Imunoexpressão das galectinas -1, -3 e -7 em cistos não odontogênicos da região oral e maxilofacial

Abstract

Non-odontogenic cysts constitute a diverse group of lesions that affect the oral and maxillofacial region, with emphasis on the nasopalatine duct cyst (NDC), the nasolabial cyst (NC), the dermoid cyst (DC) and the epidermoid cyst (EC) . Although they present important differences in terms of histogenesis and clinicopathological characteristics, several aspects related to the pathogenesis of these lesions are still incompletely understood. In the development of cystic lesions, including odontogenic cysts, researches have praised the participation of galectins, with emphasis on galectins-1, -3 and -7. Galectins correspond to a family of proteins with high affinity for carbohydrates, involved in several physiological and pathological processes. So far, however, little is known about the involvement of these proteins in the pathogenesis of non-odontogenic cysts in the oral and maxillofacial region. Thus, this study aimed to evaluate the immunoexpression of galectins-1, -3 and -7 in NDC, NC, DC, and EC. The sample consisted of 10 cases of NDC, 10 cases of NC, 10 cases of CD and 10 cases of EC. Clinical data (patients' age and gender) were collected from biopsy request forms and used to characterize the sample. In the immunohistochemical study, under 400× magnification, the percentages of cells with cytoplasmic and nuclear positivity in 05 microscopic fields were established, both for the epithelial component and for the fibrous capsule of the lesions. Data were submitted to statistical analysis using the Mann-Whitney and Spearman correlation tests (p < 0.05). For galectin-1 in the epithelial lining, cytoplasmic positivity was observed in all cases of DCCD (100%), in most EC and NDC (90%) and only 70% of NC. Higher median percentages of positivity were found in DC and EC, with no statistically significant differences between groups (p > 0.05). In the fibrous capsule, cytoplasmic expression of galectin-1 was observed in all cases of NDC, NC, DC, and EC and nuclear expression in all cases of NC, 90% of NDC and DC and in 80% of EC. In the epithelial lining, cytoplasmic positivity for galectin-3 was observed in all cases of NDC, NC, DC and EC with high percentages of positivity, but without significant differences between lesions. In the nucleus, DC and EC had higher medians when compared to NDC and NC, with statistically significant differences between groups (p < 0.05). For galectin-7, in the epithelial lining, cytoplasmic positivity was observed in all cases of DC and EC and in most NDC and NC (90%), with statistically significant differences in relation to the other groups (p < 0.05). In the nuclear region, only the NDC did not show immunopositivity in all groups (8 cases), in the fibrous capsule there was no immunopositivity. In conclusion, the results of this study suggest the participation of galectins-1, -3 and -7 in the pathogenesis of NDC, NC, DC, and EC, with emphasis on galectin-3. High cytoplasmic expression of galectin-7 and increased nuclear translocation of galectins-3 and -7 in the epithelial lining may be relevant to the development of DC and EC.