Abstract: Objective To study the effect of circITCH on the proliferation, invasion of colorectal cancer cells via targeting miR-106b. Methods Colorectal cancer cell lines SW620, HT-29,HCT116, Caco-2, SW480, and normal colon epithelial cell line NCM460 were cultured. The expression levels of circITCH and miR-106b were detected, and HT-29 cells were selected for further experiments and were divided into 7 groups: Negative control ( NC) group, circITCH group, miR-NC group, miR-106b group, NC plasmid + miR-NC group, circITCH + miR-NC group, andcircITCH + miR-106b group. The A450 value, number of invasion cells and the expression levels of PTEN and B cell translocation gene 3 (BTG3) were detected. Results The expression level of circITCH in the SW620, HT-29, HCT116, Caco-2 and SW480 cells was lower than that in theNCM460 cell, while the expression level of miR-106b was higher in the NCM460 cell (P < 0. 05).Dual-luciferase reporter gene assay showed that miR-106b could bind with circITCH reporter gene). The expression levels of circITCH, PTEN, BTG3 in the circITCH group were higher than those inthe NC group, the expression level of miR-106b, A450 value, and the number of invasion cells were lower than those in the NC group (P < 0. 05). The expression level of miR-106b, A450 value, andthe number of invasion cells in the circITCH + miR-106b group were higher than those in the circITCH + miR-NC group, the expression levels of PTEN, BTG3 were lower than those in the circITCH + miR-NC group (P< 0. 05). Conclusion CircITCH can inhibit the proliferation and invasion of colorectal cancer cells via targeting miR-106b.

Key words: colorectal cancer, circITCH, miR-106b, proliferation, invasion