2 was increased in colorectal cancer tissues, while that of miR-376a-3p was decreased when compared with adjacent tissues (P< 0. 05). The cell viability and scratch healing rate were reduced, the number of colonies formed, the number of invasive cells and the expression level of N-cadherin were decreased in the si-circUBE2D2 group and the miR-376a-3p group when compared with the si-NC group and the miR-NC group, while the expression level of E-cadherin was increased respectively ( P < 0. 05 ). Overexpression of miR-376a-3p could inhibit the luciferase activity of wild-type vector WT-circUBE2D2 (P< 0. 05). The cell viability, the scratch healing rate, the number of cell colony formed, the number of invasive cells, and the expression level of N-cadherin were increased in the si-circUBE2D2 + anti-miR-376a-3p group, while the expression level of E-cadherin was decreased when compared with the si-circUBE2D2 + anti-miR-NC group (P< 0. 05). Conclusion Interference of circUBE2D2 expression could reduce the proliferation, colony formation, migration and invasion of colorectal cancer cells by targeting miR-376a-3p.

Key words: colorectal cancer, circUBE2D2, miR-376a-3p, cell proliferation, migration, invasion