Glucocorticoid receptor expression and glucocorticoid therapeutic effect in nasal polyps

Purpose: To investigate the expression and quantity of glucocorticoid receptor-alpha and -beta in polyp tissues taken from the patients treated were subsequently treated with topical glucocorticoid (GC). Methods: Eighty patients with nasal polyps were initially enrolled in the study. All polyp specimens were obtained prior to treatment. Patients then received daily topical GC spray treatment for one month. Polyp specimens were tested for glucocorticoid receptor (GR) GR-alpha and GR-beta mRNA expression using fluorescent quantitative-reverse transcription-polymerase chain reaction (FQ-RT-PCR). Thirty healthy nasal mucosa tissue samples were tested at the same time. Results: Forty patients finished the study and were divided into two groups: GC-sensitive (n=26) and GC-insensitive (n=14), according to treatment results. GR-beta mRNA expression in the nasal polyp tissues of the GC-insensitive group (5.72 +/- 0.58 x 10(2) copies/mu g) was higher than that in the GC-sensitive group (4.82 +/- 0.28 x 10(2) copies/mu g, P<0.05) and in the normal nasal mucosa group (4.44 +/- 0.35 x 10(2) copies/mu g, P<0.01). There was also a difference in the relative expression of GR-alpha and GR-beta between the GC-sensitive group (GR-alpha/GR-beta=829.42 +/- 67.36) and the GC-insensitive group (535.7 +/- 89) (P<0.01). Conclusion: GR-beta mRNA was highly expressed in patients with nasal polyps. Down-regulation of GR-alpha mRNA suggests the existence of glucocorticoid insensitivity. Expression of GR-beta may plays an important role in the evaluation of the glucocorticoid therapeutic effect in patients with nasal polyps.