The laminin-derived peptide C16 regulates GPNMB expression and function in breast cancer.

Breast cancer is an important public health problem, and its progression may be related to the extracellular matrix (ECM), which acts as a structural scaffold and instruction source for neoplastic cells. Laminins are ECM proteins regulating tumor biology. The laminin-derived peptide C16 regulates different properties of tumor cells. Here we analyzed C16-induced differential gene expression in MDA-MB-231 breast cancer cells. MCF-10A normal-like breast cells served as control. Among different cancer-related genes, C16 induced overexpression of GPNMB. This gene encodes a transmembrane protein GPNMB (glycoprotein non-metastatic B), involved with malignant phenotype of breast cancer cells. Immunoblot validated microarray results. To correlate gene and protein expression with cellular function, we investigated whether C16 would regulate invasion in breast cancer cells. siRNA experiments strongly suggested that C16 and GPNMB cooperate to regulate invasion of highly aggressive MDA-MB-231 cancer cells. We addressed regulatory mechanisms involved in C16-mediated increase of GPNMB protein levels in MDA-MB-231 cells, and observed that C16 stimulates ß1 integrin and Src phosphorylation. Furthermore, Src inhibition decreases peptide-induced GPNMB expression levels. To contextualize in vivo our results in vitro, we addressed GPNMB immunostaining in breast cancer human tissue microarrays. Quantitative immunohistochemistry showed that GPNMB is significantly more expressed in breast cancer compared to normal tissue. We concluded that laminin-derived peptide C16 regulates gene and protein expression of GPNMB in breast cancer cells. C16 and GPNMB may cooperate to regulate invasion of highly aggressive MDA-MB-231 cells, probably through Src signaling. GPNMB presented increased expression in breast cancer in vivo compared to normal breast tissue.

A novel cell line derived from pleomorphic adenoma expresses MMP2, MMP9, TIMP1, TIMP2, and shows numeric chromosomal anomalies.

Pleomorphic adenoma is the most common salivary gland neoplasm, and it can be locally invasive, despite its slow growth. This study aimed to establish a novel cell line (AP-1) derived from a human pleomorphic adenoma sample to better understand local invasiveness of this tumor. AP-1 cell line was characterized by cell growth analysis, expression of epithelial and myoepithelial markers by immunofluorescence, electron microscopy, 3D cell culture assays, cytogenetic features and transcriptomic study. Expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) was also analyzed by immunofluorescence and zymography. Furthermore, epithelial and myoepithelial markers, MMPs and TIMPs were studied in the tumor that originated the cell line. AP-1 cells showed neoplastic epithelial and myoepithelial markers, such as cytokeratins, vimentin, S100 protein and smooth-muscle actin. These molecules were also found in vivo, in the tumor that originated the cell line. MMPs and TIMPs were observed in vivo and in AP-1 cells. Growth curve showed that AP-1 exhibited a doubling time of 3.342 days. AP-1 cells grown inside Matrigel recapitulated tumor architecture. Different numerical and structural chromosomal anomalies were visualized in cytogenetic analysis. Transcriptomic analysis addressed expression of 7 target genes (VIM, TIMP2, MMP2, MMP9, TIMP1, ACTA2 e PLAG1). Results were compared to transcriptomic profile of non-neoplastic salivary gland cells (HSG). Only MMP9 was not expressed in both libraries, and VIM was expressed solely in AP-1 library. The major difference regarding gene expression level between AP-1 and HSG samples occurred for MMP2. This gene was 184 times more expressed in AP-1 cells. Our findings suggest that AP-1 cell line could be a useful model for further studies on pleomorphic adenoma biology.

Life-threatening expansive sublingual hematoma: a stab wound with lingual artery injury.

Vascular injuries are a constant risk in facial trauma, although bone and soft tissues of the face have provided some protection to the larger blood vessels. However, penetrating injuries usually do not have this type of protection and can damage significant vascular arteries. This article presents a case of a stab wound, which led to airway obstruction arising to a large sublingual hematoma due to lingual artery injury. A healthy 44-year-old man was stabbed in the submandibular region and admitted with an airway obstruction. He was subjected to an emergency tracheotomy and evolved with progressive sublingual edema. Computed tomography (CT) angiography showed a left lingual artery injury with the formation of an expansive hematoma. The CT angiography findings helped to identify the cause of the hematoma and guided the surgery to drain the hematoma after ligation of the lingual artery. The treatment was safely performed as planned and evolved uneventfully. The patient recovered fast and well and presented normal functions 6 months after the treatment. This surgical technique is an effective method for treating such injuries because it can be safely performed when guided by CT angiography. The authors argue that the demand for vascular lesions should be routine in patients who have facial trauma.

Expression of molecules related to AKT pathway as putative regulators of ameloblastoma local invasiveness.

BACKGROUND: Ameloblastoma is an odontogenic neoplasm with local invasiveness and high recurrence. We previously suggested that growth factors, matrix metalloproteinases (MMPs), and TIMPs influence ameloblastoma invasiveness (Pathol. Res. Pract., 208, 2012, 225; Oral. Surg. Oral. Med. Oral. Pathol. Oral Radiol. Endod., 111, 2011, 474). Signals generated by this molecular network would be transduced by ERK 1/2 pathway (Oral. Surg. Oral. Med. Oral. Pathol. Oral Radiol. Endod., 111, 2011, 474). Others signaling pathways may influence ameloblastoma biology. Here, we studied expression of AKT and related molecules in ameloblastoma. METHODS: Fourteen cases of solid/multicystic ameloblastomas were examined. Immunohistochemistry was carried out to detected AKT (phospho-AKT), NF-қB (phospho-NF-қB), ß-catenin, cyclin-D1, and COX-2 in ameloblastoma samples. These molecules were evaluated in neoplastic cells and stroma. RESULTS: All proteins were detected in ameloblastoma. Expression of these markers was quantified and compared. Spearman's rank test was carried out to address positive correlations between proteins (P < 0.05). Ameloblastoma had a significant positive correlation of AKT (phospho-AKT) with ß-catenin. ß-catenin correlated with Cyclin-D1 and COX-2 in neoplastic cells. AKT (phospho-AKT) correlated with ß-catenin; ß-catenin with Cyclin-D1; AKT (phospho-AKT) with NF-қB (phospho-NF-қB); and NF-қB (phospho-NF-қB) with COX-2 in stromal cells. CONCLUSIONS: Results suggest that proteins studied are present and probably involved in a functional pathway in neoplastic cells and stroma and may therefore influence the local invasiveness of ameloblastoma.

Dentomaxillofacial manifestations of mucopolysaccharidosis VI: clinical and imaging findings from two cases, with an emphasis on the temporomandibular joint.

OBJECTIVES: Using a clinical survey, panoramic, cone-beam computed tomography (CBCT), and magnetic resonance (MR) imaging, this study was conducted to ascertain primary maxillofacial abnormalities in patients with mucopolysaccharidosis VI (MPS VI). STUDY DESIGN: Two patients previously diagnosed with MPS VI underwent clinical and imaging surveys (panoramic radiographs, CBCT, and MR imaging). RESULTS: Jaw involvement was present in all patients. The most prevalent findings were enlarged marrow spaces, osteopenia, dentigerous cyst-like follicles, effacement of the jaw structures, and osteosclerosis. This is the first study to describe temporomandibular joint (TMJ) involvement for MPS VI. CONCLUSIONS: CBCT and MR imaging were needed to observe features that were not clear in conventional radiographs. Both patients reported symptoms in the TMJ and demonstrated involvement during their examinations. A multicenter study is necessary to better document maxillofacial involvement in MPS VI.

Clinical and imagiological findings of central giant cell lesion and cherubism.

Cone beam computed tomography (CBCT) is the best examination for bone lesions of the maxilla, allowing the dentist to evaluate precisely the behavior and components of the lesion and their relationship to the surrounding structures. Central giant cell lesion and cherubism are histologically very similar lesions. Therefore clinical and radiological examinations are fundamentally important for the diagnosis. The aim of this paper is to report two cases diagnosed as central giant cell lesions and cherubism using CBCT. This imaging modality was very important for the diagnosis of the lesions presented in the current study. It also allowed observing precisely the limits of the lesions, the components, the behavior and the exact relationship to adjacent structures.

Zygomaticomaxillary complex fracture in a zygomatic bone affected by monostotic fibrous dysplasia: a very rare association.

The association between fibrous dysplasia (FD) and fractures is very rare. This paper reports the case of a zygomaticomaxillary complex fracture in a bone affected by FD, a 29-year-old man who was involved in a bicycle accident and who subsequently presented with a zygomaticomaxillary complex fracture. Computed tomography revealed multiple fractures of the left zygomaticomaxillary complex with dysplastic bone alterations. Fracture lines occurred near transitional areas between the lesion and healthy bone. The patient was treated through an intraoral approach by an open reduction and internal fixation procedure, using a titanium miniplate and screws. An incisional biopsy was performed through the maxillary sinus to confirm the diagnosis of FD. After 12 months of follow-up, there were no postoperative complications. This paper reports a rare association thought to be caused by irregular trabecular bone deposition, which increases bone thickness/resiliency and thus increases its clinical fracture resistance.

Solitary giant neurofibroma of the mental nerve: a trauma-related lesion?

Neurofibroma is a benign neoplasm derived from peripheral nerves whose etiology is still unclear. It may present as a solitary lesion or be associated with other diseases such as neurofibromatosis type I and II syndrome. This paper aims to report an extremely rare case of a solitary giant neurofibroma of the mental nerve whose etiology was related to a local trauma. A 14-year-old female patient presented an extensive left facial mass with a size of 7 × 5 × 4 cm, located between the teeth 33 and 37 in the mandible region. It has begun to grow 3 months after a local trauma. Imaging studies were suggestive of a soft-tissue lesion, with minimal bone changes and maintaining the integrity of the mandibular canal and mental foramen. Histopathological tests showed spindle cells with undulated and hyperchromatic nuclei, and sparse cytoplasm in a stroma composed of dense fibrous connective tissue. Immunohistochemistry revealed positive expression for the proteins S-100 and vimentin, confirming the diagnosis of neurofibroma. The patient underwent surgical removal of the lesion by intraoral approach and evolved with an excellent cosmetic result and no signs of recurrence after 2 years of follow up. We report a rare case of solitary giant neurofibroma whose etiology was related to a local trauma. To our knowledge, this is the first report of a mental nerve neurofibroma. Although the etiology remains unclear, we suggest the investigation of local trauma as a possible etiologic factor for solitary neurofibromas of the jaw.

Clinical and imagiological findings of central giant cell lesion and cherubism

Cone beam computed tomography (CBCT) is the best examination for bone lesions of the maxilla, allowing the dentist to evaluate precisely the behavior and components of the lesion and their relationship to the surrounding structures. Central giant cell lesion and cherubism are histologically very similar lesions. Therefore clinical and radiological examinations are fundamentally important for the diagnosis. The aim of this paper is to report two cases diagnosed as central giant cell lesions and cherubism using CBCT. This imaging modality was very important for the diagnosis of the lesions presented in the current study. It also allowed observing precisely the limits of the lesions, the components, the behavior and the exact relationship to adjacent structures.

A tomografia computadorizada de feixe cônico (TCFC) é o melhor exame para lesões ósseas da maxila, permitindo que o dentista possa avaliar com mais confiabilidade o comportamento, os componentes da lesão, e sua relação com estruturas adjacentes. A Lesão central de células gigantes e o querubismo são patologias muito semelhantes histologicamente, portanto, exames clínicos e radiológicos são de fundamental importância para o diagnóstico. O objetivo deste trabalho é relatar dois casos diagnosticados usando TCFC, um de lesões centrais de células gigantes e um de querubismo. Esta modalidade de imagem foi muito importante para o diagnóstico das patologias apresentadas neste estudo. Também permitiu observar com mais confiabilidade os limites das lesões, os componentes, o comportamento e a relação exata com as estruturas adjacentes.

Matrix metalloproteinases, tissue inhibitors of metalloproteinases, and growth factors regulate the aggressiveness and proliferative activity of keratocystic odontogenic tumors.

OBJECTIVE: The objective of this preliminary study was to evaluate the expression of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and growth factors in keratocystic odontogenic tumors (KOTs). STUDY DESIGN: The expression of MMPs, TIMPs, growth factors, and the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway were assessed by immunohistochemistry in 15 cases of KOT and 4 cases of calcifying cystic odontogenic tumor (CCOT). RESULTS: KOT samples expressed significantly higher amounts of MMPs, TIMPs, growth factors, epidermal growth factor receptor (EGFR), and ERK compared with CCOT samples, with the exception of MMP-2 and TIMP-1. CONCLUSIONS: MMP-9, TIMP-2, EGF and transforming growth factor α act together and likely regulate the proliferation and aggressiveness of KOT. ERK-1/2 serves as the transducer of signals generated by these proteins, which signal through the common receptor, EGFR. This process may be related to the increased proliferation and aggressiveness observed in KOT.

Laminin-111 derived peptides AG73 and C16 regulate invadopodia activity of a human adenoid cystic carcinoma cell line.

Adenoid cystic carcinoma is a frequently occurring malignant salivary gland neoplasm with high level of recurrence and distant metastasis long time after treatment. Metastatic tumor cells that actively migrate and invade surrounding tissues rely on invadopodia to degrade extracellular matrix (ECM) barriers. Invadopodia are actin-rich membrane protrusions that localize enzymes required for ECM degradation. Breakdown of ECM macromolecules releases fragments and bioactive peptides. We have already demonstrated that laminin-111 and its derived peptides regulate migration, invasion and protease activity of adenocarcinoma cells. Here we addressed the role of laminin-111 peptides AG73 and C16 in invadopodia activity of cells (CAC2) derived from human adenoid cystic carcinoma. CAC2 cells were treated by AG73 and C16, and subjected to fluorescent gelatin substrate degradation assay. In this assay invadopodia activity areas appear as black dots in a fluorescent background. Both peptides significantly increased invadopodia formation and activity compared to controls. We analyzed putative receptors and signaling pathways related to peptide effects. ß1 integrin silencing by siRNA decreased AG73- and C16-induced invadopodia. Furthermore inhibition of Rac1 and ERK signaling pathways decreased both C16- and AG73-related invadopodia activities. We propose that laminin-111 peptides AG73 and C16 increase invadopodia activity in CAC2 cells through ß1 integrin. Rac1 and ERK1/2 signaling pathways would transduce signals generated by both peptides.

Matrix metalloproteinases, TIMPs and growth factors regulating ameloblastoma behaviour.

AIMS: Ameloblastoma is an odontogenic neoplasm with local invasiveness and recurrence. We have previously suggested that growth factors and matrix metalloproteinases (MMPs) influence ameloblastoma invasiveness. The aim was to study expression of MMPs, tissue inhibitor of metalloproteinases (TIMPs) and growth factors in ameloblastoma. METHODS AND RESULTS: Thirteen cases of solid/multicystic ameloblastoma were examined. As a control, calcifying cystic odontogenic tumour (CCOT), a non-invasive odontogenic neoplasm with ameloblastomatous epithelium was also studied. Immunohistochemistry detected MMPs, TIMPs and growth factors in ameloblastoma and CCOT. The labelling index (LI) of MMP-9 and TIMP-2 was significantly higher in ameloblastoma compared with CCOT. The LI of epidermal growth factor (EGF), transforming growth factor (TGF)-alpha and epidermal growth factor receptor (EGFR) was also increased in ameloblastoma. This neoplasm showed greater expression of MMPs, TIMPs and growth factors compared with CCOT. We then analysed these molecules in ameloblastoma cells and stroma. Ameloblastoma cells exhibited increased LI of MMP-1, -2 and EGFR. We found a positive correlation between EGF and TIMP-1, and between TGF-alpha and TIMP-2. It is known that signals generated by growth factors are transduced by the ERK pathway. Ameloblastoma stroma exhibited the phosphorylated (activated) form of ERK. CONCLUSIONS: These results suggest an interplay involving growth factors MMPs and TIMPs that may contribute to ameloblastoma behaviour. Signals generated by this molecular network would be transduced by ERK 1/2 pathway.

Laminin-derived peptide AG73 regulates migration, invasion, and protease activity of human oral squamous cell carcinoma cells through syndecan-1 and beta1 integrin.

Squamous cell carcinoma is a prevalent head and neck tumor with high mortality. We studied the role played by laminin alpha1 chain peptide AG73 on migration, invasion, and protease activity of cells (OSCC) from human oral squamous cell carcinoma. Immunohistochemistry and immunofluorescence analyzed expression of laminin alpha1 chain and MMP9 in oral squamous cells carcinoma in vivo and in vitro. Migratory activity of AG73-treated OSCC cells was investigated by monolayer wound assays and in chemotaxis chambers. AG73-induced invasion was assessed in Boyden chambers. Invasion depends on MMPs. Conditioned media from cells grown on AG73 was subjected to zymography. We searched for AG73 receptors related to these activities in OSCC cells. Immunofluorescence analyzed AG73-induced colocalization of syndecan-1 and beta1 integrin. Cells had these receptors silenced by siRNA, followed by treatment with AG73 and analysis of migration, invasion, and protease activity. Oral squamous cell carcinoma expresses laminin alpha1 chain and MMP9. OSCC cells treated with AG73 showed increased migration, invasion, and protease activity. AG73 induced colocalization of syndecan-1 and beta1 integrin. Knockdown of these receptors decreased AG73-dependent migration, invasion, and protease activity. Syndecan-1 and beta1 integrin signaling downstream of AG73 regulate migration, invasion, and MMP production by OSCC cells.

Intraoral contact mucositis induced by cinnamon-flavored chewing gum--a case report.

Contact mucositis is an inflammatory mucosal reaction caused by many agents. A case of a 53-year-old man with contact-type allergy in oral mucosa due to cinnamon chewing gum is presented. This condition should be considered in the differential diagnosis of nonspecific oral lesions.

Integrated clinical treatment of gingival recession secondary to root perforation: case report.

Among the factors that influence the success of treatment of a root perforation, its location and possibility of contamination are determinant because the interaction of these 2 factors may result in significant periodontal injury. The management of cases of hard-to-reach contaminated perforations depends on the choice of an adequate technique. In the case reported in this article, controlled orthodontic tooth extrusion was successfully performed to treat gingival recession secondary to root perforation. The outcomes showed that this technique preserves the zone of attached gingiva, maintains the crown height, and prevents the involvement of the supporting bone tissue. The favorable clinical and radio?graphic conditions after 7 years of follow-up demonstrate the viability of this treatment approach.

SIKVAV, a laminin alpha1-derived peptide, interacts with integrins and increases protease activity of a human salivary gland adenoid cystic carcinoma cell line through the ERK 1/2 signaling pathway.

Adenoid cystic carcinoma is a frequently occurring malignant salivary gland neoplasm. We studied the induction of protease activity by the laminin-derived peptide, SIKVAV, in cells (CAC2) derived from this neoplasm. Laminin alpha1 and matrix metalloproteinases (MMPs) 2 and 9 were immunolocalized in adenoid cystic carcinoma cells in vivo and in vitro. CAC2 cells cultured on SIKVAV showed a dose-dependent increase of MMP9 as detected by zymography and colocalization of alpha3 and alpha6 integrins. Small interfering RNA (siRNA) knockdown of integrin expression in CAC2 cells resulted in decreased adhesion to the peptide. SIKVAV affinity chromatography and immunoblot analysis showed that alpha3, alpha6, and beta1 integrins were eluted from the SIKVAV column, which was confirmed by mass spectrometry and a solid-phase binding assay. Small interfering RNA experiments also showed that these integrins, through extracellular signal-regulated kinase (ERK) 1/2 signaling, regulate MMP secretion induced by SIKVAV in CAC2 cells. We propose that SIKVAV increases protease activity of a human salivary gland adenoid cystic carcinoma cell line through alpha3beta1 and alpha6beta1 integrins and the ERK 1/2 signaling pathway.