Abstract
The aim of the present study was to explore the effect of knocking down the expression of β-catenin by small interference (si)RNA on the activity of the Wnt/β-catenin signaling pathway, and the proliferation, apoptosis and invasion abilities of the human colon cancer cell line SW480. For that purpose, double-stranded siRNA targeting β-catenin (β-catenin-siRNA) was synthesized and transfected into SW480 cells. Reverse transcription-polymerase chain reaction (RT-PCR) and western blotting were used to detect the messenger (m)RNA and protein levels of β-catenin in SW480 cells. To detect cell proliferation, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed, while cell apoptosis and caspase-3 activity were detected by flow cytometry and caspase-3 activity assay, respectively. Matrigel invasion assay was performed to detect the influence of siRNA-mediated gene silencing on the invasion and metastasis of SW480 cells in vitro. The results of RT-PCR and western blot analysis demonstrated that, compared with the blank control, negative control and liposome groups, β-catenin-siRNA transfected SW480 cells had significantly decreased mRNA and protein levels of β-catenin. In addition, following β-catenin-siRNA transfection, the proliferation of SW480 cells was significantly lower than that of the blank control, negative control and liposome groups, while the apoptosis rate increased in β-catenin-siRNA transfected cells, compared with the aforementioned groups. Invasion assay showed that, following β-catenin-siRNA transfection, the number of SW480 cells infiltrating through the Matrigel membrane was significantly lower than that of the blank control, negative control and liposome groups. Following β-catenin-siRNA transfection, the caspase-3 activity in SW480 cells was lower than that in the blank control, negative control and liposome groups. These results indicate that siRNA-mediated silencing of β-catenin could inhibit the proliferation and invasion of SW480 cells and induce apoptosis, thus providing novel potential strategies for the clinical treatment of colon cancer, and may serve as a novel target for cancer therapy.