Effect of NF-κB inhibitors on the chemotherapy-induced apoptosis of the colon cancer cell line HT-29

This study aimed to investigate the impact of the combined use of the nuclear factor-kappa B (NF-kappa B) inhibitors pyrrolidine dithiocarbamate (PDTC), bortezomib or SN50, and the chemotherapy agents arsenic acid (As2O3), fluorouracil (5FU), oxaliplatin or paclitaxel on the growth and apoptosis of HT-29 cells. Cell morphology was observed using inverted microscopy, and cell viability and apoptosis were assessed using the MTT assay and flow cytometry, respectively. The activities of NF-kappa B were analyzed by western blotting and electrophoretic mobility shift assay (EMSA). Cell growth was significantly inhibited by As2O3, oxaliplatin and paclitaxel in a time- and concentration-dependent manner (P<0.05), while 5FU inhibited cell growth in a time-dependent manner only (P<0.05). The growth inhibition rate and apoptosis induction ratio were increased following the combined treatment of the chemotherapy agent and NF-kappa B inhibitor. The expression of NF-kappa B p65 was upregulated when cells were treated with a chemotherapy drug, however it was downregulated following combined treatment or treatment with an NF-kappa B inhibitor alone. In conclusion, an NF-kappa B inhibitor combined with a chemotherapy drug effectively inhibited cell proliferation, induced cell apoptosis and inhibited NF-kappa B activity to enhance the chemotherapeutic sensitivity of HT-29 cells.