Topical steroids do not downregulate expression of growth-related oncogene- in nasal polyps

Conclusions. Topical steroids did not affect expression of growth-related oncogene- (GRO- ) in nasal polyps. The results of this study suggest roles for steroid-resistant gene expression in the pathogenesis of nasal polyps and point to the need for additional pharmacological strategies. Objective. Infiltration of inflammatory cells is believed to play a role in the development of nasal polyps. GRO- is a chemokine that recruits and activates neutrophils and also possesses growth stimulatory and angiogenetic properties. An increased presence of GRO- has been demonstrated in nasal polyps compared with normal nasal tissue. In this study we evaluate the presence and expression levels of GRO- in nasal polyps before and after glucocorticoid treatment. Material and methods. Nasal polyps were surgically removed in patients before and 6 weeks after treatment with topically applied fluticasone. GRO- gene expression and the presence of GRO- peptide were detected in polyp tissue by means of in situ hybridization, quantitative real-time reverse transcriptase polymerase chain reaction and immunohistochemistry. Results. Strong GRO- gene expression and the presence of GRO- peptide were seen in both the epithelium and stromal inflammatory cells of nasal polyps. No differences in gene expression levels in tissue homogenates were found when untreated polyp tissue was compared with polyps treated for 6 weeks with topically applied steroids.