Figure 5.

Effect of IL-17 on MMP and TNF expression. (a) IL-17 does not affect the secretion of matrix metalloproteinase (MMP)-2, MMP-3, MMP-9 or tissue inhibitor of matrix metalloproteinase (TIMP). The supernatants of control and treated (IL-17 or TNFα) tumour cell lines were assayed for the presence of MMP-2, MMP-3, MMP-9 and TIMP-1 and TIMP-2 by Luminex immunoassay or ELISA. The invasive breast cancer cell lines MDA-MB231 and MDA-MBA435 were seeded into 24-well plates (1 × 10⁵/well) and rested overnight. Cells were treated with IL-17 (200 ng/ml) or TNFα (40 ng/ml) for 24 hours and the supernatants were harvested for assay. Results are representative of two independent assays and show the mean ± standard deviation of triplicate determinations for one of two experiments (*P < 0.01). The levels of MMP-2 were unaffected by any treatment, and the levels of TIMP inhibitors remained unchanged (data not shown). (b) IL-17 acts independently of TNFα. A panel of breast cancer cell lines were seeded into 24-well plates (1 × 10⁵/well) and rested overnight. Cells were left untreated (grey bar) or were treated with 200 ng/ml IL-17 (black bar) for 24 hours and the supernatants were harvested for TNFα ELISA. Results are representative of two independent assays and show the mean ± standard deviation of triplicate determinations for one of two experiments (*P < 0.01). The concentration of recombinant added TNFα (expected 40 ng/ml) required to stimulate migration was actually found to correspond to 17,205 ± 1,020 pg/ml in this assay.