A cell-to-cell interaction between tumors and host inflammatory cells is important for the subsequent cancer progression or regression. We examined the expression of interleukin-8 (IL-8) mRNAs by 9 human lung cancer cell lines and the influences of cytokines on IL-8 production and its gene expression. Substantial expressions of IL-8 gene were detected in 3 lung cancer cell lines (RERF-LC-OK, Lu-134-A-H, YO-88 cells). Moreover, 4 lung cancer cell lines (RERF-LC-MS, RERF-LC-OK, A549 and YO-88) were used to examine the effects of exogenous cytokines--interleukin-1 beta (IL-1 beta), tumor necrosis factor alpha (TNF-alpha) and granulocyte-macrophage colony-stimulating factor--on IL-8 production by the cells at protein and gene levels. TNF-alpha and IL-1 beta significantly augmented the levels of mRNA expression for IL-8 and its production. These observations indicate that tumor-derived IL-8 may be important in recruiting inflammatory neutrophils and promoting interaction between lung cancer and inflammatory cells.