ABSTRACT
Background: Colon cancer is one of the common malignant tumors with high morbidity and mortality. Cullin7 is located at chromosome 6p21.1, which is closely related to the occurrence and development of malignant tumors. Aims: To investigate the effect of down-regulating Cullin7 on proliferation and apoptosis of colon cancer cells. Methods: qRT-PCR and Western blotting were used to detect the expressions of Cullin7 mRNA and protein in colon cancer tissue and adjacent tissue, respectively. The Cullin7 gene was silenced by siRNA, and the silencing effect was detected by qRT-PCR and Western blotting. Cell proliferation was detected by CCK-8 assay, and apoptosis was detected by flow cytometry. The protein expressions of cleaved caspase-3, β-catenin and C-myc were detected by Western blotting. Colon cancer cells were treated with siRNA Cullin7 plus Wnt signaling pathway inhibitor FH-535, cell apoptosis was detected by flow cytometry, the protein expressions of cleaved caspase-3, β-catenin and C-myc were detected by Western blotting. Results: The expressions of Cullin7 mRNA and protein in colon cancer tissue were significantly higher than those in adjacent tissue (P<0.05). Compared with the control group, the expressions of Cullin7 mRNA and protein in siRNA Cullin7 1 group, siRNA Cullin7 2 group and siRNA Cullin7 3 group were significantly decreased (P<0.05), especially in the siRNA Cullin7 2 group. Compared with the control group, after silencing the expression of Cullin7, the proliferation activity of colon cancer cells was significantly decreased, apoptosis rate was significantly increased, expression of cleaved caspase-3 protein was significantly up-regulated, and expressions of β-catenin and C-myc protein were significantly down-regulated (P<0.05). Compared with siRNA Cullin7 2 group, apoptosis rate was significantly increased, expression of cleaved caspase-3 protein was significantly up-regulated, and expressions of β-catenin and C-myc protein were significantly down-regulated in siRNA Cullin7 2 plus Wnt signaling pathway inhibitor FH-535 group (P<0.05). Conclusions: Cullin7 gene is involved in the proliferation and apoptosis of colon cancer HCT116 cells. Silencing Cullin7 can inhibit cell proliferation and induce cell apoptosis through Wnt/β-catenin signaling pathway.