We used an organ Culture of nasal polyps (Nil) to provide ex vivo model to study the expression of pro-angiogenic cytokines and the effect of glucocorticoids in the pathogenesis of NP. Glucocorticoids are the drugs of choice for clinical treatment of NP; however, their mechanism of action is not fully understood. The cell-cell and cell-matrix integrity is well maintained in cultured NP. Expression of IL-6, IL-8, bFGF, GRO, and MCP-1 was increased in Cultured Nil compared to pre-cultured NP. Expression levels of IL-6, bFGF, and GRID in Cultured Nil were downregulated by dexamethasone (DEX) treatment, while MCP-1 expression was not suppressed. Further, RT-PCR and immunohistochemical analysis showed that HIFI 1 alpha and VEGF were Suppressed in DEX-treated NP compared to untreated NP. Taken together, these results suggest that ex vivo organ culture can be considered a useful model to Study the pathogenesis and regulation of pro-angiogenic cytokines in nasal polypogenesis. (C) 2008 Elsevier Inc. All rights reserved.