Interleukin-8 does not influence proliferation of the SGC7901 gastric cancer cell line

Interleukin-8 (IL-8), an important inflammatory factor, is induced by Helicobacter pylori infection and is clearly associated with gastric cancer. IL-8 levels have been revealed to correlate significantly with the adhesion, migration and invasion of gastric cancer cells. However, whether IL-8 influences cell proliferation in gastric cancer remains unclear. In the present study, the effect of IL-8 on the proliferation of the SGC7901 human gastric cancer cell line was investigated. SGC7901 cells were exposed to various concentrations of IL-8 (0, 0.2, 0.5, 0.8 and 1 ng/ml) for one to seven days. Cell proliferation was detected by Cell Counting Kit-8 assay. In addition, proliferating cell nuclear antigen (PCNA) protein and mRNA levels were measured by immunofluorescence, western blotting and quantitative polymerase chain reaction. Following exposure of SGC7901 cells to the various concentrations of IL-8, no significant changes in terms of cell proliferation were identified. However, IL-8 was shown to regulate PCNA protein and mRNA expression levels; at a concentration of 0.8 ng/ml, IL-8 significantly elevated the PCNA protein and mRNA expression levels, whereas IL-8 significantly inhibited these levels at other concentrations, compared with no treatment. In conclusion, IL-8 does not affect the proliferation of SGC7901 cells. However, IL-8 dosage was associated with PCNA protein and mRNA expression levels.