Prognostic value of the expression and localization of cell proliferation and apoptosis markers in unicystic ameloblastomas.

The aim of this study was to verify whether the expression of cell proliferation and apoptosis markers in different types of unicystic ameloblastoma (UA) is associated with the location of neoplastic cells. Immunohistochemical study with a sample of 32 cases of UA, 11 cases of conventional ameloblastoma (CAM) and ten dental follicles (DF) cases was performed. Cell proliferation was assessed using Ki-67 status, and apoptosis by caspase-3 expression. Mural UA (MUA) showed a higher immunostaining of Ki-67 (p < 0.05) and a lower immunostaining of Caspase-3 (p < 0.05) compared with luminal and intraluminal subtypes of UA and CAM. The neoplastic cells of the MUA's cystic capsule showed a higher expression of Ki-67 protein (p < 0.0001) and a lower expression of Caspase-3 (p < 0.0001) compared with the lumen. DF showed lower Ki-67 and Caspase-3 immunostaining (p < 0.05) than neoplasms. The higher immunoexpression of Ki-67 and the lower immunoexpression of Caspase-3 in MUA, in the parenchyma cells within the cystic capsule, suggest an association between the biological behaviour and location of neoplastic cells in a tumour.

Platelet-rich fibrin stimulates the proliferation and expression of proteins related to survival, adhesion, and angiogenesis in gingival fibroblasts cultured on a titanium nano-hydroxyapatite-treated surface.

OBJECTIVES: This in vitro study aimed to evaluate the cell viability and expression of proteins related to angiogenesis, adhesion, and cell survival (vascular endothelial growth factor, paxillin, vinculin, fibronectin, and protein kinase B) in gingival fibroblasts that were cultured on titanium discs treated with or without nanohydroxyapatite and exposed to platelet-rich fibrin (PRF)-conditioned medium. METHODS: To obtain the conditioned medium, the PRF membranes were prepared and incubated for 48 h in a culture medium without fetal bovine serum. Analyses were performed at 24 and 48 h for the cells cultured on machined-titanium discs or surfaces treated with nanohydroxyapatite in a control medium or PRF-conditioned medium, resulting in four experimental groups (CT-TI, CT-NANO, PRF-TI, and PRF-NANO). RESULTS: A decrease in the viability of the gingival fibroblasts was not observed in any of the experimental groups. The PRF-NANO group showed significantly higher immunoexpression of paxillin and AKT at 24 and 48 h (p < 0.01). The same result was observed for vinculin expression at 24 h (p < 0.001). The expression of fibronectin at 48 h and VEGF at 24 and 48 h was significantly higher when the cells were exposed to the PRF-conditioned medium, regardless of the disc surface (p < 0.05). CONCLUSION: Gingival fibroblasts cultured on a nanohydroxyapatite-treated surface and in a PRF-conditioned medium showed a greater expression of proteins modulating adhesion, angiogenesis, and cell survival. Our results may contribute to the understanding of the mechanisms related to peri-implant soft tissue sealing.

Immunoexpression of stem cell markers SOX-2, NANOG AND OCT4 in ameloblastoma.

Background: Ameloblastoma (AME) is characterized by a locally invasive growth pattern. In an attempt to justify the aggressiveness of neoplasms, the investigation of the role of stem cells has gained prominence. The SOX-2, NANOG and OCT4 proteins are important stem cell biomarkers. Methodology: To verify the expression of these proteins in tissue samples of AME, dentigerous cyst (DC) and dental follicle (DF), immunohistochemistry was performed and indirect immunofluorescence were performed on the human AME (AME-hTERT) cell line. Results: Revealed expression of SOX-2, NANOG and OCT4 in the tissue samples and AME-hTERT lineage. Greater immunostaining of the studied proteins was observed in AME compared to DC and DF (p < 0.001). Conclusions: The presence of biomarkers indicates a probable role of stem cells in the genesis and progression of AME.

Gene expression in cell lines from human ameloblastoma immortalized using hTERT and HPV16-E6/E7.

OBJECTIVE: The aim of this study was to evaluate and compare alterations in gene expression using two distinct immortalization methods (hTERT and HPV16-E6/E7) in ameloblastoma cell lines. MATERIALS AND METHODS: A primary cell culture derived from human ameloblastoma (AME-1) was established and immortalized by two different methods using a transfection processes to hTERT and HPV-E6/E7. The RNA-seq was used to verify which immortalization method had less influence on gene expression. It was performed in four steps: extraction and collection of mRNA, PCR amplification, comparison with the human reference genome, and analysis of differential expression. The genes with differentiated expression were identified and mapped. RESULTS: RNA-seq revealed genetic alterations in ameloblastoma cell lines after the immortalization process, including increased expression of tumor genes like MYC, E2F1, BRAF, HRAS, and HTERT, and a decrease in tumor suppressor genes like P53, P21, and Rb. CONCLUSIONS: It is possible to affirm that cell immortalization is not an inert method regarding gene regulation mechanisms and the hTERT method (AME-TERT) presented fewer changes in gene expression levels.

Bilateral Sinonasal Inverted Papilloma: Report of an Uncommon Case Involving Sinuses of the Face and Orbital Cavity.

BACKGROUND Nasosinusal papilloma is a benign aggressive tumor. It usually occurs unilaterally in the nasal cavity and can extend to the sinuses. The diagnosis is made by the correlation of findings observed in tomographic and histopathological exams. The recommended treatment is surgical excision with clinical monitoring. Orbital involvement occurs in about 9% of cases of advanced SIP. However, there is no report of cases of a benign tumor that invaded the adjacent soft tissues. Therefore, our objective is to report an unusual case of SIP that bilaterally involved the nasal cavity and maxillary sinuses, and extended to involve the ethmoidal cells and sphenoid and frontal sinuses. CASE REPORT In this article, we report an unusual presentation of sinonasal inverted papilloma (SIP) in a 60-year-old man. The tumor bilaterally involved the nasal cavity and maxillary sinuses and extended to involve the ethmoidal cells and the sphenoid and frontal sinuses, as well as the orbital cavity on the right side. An open surgical procedure was performed for complete removal of the lesion and follow-up with imaging exams. CONCLUSIONS The involvement of these structures is uncommon in SIP. This highlights the importance of this case report. Diagnosis and surgical treatment must be carefully planned. In this work, we describe all the steps that helped guide the choice of the best surgical technique to be performed and offer the best clinical follow-up.

Basal Cell Nevus Syndrome with Unusual Associated Findings: A Case Report with 17 Years of Follow-Up.

BACKGROUND Nevoid basal cell carcinoma syndrome (NBCCS), also known as Gorlin-Goltz syndrome (GGS), is an inherited autosomal dominant disorder caused by mutations in the patched (PTCH) tumor-suppressor gene, which has high penetrance and variable phenotypic expressivity. In 1960, Gorlin and Goltz defined the condition by 3 main characteristics: multiple basal cell carcinomas, odontogenic keratocyst (OKC), and skeletal anomalies. Nowadays, many neurologic, ophthalmic, endocrine, and genital manifestations are known to be associated with this syndrome. Considering the complexity of the clinical manifestations, a multidisciplinary approach is necessary for the diagnosis and follow-up of patients with NBCCS. CASE REPORT We report the case of a 27-year-old woman who presented with multiple maxillary and mandibular OKCs, as well as mandibular dentigerous cysts, all detected by X-ray. The medical records of the patient reported other findings such as falx cerebri calcification, osteolysis in femoral bones, and focal bone alteration suggestive of simple bone cysts. Based on the presented manifestations, it was concluded that the patient had characteristics of NBCCS. A multidisciplinary approach was necessary, and odontological intervention was used in managing treatment of the jaw cysts. CONCLUSIONS In view of this combination of findings, it is of primary importance for dental surgeons and physicians to be able to recognize the signs and symptoms of NBCCS in order to achieve an early diagnosis and avoid the progression of oral cysts, the metastasis of skin lesions, and progression of other less frequent manifestations.

HIF-1α Is Associated with Resistance to Hypoxia-Induced Apoptosis in Ameloblastoma.

BACKGROUND: Ameloblastoma (AMB) is a benign odontogenic tumour, with an aggressive local behaviour and a high rate of recurrence. Previous studies have demonstrated that hypoxia-induced factor alpha 1 (HIF-1α) and activated caspase-3 contribute to tumour invasiveness and cytogenesis in ameloblastoma. Hypoxia increases HIF-1α levels, which triggers a number of signalling pathways. This paper aimed to present data in the study of hypoxia-activated signalling pathways that modulate proapoptotic and antiapoptotic events in AMB. METHODS: Twenty cases of AMB and ten cases of dental follicle (DF) were used to analyse the immunoexpression of HIF-1α, p53, BNIP3, Bcl-2, IAP-2, GLUT1, and Bax. To contribute to the study, an analysis of expression and genetic interaction was performed using the cell line AME-1. RESULTS: AMB and DF expressed the studied proteins. These proteins showed significantly greater immunoexpression in AMB compared with the DF (p < 0.05). HIF-1α showed an important association with GLUT1, and a positive correlation was observed among p53, Bcl-2, and IAP-2. Transcriptomic analysis showed the significant expression of the studied proteins, and the network generated showed a direct association of HIF-1αF with GLUT1 (SLC2A1), TP53, and LDHA. Interestingly, GLUT1 also exhibited direct interaction with TP53 and LDHA. CONCLUSION: In AMB tumorigenesis, hypoxia is possibly related to antiapoptotic events, which suggests an important role for HIF-1α, GLUT1, Bcl-2, IAP-2, and possibly p53.

Metallothionein Expression and its Influence on the In Vitro Biological Behavior of Mucoepidermoid Carcinoma.

Mucoepidermoid carcinoma (MEC) is the most common tumor in the salivary glands, often presenting with recurrence and metastasis due to its high invasive capacity. Metallothionein (MT), a zinc storage protein that supplies this element for protease activity, is probably related to mucoepidermoid carcinoma behavior. This prompted us to characterize a cell line derived from mucoepidermoid carcinoma and to correlate metallothionein expression with transforming growth factor-α (TGF-α), tumor necrosis factor-α (TNF-α) and matrix metalloproteinases (MMPs). Transcriptomic analysis and cytogenetic assays were performed to detect the expression of genes of interest and cellular chromosomal alterations, respectively. MEC cells with a depleted metallothionein 2A (MT2A) gene were subjected to Western blot to correlate metallothionein expression with growth factors and MMPs. Additionally, cells with depleted MT were subjected to migration and invasion assays. The transcriptomic study revealed reads mapped to cytokeratins 19 and AE1/AE3, α-smooth muscle actin, vimentin, and fibronectin. Cytogenetic evaluation demonstrated structural and numerical alterations, including the translocation t(11;19)(q21;p13), characteristic of MEC. Metallothionein depletion was correlated with the decreased expression of TGF-α and MMP-9, while TNF-α protein levels were augmented. Migration and invasion activity were diminished after metallothionein silencing. Our findings suggest an important role of MT in MEC invasion, through the regulation of proteins involved in this process.

Epstein-Barr virus (EBV) in periodontal sites of human immunodeficiency virus (HIV)-positive individuals in North Brazil: a cross-sectional study.

OBJECTIVE: This study aimed to investigate the Epstein-Barr virus (EBV) prevalence and viral load in subgingival sites of human immunodeficiency virus type 1 (HIV-1) positive (HIV+) individuals, correlating subgingival EBV load to the clinical periodontal condition, HIV systemic load, EBV systemic load, and use of antiretroviral therapy (ART). METHOD AND MATERIALS: Ninety individuals were recruited and divided into three categories: those without periodontal disease (G1), with gingivitis (G2), and with periodontitis (G3). Subgingival biofilm and blood samples were analyzed by quantitative polymerase chain reactions (qPCR). A questionnaire was administered to collect general information about patients, and data regarding HIV and use of ART were accessed from their medical records. RESULTS: EBV was detected in 85.6% of the samples. Comparing subgingival and systemic load of EBV in G1, G2, and G3, there was a statistical difference only in G3 (3.93 log10 copies/mL and 5.47 log10 copies/mL, respectively; P = .014), where EBV load was higher in periodontal pockets than in the blood. All groups had high EBV loads in subgingival sites (> 2,000 copies/mL). A positive linear correlation between systemic HIV load and EBV subgingival load was found in G1 and G2 (r = 0.647; P < .001), but not in G3. Only G1 individuals using ART had lower subgingival EBV loads than those not using it (5.03 log10 copies/mL, and 7.14 log10 copies/mL, respectively; P = .0348). CONCLUSIONS: Subgingival sites, especially the periodontal pockets, are suggested to act as a reservoir of EBV in HIV+ individuals. Therefore, the identification of latent EBV infections in this easily accessible site might help to improve quality of life in patients with HIV by maintaining oral/periodontal health. In addition it might encourage new approaches in investigating EBV-associated disorders in HIV+ patients.

HIF-1α is Overexpressed in Odontogenic Keratocyst Suggesting Activation of HIF-1α and NOTCH1 Signaling Pathways.

Background: The odontogenic keratocyst (OKC) is an odontogenic cyst that shows aggressive and intriguing biological behavior. It is suggested that a hypoxic environment occurs in OKC, which led us to investigate the immunoexpression and location of hypoxia-inducible factor 1-alpha (HIF-1α) and other hypoxia-related proteins. Methods: Twenty cases of OKC were evaluated for the expression of Notch homolog 1 (NOTCH1), HIF-1α, disintegrin and metalloproteinase domain-containing protein 12 (ADAM-12), and heparin-binding epidermal growth factor-like growth factor (HBEGF) by immunohistochemistry and compared to eight control cases of calcifying odontogenic cystic (COC), orthokeratinized odontogenic cyst (OOC), and normal oral mucosa (OM) in basal and parabasal layers. Results: In OKC, all the proteins tested were expressed significantly higher in both basal (except for NOTCH1 and HBEGF in OOC) and suprabasal epithelial layers compared to controls. Looking at the epithelial layers within OKC, we observed an increased NOTCH1 and HIF-1α expression in parabasal layers. Conclusions: These results suggest that hypoxia occurs more intensively in OKC compared to COC, OM, and OOC. Hypoxia appeared to be stronger in parabasal layers as observed by higher HIF-1α expression in upper cells. Overexpression of NOTCH1, ADAM-12, and HBEGF in OKC was observed, which suggests that microenvironmental hypoxia could potentially regulate the expression of hypoxia-related proteins, and consequently, its clinical and biological behavior.

HIF-1α, NOTCH1, ADAM12, and HB-EGF are overexpressed in mucoepidermoid carcinoma.

OBJECTIVE: Intratumoral hypoxia (IH) occurs during cellular proliferation of malignant tumors. This phenomenon is characterized by a decrease in oxygen levels in the neoplastic microenvironment. Throughout this condition, the proteins HIF-1α, NOTCH1, ADAM12, and HB-EGF can be activated, triggering signaling pathways associated with tumor invasiveness through invadopodia formation. This study aimed to evaluate the immunostaining of HIF-1α, NOTCH1, ADAM12, and HBEGF in 19 cases of mucoepidermoid carcinoma (MEC) and 10 samples of salivary glands (control group). STUDY DESIGN: The immunoperoxidase technique was employed to detect the proteins of interest. The Student t test was used to compare immunoexpression between MEC samples and the control group. RESULTS: Protein immunostaining was statistically significantly higher in MEC samples than in the control group (P < .01), and the proteins were especially overexpressed in epidermoid cells of MEC. CONCLUSIONS: We suggest that there is an association between the NOTCH1 signaling pathway activated by IH and the biologic behavior of MEC.

Interfragmentary screw fixation of the zygomatic arch in complex midface and zygomaticomaxillary fractures.

Zygomatic arch reduction and fixation is a key point in the treatment of complex midface and zygomaticomaxillary fractures. High-impact frontal trauma can cause posterior displacement of zygomatic bone, with a sagittal fracture of the root of the zygomatic arch extending posteriorly to the glenoid fossa. Miniplate and screw fixation of this fracture requires a large detachment of soft tissue, thus being technically more difficult for proper fixation and increasing the risk of soft tissue damage. This report describes an operative approach for fixation of this type of fracture using an adaptation of the lag screw technique. After the initial reduction of zygomatic bone, the proximal segment of the zygomatic arch containing the sagittal fracture is anatomically reduced and a 2.0-mm titanium screw is placed with an inferior inclination of 10° to 15° into the mastoid cells of the temporal bone, thus avoiding intracranial screw placement. This technique showed excellent results in reduction and long-term stability. It facilitates the surgical procedure, decreases the risk of soft tissue damage, and can lower costs compared with conventional miniplate and screw fixation.

Giant life-threatening external carotid artery pseudoaneurysm caused by a mandibular condylar fracture.

OBJECTIVE: Vascular lesions are rare complications associated to mandibular condylar fractures. This paper aims to describe a case of a giant pseudoaneurysm involving the external carotid artery (ECA) caused by a condylar fracture. CASE REPORT: A 33-year-old man was the victim of traffic accident and presented with a panfacial fracture, including a bilateral condylar fracture. The condylar fracture was treated by closed reduction, and 4 weeks after treatment, the patient developed facial edema, which suggested postoperative infection. An attempt at draining it resulted in intensive bleeding. A computed tomographic angiography showed a huge pseudoaneurysm originating from the ECA. The patient was treated with surgery with ligation of the ECA and drainage of the pseudoaneurysm. CONCLUSION: Vascular complications associated with condylar fractures are rare, but surgeons should be aware of this type of complication, especially because of the high risk of serious damage, including death. The use of computed tomographic angiography is very helpful in the diagnosis of vascular lesions and also guides treatment.

Prescrição de higiene bucal nos prontuários de pacientes internados em uma cidade da Amazônia / Oral hygiene prescription in medico records of patients in o city of Amazônia

O objetivo deste trabalho foi registrar os cuidados bucais prescritos nos prontuários dos pacientes internados no Hospital de Pronto-Socorro Municipal Mario Pinotti, tendo como me todologia a avaliação dos prontuários de pacientes que tiveram internação mínima durante 2 horas, pelo fato de que todo paciente deveria ter recebido higiene bucal independentemente de suas condições físicas e motoras, onde de 415 prontuários analisados, apenas 28,19% receberam prescrição de higiene bucal. Com relação ao tempo de internação, a maior parte, 52,29% permaneceu internada por período acima de 2 a 7 dias, e a maioria (56,63%) foi do gênero masculno. Observaram-se como motivos de internação mais frequentes: doenças bacterianas (4,34%) pneumonia/gripe (7,23%); apendicectomia (11 ,33%); traumatismos (16,14%); e acidente vascular encefálico (18,55%). Concluiu-se que não há uma efetiva importância dos cuidados bucas no âmbito hospitalar dos pacientes internados com a maioria deles não recebendo nenhuma prescrição de higiene bucal.

The purpose of this paper was to report prescribed oral care in the medical records of hos pitalized patients from Pronto Socorro Municipal Mario Pinotti Hospital. The methodology consists of evaluating the medical records of patients who were hospitalized for at least 24 hours assuming that every patient should have received oral hygiene regardless of their physical and motor conditions. According to the 415 analyzed records, oral hygiene was prescribed for just 28.19% of patients (117). Regarding hospitalization, the majority of patients (52.29% - 217) had a period of hospitalization between over 2 days and 7 days and most of them were male (56,63% - 235). The most frequent reasons for hospitalization were: bacterial diseases 4.34% (18 patients), pneumonia / flu symptoms 7.23% (30 patients), appendectomy 11.33% (47 patients); trauma 16.14% (67 patients); stroke 18.55% (77 patients) and others reasons represented 42,41% (176 patients). Data suggests that there is not much importance placed on oral care in hospitais for hospitalized patients, since most of them received no required care for ora hygiene.

Odontodisplasia regional / Regional odontodysplasia

The present article reports on a case of a dental development anomaly in an 18-month old patient whose parents sought treatment with the chief complaint of ?missing teeth?. The diagnosis of regional odontodysplasia or ?ghost teeth? involving incisors and canine, both deciduous and permanent, of the upper right side of the mouth was based on radiographic features of the condition: marked reduction of enamel and dentin radiopacity, which are present in thin layers involving large pulp cavity of the teeth affected, usually belonging to a particular quadrant. At the age of three years and six months, the patient was still under observation, and received partial denture rehabilitation as a first step, since the clinical condition of the element 51 resulted in its extraction and the beginning of the child?s school life required esthetic and functional rehabilitation. The other affected teeth were preserved, contributing to the alveolar development. The patient remains under regular follow-up and the treatment plan for the permanent dentition will depend on the degree of dental involvement.

O presente artigo relata um caso de anomalia de desenvolvimento dentário em paciente aos dezoito meses de idade, cujos pais buscaram atenção odontológica com a queixa de ?falta de dentes?. O diagnóstico de Odontodisplasia regional ou ?dentes fantasma? envolvendo incisivos e canino, decíduos e permanentes, do quadrante superior direito foi baseado nas características radiográficas da condição: marcante redução na radiopacidade de esmalte e dentina, que se apresentam em finas camadas envolvendo ampla cavidade pulpar nos dentes afetados, geralmente pertencentes a um quadrante particular. Aos três anos e meio de idade, estando em controle periódico, a paciente recebeu prótese parcial removível como primeira medida reabilitadora, uma vez que a condição clínica do elemento 51 implicou sua perda, e o início da vida escolar da criança exigia reabilitação estética e funcional. Os demais dentes afetados foram conservados, contribuindo para o bom desenvolvimento alveolar. A paciente permanece em acompanhamento regular, sendo que o plano de tratamento para a dentição permanente dependerá do grau da anomalia em seus elementos.

The importance of early diagnosis and an accurate tumoral evaluation in the treatment of mandibular osteossarcoma / Importância do diagnóstico precoce e de uma precisa avaliação tumoral no tratamento de um osteossarcoma em mandíbula

Purpose: Osteosarcoma is a malignant bone neoplasm with aggressive clinical evolution which is usually diagnosed in late stages of the disease, when primary tumor reaches significant dimensions. In many cases, an aggressive surgical treatment, which includes major bone resection and is sometimes associated with radiotherapy and chemotherapy, is required for better control of local recurrence and metastasis in such lesions.Case Description: This paper reports an early-diagnosed case of osteosarcoma in the left side of the mandible and an accurate evaluation of the tumor involvement by means of Cone Beam Computerized Tomography. Conclusion: The early diagnosis of osteosarcoma is an uncommon condition that has good influence both on the treatment and prognosis of such tumor. This early diagnosis and an accurate evaluation of the tumor involvement were determining factors for conservative, curative surgical procedure with minimum sequelae. The pericementary space should be especially observed, since its thickness is a much more common feature in osteosarcomas. Studies that allow for identifying osteosarcomas in earlier stages should be conducted in order to enable longer survival and better quality of life.

Objetivo: O osteossarcoma é uma neoplasia maligna do osso que possui um comportamento clínico agressivo, geralmente diagnosticado em estados tardios da doença, quando o tumor primário atinge dimensões significativas. Em muitos casos, tratamento cirúrgico agressivo com grandes ressecções ósseas e a necessidade de associação à rádio ou quimioterapia se fazem necessários para melhor controle de recidivas locais e metástases em tais lesões. Descrição do Caso: No presente trabalho os autores relataram um caso de osteossarcoma na região de corpo e ramo mandibular esquerdo diagnosticado precocemente e avaliado de forma precisa pela tomografia computadorizada tipo cone beam. Conclusão: O diagnóstico precoce do osteossarcoma é uma condição pouco comum que afeta de forma favorável tanto o tratamento quanto o prognóstico deste tumor. A associação deste diagnóstico precoce com uma avaliação precisa do envolvimento tumoral foram determinantes na execução de um tratamento cirúrgico conservador e ainda assim com finalidade curativa, com um mínimo de sequelas. O espaço pericementário deve ser especialmente observado, pois seu espessamento é muito mais comum em osteossarcomas. Estudos que possibilitem identificar esta lesão de forma mais precoce e precisa devem realizados, a fim de possibilitar uma sobrevida maior com melhor qualidade de vida.

Distraction osteogenesis in Goldenhar Syndrome: Case report and 8-year follow-up

Goldenhar syndrome is a well-known condition featuring the following triad of anomalies: ocular abnormalities, microtia and vertebral anomalies. This syndrome involves structures arising from the first and second branchial arches. Craniofacial anomalies, including mandibular, zygomatic and/or maxillary hypoplasias are found in 50% of patients with Goldenhar syndrome. Patients with this syndrome may present unilateral or bilateral underdevelopment of the mandible. Severaltreatments for the correction of the dento-facial deformity have been described, among them distraction osteogenesis is one that shows promising results. Distraction osteogenesis is the process of bone formation that occurs during slow separation of the segments of bone after an osteotomy and it has been used to alleviate facial asymmetry. Mandibulardistraction osteogenesis has been applied for many years, but long-term reports present controversial results. The purpose of the case report is to describe the immediate and long-term effects of distraction osteogenesis used to treat mandible asymmetry in a 5-year-old boy with Goldenhar syndro

Análise da expressão e mecanismos de ação da proteína COX-2 em cultura de células de carcinoma epidermóide bucal humano / Analysis expression and action mechanisms of COX-2 protein in culture of human oral squamous cell carcinoma

Celecoxib é um antiinflamatório não esteroidal (AINE), inibidor seletivo da ciclooxigenase-2 (COX-2) usado em pesquisas recentes como agente anticarcinogênico. Os seus efeitos anti-neoplásicos dependem por um lado da suacapacidade de inibir a COX-2, mas por outro lado também age por mecanismos que independem da COX-2, em resumo o seu mecanismo de ação ainda não é completamente conhecido. O objetivo desta tese foi estudar os efeitos do celecoxib sobre as taxas de apoptose e os índices de proliferação celular de quatro linhagens celulares, Hn-6, Hn-19, Hn-30, Hn-31, de CECP e uma linhagem de queratinócitos mutada (HaCat), além de verificar se há correlação entre a expressão das proteínas COX-2, pAkt, ß-catenina, CD1 e NFKB e a inibição da proliferação celular. As células foram divididas em dois grupos: a, grupo controle; b, células cultivadas tratadas com celecoxib. A análise da expressão das proteínas pAkt, NFKB, ß-catenina, COX-2 e CD1 foi feita através da técnica de Western-blot. A indução de apoptose foi estudada com o Kit de Anexina. A proliferação celular foi monitorada através de curva de crescimento, com contagem celular na câmara de Neubauer e com o teste de viabilidade celular (Kit Cell Titer96) e a localização intracelular das proteínas foi avaliada por imunofluorescência. Os resultados mostraram significante aumento noíndice celular de apoptose e diminuição da proliferação celular. Após o tratamento com celecoxib, a imunofluorescência mostrou que a proteína CD1 teve diminuição da expressão nuclear, a ß-catenina exibiu discreto aumento citoplasmático, o pAkt também passou a ser expresso no citoplasma da Hn6, enquanto as outras proteínas estudadas mantiveram o mesmo padrão de localização na célula. O western blot complementou os resultados da imunofluorescência indicando uma diminuição nos níveis de CD1.