Co-overexpression of Bag-1 and heat shock protein 70 in human epidermal squamous cell carcinoma: Bag-1-mediated resistance to 5-fluorouracil-induced apoptosis.

BACKGROUND: The aim was to determine whether Bcl-2-associated athanogene-1 (Bag-1) and/or its binding protein heat shock protein-70 (Hsp70) exhibit deregulated expression in epidermal squamous cell carcinoma (SCC) and whether Bag-1 confers apoptosis resistance. METHOD: Immunohistochemistry for Bag-1 and Hsp70 was performed on 60 epidermal SCC and 10 normal skin samples. The epidermal SCC cell line SCC-13 was treated with 5-fluorouracil (5-FU) after Bag-1 knockdown to determine whether high Bag-1 levels contribute to growth and/or apoptosis resistance. RESULTS: Normal epithelium expressed primarily nuclear Bag-1. Most tumours showed reduced nuclear Bag-1 staining, but a subset exhibited strong Bag-1 staining, with cytoplasmic Bag-1 staining intensity correlating with cytoplasmic Hsp70 staining intensity (r(s)=0.462; P<0.001) and less differentiation (P<0.001). Bag-1 knockdown resulted in markedly reduced SCC-13 cell yield, increased spontaneous apoptosis and enhanced sensitivity to 5-FU-induced apoptosis. Apoptosis induced by 5-FU in the Bag-1-knockdown cells was significantly greater than the additive apoptotic effect of 5-FU or Bag-1 knockdown alone. CONCLUSIONS: Overexpression of Bag-1 and Hsp70 in poorly differentiated SCC may confer both enhanced tumour cell growth and apoptosis resistance. Bag-1 may contribute to the resistance of more advanced epidermal SCC to chemotherapy.

Metastatic dissemination of human malignant oral keratinocyte cell lines following orthotopic transplantation reflects response to TGF-beta 1.

This study examined the behaviour of nine human malignant oral keratinocyte cell lines following orthotopic transplantation to the floor of the mouth of athymic mice. Tumourigenesis, local spread, and metastatic dissemination were correlated with known cellular responses to transforming growth factor-beta 1 (TGF-beta 1). Six of nine cell lines were tumourigenic; four of these cell lines showed local spread which was characterized by vascular and bone invasion. Metastatic spread was uncommon, with only 9% of animals with primary tumours developing metastases and these were almost exclusively found in the regional lymph nodes; there was one pulmonary metastasis and no liver deposits. Tumour cell behaviour did not reflect the clinical stage of the original tumours. Cell lines that were resistant to TGF-beta 1-induced growth inhibition were more likely to form primary tumours, exhibit local spread, and metastasize than cells that were growth-inhibited by the ligand. The data demonstrate that tumourigenicity and tumour behaviour in this orthotopic mouse model varied between cell lines and that the pattern of local invasion and metastasis was similar to that seen in human oral cancer. Furthermore, cell lines that were refractory to the growth inhibitory effects of TGF-beta 1 behaved more aggressively than cells that underwent ligand-induced cell-cycle arrest.

Salivary gland basal cell adenocarcinoma: a report of cases in a cat and two dogs.

Basal cell adenocarcinoma of the salivary gland is described in a cat and two dogs; tumour tissue was characterized by cords and islands of epithelial cells with a distinct basal layer. The tumours were stained by various immunohistochemical methods. In addition to positive staining with cytokeratin 14 and pancytokeratin (CKs 5, 6, 8, 17 and 19), there was also staining with Jack bean agglutinin A (ConA) and soya bean agglutinin (SBA); this occurs in many other types of salivary gland tumours and is a feature of normal salivary gland acinar cells. In one dog there was also staining with SBA. This is the first report of this tumour in domestic animals; the immunohistochemical characteristics did not distinguish it from other salivary gland tumours.

Intramuscular capillary hamartoma of the tongue.

Intramuscular vascular lesions in the tongue are rare and are usually the capillary form of haemangioma. A case is described of a lingual mass that resembled intramuscular haemangioma but had unique histological features that do not appear to have been described previously. The term intramuscular capillary hamartoma is suggested to describe it.

Oral epithelial dysplasia: clinical characteristics of western European residents.

To detail the clinical presentation of oral epithelial dysplasia in a large cohort of residents in western Europe. Descriptive statistical analysis of the data were calculated using chi-square and Fisher's exact tests. Oral epithelial dysplasia manifested typically as a white or mixed red and white lesion on the tongue, buccal mucosa or floor of mouth. The peak age of presentation of oral epithelial dysplasia was the 6th decade. Most clinically detected lesions had only mild oral epithelial dysplasia. Although uncommon, lesions with severe dysplasia were most likely to arise on the floor of mouth or lateral border of tongue. Oral epithelial dysplasia is likely to manifest as a solitary white patch, but it is not possible to accurately predict the likely degree of dysplasia from the clinical features of such lesions.

A study of the clinical characteristics of benign trigeminal sensory neuropathy.

PURPOSE: The purpose of this study was to describe the clinical characteristics of a series of patients presenting with benign trigeminal sensory neuropathy. PATIENTS AND METHODS: We conducted a retrospective analysis of the clinical and pathologic characteristics of 23 patients presenting with facial numbness of unknown etiology. RESULTS: Patients presented with diverse medical histories but could be grouped into those with a connective tissue disorder, neurologic disease, psychologic problems, or a medical history of unknown significance. The age of the patient, the severity and distribution of the trigeminal neuropathy, and symptoms other than neuropathy closely reflected the patient's medical history. The majority of patients underwent magnetic resonance imaging, but the results did not facilitate the diagnosis of the condition or reflect the extent and severity of the symptoms. In 60% of patients, the symptoms remained unchanged during the course of the study and outcome was not influenced by medical treatment. CONCLUSIONS: The diagnosis and management of benign trigeminal sensory neuropathy remain a significant clinical challenge.

Focal acantholytic dyskeratosis arising in an intraoral skin flap.

A case is described of a patient with a myocutaneous pectoralis major flap who presented with an oral lesion of focal acantholytic dyskeratosis that was clinically suspicious of recurrent tumour.

Sebaceous carcinoma of the salivary gland in a cat.

Sebaceous carcinoma of the submandibular salivary gland is described in a cat, tumour cells were characterized histologically by moderate amounts of pale eosinophilic or vacuolated cytoplasm. Tumour cells were stained with antibody to cytokeratins (CKs 5. 6, 8, 17 and 19) and with lectins Con A and wheat germ agglutinin (WGA); this occurs in many other types of salivary gland tumour and is a feature of normal salivary gland acinar cells.

Parotid Warthin's tumour Bristol Royal Infirmary (1985-1995): a study of histopathology in 33 cases.

This is a study of 33 (32 patients) confirmed Warthin's tumours (adenolymphomas) treated surgically at Bristol Royal Infirmary (1985--1995) focussing specifically upon 17 salient histopathological features together with capsular measurement by micrometry. Twenty-four out of 33 tumours had 'thin' capsules (< or = 200 microm), whereas 5/9 'thick' capsules were associated with gross tumour degeneration. The degenerative features including cystic change, squamous metaplasia, corpora amylacea like bodies, etc. were quantified. Tumours were classified into subtypes (typical, stroma poor, etc). These variations were not associated with age or sex. In 20/33 tumours a marginal sinus suggested a lymph node origin. Fine needle aspiration cytology (FNA) smears showing degeneration features are a diagnostic problem, but histopathological features are reflected in such smears and their recognition enhances diagnostic precision, enabling controlled surgical enucleation, the ideal operation, to be performed in most cases. In this study only 12 tumours were so treated; 11 others received parotidectomy. The theories of histogenesis are reviewed and discussed.

Pleomorphic adenomas of the major salivary glands: a study of the capsular form in relation to surgical management.

This was a retrospective study of 126 primary pleomorphic adenomas to correlate capsular characteristics with tumour histopathology in relation to current surgical debate (parotidectomy versus local excision). Capsular thickness was measured by micrometry and tumours classified into subtypes (1-4). Evidence of fine needle aspiration damage (needle tracks, infarction) was sought. Minimal changes were seen in eight tumours. Tumour growth features (bosselations, enveloping) were present in 57% and 33%, respectively, also microinvasion (42%) and tumour 'buds' (12%). Parotid lesions possessed thicker capsules than submandibular tumours. There was little correlation between capsular thickness and cellular structure. The significant exception was large (> 25 mm) hypocellular parotid tumours which had thinner capsules and could be vulnerable to operative rupture. In 110 standard operations (parotidectomy, submandibular gland excision), capsular exposure was evident in 81%. Field irrigation is recommended to lessen the risk of tumour seeding. This study reaffirms many elements of capsular weakness and suggests that parotidectomy is the operation of choice.

Overexpression of JunB in undifferentiated malignant rat oral keratinocytes enhances the malignant phenotype in vitro without altering cellular differentiation.

Our study examined the expression of AP-1 family members in keratinocytes derived from the rat-4NQO model of oral carcinogenesis in which extremes of epithelial differentiation and tumour cell aggressiveness are evident. The constitutive expression of JunB was diminished in the undifferentiated, more aggressive tumour phenotype compared with the well-differentiated, less aggressive keratinocytes, whereas the expression of other AP-1 family members (c-jun, junD, c-fos, fra1, fra2 and fosB) was either very weak or variable. After transfection of the undifferentiated keratinocytes with junB cDNA, clonal populations were isolated that expressed similar levels of JunB protein as the well-differentiated cells. Both untransfected and transfected cell lines were keratin negative and vimentin positive. Increased expression of JunB in the transfected cells resulted in up-regulation of c-Jun and Fra1 and an enhanced AP-1 activity as demonstrated by transcriptional activation of the prototypic AP-1 dependent promoter, MMP-1. JunB transfected cells grew more quickly than vector-only controls and were refractory to the growth inhibitory effects of TGF-beta1. Over-expression of JunB resulted in the elevated expression of the AP-1 dependent proteinase, MMP-9, whereas the expression of the AP-1 independent enzyme, MMP-2, was unaffected. JunB transfected keratinocytes were highly invasive in an in vitro assay of tumour cell invasion compared with vector controls. The results indicate that increased expression of JunB above baseline levels in undifferentiated rat keratinocytes does not alter epithelial differentiation but enhances the malignant phenotype in vitro, possibly by altering the dynamics of the AP-1 complex.

Oral mucosal non-Hodgkin's lymphoma--a dangerous mimic.

Reports of T-cell lymphomas in the oral cavity are rare. Most have presented as a persisting ulcerated swelling. This paper reports two men, one of whom presented with a short history of increasing facial swelling and pain apparently related to a lower premolar tooth, and the other who had recurrent oral ulceration in several sites over a period of years. These types of cases are likely to present initially to general dental practitioners.

Endogenous TGF-beta1 inhibits the growth and metastatic dissemination of rat oral carcinoma cell lines but enhances local bone resorption.

This study examined the effect of stable transfection of latent transforming growth factor-beta1 (TGF-beta1) cDNA into a predominantly polygonal, 4 nitroquinoline N-oxide (4NQO)-induced rat oral keratinocyte cell line. Seven polygonal and five spindle clonal populations were isolated that overexpressed TGF-beta1 protein by approximately two- to four-fold compared to vector-only transfected controls. Neutralisation experiments indicated that the majority of protein was in the latent form. There was no change in the proportion of polygonal and spindle cells in vitro after transfection with TGF-beta1 cDNA. Polygonal and spindle cells that overexpressed TGF-beta1 produced similar amounts of protein and grew more slowly in vitro than controls. The parent cell line and all transfected cells were growth inhibited (60-75%) by exogenous TGF-beta1. Orthotopic transplantation of the parent and the vector-only control cell lines resulted in primary tumours in the floor of the mouth in almost 100% (20/21) of athymic mice, with no evidence of bone resorption at the site of the primary tumour and pulmonary metastatic tumour deposits in some 40% (7/20) of these animals. The polygonal and spindle cells that overexpressed TGF-beta1 behaved similarly following orthotopic transplantation. A 96% (23/24) primary tumour take was evident following transplantation of cells that overexpressed TGF-beta1, with a significantly (P<0.02) higher number of animals showing bone resorption at the site of the primary tumour (35%; 8/23) compared to controls. By contrast, there was a significant (P<0.03) decrease in the number of animals with pulmonary metastases (4%; 1/23) following transplantation of TGF-beta1 overexpressing cells compared to controls. Overexpression of TGF-beta1 did not alter tumour cell differentiation in vivo. The results demonstrate that endogenous TGF-beta1 functions as a tumour suppressor in the rat-4NQO model of oral carcinogenesis without altering tumour cell morphology or differentiation but can also act to promote local bone resorption.

Salivary duct carcinoma in five cats.

Carcinomas of salivary gland ducts are described in five cats. The typical histological pattern was the formation of large cell aggregates resembling dilated ducts, often with central necrosis and a looping pattern. All tumours were labelled with antibody to cytokeratins (CKs) 5, 6, 8, 14, 17 and 19. Labelling of tumour cells with CK14 suggested basal cell differentiation. All tumours stained with Jack bean (Canavalia ensiformis) agglutinin (Con A); this is a feature of normal salivary gland ducts but is seen in other salivary gland tumours. Staining of tumour cells at the luminal surface of ductal structures with wheat germ (Triticum vulgaris) agglutinin (WGA) in the cat tumours was similar to that seen in ducts of normal cat salivary glands but occurs in other cat tumours. Other immunohistochemical staining results were unremarkable. 1999 Harcourt Publishers Ltd.

Loss of differentiation of 4NQO-induced rat malignant oral keratinocytes correlates with metastatic dissemination and is associated with a reduced cellular response to TGF-beta1 and an altered receptor profile.

This study examined the metastatic capacity of clonal populations of 4NQO-induced rat malignant oral keratinocytes following orthotopic transplantation to athymic mice. Polygonal and spindle cells formed well-differentiated squamous cell carcinomas (keratin positive and vimentin negative) and undifferentiated spindle cell tumours (keratin negative and vimentin positive), respectively, in almost 100% of animals at the site of inoculation (floor of mouth). Transplantation of 5x 10(6) cells of either cell type at high cell density resulted in approximately 50% of animals forming pulmonary metastases. By contrast, inoculation of 2x 10(6) differentiated polygonal cells resulted in the formation of significantly fewer pulmonary metastases than the undifferentiated spindle cells. A single well-differentiated clone of polygonal cells and 3 of 4 of the undifferentiated spindle cell lines produced comparable levels of TGF-beta1. One undifferentiated spindle cell line expressed significantly more TGF-beta1 and, following transplantation orthotopically, fewer animals formed pulmonary metastases despite the formation of primary tumours in almost all grafted animals, suggesting that TGF-beta1 can act as a tumour suppressor in this cell type. All cell lines produced comparable amounts of TGF-beta2. The clones of polygonal cells were markedly inhibited and the spindle cells were only partially inhibited by exogenous TGF-beta1. Both cell types expressed high-affinity TGF-beta cell surface receptors; the ratio of type I to type II TGF-beta receptors was 1.0:<3.0 in the spindle cells and 1.0:17.9 in the polygonal clone. The results suggest that differentiated rat malignant oral keratinocytes are less aggressive and have a decreased potential to metastasise than their undifferentiated spindle cell counterparts. This may be attributable, in part, to a change in TGF-beta receptor profile leading to the partial loss of response to exogenous TGF-beta1.

Adenosquamous carcinoma of the mouth: a rare variant of squamous cell carcinoma.

Adenosquamous carcinoma is a rare tumour in the oral cavity and is characterised histologically by carcinomatous change in surface epithelium, in association with adenocarcinoma affecting the ducts of minor salivary glands. Only a dozen cases have previously been reported in the oral cavity, but all have shown an aggressive course with 60% of patients dying of disease. We report three further cases and review the literature, which suggests that this lesion should be regarded as a high-grade variant of squamous cell carcinoma.

Cytokeratin immunostaining in normal dog major and minor salivary glands.

Immunohistochemical staining, with a monoclonal antibody specific for cytokeratins 5, 6, 8, 17 and 19 of dog submandibular, sublingual, parotid, palatine, tongue and zygomatic salivary glands resulted in staining of myoepithelial cells, duct epithelial cells (including intercalated, striated and secretory ducts) and some acinar epithelial cells. Differences in acinar staining between glands reflected the predominance of serous or mucous cells. Acinar epithelial staining was confined to serous cells in sublingual and zygomatic glands and in some parotid glands; serous cells in other parotid glands, and serous demilunes in submandibular, tongue and palatine glands, were unstained. Mucous cells were not stained in any of the glands.

Langerhans cell histiocytosis presenting as bilateral eosinophilic granulomata in the molar region of the mandible. A case report.

Eosinophilic granuloma represents one of a triad of lesions encompassing a disease under the generic name, histiocytosis X or Langerhans cell histiocytosis. Localised eosinophilic granuloma, multifocal eosinophilic granuloma, Hand-Schüller-Christian disease, and the most malignant form of histiocytosis, Letterer-Siwe disease, can all present as destructive bony lesions of the jaws. The present case was a 30-year-old man who presented with almost total destruction of the periodontal support to the left and right mandibular, 1st and 2nd molars. Whereas the radiographic features were typical of eosinophilic granuloma, the clinical appearance and mirror image presentation were unusual.

Overexpression of autocrine TGF-beta 1 suppresses the growth of spindle epithelial cells in vitro and in vivo in the rat 4NQO model of oral carcinogenesis.

We examined the effect of the stable transfection of latent TGF-beta 1 cDNA, under the control of a cytomegalovirus promoter in the expression vector pcDNA3, into a 4NQO-induced clonal rat oral keratinocyte cell line that formed undifferentiated spindle cell tumours following subcutaneous transplantation to athymic mice. Test cells containing latent TGF-beta 1 cDNA produced a 2.3-fold increase in TGF-beta 1 protein compared to pcDNA3 controls as demonstrated by ELISA. Neutralisation experiments indicated that the majority of the protein was in the latent form. Untransfected and transfected (containing either TGF-beta 1 cDNA or pcDNA3) cell lines were keratin negative and vimentin positive. Cells transfected with TGF-beta 1 were inhibited more than pcDNA3 controls when cultured in an anchorage dependent or independent environment. Subcutaneous transplantation of cells overproducing TGF-beta 1 resulted in tumours of significantly smaller volume than vector-only controls. Further, orthotopic transplantation of cells containing TGF-beta 1 cDNA to the floor of the mouth in athymic mice markedly inhibited the development of pulmonary metastases compared to vector-only controls. Both test and control cell lines in athymic mice formed undifferentiated tumours with a complete absence of keratin elaboration. Subcutaneous xenografts were recultured and cells containing the TGF-beta 1 cDNA produced a similar amount of TGF-beta 1 peptide as the cells containing pcDNA3 only. The production of TGF-beta 1 by both of the xenograft-derived cell lines was significantly less than the parent, pre-transplanted cell lines and the untransfected cell line. All of the cell lines were inhibited by exogenous TGF-beta 1. Our results demonstrate that autocrine TGF-beta 1 functions as a tumour suppressor in vitro and in vivo in 4NQO-induced spindle tumour cells that are growth inhibited by the ligand. Furthermore, tumour formation in athymic mice is associated with selection for a cell phenotype with diminished autocrine TGF-beta 1 production.