Aspirin increases chemosensitivity of colorectal cancer cells and inhibits the expression of toll-like receptor 4

Abstract Background Chemotherapy resistance is an important bottleneck affecting the efficacy of chemotherapy in colon cancer. Therefore, improving the chemotherapy sensitivity of colorectal cancer cells is of great significance for improving the prognosis of patients with colon cancer. Methods CCK-8 assay was employed to examine the cell viability of colorectal cancer cell lines. Realtime-PCR and western blot were used to explore toll-like receptor 4 (TLR4) expression in colorectal cancer cell lines. The functions of TLR4 in the stemness of the colorectal cancer cell lines were analyzed by infecting cells with lentivirus containing TLR4 siRNA. Results We found that aspirin could effectively enhance the chemosensitivity of CT26 and HCT116 colorectal cancer cell lines. Aspirin can also inhibit the stemness of colorectal cancer cell including inhibiting the number of clone formation and reducing the volume and number of cell spheres and inducing the down-regulation of stemness-related genes. Besides that, aspirin also lead to down-regulation of TLR4 expression in colorectal cancer cells. The TLR4 positive colorectal cancer cells demonstrated a higher chemotherapy resistance potential than TLR4 negative colorectal cancer cells. In addition, the stemness of TLR4 positive colorectal cancer cells is stronger than TLR4 negative colorectal cancer cells. Conclusion The results of our study indicate that aspirin increases chemosensitivity of colorectal cancer cells and inhibits the expression of toll-like receptor 4.