Aberrant expression of the tight junction molecules claudin-1 and zonula occludens-1 mediates cell growth and invasion in oral squamous cell carcinoma.

We reported that altered cell contact mediated by E-cadherin is an initial event in the pathogenesis of oral epithelial malignancies. To assess other effects of cell adhesion, we examined the expression levels of tight junction (TJ) molecules in oral carcinoma in situ (CIS) and squamous cell carcinoma (SCC). To identify changes in the expression of TJ molecules, we conducted an analysis of the immunohistochemical profiles of claudin-1 (CLDN-1) and zonula occludens-1 (ZO-1) in surgical specimens acquired from patients with oral SCC containing foci of epithelial dysplasia or from patients with CIS. We used immunofluorescence, Western blotting, reverse-transcription polymerase chain reaction, and RNA interference to evaluate the functions of CLDN-1 and ZO-1 in cultured oral SCC cells. TJ molecules were not detected in normal oral epithelial tissues but were expressed in SCC/CIS cells. ZO-1 was localized within the nucleus of proliferating cells. When CLDN-1 expression was inhibited by transfecting cells with specific small interference RNAs, SCC cells dissociated, and their ability to proliferate and invade Matrigel was inhibited. In contrast, although RNA interference-mediated inhibition of ZO-1 expression did not affect cell morphology, it inhibited cell proliferation and invasiveness. Our findings indicated that the detection of TJ molecules in the oral epithelia may serve as a marker for the malignant phenotype of cells in which CLDN-1 regulates proliferation and invasion.

Mandibular tori as bone grafts: an alternative treatment for periodontal osseous defects - clinical, radiographic and histologic morphology evaluation.

OBJECTIVES: The present study was designed to evaluate the clinical, radiographic and histochemical significance of using the mandibular tori as autogenous bone graft for treatment of intraosseous defects in patients with chronic periodontitis. MATERIALS AND METHODS: Twenty-eight sites from 14 patients with chronic periodontitis were included in this study. Each patient was treated with split mouth design; one site received torus mandibularis bone graft and the other site received a full-thickness fap alone. Histopathologic assessment was evaluated on removal of torus mandibularis to evaluate its histologic structure and by the end of the study 9 month later. Clinical and radiographic parameters were re-evaluated at 3 months interval for 1 year. RESULTS: The results of the present study revealed significant gain in the clinical attachment level (CAL) (88.4%, 4.53 ± 0.06 mm) for torus mandibularis sites compared to (39.7%, 2.01 ± 0.04 mm) for full-thickness fap. Moreover, there was a reduction in the probing pocket depth (PPD) of (75.4%, 5.75 ± 0.12 mm) for torus mandibularis sites and (49.6%, 3.73 ± 0.14 mm) for sites treated with a full-thickness fap only; CAL and PPD differences were significant at p-value ≤0.01. Concomitantly, significant radiographic increase in the bone height and density were recorded in the test group. CONCLUSION: The use of mandibular tori as autogenous bone graft could provide benefits as a periodontal therapeutic modality and enhance regenerative potential of periodontal intraosseous defects.

Radiation-induced undifferentiated high-grade pleomorphic sarcoma (malignant fibrous histiocytoma) of the mandible: report of a case arising in the background of long-standing osteomyelitis with a review of the literature.

We report a rare case of radiation-induced undifferentiated high-grade pleomorphic sarcoma (UPS) (malignant fibrous histiocytoma, MFH) in the right mandible of a 44-year-old woman. The patient had suffered from osteomyelitis of the same region of the mandible for several years, which was considered to be due to radiotherapy for a malignant lymphoma in her right neck 19 years before. The tumor appeared as an exophytic and invasive growth in the molar region of the mandible. Histopathologically, the tumor consisted of an interlacing proliferation of vimentin-immunopositive spindle-shaped fibroblastic cells with bizarre nuclei with high Ki-67 labeling scores, and tumor cells showed storiform patterns mixed with pleomorphic cells. Taking the history of radiation into consideration, we diagnosed the lesion as radiation-induced MFH/UPS. Including the present case, there have been only 14 documented cases of radiation-induced UPS in the jawbone, and this is the first UPS case arising in the follow-up period of long-standing osteomyelitis.

Biological impact of vascular endothelial growth factor on vessel density and survival in multiple myeloma and plasmacytoma.

We compared the differences in a number of angiogenesis-related immunohistochemical parameters, including microvascular density (MVD) and tumor cell activity, between multiple myeloma (MM) and solitary plasmacytoma (SP). Tissue sections from tumors of MM and SP were immunohistochemically stained and analyzed using ImageJ image analysis software for the expression of vascular endothelial growth factor (VEGF), VEGF receptors (Flt-1 and Flk-1), inducible nitric oxide (iNOS), and anti-apoptotic (Bcl-2) protein. Tumor tissues were cytologically graded as high-, intermediate-, or low-grade. Two pathologists determined the MVD of each section independently by recording the average number of CD34+ blood vessels in 500 unit fields. The arithmetic means for MVD were statistically analyzed using the Student's t-test and the significance level was calculated at P-value <0.001. The results indicate a direct correlation between upregulation of iNOS/VEGF in high-grade tumors. For MM, an increase in MVD is also correlated with a high-grade. Tumor survival signaling by Bcl-2 in both SP and MM emphasizes the fact that VEGF has a bimodal role that is mainly angiogenic in MM and tumorigenic, promoting tumor cell survival in SP.

The pathogenic role of Epstein-Barr virus (EBV) in sclerosing polycystic adenosis.

Sclerosing polycystic adenosis (SPA) is a pathology of the salivary gland which occurs infrequently and has a controversial etiology. In this study, we investigated the possible roles of HPV and EBV in the pathogenesis of SPA. Archived cases of salivary gland lesions were retrieved, and their diagnoses were re-evaluated; cases that fit the diagnosis of SPA were selected and subjected to Alcian Blue-Periodic Acid Schiff's histochemical staining and immunohistochemical staining for HPV-1, EBV, S-100, and Bcl-2 proteins in addition to the proliferative marker Ki-67. In addition, RNA extracted from formalin-fixed, paraffin-embedded tissues was subjected to RT-PCR to confirm any positive immunohistochemical results. Co-localization of EBV and Bcl-2 in lesional cells was the most striking finding; Ki-67 was expressed in basal cells, while no expression was seen in the adjacent salivary gland cells. Our EBV (+) ve immunostaining results were confirmed by RT-PCR using RNA extracted from paraffin sections. Our results suggest a significant pathogenic role of EBV in SPA. Moreover, they provide new evidence on the neoplastic nature of SPA.

Oral solitary fibrous tumor: a cytogenetic analysis of tumor cells in culture with literature review.

Solitary fibrous tumor (SFT) is an uncommon spindle-cell neoplasm of mesenchymal origin. Because the pathogenetic background of SFT is still controversial, cytogenetic analysis could help in tumor diagnosis and prognosis. In this study, cultured SFT cells from a lower lip lesion that presented characteristic immunopositivity for CD34, vimentin, CD99, and BCL2 showed a unique cytogenetic finding: 46,XX,inv(2)(p21q35),t(3;12)(q25;q15). To our knowledge, this is the third report of cytogenetic result of a case involving the oral cavity. The SFT cells in culture that maintained their immunohistochemical expression of diagnostic molecules, showed unique chromosomal changes previously unreported when compared with already documented ones. Our data suggest that the complicated pathogenetic nature of SFT is possibly tumor- or organ-related.

Perlecan, a basement membrane-type heparan sulfate proteoglycan, in the enamel organ: its intraepithelial localization in the stellate reticulum.

The localization and biosynthesis of perlecan, a basement membrane-type heparan sulfate proteoglycan, were studied in developing tooth germs by using murine molars in neonatal and postnatal stages and primary cultured cells of the enamel organ and dental papilla to demonstrate the role of perlecan in normal odontogenesis. Perlecan was immunolocalized mainly in the intercellular spaces of the enamel organ as well as in the dental papilla/pulp or in the dental follicle. By in situ hybridization, mRNA signals for perlecan core protein were intensely demonstrated in the cytoplasm of stellate reticulum cells and in dental papilla/pulp cells, including odontoblasts and fibroblastic cells in the dental follicle. Furthermore, the in vitro biosyntheses of perlecan core protein by the enamel organ and dental papilla/pulp cells were confirmed by immunofluorescence, immunoprecipitation, and reverse transcriptase-polymerase chain reaction. The results indicate that perlecan is synthesized by the dental epithelial cells and is accumulated in their intercellular spaces to form the characteristic stellate reticulum, whose function is still unknown.

Vascular endothelial growth factor in salivary pleomorphic adenomas: one of the reasons for their poorly vascularized stroma.

To better understand the poorly vascularized background of the stroma of pleomorphic adenomas, we attempted to determine the expression of molecules related to blood vessels and hypoxic conditions in pleomorphic adenoma. Surgical specimens and tumor cells in primary culture of salivary pleomorphic adenomas were used for immunohistochemistry for CD31, vascular endothelial growth factor (VEGF) and its receptors Flk-1 and Flt-1, as well as for hypoxia markers, such as hypoxia-inducible factor-1alpha (HIF-1alpha) and lactate dehydrogenase-1 (LDH). At the same time, alternative splicing modes of the VEGF gene and expression levels of the HIF-1alpha gene were analyzed in surgical specimens by means of reverse-transcription polymerase chain reaction (RT-PCR) and direct sequencing of the PCR products. In addition to co-immunolocalization with CD31+ vascular endothelial cells, VEGF and its receptors were demonstrated in normal duct epithelial and myoepithelial cells as well as in tumor cells in ductal structures and in myxochondroid stromata. Immunolocalizations for HIF-1alpha and LDH were confirmed in the VEGF-positive area. Immunofluorescence signals for VEGF and others were confirmed in pleomorphic adenoma cells in culture. RT-PCR results showed that there were at least four splicing modes of the VEGF gene, among which VEGF(121) was most enhanced, and higher HIF-1alpha levels in pleomorphic adenomas. The results suggest that pleomorphic adenoma cells produce VEGF in several functional forms for their own proliferation or differentiation, and that the VEGF expression is controlled by hypoxic circumstances of poorly vascularized pleomorphic adenomas.

Angiogenesis in mucous retention cyst: a human in vivo-like model of endothelial cell differentiation in mucous substrate.

BACKGROUND: Mucous retention cysts contain a mucous pool in the lumina, in which pure angiogenic processes are occasionally observed. By using this unique human material, our aim was to understand the in vivo angiogenic process. METHODS: Fifteen surgical tissue samples of mucous retention cysts of the lip were examined for expression of vascular endothelial markers and extracellular matrix molecules by immunohistochemistry and in situ hybridization (ISH). RESULTS: Endothelial cells forming new vascular channels showed immunopositivities for CD31, CD34, vascular endothelial growth factor (VEGF), and von Willebrand factor (vWF). These newly formed capillaries were surrounded by tenascin-positive matrices and further by a dense infiltration of CD68-positive cells with foamy to epitheloid appearances. Some of these cells were simultaneously positive for CD34, VEGF, and one of its receptors, Flk-1, and they showed definite mRNA as well as protein signals for tenascin. In addition, these cells often tended to be aligned, which suggested tubule formation. CONCLUSION: The results suggest that monocyte/macrophage lineage cells are a major source for endothelial cells at least in mucous retention cysts and that tenascin produced by those cells plays an important role in differentiation of endothelial cells.

Angiolipoma of the buccal mucosa: a possible role of mast cell-derived VEGF in its enhanced vascularity.

A case of angiolipoma occurring in the buccal mucosa of a 69-year-old male is described. The patient had noticed a painless mass in his buccal mucosa for 2 years. The surgically removed tumor, measuring 9 mm in diameter, was mainly located in the submucosal layer with focal expansion into the muscle layer. Histologically, the tumor was well-demarcated and composed of proliferations of mature fat cells and fibrous connective tissue containing many small blood vessels, which were evenly distributed. There was diffuse infiltration of a large number of mast cells, which were immunopositive for vascular endothelial growth factor (VEGF) especially around blood vessels, suggesting that VEGF produced by mast cells in angiolipomas plays an important role in the vascular proliferation in this particular tumor.