Interleukin-33 (IL-33), a damage-associated molecular pattern molecule, is a
cytokine within the
IL-1 interleukin family that binds to the plasma membrane receptor suppression of tumorigenicity 2 on numerous cell types.
IL-33 has been extensively studied in its role in
autoimmune diseases, host responses to pathogens and
allergens, and has been associated with tumorigenic effects in
cancer research. The present study was performed to investigate the effects of
IL-33 on
colon cancer cells, based off the previous data that have demonstrated an anti-
tumor effect of
IL-33 on
pancreatic cancer cells. The effects of
IL-33 on proliferation, cell survival and apoptosis on human HCT-116
colon cancer cells were examined using clonogenic survival assays, proliferation and
caspase-3 activity kits,
terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining and immunocytochemistry. It was determined that the HCT-116 cells demonstrated an notable decrease in optical density value upon incubation with
IL-33, along with a decrease in the number of colonies, compared with the controls. It was further determined that the anti-proliferative effect of
IL-33 on HCT-116 cells was associated with downregulation of the pro-proliferative molecules
cyclin B,
cyclin D and
cyclin dependent kinase 2. An apoptosis-inducing effect of
IL-33 on HCT-116 cells was associated with downregulation of the anti-apoptotic molecules Flice-like inhibitory
protein and
B-cell lymphoma 2. Taken together, the results indicated that
IL-33 inhibits the growth of
colon cancer by suppressing cellular proliferation, whilst simultaneously promoting apoptosis.