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To evaluate the immunoexpression of DNA base excision repair (BER) [apurinic/apyrimidinic endonuclease 1 (APE-1), X-ray repair cross complementing 1 (XRCC-1)] and nucleotide excision repair (NER) [xeroderma pigmentosum complementation group (XPF)] proteins in benign epithelial odontogenic lesions with different biological behaviors.Thirty solid ameloblastomas, 30 non-syndromic odontogenic keratocysts (NSOKCs), 29 syndromic odontogenic keratocysts (SKOCs), 30 dentigerous cysts (DCs) and 20 dental follicles (DFs) were evaluated quantitatively for APE-1, XRCC-1 and XPF through immunohistochemistry.Nuclear expression of APE-1 was significantly higher in NSOKCs, SOKCs, and ameloblastomas in comparison to DCs (p0.001). Nuclear expression of XRCC-1 was higher in NSOKCs and SOKCs than in DCs (p0.05). At the nuclear level, XPF expression was higher in NSOKCs and SOKCs than in DCs and ameloblastomas (p0.05). A statistically significant higher expression of APE-1 (nuclear), XRCC-1 (nuclear), and XPF (nuclear and cytoplasmic) was found in all odontogenic lesion samples as compared to DFs (p0.05). For all lesions, there was a positive correlation between nuclear expression of APE-1 and XRCC-1 or XPF (p0.05).Our results suggest a potential involvement of APE-1, XRCC-1 and XPF proteins in the pathogenesis of benign epithelial odontogenic lesions, especially in those with more aggressive biological behavior, such as ameloblastomas, NSOKCs, and SOKCs. We also showed that the expression of APE-1 was positively correlated with the nuclear expression of XRCC-1 and XPF, which may suggest an interaction between the BER and NER pathways in all odontogenic lesions studied herein.

Objective Despite their similar cellular origin, pleomorphic adenomas (PA) and adenoid cystic carcinomas (ACC) present distinct behaviors. This study aimed to analyze the immunoexpression of E-cadherin in PA and ACC of salivary glands, and to investigate differences in its expression in relation to E-cadherin gene ( CDH1 ) -160C/A polymorphism. Design Twenty-four PA (15 cell-rich and 9 cell-poor tumors) and 24 ACC (10 tubular, 8 cribriform and 6 solid tumors) were selected for the analysis of pattern of distribution, and cellular localization of E-cadherin. In addition, E-cadherin expression was evaluated using the H-score scoring system. The CDH1 -160C/A polymorphism was investigated by PCR-RFLP. Results No significant differences in pattern of distribution ( p = 0.181) and cellular localization ( p = 0.192) of E-cadherin were observed between PA and ACC. Comparison of PA and ACC cases revealed a higher median H-score in the latter ( p = 0.036). Cell-rich PA presented a higher H-score than cell-poor tumors ( p = 0.013), whereas no significant differences in E-cadherin expression were observed between ACC subtypes ( p = 0.254). The heterozygous genotype of the CDH1 -160C/A polymorphism was detected in only one PA and one ACC. H-scores for tumors carrying the polymorphism were below the lower quartile of their respective groups. Conclusions The results suggest that E-cadherin expression in PA and ACC is mainly related to cellular composition (epithelial cells versus myoepithelial cells) and degree of differentiation of myoepithelial cells in these tumors. The CDH1 -160C/A polymorphism does not seem to significantly influence the expression of E-cadherin in PA and ACC of salivary glands.

Objective Analyze the presence of myofibroblasts (MFBs) in oral fibrous lesions and investigate TGF-β1 and IFN-γ expression by immunohistochemistry during their differentiation. Design Twenty giant cell fibromas (GCFs), 20 fibromas (FIBs), and 20 fibrous hyperplasias (FHs) were selected. To evaluate the presence of MFBs, anti-α-SMA-immunoreactive cells were quantified in connective tissue. TGF-β1 and IFN-γ expressions were evaluated in epithelial and connective tissue by determining the percentage of immunoreactive cells. Results Higher MFBs concentrations were observed in GCFs (median of 20.00), followed by FHs (15.00) and FIBs (14.00) (P = 0.072). No significant correlation between TGF-β1 or IFN-γ immunoexpression and the number of MFBs in oral fibrous lesions was observed (P > 0.05). Conclusions The higher density of MFBs found in GCFs, followed by FHs and FIBs, reaffirms the fibrogenic role of these cells, while the higher concentrations detected in GCFs, including evidence of giant MFBs, also suggest a role in the neoplastic behavior of these lesions. No correlation was observed between TGF-β1 and IFN-γ in the myofibroblastic transdifferentiation process of the analyzed lesions.

Objectives To compare the number of FoxP3 + cells between periapical granulomas (PGs) and radicular cysts (RCs), and to correlate this number with the intensity of the inflammatory infiltrate in these lesions and with epithelial thickness of RCs. Study design Thirty PGs and 30 RCs were submitted to immunohistochemical analysis using an anti-FoxP3 polyclonal antibody. FoxP3 + cells were counted under a light microscope (×400 magnification) in five fields and the mean value was calculated for each specimen. Statistical tests were used to evaluate differences in the number of FoxP3 + cells according to type of lesion (PG vs. RC), intensity of the inflammatory infiltrate (grade I/II vs. grade III), and epithelial thickness of RCs (atrophic vs. hyperplastic). Results FoxP3 + cells were detected in most PGs (93.3%) and RCs (93.3%). The median number of FoxP3 + cells was 2.40 in PGs and 1.00 in RCs, with this difference being statistically significant ( P = 0.005). No significant differences in the number of FoxP3 + cells were observed in terms of the intensity of the inflammatory infiltrate ( P = 0.465) or epithelial thickness of RCs ( P = 0.737). Conclusions The present results suggest a greater participation of regulatory T cells in the modulation of the inflammatory response in PGs. In addition, the presence of a less effective regulatory environment in RCs, together with the high levels of inflammatory mediators as reported in the literature, may contribute to the greater growth potential of these lesions.

Objective The aim of this study was to immunohistochemically analyse bone resorption regulators (receptor activator of nuclear factor kappa B ligand [RANKL] and osteoprotegerin [OPG]), angiogenic index, and myofibroblasts in Gorlin syndrome-related odontogenic keratocysts (SOKCs) and non-syndrome odontogenic keratocysts (NSOKCs). Study design Twenty-two SOKCs, 22 primary NSOKCs, and eight recurrent NSOKCs were evaluated by immunohistochemistry using anti-RANKL and anti-OPG antibodies. The angiogenic index was determined by microvessel count (MVC) using anti-CD34 antibody. Anti-α-smooth muscle actin (α-SMA) antibody was used for the identification of myofibroblasts. Results Analysis of the expression of RANKL and OPG in the epithelial lining and fibrous capsule did not reveal significant differences between groups (P > 0.05). In the epithelial lining, the RANKL/OPG ratio was RANKL < OPG and RANKL = OPG in most primary NSOCKs (54.5%) and SOKCs (59.1%), respectively (P > 0.05). In the fibrous capsule, the ratio was RANKL = OPG in most primary (81.8%) and recurrent NSOKCs (75.0%) and in most SOKCs (45.5%) (P > 0.05). No significant differences in the angiogenic index or number of myofibroblasts were observed between primary NSOKCs, recurrent NSOKCs, and SOKCs (P > 0.05). Conclusions The present results suggest that differences in the biological behaviour of SOKCs and NSOKCs may not be related to the expression of RANKL and OPG, to the RANKL/OPG ratio, to the angiogenic index, or to the number of myofibroblasts in these lesions.

Objectives The present study evaluated the immunohistochemical expression of BMP-2 and BMP-4 and of their receptors (BMPR-IA and BMPR-II) in solid ameloblastoma (SA), unicystic ameloblastoma (UA) and adenomatoid odontogenic tumor (AOT) in order to obtain a better understanding of their role in the development and biological behavior of these tumors. Design This study analyzed these proteins in 30 cases of SA, 10 cases of UA, and 30 cases of AOT. Immunoexpression was evaluated in the parenchyma and stroma by attributing the following scores: 0, no stained cells; 1, ≤10%; 2, >10% and ≤25%; 3, >25% and ≤50%; 4, >50% and ≤75%.; 5, >75% stained cells. Results In SAs, positive correlations were observed between the stromal and parenchymal expression of BMP-2 (p

Periodontal disease is an infectious disease resulting from the immunoinflammatory response of the host to microorganisms present in the dental biofilm which causes tissue destruction. The objective of this study was to evaluate the immunohistochemical expression of matrix metalloproteinase 7 (MMP-7), extracellular matrix metalloproteinase inducer (EMMPRIN) and cyclophilin A (CypA) in periodontal disease.Gingival tissue samples were divided as follows: clinically healthy gingiva (n=32), biofilm-induced gingivitis (n=28), and chronic periodontitis (n=30). Histological sections of 3μm were submitted to immunoperoxidase method and undergone quantitative analysis. The results were analyzed statistically by the Mann-Whitney and Spearman correlation tests, with the level of significance set at 0.05 (α=0.05).Immunopositivity for MMP-7, EMMPRIN and CypA differed significantly between the three groups, with higher percentages of staining in chronic periodontitis specimens, followed by chronic gingivitis and healthy gingiva specimens (p0.05). Immunoexpression of CypA and MMP-7 was higher in the intense inflammatory infiltrate observed mainly in cases of periodontitis (p0.05). CypA expression was positively correlated with MMP-7 (r=0.831; p0.001) and EMMPRIN (r=0.289; p=0.006). In addition, there was a significant positive correlation between probing depth and expression of MMP-7 (r=0.726; p0.001), EMMPRIN (r=0.345; p=0.001), and CypA (r=0.803; p0.001).These results suggest that MMP-7, EMMPRIN and CypA are associated with the pathogenesis and progression of periodontal disease.

This study analysed the immunohistochemical expression of mast cell tryptase in giant cell fibromas (GCFs). In addition, the possible interaction of mast cells with stellate giant cells, as well as their role in fibrosis and tumour progression, was investigated. For this purpose, the results were compared with cases of inflammatory fibrous hyperplasia (IFH) and normal oral mucosa. Thirty cases of GCF, 30 cases of IFH and 10 normal mucosa specimens used as control were selected. Immunoreactivity of mast cells to the anti-tryptase antibody was analysed quantitatively in the lining epithelium and in connective tissue. In the epithelial component (p=0.250) and connective tissue (p=0.001), the largest mean number of mast cells was observed in IFHs and the smallest mean number in GCFs. In connective tissue, the mean percentage of degranulated mast cells was higher in GCFs than in IFHs and normal mucosa specimens (p0.001). Analysis of the percentage of degranulated mast cells in areas of fibrosis and at the periphery of blood vessels also showed a larger mean number in GCFs compared to IFHs and normal mucosa specimens (p0.001). The percent interaction between mast cells and stellate giant cells in GCFs was 59.62%. In conclusion, although mast cells were less numerous in GCFs, the cells exhibited a significant interaction with stellate giant cells present in these tumours. In addition, the results suggest the involvement of mast cells in the induction of fibrosis and modulation of endothelial cell function in GCFs.