Michelle Agostini

ADAM17 mediates OSCC development in an orthotopic murine model

BackgroundADAM17 is one of the main sheddases of the cells and it is responsible for the cleavage and the release of ectodomains of important signaling molecules, such as EGFR ligands. Despite the known crosstalk between ADAM17 and EGFR, which has been considered a promising targeted therapy in oral squamous cell carcinoma (OSCC), the role of ADAM17 in OSCC development is not clear.MethodIn this study the effect of overexpressing ADAM17 in cell migration, viability, adhesion and proliferation was comprehensively appraised in vitro. In addition, the tumor size, tumor proliferative activity, tumor collagenase activity and MS-based proteomics of tumor tissues have been evaluated by injecting tumorigenic squamous carcinoma cells (SCC-9) overexpressing ADAM17 in immunodeficient mice.ResultsThe proteomic analysis has effectively identified a total of 2,194 proteins in control and tumor tissues. Among these, 110 proteins have been down-regulated and 90 have been up-regulated in tumor tissues. Biological network analysis has uncovered that overexpression of ADAM17 regulates Erk pathway in OSCC and further indicates proteins regulated by the overexpression of ADAM17 in the respective pathway. These results are also supported by the evidences of higher viability, migration, adhesion and proliferation in SCC-9 or A431 cells in vitro along with the increase of tumor size and proliferative activity and higher tissue collagenase activity as an outcome of ADAM17 overexpression.ConclusionThese findings contribute to understand the role of ADAM17 in oral cancer development and as a potential therapeutic target in oral cancer. In addition, our study also provides the basis for the development of novel and refined OSCC-targeting approaches.

Integrated Proteomics Identified Up-Regulated Focal Adhesion-Mediated Proteins in Human Squamous Cell Carcinoma in an Orthotopic Murine Model

Understanding the molecular mechanisms of oral carcinogenesis will yield important advances in diagnostics, prognostics, effective treatment, and outcome of oral cancer. Hence, in this study we have investigated the proteomic and peptidomic profiles by combining an orthotopic murine model of oral squamous cell carcinoma (OSCC), mass spectrometry-based proteomics and biological network analysis. Our results indicated the up-regulation of proteins involved in actin cytoskeleton organization and cell-cell junction assembly events and their expression was validated in human OSCC tissues. In addition, the functional relevance of talin-1 in OSCC adhesion, migration and invasion was demonstrated. Taken together, this study identified specific processes deregulated in oral cancer and provided novel refined OSCC-targeting molecules.

Oral verruciform xanthoma: a clinicopathologic and immunohistochemical study of 20 cases

Verruciform xanthoma of the oral cavity is an uncommon benign lesion that usually affects the palate and gingiva mainly as a well‐circumscribed solitary yellowish to whitish plaque or nodule, which is promptly recognized microscopically by identification of sub‐epithelial foamy macrophages. The aim of this study was to evaluate the clinicopathologic and immunohistochemical features of 20 cases of oral verruciform xanthoma. All cases were evaluated by conventional hematoxylin/eosin staining and six of those were submitted to immunohistochemical reactions for CD68, CD63, CD163, syndecan‐1 (CD138), S‐100 protein and cytokeratins (CK) 8, 14 and 19. Oral verruciform xanthoma presented as yellowish papillary nodules affecting mainly the palate (30%), buccal mucosa (30%) and gingiva (25%) of middle‐aged male patients. Most cases presented papillary epithelial hyperplasia and sub‐epithelial foamy cells, which were immunopositive for CD68, CD63 and CD163 in all cases. The orange parakeratin superficial layer was negative for CK14 and presented a distinct granular membrane pattern of positivity for CD138. S‐100 protein, CK8, and CK19 were negative.

Clinicopathologic and immunohistochemical features of five new cases of solitary fibrous tumor of the oral cavity

OBJECTIVE To describe the clinicopathologic and immunohistochemical features of five cases of oral solitary fibrous tumor. STUDY DESIGN Clinical data were collected from charts of two oral pathology laboratories of Latin America. All cases were evaluated by conventional hematoxylin and eosin staining and an extended immunohistochemical panel comprising vimentin, CD34, CD99, bcl-2, HHF-35, smooth muscle actin, calponin, S-100 protein, h-caldesmon, and Ki-67. RESULTS The study included 1 male (20%) and 4 female (80%) patients, with a median age of 43 years. The most common affected site was the buccal mucosa (40%). Tumors were characterized by proliferation of spindled and ovoid cells in a variably vascular and collagenized stroma. All tumors were positive for vimentin, CD34, bcl-2, and CD99. Recurrence was not observed after complete surgical enucleation. CONCLUSIONS Oral solitary fibrous tumors usually appear as well-delimited submucous nodules with a firm-rubbery consistency and covered by intact mucosa. Immunoreactivity for CD34, bcl-2, and CD-99 is helpful to confirm the diagnosis.

Suppression of MAGE-A10 alters the metastatic phenotype of tongue squamous cell carcinoma cells

MAGE-A10 is a member of the MAGE protein family (melanoma associated antigen) which is overexpressed in cancer cells. Although MAGE-A10 has been characterized for some time and is generally associated to metastasis its function remains unknown. Here we describe experiments using as models oral squamous cell carcinoma (OSCC) cell lines displaying increasing metastatic potential (LN1 and LN2). These cell lines were transduced with lentivirus particles coding for short hairpin against MAGE-A10 mRNA. Repression of MAGE-A10 expression in LN2 cells altered their morphology and impaired growth of LN1 and LN2 cell lines. Furthermore, repression of MAGE-A10 expression increased cell-cell and cell matrix adhesion. Furthermore shMAGEA10 cells were shown to assemble aberrantly on a 3D culture system (microspheroids) when compared to cells transduced with the control scrambled construct. Cell migration was inhibited in knocked down cells as revealed by two different migration assays, wound healing and a phagokinetic track motility assay. In vitro invasion assay using a leiomyoma tissue derived matrix (myogel) showed that shMAGEA10 LN1 and shMAGEA10 LN2 cells displayed a significantly diminished ability to penetrate the matrices. Concomitantly, the expression of E-cadherin, N-cadherin and vimentin genes was analyzed. shMAGEA10 activated the expression of E-cadherin and repression N-cadherin and vimentin transcription. Taken together the results indicate that MAGE-A10 exerts its effects at the level of the epithelial-mesenchymal transition (EMT) presumably by regulating the expression of adhesion molecules.

Angiogenesis and evading immune destruction are the main related transcriptomic characteristics to the invasive process of oral tongue cancer

Metastasis of head and neck tumors is responsible for a high mortality rate. Understanding its biochemistry may allow insights into tumorigenesis. To that end we carried out RNA-Seq analyses of 5 SCC9 derived oral cancer cell lines displaying increased invasive potential. Differentially expressed genes (DEGs) were annotated based on p-values and false discovery rate (q-values). All 292 KEGG pathways related to the human genome were compared in order to pinpoint the absolute and relative contributions to the invasive process considering the 8 hallmarks of cancer plus 2 new defined categories, as well as we made with our transcriptomic data. In terms of absolute contribution, the highest correlations were associated to the categories of evading immune destruction and energy metabolism and for relative contributions, angiogenesis and evading immune destruction. DEGs were distributed into each one of all possible modes of regulation, regarding up, down and continuum expression, along the 3 stages of metastatic progression. For p-values twenty-six genes were consistently present along the tumoral progression and 4 for q-values. Among the DEGs, we found 2 novel potentially informative metastatic markers: PIGG and SLC8B1. Furthermore, interactome analysis showed that MYH14, ANGPTL4, PPARD and ENPP1 are amenable to pharmacological interventions.

Clinicopathologic conference: bluish gingival nodule

CLINICAL PRESENTATIONA 35-year-old woman was referred for management ofa slow-growing nodule of 6 months’ duration in themaxillary gingiva. The medical history and extraoralexamination of the patient were unremarkable, with nohistory of trauma in the region. Intraoral examinationrevealed a dome-shaped, well-defined bluish nodulemeasuring 1 cm, localized in the buccal aspect of theattached gingiva between the upper right canine andfirst premolar. The nodule was asymptomatic, soft inconsistency, and covered by a smooth surface display-ing discrete capillaries. The gingival papilla was pre-served, and there was no sign of dental plaque-inducedgingival inflammation. Adjacent teeth did not showevidence of calculus or carious lesions. Periapicalradiography revealed discrete, well-defined, superficialbone resorption of the alveolar crest, indicating theextraosseous location of the lesion (Figure 1).DIFFERENTIAL DIAGNOSISThe differential diagnosis in the current case includedperipheralbluishgingivallesions,suchasperipheralgiantcell lesion, gingival cyst of theadult, melanocytic nevus,angioleiomyoma, Kaposi sarcoma, and melanoma.Peripheral giant cell lesion is a reactive lesion thatoccurs in the gingiva or alveolar ridge of adult patientsand may present a bluish to reddish color and smoothsurface,

Oral and maxillofacial metastasis of male breast cancer: Report of a rare case and literature review

Oral and maxillofacial metastatic tumors are uncommon, with the breast, prostate, lung, and kidney representing the most common primary sites. Less than 1% of all breast cancers occur in male patients, and to date, only 8 cases of metastatic breast adenocarcinoma to the oral and maxillofacial region in a male patient have been reported in the literature. An 88-year-old male with previous history of a successfully treated primary breast adenocarcinoma 12 years earlier was referred for evaluation of an oral swelling lasting 6 months. Intraoral examination revealed a 2-cm reddish, pedunculated nodule with a smooth surface located in the left retromolar region. Imaging revealed maxillary sinus involvement. The patient underwent incisional biopsy, and microscopic evaluation revealed invasive tumor islands compounded by malignant epithelial cells, sometimes exhibiting ductal arrangement, which were positive for the estrogen receptor and gross cystic disease fluid protein 15. The final diagnosis was metastatic breast adenocarcinoma. Breast metastases are exceedingly rare in the oral and maxillofacial region of male patients; however, clinicians should consider breast metastasis when evaluating reddish oral nodules in older patients, including men, especially those with a history of malignancy.

Congenital dilatation of the submandibular duct

Congenital dilatation of the submandibular duct also known as imperforate submandibular duct is a rare condition of unknown etiology, clinically characterized as a well-defined, fluctuant swelling in the floor of the mouth, and microscopically defined as a cystic cavity covered with pseudostratified columnar epithelium consistent with a dilated salivary duct. A 1-month-old female presented with a translucent, smooth cystic swelling in the floor of the mouth causing breastfeeding difficulty. The lesion was surgically excised and microscopically, a cystic cavity lined with pseudostratified columnar epithelium was observed. The final diagnosis was congenital dilatation of the submandibular duct. Dentists and otolaryngologists should consider congenital dilatation of the submandibular duct when evaluating fluctuant swelling in the floor of the month of infants.

Primordial Odontogenic Tumor: Report of a New Case and Literature Review

Primordial odontogenic tumor (POT) was recently recognized in the 2017 World Health Organization (WHO) Classification as a distinct mixed odontogenic tumor most commonly observed in the posterior mandible of young patients. POT appears as an expansile radiolucency associated to an unerupted tooth. The aim of the present study was to perform a retrospective microscopic evaluation of pediatric odontogenic tumors diagnosed in an Oral Pathology Laboratory from Rio de Janeiro—Brazil, in order to reclassify potential cases as POT. From 150 cases of odontogenic tumors in children diagnosed in the last 50 years, one case filled the criteria for POT, being therefore better diagnosed as such. The patient was in the first decade of life and presented a well-defined expansile tumor in the posterior mandible, which had been initially diagnosed as immature complex odontoma. To the best of our knowledge, only 12 cases of POT have been reported in the English-language literature. We herein present an additional case of POT and review of its clinicopathological findings is offered.