Expression of Matrix Metalloproteinase-2 and -9 in Recurrent Nasal Polyposis

Abstract

Objective: Matrix metalloproteinase (MMP) is involved in the upper airway remodeling process. We hypothesized that MMP had an additive effect to the formation of recurrent nasal polyp. We also investigated the association of MMP’s functional promoter polymorphism and its labeling index in different tissues.

Method: Thirty-two patients with recurrent nasal polyps and 30 patients without recurrence of nasal polyp (non-recurrent) after surgery were collected. Inferior turbinate mucosa obtained from 31 patients without chronic rhinosinusitis were used as controls. Two promoter functional single nucleotide polymorphisms were selected. Tissue samples were frozen for immunohistohemistry.

Results: The expression of MMP-9 was significantly enhanced in gland, but not in surface epithelium, for recurrent nasal polyp (P = .016) and non-recurrent nasal polyp (P = .005) compared with the control. MMP-2 positivity was significantly increased in surface epithelium, but not in gland, for recurrent nasal polyp (P = .004), and a trend toward significance for non-recurrent nasal polyp compared to the control. However, there was no statistically significant difference of MMP-9 and -2 expressions between recurrent nasal polyp and non-recurrent nasal polyp. The genetic polymorphism of MMP-2 and -9 functional promoters was not associated with the intensity of immunohistochemical labeling index.

Conclusion: These results suggested up-regulation of MMP-9 in gland and MMP-2 in surface epithelium were characteristic of both recurrent nasal polyp and non-recurrent nasal polyp. The pathogenesis of recurrent nasal polyps may involve a mechanism other than MMP.