SILVIA VANESSA LOURENCO
Projetos de Pesquisa
Unidades Organizacionais
ODE, FO - Docente
LIM/06 - Laboratório de Imunopatologia da Esquistossomose e outras Parasitoses, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/06 - Laboratório de Imunopatologia da Esquistossomose e outras Parasitoses, Hospital das Clínicas, Faculdade de Medicina - Líder
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- CD24 and CD44 in salivary gland pleomorphic adenoma and in human salivary gland morphogenesis: differential markers of glandular structure or stem cell indicators?(2013) IANEZ, Renata C. F.; COUTINHO-CAMILLO, Claudia M.; BUIM, Marcilei E.; PINTO, Clovis A. L.; SOARES, Fernando A.; LOURENCO, Silvia V.Aims Salivary gland neoplasms originate from salivary gland compartments, to which they are histologically related. Pleomorphic adenoma (PA) is a benign salivary gland neoplasm that comprises epithelial and myoepithelial cells and a complex stroma, whose structure, architecture and origin (from intercalated ducts) suggest stem cell participation. We compared the expression of CD24 and CD44 in PA and in developing human salivary glands to investigate whether these markers can be considered as cancer stem cell markers. Methods and results One hundred and one cases of PA and salivary gland specimens from 20 human fetuses were examined by immunohistochemistry and real-time reverse transcription polymerase chain reaction (RT-PCR). All PAs were positive for CD24 and CD44 by immunohistochemistry: neoplastic luminal structures were positive for CD24; modified myoepithelial cells were positive for CD44. In fetal salivary glands, these markers were restricted to the intercalated duct region. Real-time RT-PCR assays detected increased expression of CD44, but not CD24, in PA specimens in comparison with normal salivary gland controls. Conclusions PA and stem cells share the expression of CD24 and CD44; their value as markers of neoplastic cell multipotency and the implications of their expression for tumour behaviour are yet to be determined.
- Immunostaining study of cytokeratins in human hair follicle development(2020) SILVA, Laura Maria Andrade; HSIEH, Ricardo; LOURENCO, Silvia Vanessa; VALENTE, Neusa Yuriko Sakai; PAIVA, Geise Rezende; FERNANDES, Juliana DumetBackground: The hair follicle is a unique structure, one of the most dynamic structures in mammalians, which can reproduce in every new cycle all the mechanism involved in its fetal development. Although a lot of research has been made about the human hair follicle much less has been discovered about the importance of the cytokeratins (CKs) in its development. Objective: Study the immunohistochemical pattern of epithelial CKs during human hair follicle development. Methods: We performed an immunohistochemical study using fresh post-mortem skin biopsies of human fetuses between 4 and 25 weeks of gestational age to study the expression of cytokeratins (CKs): CK1, CK10, CK13, CK14, CK16 and CK20 during human hair follicle fetal development. Study limitations: Restrospective study with a good number of makers but with a small population. Results/conclusion: We found that, the CKs were expressed in an intermediate time during follicular development. The epithelial CKs (CK1, CK14, CK10, CK13) and the epithelial CKs witha proliferative character such as CK16 were expressed first, as markers of cellular maturation and follicular keratinization. At a later phase, CK20 was expressed in more developed primitive hair follicles as previously discussed in literature. (C) 2020 Sociedade Brasileira de Dermatologia.
- Characteristics of aquaporin 1, 3, and 5 expression during early murine salivary gland development(2021) PAULA, Fernanda de; TUCKER, Abigail S.; TESHIMA, Tathyane Harumi N.; SOUZA, Milena Monteiro de; COUTINHO-CAMILLO, Claudia Malheiros; NICO, Marcello Menta S.; LOURENCO, Silvia VanessaAquaporins (AQPs) are essential to coordinate the transit of water and ions through the cell membrane. In salivary glands (SGs), AQPs have been associated with saliva formation, facilitating water absorption through the epithelium during the formation of hypotonic saliva, which is then secreted into the oral cavity. Different members of the AQP family have been suggested to play distinct roles during embryonic development, highlighted by their specific expression patterns. Here, we have investigated the expression patterns of AQP-1, AQP-3 and AQP-5 by immunofluorescence at key stages of salivary gland development, utilising cultured mouse embryonic submandibular (SMG) and sublingual (SLG) glands. The expression of AQPs was compared to a mitotic marker, phospho-histone 3 (PH3), a myoepithelial marker, smooth muscle actin (SMA), and a vascular marker, CD31. Qualitative analysis revealed that AQP-1 and AQP-3 were primarily expressed during the earlier phases of SG morphogenesis and were associated with cells undergoing mitotic processes (PH3-positive). AQP-5, in contrast, was not associated to mitotic figures, but was predominantly expressed during late stages of SG morphogenesis. Our results highlight that AQPs are expressed from early stages of SG morphogenesis and exhibit complimentary expression patterns that may contribute to the morphogenesis of salivary glands.
- Adhesion Molecules in Primary Oral Mucosal Melanoma: Study of Claudins, Integrins and Immunoglobulins in a Series of 35 Cases(2013) BOLOGNA, Sheyla Batista; NICO, Marcello Menta S.; HSIEH, Ricardo; COUTINHO-CAMILLO, Claudia Malheiros; BUIM, Marcilei E.; FERNANDES, Juliana Dumet; SANGUEZA, Martin; SOARES, Fernando Augusto; LOURENCO, Silvia VanessaPrimary oral mucosal melanoma is a rare aggressive tumor. Recent studies have demonstrated a correlation between increased tumor invasion and the metastatic phenotype and altered adhesion molecule expression profiles. The present study analyzed the expression of integrins, claudins, and immunoglobulin-like adhesion molecules in oral mucosal melanomas and correlated results with clinical parameters. Immunohistochemical analyses of the expression patterns of these molecules were performed on thirty-five cases of primary oral mucosal melanomas organized in a tissue microarray. The results were correlated with clinical and histological features of the cohort. A number of integrin subunits were negative and this was related with vascular invasion. Positivity of integrin beta-3 and CD166 (activated leukocyte cell adhesion molecule) was statistically associated with extensive vascular invasion (P < 0.05). Lower expression of CD54 (intercellular cell adhesion molecule) was associated with cases with extensive necrosis. Most cases with metastatic disease were negative for CD66 (carcinoembryonic antigen-related cell adhesion molecule). Several subunits of claudins were negative and, although not statistically significant, this lack of expression was partially associated with histological factors of poor prognosis. Altered patterns of adhesion molecule expression, mainly integrins and immunoglobulin-like proteins, may participate in the pathogenesis and outcome of oral mucosal melanomas.