Objective:To investigate the effect of nuclear factor-erythroid 2-related factor 2 (Nrf2) gene on the proliferation and apoptosis of colorectal adenocarcinoma cells in vitro, and the role of Nrf2 gene in regulation of epithelial-mesenchymal transition (EMT) pathway.Methods:Three Nrf2 small interfering RNA (siRNA) sequences were designed and synthesized, namely siRNA-223, siRNA-538 and siRNA-756, and the unrelated sequences were designed and synthesized. The plasmids carrying various siRNA sequences of Nrf2 were constructed, and the plasmids carrying siRNA sequences and the plasmids carrying unrelated sequences were transfected into human colorectal adenocarcinoma Caco-2 cells, namely interference group and empty vector group, respectively. Additionally, Caco-2 cells without any treatment were used as the control group. Real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blotting (WB) methods were used to detect the relative expression of Nrf2 gene in transcription and translation levels in each group of cells, in order to verify the interference effect of Nrf2; the siRNA with the best interference effect was selected for subsequent experiments. CCK-8 method was used to detect the proliferation ability of each group of cells (expressed as absorbance value); RT-qPCR was used to detect the relative expression of EMT pathway-related factors [vimentin (Vim), N-cadherin (N-cad) and E-cadherin (E-cad)] in transcription level in each group of cells; WB method was used to detect the expression of pro-apoptotic protein Bax in each group of cells.Results:The results of RT-qPCR and WB methods showed that compared with the control group and the empty group, the relative expression of Nrf2 gene in transcription and translation levels in Caco-2 cells of the siRNA-756 interference group were the lowest, and the differences were statistically significant (all P < 0.05). The CCK-8 results showed that the absorbance values of Caco-2 cells in the control group, empty group and siRNA-756 interference group after 48 hours of culture were (100±5)%, (94±4)% and (82±5)%, respectively; compared with the control group and the empty group, the siRNA-756 interference group had lower absorbance value, and the differences were statistically significant (all P < 0.05). The results of RT-qPCR method showed that the relative expression of Vim and N-cad in transcription level in the siRNA-756 interference group were higher than those in the control group and the empty vector group, and the differences were statistically significant (all P < 0.05); the relative expression of E-cad in transcription level was lower than those in the control group and the empty vector group, and the differences were statistically significant (both P < 0.05). The results of WB method showed that the relative expression of Bax protein in the siRNA-756 interference group was higher than that in the control group, and the difference was statistically significant ( P < 0.05). Conclusions:Interference with Nrf2 expression in vitro can weaken the proliferation and anti-apoptotic abilities of human colorectal adenocarcinoma Caco-2 cells. The mechanism may be that Nrf2 regulates the expression of Vim, N-cad and E-Cad in the EMT pathway to enhance the EMT ability of tumor cells.