Search

Transforming growth factor-β (TGF-β) is known to act as a tumour suppressor early in carcinogenesis, but then switches to a pro-metastatic factor in some late stage cancers. However, the actions of TGF-β are context dependent, and it is currently unclear how TGF-β influences the progression of human squamous cell carcinoma (SCC). This study examined the effect of overexpression of TGF-β1 or TGF-β2 in Ras-transfected human malignant epidermal keratinocytes that represent the early stages of human SCC. In vitro, the proliferation of cells overexpressing TGF-β1 or TGF-β2 was inhibited by exogenous TGF-β1; cells overexpressing TGF-β1 also grew more slowly than controls, but the growth rate of TGF-β2 overexpressing cells was unaltered. However, cells that overexpressed either TGF-β1 or TGF-β2 were markedly more invasive than controls in an organotypic model of SCC. The proliferation of the invading TGF-β1 overexpressing cells in the organotypic assays was higher than controls. Similarly, tumours formed by the TGF-β1 overexpressing cells following transplantation to athymic mice were larger than tumours formed by control cells and proliferated at a higher rate. Our results demonstrate that elevated expression of either TGF-β1 or TGF-β2 in cells that represent the early stages in the development of human SCC results in a more aggressive phenotype.

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 (rs=0.462; P

It is now generally accepted that TGF-β acts as a pro-metastatic factor in advanced human breast cancer. However, it is well documented, that TGF-β is context dependent, and whether the TGF-β pathway switches to promote metastasis during the progression of squamous cell carcinoma (SCC) is unknown. This study examined the role of TGF-β signalling in SCC using a series of genetically related keratinocyte cell lines representing later stages of the disease, stably transduced with a dominant negative TβRII cDNA (dnTβRII). We demonstrated that clones expressing dnTβRII lost their growth inhibitory response to TGF-β in vitro, while ligand expression remained unchanged. Following transplantation of transduced cells to athymic mice in vivo, we showed that attenuation of the TGF-β signal resulted in a loss of differentiation and increased metastasis. In human tissue samples loss of TGF-β signal transduction as measured by pSmad2 activity also correlated with a loss of differentiation. Id1, previously shown to be down regulated by TGF-β, an inhibitor of differentiation and associated with metastasis, was weakly expressed in focal areas of a small number of human tumours but expression did not correlate with low levels of pSmad2. Our data demonstrate that TGF-β does not switch to promote metastasis in late stage human SCC of the skin and that inhibition of TGF-β signalling results in a loss of differentiation and increased metastasis in the later stages of this disease.

Squamous cell carcinomas (SCC) of minor salivary gland origin are extremely rare. We present an unusual case of a 29-year-old female patient who presented with a well-differentiated SCC of minor salivary gland origin arising in the lower lip. Wedge resections of the lip, including bilateral mental nerve excision, were required to clear the tumor because of striking pathological evidence of perineural invasion distant from the primary tumor site.

Diffuse, non-inflammatory, non-neoplastic enlargement of the major salivary glands (sialosis) is uncommon and has various systemic causes. This paper examines 35 patients whose persistent swelling of the parotid was diagnosed as sialosis, and shows that diabetes mellitus and alcoholism are the most common causes.

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

Radial forearm free flaps are used routinely to reconstruct oro-facial tissues following resection of oral squamous cell carcinoma. Surprisingly, there is little information regarding their behaviour following engraftment. The present report is a clinico-pathological study of 10 patients who had incisional biopsies of cutaneous free flaps after the presence of a white patch or erythema raised clinical suspicion. Tissues were stained with haematoxylin and eosin, diastase-periodic acid-Schiff reagent and labelled immunohistochemically for Ki-67 and p53. Four of 10 specimens showed severe epithelial dysplasia within the graft, which was contiguous with dysplasia in the adjacent oral mucosa; the remaining grafts had features typical of candidosis (n=4) or hyperkeratosis (n=2). Grafts with dysplasia had a significantly higher Ki-67 labelling index than lesions in the 'non-dysplastic' group. There were no significant differences in the Ki-67 labelling index between areas of dysplasia in the graft and areas of dysplasia in the adjacent oral epithelium. p53 staining was present in all strata of the epithelium in the dysplastic grafts and adjacent dysplastic mucosa, but was absent or weakly expressed in the stratum basale of grafts showing reactive changes only. None of the dysplastic lesions progressed to carcinoma despite a mean follow-up period of 32 months; one patient developed a recurrent mucosal tumour at the resection margin. These observations indicate that cutaneous free flaps grafted to a site of field cancerisation can develop severe epithelial dysplasia with concomitant deregulation of proliferation and increased p53 expression. Such changes raise the possibility that these lesions have the potential for malignant transformation.

Summary The histopathology of the salivary glands is a complex and difficult area of diagnostic pathology. In the latest WHO classification there are 40 named neoplasms many of which have variable histological features that can challenge even the most experienced specialist pathologist. In addition, the salivary glands can be affected by a range of non-neoplastic conditions, some of which have only recently been described. These often present clinically like tumours and may have pathological features similar to some of the neoplasms, making diagnosis difficult and errors serious. The purpose of this paper is briefly to review non-neoplastic lesions of the salivary glands and to aid the diagnostic pathologist by describing the key histopathological features of each. The entities covered include: sclerosing polycystic adenosis, cheilitis glandularis, salivary gland hyperplasias, necrotizing sialometaplasia, subacute necrotizing sialadenitis, non-neoplastic oncocytic lesions, salivary gland cysts, lymphoepithelial cysts, polycystic (dysgenetic) disease and HIV associated cystic disease.

We examined the effect of stable transfection of dominant negative TbetaR-II (dn TbetaR-II) cDNA in a human oral carcinoma cell line that contained normal Ras and was growth inhibited by TGF-beta1. Two clonal cell lines containing dn TbetaR-II were isolated and compared to the vector-only control and parent cell line. The treatment of cells with exogenous TGF-beta1 resulted in a decrease in ligand-induced growth inhibition and loss of c-myc downregulation in test cells compared to controls; transcriptional activation of certain genes including fra-1 and collagenase was retained. Cells containing dn TbetaR-II grew faster in monolayer culture, expressed less keratin 10 and exhibited increased motility and invasion in vitro compared to control cell lines. Endogenous TGF-beta1 production and the regulation of MMP-2 and MMP-9 by TGF-beta1 remained unchanged. After orthotopic transplantation to the floor of the mouth in athymic mice, cells containing dn TbetaR-II formed comparable numbers of primary tumours at the site of inoculation as controls but the tumours were less differentiated as demonstrated by the absence of keratin 10 immunostaining. Further, metastatic dissemination to the lungs and lymphatics was more evident in grafts of cells containing dn TbetaR-II than controls. Taken together, the results demonstrate that attenuation of TGF-beta signalling through transfection of dn TbetaR-II cDNA leads to an enhanced growth rate, a loss of tumour cell differentiation and an increase in migration and invasion, characteristics that corresponded to the development of the metastatic phenotype.

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.

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. © 2003 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 61:325-332, 2003

This study examined the role of TGF-beta1 in human keratinocyte malignancy. Two carcinoma-derived human oral keratinocyte cell lines, BICR 31 and H314, were selected on the basis of their known resistance to TGF-beta1-induced G(1) arrest, the presence of wild type TGF-beta cell surface receptors and normal Ras. Smad 4 protein was undetectable in both cell lines, but Smad 2 and Smad 3 were expressed at levels comparable with a fully TGF-beta responsive cell line, and treatment of the cells with TGF-beta1 resulted in the phosphorylation of Smad 2. Treatment with exogenous TGF-beta1 resulted in a failure to induce transcription from an artificial Smad-dependent promoter and a failure to down-regulate c-myc, but resulted in an up-regulation of AP-1 associated genes (Fra-1, JunB and fibronectin). Transient transfection of Smad 4 into BICR 31 restored TGF-beta1-induced growth inhibition and Smad-dependent transcriptional activation. Protracted treatment of cells with exogenous TGF-beta1 resulted in the attenuation of cell growth in vitro. To over-express TGF-beta1, both cell lines were transfected with latent TGF-beta1 cDNA; neutralization studies of conditioned media demonstrated that whilst the majority of the peptide was in the latent form, a small proportion was present as the active peptide. Cells that over-expressed endogenous TGF-beta1 grew more slowly in vitro compared to both the vector-only controls and cells that did not over-express the peptide. Orthotopic transplantation of cells that over-expressed endogenous TGF-beta1 to the floor of the mouth in athymic mice resulted in marked inhibition of primary tumor formation compared to controls. Expression of a dominant-negative TGF-beta type II receptor in cells that over-expressed endogenous TGF-beta1 resulted in enhanced cell growth in vitro and diminished the tumor suppressor effect of the ligand in vivo, indicating that the endogenous TGF-beta1 was acting in an autocrine capacity. The results demonstrate that over-expression of endogenous TGF-beta1 in human malignant oral keratinocytes leads to growth inhibition in vivo and tumor suppression in vitro by mechanisms that are independent of Smad 4 expression and TGF-beta1-induced G(1) arrest.

Bag-1 is an anti-apoptotic protein that promotes metastasis in some tumour cell types. To determine whether Bag-1 expression is altered in 64 oral squamous cell carcinomas, tumour samples were compared with 17 samples of normal oral epithelium. Normal oral epithelia had pronounced nuclear staining in the basal and maturation layers and weak cytoplasmic staining that was most pronounced in the basal and suprabasal layers. Oral squamous cell carcinomas demonstrated a tendency for reduced nuclear staining intensity (p=0.036). Cytoplasmic staining intensity was not significantly different between tumour and normal tissue. However, many tumours were observed to have less of a difference between nuclear staining intensity and cytoplasmic staining intensity than normal oral epithelium. Furthermore, in lymph node metastases, cytoplasmic Bag-1 staining was stronger in 8/13 cases than in corresponding primary tumours (p=0.021). Western blotting using nine oral primary carcinoma cell lines and four normal keratinocyte cultures showed that the isoforms Bag-1s, Bag-1M, and Bag-1L were expressed in normal and malignant oral epithelial cells. Bag-1L unique sequences were shown to adopt an exclusively nuclear, and predominantly nucleolar, localization by use of transiently transfected N-terminal Bag-1L-EGFP. However, levels of Bag-1L in carcinoma cells did not differ significantly from those of normal keratinocytes. Therefore the reduced nuclear staining observed in oral squamous cell carcinomas compared with normal epithelium may reflect changes in the localization of Bag-1 isoforms, rather than decreased expression of Bag-1L. Alterations in the relative proportions of Bag-1S, Bag-1M, and Bag-1L were detected in 6/9 oral carcinoma cell lines; 5/9 oral carcinoma cell lines had a significantly greater proportion of Bag-1M than normal keratinocytes and in another cell line, Bag-1L was significantly underrepresented. Overall, the results suggest that Bag-1 deregulation plays a role in oral carcinogenesis at two different stages: during primary carcinoma development and during lymph node metastasis.

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.

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

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.

Neural invasion is a relatively common feature of squamous cell carcinomas of the head and neck and malignant salivary gland tumours. The symptoms depend on the location and the particular nerves involved, and include pain, anaesthesia, paraesthesia and cranial nerve palsy. The present case appears to be unique. A mucoepidermoid carcinoma showed evidence of neural involvement and presented with nerve stimulation inducing myokymia, rather than nerve destruction, which is the usual consequence of tumoral nerve invasion.

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.

Oral squamous cell carcinoma (SCC) is a major world health problem, but the changes leading to the development of malignancy remain essentially unknown. Early changes are thought to include the loss of tumour suppressor genes on chromosomes 3p, 9p, and 17p. Although what genes are involved on chromosome 3 remains speculative, p16 (9p21) and p53 (17p13) are inactivated in a high proportion of oral dysplastic lesions and carcinomas. SCC-derived cell lines are immortal, have decreased growth requirements in vitro, and show a variable capacity to form tumours in athymic mice. Normal oral keratinocytes and cells from potentially malignant lesions invariably senesce at early culture passage, have strict growth requirements in vitro, and are nontumorigenic in vivo. By contrast to normal oral keratinocytes, cells from potentially malignant lesions are defective in their capacity to terminally differentiate in suspension culture. Loss of cellular senescence and gain of the immortal phenotype is associated with inactivation of p16 and p53.

Oral cancer, although uncommon in the Western world, accounts for up to 40% of all malignancies in parts of India and South East Asia. Recognised aetiological agents of oral cancer include tobacco and alcohol. This paper reviews the spectrum of molecular changes found in oral squamous cell carcinomas from Western (U.K., U.S.A., Australia) and Eastern (India, S.E. Asia) countries. p53 mutations are common in tumours from the West (47%) but are infrequent in the East (7%). Tumours from India and South East Asia are characterised by the involvement of ras oncogenes, including mutation, loss of heterozygosity (H-ras) and amplification (K- and N-ras), events which are uncommon in the West. The possibility that these genetic differences reflect aetiology and/or ethnic origin is discussed.

Transforming growth factor-β (TGF-β) is known to act as a tumour suppressor early in carcinogenesis, but then switches to a pro-metastatic factor in some late stage cancers. However, the actions of TGF-β are context dependent, and it is currently unclear how TGF-β influences the progression of human squamous cell carcinoma (SCC). This study examined the effect of overexpression of TGF-β1 or TGF-β2 in Ras-transfected human malignant epidermal keratinocytes that represent the early stages of human SCC. In vitro, the proliferation of cells overexpressing TGF-β1 or TGF-β2 was inhibited by exogenous TGF-β1; cells overexpressing TGF-β1 also grew more slowly than controls, but the growth rate of TGF-β2 overexpressing cells was unaltered. However, cells that overexpressed either TGF-β1 or TGF-β2 were markedly more invasive than controls in an organotypic model of SCC. The proliferation of the invading TGF-β1 overexpressing cells in the organotypic assays was higher than controls. Similarly, tumours formed by the TGF-β1 overexpressing cells following transplantation to athymic mice were larger than tumours formed by control cells and proliferated at a higher rate. Our results demonstrate that elevated expression of either TGF-β1 or TGF-β2 in cells that represent the early stages in the development of human SCC results in a more aggressive phenotype.

External beam radiotherapy treatment of malignant conditions in the head and neck can give rise to several adverse oral effects if the oral or salivary tissues are within the field of beam. We report on a patient with widespread oral melanotic hyperpigmentation that developed after a course of radiotherapy for metastatic carcinoma in the cervical lymph nodes. As no other local or systemic cause was evident it is possible this abnormal hyperpigmentation was a result of the radiotherapy. The development of oral melanotic macules as a consequence of radiotherapy has not been previously described.

There has been considerable controversy as to whether oral lichen planus (LP) has a premalignant potential. This study retrospectively examined the records of 241 British patients with histologically confirmed LP seen during the 10-year period 1982-92. Nine patients (3.7%) were known to have developed well-differentiated invasive carcinoma or carcinoma in situ in an area of LP. Most carcinomas at presentation were in areas of atrophic and/or erosive LP, 6 were in patients older than 65 years, and 6 were on the tongue. The results support a small but clinically important premalignant potential for LP.

The salivary disease in two patients with human immunodeficiency virus infection was investigated by technetium pertechnetate scintiscanning. Although there was good histologic evidence of benign lymphoepithelial disease, scintiscanning failed to delineate any salivary lesions. Technetium pertechnetate scintiscanning seems to be of little value in the detailed investigation of salivary disease in human immunodeficiency virus infection, though gallium scanning can help. Fine needle aspiration or biopsy remain the main diagnostic tools.

Background: The presence of lichenoid or granulomatous inflammation in an oral mucosal biopsy usually suggests a distinct range of diagnostic possibilities. However, the presence of both patterns of inflammation in the same biopsy is uncommon. Methods: A clinico-pathological study of six patients. Results: All the patients in this study presented with similar mucosal lesions of the upper lip. Microscopically the lesions were characterized by the presence of lichenoid inflammation with concomitant granulomatous inflammation. The lesions were persistent and refractory to treatment with steroid medications, but remained localized and did not appear to herald the onset of systemic inflammatory or neoplastic disease. Conclusion: We propose the designation ‘lichenoid and granulomatous stomatitis’ for the cases described in this study. The clinico-pathological features of a subset of these cases suggest an unusual drug eruption.

Oral carcinomas are known to have a greater apoptotic index than normal oral epithelium, evident as shrinking cells with condensed chromatin. In this study, these morphologically apoptotic cells stained positively for cleaved (active) caspase-3. In normal oral epithelium, cleaved caspase-3 positive-cells were only rarely detected. The terminally differentiated surface epithelial layers did not express cleaved caspase-3. The caspase-3 pro-enzyme showed a gradient of expression in normal oral epithelium, decreasing with differentiation. No expression was detectable in surface epithelial layers. Lack of expression of the major 'executioner' caspase-3 may, at least in part, explain differences in morphology between terminally differentiated and apoptotic cells. In cancers of different tissue origins, caspase-3 pro-enzyme expression can be either increased or decreased compared with normal tissue counterparts. To determine how caspase-3 expression alters during oral carcinogenesis, caspase-3 expression was compared in 39 samples of normal oral epithelium and 54 oral squamous cell carcinomas. Squamous cell carcinomas had more intense caspase-3 staining than normal epithelium (p < 0.001). Moreover, within the oral squamous cell carcinoma series, there was significantly more intense nuclear and cytoplasmic staining with increasing STNMP stage (p = 0.017 and 0.03, respectively). This was a reflection of significant associations with site (S), palpable lymph nodes (N), and differentiation (P). Both caspase-3 staining intensity and the percentage of cells positive for caspase-3 were inversely associated with differentiation. Studies of the mechanisms by which high levels of caspase-3 expression are tolerated in oral carcinoma cells may identify targets that can be used to harness caspase-3 overexpression for therapeutic benefit.

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 involvement, particularly salivary gland enlargement (sialosis), is a recognised complication in bulimia. We report the rare association of sialosis and necrotising sialometaplasia with bulimia in the same patient. The association of sialosis and necrotising sialometaplasia in the same patient with bulimia has been reported previously in two patients and may be coincidental, but the appearance in this additional patient suggests it may be prudent to explore this further.

We investigated the potential of cyclooxygenase (COX)-2 as anappropriate chemopreventive and/or therapeutic target for oral cancer.Immunohistochemical analysis of COX-2 expression was carried out on 37 oral squamous cell carcinomas (OSCCs) and 23 normal oral epithelium samples. We investigated whether the COX-2-selective inhibitor NS398 induced growth inhibition in four human OSCC cell lines and whether this was COX-2 dependent.COX-2 staining was more intense in the carcinomas compared with normal epithelium (P0.001). Early-stage tumors (stages I and II) had significantly higher epithelial COX-2 staining than late-stage tumors (stages III and IV; P = 0.034), and overexpression of COX-2 was detected in hyperplastic and dysplastic epithelium. Treatment of OSCC cells with NS398 for 72 h at concentrations of 50 micro M and above resulted in growth inhibition accompanied by a reversible G(0)-G(1) arrest, but no apoptosis or terminal differentiation. However, a concentration of 10 micro M was sufficient to abolish secreted prostaglandin E(2) (PGE(2)) production. Over a longer treatment time, lower concentrations of NS398 were growth inhibitory. Growth inhibition of the OSCC cell line H357 was detected after treatment with 5 micro M NS398 as well as 100 micro M NS398 for 6-12 days. In cultures treated with 5 micro M NS398, but not in those treated with 100 micro M NS398, restoration of PGE(2) to control levels abrogated growth inhibition.NS398 inhibits the growth of OSCC cells by mechanisms that are dependent and independent of suppression of PGE(2) synthesis. Molecular targeting of COX-2, PGE(2) synthase, or PGE(2) receptors may be useful as a chemopreventive or therapeutic strategy for oral cancer.

Benign cartilaginous tumors of the intraoral soft tissues are rare and are typically seen in the tongue, buccal mucosa, or soft palate. They comprise a diverse group of lesions that are usually defined as cartilaginous choristomas or chondromas. The case reported was located on the palatal maxillary gingiva of the first premolar of a 56-year-old white woman. It appeared as a small firm tumor covered by normal mucosa, with the underlying bone intact on radiographic examination. Histologic examination of the excised lesion revealed a circumscribed mass of cartilaginous tissue with occasional cells presenting atypical nuclear features. Two years after initial presentation, the patient is free of recurrence.

White sponge nevus (WSN) is a benign hereditary lesion of the mucous membranes. DNA extracted from a biopsy specimen of oral WSN was assayed for the presence of DNA sequences homologous to human papillomavirus (HPV) types 1, 2, 4, 6, 11, 13, 16, and 18 by Southern blot hybridization. Only HPV-16 homologous DNA sequences were detected at a copy number of approximately 200 to 250 genome copies per diploid cell. The viral DNA sequences did not appear to be integrated into the host cell chromosome. The finding of HPV-16 in an inherited lesion such as WSN indicates that caution must be exercised in ascribing a causal association in relation to the demonstration of HPV in other mucosal disorders.

DNA was extracted from an odontogenic keratocyst and assayed for the presence of human papilloma virus (HPV) type 16 DNA sequences using high stringency Southern blot hybridization. HPV type 16 homologous DNA sequences were detected at a copy number of 50-100 genome copies per diploid cell. The oral HPV DNA was not identical to the prototype HPV 16 when cleaved with the restriction enzyme Pst-I, since it appeared to lack the Pst-I C fragment (L2/L1 ORFs) and contained "off-sized" high molecular weight fragments suggestive of integration events into the host cell chromosome.

Multiple hamartoma syndrome (Cowden's syndrome), a rare genodermatosis with predominant mucocutaneous features, particularly hamartomas, and Cowden/Lhermitte-Duclos disease, the combination of multiple hamartomas with cerebellar hypertrophy, typically present with cutaneous and oral papillomatosis as major features of both uncommon disorders. This article details the clinical features of three patients with multiple hamartoma syndrome and one with both disorders.

Ameloblastoma is uncommon in the maxilla, comprising about 15% of all reported ameloblastomas. Ameloblastomas are locally aggressive and, when involving the maxilla, potentially lethal. The long term outcome of 13 patients with ameloblastoma in the maxilla for whom surgery was the primary treatment between 1951–1990 was studied. Patient records from both private and public practices in Melbourne, Australia were examined as were those cases reported to the Bone Tumour Registry at the University of Bristol, England. The study showed that control of disease was achieved in all patients where the tumour was limited to the confines of the maxilla (10 cases). The mean follow-up period in this group was 7 years (range 2–20 years). In the three cases that recurred all had preoperative radiological evidence of posterior maxillary sinus wall destruction and/or pterygoid plate erosion. Two patients died of extensive local recurrence and one has persistence of the disease. Histopathological examination confirmed the diagnosis of ameloblastoma in each case with a variety of histological patterns being noted. It is concluded that notwithstanding histological type, the extent of the tumour at presentation and the adequacy of the surgical approach and removal were the main factors in successfully managing the disease.

Erythema multiforme is a vesiculobullous condition that may affect skin and/or mucosa. Oral lesions are characterized by hemorrhagic crusting of the lips and ulceration mainly of the non-keratinized mucosa. This paper describes a patient who presented with gingival lesions as well as the more typical oral signs of erythema multiforme.

A patient with a rare combination of bilateral lingual necrosis and intestinal infarction, caused by giant cell arteritis, is described and the literature reviewed.

LH39 monoclonal antibody detects a novel component of epithelial and endothelial basement membranes. The expression of LH39 antigen was investigated by immunohistochemistry in 55 oral squamous cell carcinomas and compared with 15 pyogenic granulomas of skin and oral mucosa, 20 non-specific oral ulcers, and 20 specimens of normal oral mucosa. The distribution of this basement membrane epitope was compared with that of other basement membrane components, type IV collagen, and laminin. LH39 monoclonal antibody labelled basement membrane surrounding small blood vessels in normal human organs. In oral squamous cell carcinomas, in contrast to the other basement membrane antigens, the LH39 epitope was not detectable in vessels within histologically recognizable tumour stroma. Neovascularization is known to attend malignant neoplasms and this finding was interpreted as absence of LH39 antigen within newly formed vessels. In support of this hypothesis, LH39 immunoreactivity was absent in newly formed blood vessels within pyogenic granulomas and the granulation tissue within ulcers. As increasing neovascularization is reported to correlate with a rising rate of metastasis, assessment of tumour angiogenesis may be of value in selecting patients for initial aggressive therapy.

The murine monoclonal antibody, LH39 was characterized in this study and appeared to bind to a novel basement membrane epitope. This antigen was expressed in the epithelial basement membrane of human tissue derived from all three germ cell layers and in basement membranes surrounding small blood vessels within the stroma of all organs examined. LH39 antigen could be first detected in fetal skin at the dermo-epidermal junction at 7 weeks estimated gestational age but was not present in the dermal vasculature until 16 weeks. When tested against tissue from a range of lower mammalian species, LH39 antigen appeared to be primate-specific. The epithelial basement membrane zone in organotypical cultures, where there is de novo synthesis of basement membrane components, contained abundant LH39 antigen in contrast to other basement membrane components, type IV collagen, laminin, and type VII collagen. Ultrastructural localization of LH39 epitope, using immunogold electron microscopy on unfixed freshly frozen tissue, was to the lamina lucida. No cross-reactivity could be detected between LH39 and laminin, fibronectin, and collagens I, III, IV, and V using the ELISA assay. In vitro studies with a range of proteolytic enzymes suggested that the antigen was non-collagenous in nature. LH39 precipitated a polypeptide with a molecular weight of 185 kD from extracts of metabolically labelled cultured keratinocytes, and polypeptides of 185 and 200 kD from the culture medium. The tissue distribution of LH39 antigen suggested that it may be an epitope within anchoring filaments. Potential applications of this antibody include the study of benign and malignant human vascular disorders, diseases and tumours associated with angiogenesis, epithelial neoplasms, and conditions of tissue regeneration and repair, such as wound healing.

Two cases of pyostomatitis vegetans, an uncommon oral manifestation of ulcerative colitis, are reported, and the literature is reviewed.

Many associations of lichenoid reactions have been described but this case appears to be a previously unreported association—with multiple myeloma. This case also demonstrates the necessity of a mucosal biopsy with adequate hematologic and serologic investigations to obtain a definitive diagnosis.

Cysts of the mandibular condyle are rare and their diagnosis and treatment can be difficult. A case in a young girl is described where the histology was that of a solitary bone cyst but the presentation and behaviour more closely resembled an aneurysmal bone cyst.

Desquamative gingivitis is a manifestation of various dermatoses, particularly lichen planus and mucous membrane pemphigoid. A rare example of adult linear immunoglobulin A disease manifesting as desquamative gingivitis is presented. Although the initial clinical features were typical of desquamative gingivitis, the persistence of ulceration after dental extractions was unusual, and the management of the oral lesions proved difficult. The clinical, immunopathologic, and therapeutic aspects of linear immunoglobulin A dermatoses are reviewed.