Estudo da imunoexpressão de RANKL e OPG, do índice angiogênico (CD34) e da presença de miofibroblastos (α-SMA) em ceratocistos odontogênicos isolados e associados à síndrome de Gorlin

The odontogenic keratocysts are distinguished from other odontogenic cystic lesions by their potentially aggressive clinical behavior and association, in some cases, with Gorlin syndrome. Studies have suggested that syndrome keratocysts, in comparison with sporadic lesions, have higher growth and infiltration capacity and higher recurrence tendency. The aim of this study was to analyze, by means of immunohistochemistry, the expressions of receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG), the angiogenic index (CD34) and the presence of myofibroblasts (α-SMA) in primary and recurrent sporadic keratocysts and in keratocysts associated with Gorlin syndrome. The sample was composed by 30 sporadic keratocysts (22 primary and 8 recurrent) and 22 syndrome keratocysts. In the epithelium and in the fibrous capsule of the lesions, the immunoexpression of RANKL and OPG was evaluated by determination of the percentage of positive cells, according to the following scores: 0 (less than 10% of positive cells), 1 (11% - 50% of positive cells), 2 (51% - 75% of positive cells) and 3 (more than 76% of positive cells). In addition, cases were classified according to the RANKL score/ OPG score ratio, as follows: RANKL > OPG, RANKL < OPG, and RANKL = OPG. The angiogenic index was analyzed by counting the microvessels immunoreactive to anti-CD34 antibody in 5 fields (200). The analysis of myofibroblasts was performed by counting the cells immunoreactive to anti-α-SMA antibody in 10 fields (400). The analysis of the expressions of RANKL and OPG in the epithelial lining and in the fibrous capsule did not reveal significant differences between groups (p > 0.05). Regarding the RANKL/ OPG ratio in the epithelial lining, most sporadic primary (54.5%) and syndrome lesions (59.1%) showed RANKL < OPG ratio and RANKL = OPG ratio, respectively (p > 0.05). With respect to the RANKL/ OPG ratio in the fibrous capsule, the majority of sporadic primary (81.8%) and sporadic recurrent lesions (75.0%) and most syndrome lesions (45.5%) showed RANKL = OPG ratio (p > 0.05). The mean number of microvessels was 69.2 in sporadic primary lesions, 67.6 in recurrent lesions, and 71.6 in syndrome lesions, with no significant differences between groups (p > 0.05). The mean number of myofibroblasts was 34.4 in sporadic primary lesions, 29.3 in recurrent lesions, and 33.7 in syndrome lesions, with no significant differences between groups (p > 0.05). In conclusion, the results of the present study suggest that the differences in the biological behavior between sporadic keratocysts and keratocysts associated with Gorlin syndrome may not be related to the expressions of RANKL and OPG, the RANKL/ OPG ratio, the angiogenic index or the number of myofibroblasts in these lesions

Estudo da expressão imuno-histoquímica das MMPs -2, -7, -9 e -26 e TIMPs -1 e -2 em adenomas pleomórficos e carcinomas adenóides císticos de glândulas salivares menores

The balance between the expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) has been related to various physiological and pathological processes, including salivary gland morphogenesis and tumor invasion and metastasis processes. Pleomorphic adenoma (PA) and adenoid cystic carcinoma (ACC) respectively represent benign and malignant neoplasias of salivary glands. Although they share the same cell origin, they present distinct biological behavior. The aim of this study was to compare the immunohistochemical expression of MMPs -2, -7, -9 and -26, and of TIMPs -1 and -2, in cases of PA and ACC of minor salivary glands. Twenty cases of PA and twenty cases of ACC were assessed according to the presence, intensity and location of MMPs and TIMPs in the tumor parenchyma. Most of the PAs and ACCs presented a high expression of MMP -2, -7, -9 and -26 and of TIMP -1 and -2, predominantly located in tumor cells. There was no significant difference in the expression of MMPs -2 (p=0.359), -7 (p=0.081) and -26 (p=0.553), as well as of TIMPs -1 (p=0.657) and -2 (p=0.248), between the parenchyma of PAs and ACCs. However, MMP-9 showed a significant difference of expression between the two tumors, with the ACC showing more intense marking for this gelatinase (p=0.041). The strong expression of MMP-9 observed in the parenchyma suggests that this gelatinase may play an important role in the biological behavior of these tumors. On the other hand, although there was no significant difference between the marking of MMP -2, 7 and 26 in the studied tumors, the data, when analyzed as a whole, suggest that these proteases may take part in the process of tissue remodeling in both tumors, but do not present a direct relation with the pattern of aggressiveness of ACC. Nonetheless, matrilisins may indirectly influence the behavior of this tumor due to their capacity of activating MMP-9, strongly expressed in the parenchyma of ACC

Expressão imuno-histoquímica das integrinas a2ß1, a3ß1 e a5ß1 em adenoma pleomórfico de glândula salivar menor e maior e carcinoma adenóide cístico

Pleomorphic adenoma and adenoid cystic carcinoma (ACC) consist benign and malignant neoplasm from salivary gland, respectively. These neoplasms share some characteristics, such as cellular origin and considerable production of extracellular matrix, however, with distinct biological behavior. The aim of the present study was to compare the expression of D2E1, D3E1 e D5E1 integrins in pleomorphic adenoma from minor and major salivary glands and ACCs. Furthermore, it was investigated possible differences in the expression of these integrins according to histological subtypes of ACC. Fourteen cases of pleomorphic adenoma from major salivary gland, fourteen cases from minor salivary gland and ten cases of ACC were selected. It was taken into consideration the presence or absence, localization and intensity of integrin immunoexpression. The cases of pleomorphic adenoma were grouped in order to compare the expression between the distinct neoplasms. It was observed a highly significant difference (p<0,0001) in relation to D2E1 integrin between the neoplasms since pleomorphic adenoma showed a pronounced immunostaining. It was not possible to perform statistical tests considering the D2E1 integrin expression; nevertheless, it could be observed a tendency of higher staining in pleomorphic adenoma. For comparative reasons the cases ACCs were divided in two groups: solid and tubular/cribriform. It was not detected significant differences in regard to D2E1 integrin; and statistical analysis could not be realized in relation to D3E1 and D5E integrin expression. However, it was also verified a tendency of absence or reduced expression in the solid subtype. It can be concluded that the reduced D2E1 integrin expression observed in CACs may be related to a lesser degree of cell differentiation in this neoplasm and the reduced D5E1 integrin expression can be associated with aggressive biological behavior. Moreover, the absence and/or reduced expression of the studied integrins in solid ACC suggests a role in pathogenesis and more aggressive biological behavior of this histological subtype