IL-1β stimulates CXCL5 and CXCL8 gene expression and protein secretion in A549 cells in a time- and dose-dependent manner. IL-1β stimulates CXCL5 and CXCL8 gene expression and protein secretion in A549 cells in a time- and dose-dependent manner. A, A549 cells were incubated with control medium or with medium containing 2.5 ng/mL IL-1β for the indicated times. Total RNAs were collected from the cells and expression of the indicated genes was measured by quantitative RT-PCR. GAPDH was used as an internal control for normalizing the RNA loading. B, A549 cells were incubated with IL-1β at the indicated concentrations for 8 h. Total RNAs were collected from the cells for quantitative RT-PCR. C, culture media were collected from A549 cells with treatment as in B and the concentrations of CXCL5 and CXCL8 were measured with ELISA. Columns, mean; bars, SE. *, P < 0.05; **, P < 0.01; ***, P < 0.001, compared with untreated control. Hongxia Sun et al. Cancer Prev Res 2008;1:316-328 ©2008 by American Association for Cancer Research