[Expression of TGF-β1 and PCNA in cyclosporin A-induced gingival overgrowth]

To investigate the expression of transforming growth factor-β1(TGF-β1) and proliferating cell nuclear of antigen (PCNA) in cyclosporin A(CsA)-induced gingival overgrowth (GO) tissues.

After extraction of half of the maxillary molars, 20 male Sprague-Dawley rats were randomized into a CsA-injection group (10mg·kg⁻·d⁻¹) or a normal saline control group. Ten rats per group were sacrificed at the fourth week after injection. The gingival width was measured under a stereo-microscope. After full demineralization of the mandible, gingival specimens were taken. The linear measurements and the immunohistochemistry analysis of TGF-β1 and PCNA were made using the software of Image Pro-plus 6.0. The data was analyzed with SAS6.12 software package.

The percentage of cells positive staining for TGF-β1 and PCNA was significantly higher in the CsA rats than in the control rats (P<0.05), but there was no significant difference between the edentulous and denti-gingiva in the same group(P>0.05).

The upregulation of TGF-β1 may have no direct relations with gingival inflammation in CsA-induced gingival overgrowth.In addition, TGF-β1 may be one of the key cytokines for CsA-induced gingival overgrowth. Increased epithelial proliferative activity may be the main cause of epithelial hyperplasia.