Abstract:

Objective To investigate the biological functions of IL-18 on the human lung cancer cell A549，including its role in cancer-related processes. Methods A plasmid expressing IL-18 or a control plasmid were transfected into the A549 human lung cancer cell line，and antibiotic selection was used to identify stable transfectants. The resulting respective cell lines，IL18-A549 and NC-A549，were compared in terms of proliferation， apoptosis， movement，invasion and migration. Results The IL18-A549 cell line stably expressed IL-18， and comparison with the NC-A549 cell line suggested that IL-18 promotes proliferation（P<0.05）. The rate of healing in a wound healing assay was significantly higher for IL18-A549 cells（62.0±5.7）% than for control cells （31.2±3.7）%（P<0.05），and the percentages of cells showing migration and invasion in a transwell assay were significantly higher for IL18-A549（48% and 33%） than for controls （9% and 11%；P<0.05）. Flow cytometry showed similar rates of early，late and total apoptosis between IL-18 transfectants and control cells. Conclusion IL-18 promotes proliferation，movement，invasion and migra-tion of A549 cells，and may play a key role in human lung cancer. Inhibiting IL-18 function may be useful for treating lung cancer.

Key words: Lung neoplasm, Interleukin 18, Biological function