OBJECTIVETo explore the significance of protein kinase C (PKC) in proliferation and infiltration of eosinophils in nasal polyps.

METHODSWith in situ hybridization and immunohistochemistry staining methods, PKC, pro-apoptotic, and anti-apoptotic gene (Bax, bcl-2) expressions were measured in nasal polyp tissues from 26 patients and inferior turbinate mucosa tissues (ITMTs) from 20 healthy persons. The May-Grünwald-Giemsa (MGG) staining method was used to identify eosinophils.

RESULTSIn eosinophils, the positive cell expressive rates of Bcl-2 mRNA and its protein were significantly higher in the group with nasal polyps than in the ITMT group (P < 0.01). Although the positive cell expressive rate of Bax mRNA and associated protein were a little higher in the group with nasal polyp tissues than in the ITMT group, the difference was not significant (P > 0.05). There was PKC expression in the eosinophils of 26 cases of nasal polyps, but occasional PKC expression in 7 of 20 ITMT cases. In the two groups, PKC positive cell expression was significantly different, and the expression of PKC and bcl-2 mRNA as well as associated protein in eosinophils of nasal polyps showed a remarkably positive relationship (r1 = 0.0875, r2 = 0.0823, P < 0.01).

CONCLUSIONSIncreased PKC expression in eosinophils of nasal polyp tissues is closely associated with apoptosis inhibition, and it is presumed that eosinophil apoptosis inhibition in nasal polyp tissues is obtained by activation of the PKC signal transduction pathway.