Upregulated CD44v9 Expression Inhibits the Invasion of Oral Squamous Cell Carcinoma Cells

OBJECTIVES

CD44 is one of the cell surface molecules that play an important role in cancer metastasis. In oral squamous cell carcinoma (OSCC), the downregulation of CD44v9 has been shown to be associated with tumor metastasis. We found that treatment with an anti-CD44v9 antibody enhanced the invasive potential of OSCC cell lines. Based on previous studies and our results, reduced expression of CD44v9 may be correlated with an increased invasive potential, i.e. the overexpression of CD44v9 may inhibit the invasive activity of OSCC cells.

METHODS

To study this correlation, we transfected the CD44v9 gene into HSC-4 cells with low CD44v9 expression and examined their invasive potential using the cell culture invasion assay and a three-dimensional culture invasion assay.

RESULTS

Overexpression of CD44v9 resulted in a downregulation of the invasive potential of HSC-4 cells. Moreover, CD44v9-transfected cells did not invade reorganized stroma, while parent HSC-4 cells exhibited diffuse invasion into reorganized stroma by the three-dimensional culture invasion assay.

CONCLUSIONS

Overall, these findings suggest that the inhibition of the invasive potential by upregulation of CD44v9 expression may be due to enhanced cell-cell adhesion. In our opinion, the upregulation of CD44v9 may be a target for future cancer treatment.

Tumour necrosis factor-alpha but not interferon-gamma is the main inducer of inducible protein-10 in skin fibroblasts from patients with atopic dermatitis

BACKGROUND

Inducible protein (IP)-10 belongs to the CXC chemokine subfamily and acts through the CXCR3 receptors that attract T lymphocytes. Keratinocytes are thought to be the main cell source of this chemokine in the skin, but other sources need to be elucidated.

OBJECTIVES

To determine whether skin fibroblasts, besides keratinocytes, are able to produce IP-10 and the possible involvement of these cells in pathogenesis of atopic dermatitis (AD).

METHODS

We studied the production pattern of IP-10 in dermal fibroblasts obtained from healthy donors, AD patients and in the HaCaT cell line (normal human keratinocytes) used as control. We stimulated fibroblasts after the sixth and seventh passage with tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma, interleukin (IL)-4, and by means of reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay analysis detected the production pattern of IP-10. To determine whether a different pattern of production of IP-10 by fibroblasts corresponds to the level of this chemokine in the plasma of patients with AD, we also checked the plasma IP-10 levels in 33 AD patients and 10 healthy donors.

RESULTS

The pattern of chemokine production between dermal fibroblasts and HaCaT cells was different. The main inducer of IP-10 in fibroblasts was TNF-alpha, whereas IFN-gamma was the main inducer of IP-10 in HaCaT cells. We demonstrate that fibroblasts from AD patients have higher IP-10 expression and are more sensitive to TNF-alpha stimulation compared with healthy controls. Consequently, IP-10 levels in plasma of AD patients were higher than in healthy donors.

CONCLUSIONS

Skin fibroblasts could be an important source of IP-10. TNF-alpha is the main inducer of IP-10 by skin fibroblasts, but not IFN-gamma or IL-4. The increased level of IP-10 in the plasma of patients with AD could be connected with increased activity of skin fibroblasts.

Immunolocalization of CXC�chemokine and recruitment of polymorphonuclear leukocytes in the rat molar periodontal tissue after topical application of lipopolysaccharide

This study investigated the recruitment of polymorphonuclear leukocytes (PMNs) and the immunolocalization of CXC chemokines, including macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant-2 (CINC-2) in rat periodontal tissue after topical application of lipopolysaccharide (LPS; 5 mg/ml) from Escherichia coli into the rat molar gingival sulcus. In normal periodontal tissues, a small number of MIP-2- and CINC-2-positive cells were seen in junctional epithelium (JE), especially in its coronal half. After topical application of LPS, a prominent increase of MIP-2- and CINC-2-positive JE cells was observed. Almost all JE cells strongly expressed them at day 1 and day 2, and then the number of chemokine-positive cells returned to normal at day 7. Corresponding to these chemokine expressions, LPS application induced a significant increase in the number of PMNs in the sub-JE area from 1 h to 2 days and a significant increase in JE area from 3 h to 5 days, indicating a dynamic flow of PMNs from the sub-JE area into JE. These findings indicated that JE cells produced MIP-2 and CINC-2 in response to LPS stimulation and suggested that MIP-2 and CINC-2 may be responsible for PMN migration toward the periodontal pathogen and may play an important role in the initiation of inflammation and subsequent periodontal tissue destruction.

The inflammatory paradental cyst: a critical review of 342 cases from a literature survey, including 17 new cases from the author's files

BACKGROUND

A total of 325 cases of inflammatory paradental cysts (IPCs) and 17 own cases were reviewed. Although known since 1930, the IPC is still unrecognized by many clinicians. The IPCs show a relative frequency of 0.9-4.7%. The majority of cysts occur distally or distobuccally to vital, permanent mandibular molars with a history of pericoronitis (IPC/3rd mandibular molar alone accounts for 64.9%). Radiologically, the cyst appears as a well-defined, semilunar unilocular radiolucency.

MATERIALS AND METHODS

Cases of inflammatory paradental cysts and related lesions were retrieved from a worldwide literature survey. In addition, 17 new cases from the files of the authors have been added.

RESULTS

The mean ages for patients with IPC/1st, 2nd and 3rd mandibular molars are 8.7, 17.4 and 27.6 years, respectively. The male:female ratio was 1 : 0.9 for IPC/1st and 2nd mandibular molars, and 1 : 0.4 for 3rd mandibular molar.

CONCLUSION

Reduced enamel epithelium, cell rests of Malassez and remnants of the dental lamina stimulated by inflammation are thought to play a role in the pathogenesis of IPC. Histological features are indistinguishable from those of the inflammatory, periapical (radicular) cyst.

Atypical carcinoid (neuroendocrine carcinoma) of the gingiva: Counterpart of a laryngeal tumor

Intraoral localization of neuroendocrine carcinoma, usually called Merkel cell carcinoma, is extremely rare. A case of neuroendocrine carcinoma that was a counterpart of laryngeal neuroendocrine carcinoma but was not a Merkel cell carcinoma, occurring at the mandibular gingiva in a 69-year-old Japanese man, is described. The tumor formed a cauliflower-like mass, measuring 20 x 20 mm, with a small area of necrosis. A computed tomography image showed metastasis in the right submandibular lymph node. Histopathologically, the tumor was composed of immature, small round cells that formed anastomosing trabecular nests. Few mitotic and no necrotic features were observed in the nests. Immunohistochemical studies showed positive staining for chromogranin, synaptophysin and neuron-specific enolase in the tumor nests. We diagnosed it as an atypical carcinoid (neuroendocrine carcinoma), a counterpart to the same type of tumor occurring in the larynx. The present case is an extremely rare case of neuroendocrine carcinoma without the feature of Merkel cell carcinoma arising from the gingiva.

Dedifferentiated malignant myoepithelioma of the parotid gland

Dedifferentiated salivary gland tumor is a rare, recently recognized tumor type. A case of dedifferentiated malignant myoepithelioma in a 59-year-old man who presented with a painful mass in the left preauricular region is reported. Histologically, two distinct neoplastic cell populations were observed in the same tumor mass. The first population was composed of solid nests of polygonal eosinophilic or glycogen-rich clear cells showing neoplastic myoepithelial immunocytological features, such as positivity for cytokeratins, vimentin, S-100 protein (S-100), alpha-smooth muscle actin (SMA) and glial fibrillary acidic protein (GFAP). A multinodular growth pattern, necrosis and occasional mitotic figures suggested malignancy. This population was diagnosed as low-grade malignant myoepithelioma. The second population infiltrated diffusely into the parotid gland and facial nerves. It consisted of polygonal or short spindle cells with obvious pleomorphism and atypical mitoses. The tumor cells were positive for vimentin and cytokeratins, and showed an accumulation of p53 and cyclin D1. S-100 protein, SMA and GFAP were negative. This population was regarded as undifferentiated carcinoma. A final diagnosis of dedifferentiated malignant myoepithelioma was made. This seems to be the first published case of dedifferentiation in malignant myoepithelioma. Because any tumor type can undergo dedifferentiation with accumulation of additional genetic changes, complete sampling should be the standard approach to all salivary gland tumors in order to avoid missing a dedifferentiation component.

Establishment of an oral squamous cell carcinoma cell line with high invasive and p27 degradation activities from a lymph node metastasis

The extent of lymph node metastasis is a major determinant in the prognosis of oral squamous cell carcinoma (OSCC). We present here a new OSCC cell line, MSCC-1, established from a lymph node metastasis of a patient with OSCC of gingiva. First, we examined the expression of p27, p53 and Ki-67 in non-neoplastic mucosa, primary and metastatic cancer lesions by immunohistochemistry. Metastatic cancer cells in the lymph node showed the reduced expression of p27 in comparison with cancer cells in the primary lesion. Cancer celLs both in the primary and metastatic lesions showed overexpression of p53 and Ki-67. Overexpression of p53 and reduced expression of p27 in MSCC-1 cells were also determined by western blot analysis. To characterize MSCC-1 cells, furthermore, we examined the invasive activity and cell proliferation of MSCC-1, comparing with those of other OSCC cell lines, HSC-2 and HSC-3 cells. The invasive capacity of MSCC-1 cells was significant higher than HSC-2 and HSC-3 cells, but cell growth of MSCC-1 cells was slower than HSC-2 and HSC-3 cells. Moreover, we examined the p27 degradation activity by in vitro degradation assay. Interestingly, MSCC-1 cells have the strongest p27 degradation activity among the OSCC cell lines examined. In the present study, we newly established MSCC-1 cells with strong invasiveness and p27 degradation activity from a metastatic lesion. These findings suggest that high activity of p27 degradation may concern with invasiveness of OSCC cells and that MSCC-1 cells can be a useful cell model for studying the detailed mechanism of p27 degradation, invasion and metastasis of OSCC.

Verruciform xanthoma--biological profile of 282 oral lesions based on a literature survey with nine new cases from Japan

The biological profile of oral verruciform xanthoma (VX) is presented based on a world-wide literature survey of 282 cases. From 1979 onwards, extraoral cases have also been reported. This rare, harmless lesion with a sessile or pedunculated base is a red/pink, papillary/granular/verrucous mucosal growth, occurring in females (mean age, 54.9 yrs) and males (mean age, 44.2 yrs) in a female:male ratio of 1:1.1. The most common location is by far the gingival margin and other areas of the masticatory oral mucosa. Comparison between 173 non-Japanese and 109 Japanese patients with oral VX showed few discrepancies in epidemiological data, indicating only few significant ethnic differences between the two cohorts. Histomorphologically, the epithelium covering the lesion can be divided into three groups: (A) a verrucous, (B) a papillary and (C) a flat pattern. The hallmark of all VX, irrespective of the lesion being intra- or extraoral is, however, the presence of vacuolated, foam or xanthoma cells which ultimately replace the connective tissue between the epithelial ridges. The xanthoma cells have been shown to be cells of the monocyte/macrophage lineage. The present concept of the etiology and pathogenesis of VX, including the possible viral (HPV) association is revised, based on both intra- and some extraoral cases, and it is concluded that it is still far from being clarified.

Inhibition of CD44v9 upregulates the invasion ability of oral squamous cell carcinoma cells

The aim of the present study has been to determine the role of CD44v9 in the metastatic process of oral squamous cell carcinoma (OSCC). We have examined the expression intensity of CD44v9 in four OSCC cell lines, and using cell culture insert investigated the invasion ability of the cells expressing CD44v9 at higher levels (HSC-2, HSC-3), and the cells expressing this protein at lower levels (HSC-4, KB) with or without the treatment with an anti-CD44v9 antibody. In the highly expressing cells, the addition of anti-CD44v9 antibody enhanced their invasion ability, whereas it showed no effect on the invasion ability of the weakly expressing cells. These results suggest that the reduction of CD44v9 expression may weaken cell-to-cell adhesion in OSCC and make the tumor cells detach easily from their nests, resulting in the enhancement of their invasion ability. It may ultimately promote the establishment of a metastatic lesion.

Solitary fibrous tumor with malignant potential arising in sublingual gland

A rare case is described of a solitary fibrous tumor (SFT) with malignant potential arising in the sublingual gland. A 59-year-old man presented with a 4-month history of a slowly enlarging painless mass in the center of the floor of the mouth. The tumor was a well-demarcated, firm mass with a multicystic lesion. The tumor exhibited highly cellular areas of spindle cells with patternless architecture alternating with hypocellular areas. The tumor cells were positive for CD34 and bcl-2 as well as vimentin, and negative for epithelial, myogenic, neurogenic and histiocytic markers. The tumor cells formed multiple satellite nodules around dilated ducts in the multicystic lesion, indicating infiltrative growth. In addition, areas exhibiting higher cellularity with increased mitoses were noticed in the satellite nodules, although cellular atypia was not obvious. These findings led to a final diagnosis of SFT with malignant potential. There has been no recurrence or metastasis for 27 months after the surgery. Solitary fibrous tumor of the salivary gland must be differentiated from various spindle cell neoplasms including myogenic, peripheral nerve sheath, fibroblastic and fibro-histiocytic spindle cell neoplasms, hemangiopericytoma and myoepithelioma. In addition to characteristic morphological features, an immunohistochemical positivity for CD34 and bcl-2 may aid in the diagnosis of SFT.

Pleomorphic adenoma with extensive adenoid cystic carcinoma-like cribriform areas of parotid gland

We report an interesting case of pleomorphic adenoma (PA) with extensive adenoid cystic carcinoma (ACC)-like cribriform areas of parotid gland along with a discussion of the differential diagnosis. The patient was a 62-year-old-female who presented with a 5-month history of a slow-growing painless mass in the left preauricular region. Pathological examination of the excised mass revealed a well-encapsulated tumor consisting of typical PA areas and extensive ACC-like cribriform areas. The transition between both areas was frequently observed. There was no clinical or histological evidence of a longstanding PA, such as prominent hyalinization with dystrophic calcification. Immunohistochemically, the neoplastic myoepithelial cells of the PA areas showed frequent expression of vimentin and S-100 protein, along with occasional positivity for glial fibrillary acidic protein and alpha-smooth muscle actin. The immunoreactivity of the neoplastic myoepithelial/basal cells forming cribriform nests was essentially identical to that of the PA areas. The difference of immunoreactivity of the basal/myoepithelial cells between PA and ACC may have some discriminatory advantage. In addition, the low proliferative activity observed in the entire tumor suggested that the cribriform nests resembling ACC are also the component of PA.

Transfection of p27(Kip1) threonine residue 187 mutant type gene, which is not influenced by ubiquitin-mediated degradation, induces cell cycle arrest in oral squamous cell carcinoma cells

OBJECTIVE

It is well known that reduction of the cyclin-dependent kinase inhibitor p27(Kip1) protein correlates with the malignant behavior of various cancers including oral squamous cell carcinoma (OSCC). The loss of p27(Kip1) protein is suggested to be due to the enhancement of its posttranslational degradation. In the present study, to evaluate the effects of p27(Kip1) transfection on the cell cycle, we transfected OSCC cell lines with a high activity of p27(Kip1) degradation with p27(Kip1) threonine 187-to-alanine (T187A) mutant gene, which is not influenced by ubiquitin-mediated degradation, as well as with wild type gene.

METHODS

We transfected p27(Kip1) T187A mutant and wild type gene into OSCC cell lines (HSC2 and HSC3) by using an ecdysone-inducible gene expression system.

RESULTS

After treatment with ponasterone A, we could find an induction of both p27(Kip1) wild type and T187A mutant protein. Both wild type and T187A mutant protein induced by 5 microM ponasterone A inhibited cell growth and increased cell number at the G1 phase. After treatment with 1 microM ponasterone A, ectopic p27(Kip1) protein was degraded in wild type clones, but not in T187A mutant clones. Moreover, transfection of the T187A mutant gene was more effective in inhibiting cell growth even by induction of a small amount of protein.

CONCLUSION

We suggest that the transfection of the p27(Kip1) T187A mutant gene can be a modality of cancer gene therapy for OSCC.

Malignant myoepithelioma arising from recurrent pleomorphic adenoma of minor salivary gland

Malignant myoepitheliomas of the salivary gland are very rare tumors which may either arise de novo or develop in a pre-existing pleomorphic adenoma. We report a case of malignant myoepithelioma of the minor salivary gland that progressed from benign pleomorphic adenoma. The original pleomorphic adenoma was resected in 1979 (the '79 tumor). The first recurrent tumor was operated in 1995 (the '95 tumor). The '95 tumor was diagnosed as pleomorphic adenoma. Although the myoepithelial tumor component was more prevalent in the '95 tumor, histological features of the first recurrent tumor were similar to the '79 tumor. The second recurrent tumor showed more aggressive clinical features (the '98 tumor). It also showed massive growth of myoepithelial tumor cells with bone invasion, which led to the diagnosis of the '98 tumor as malignant myoepithelioma. With adequate surgical margin, the patient has been free from tumor recurrence for 20 months.

High expression of S-phase kinase-interacting protein 2, human F-box protein, correlates with poor prognosis in oral squamous cell carcinomas

Reduced expression of p27(Kip1), a cyclin-dependent kinase (Cdk) inhibitor, is frequently found in various cancers, including oral squamous cell carcinoma (OSCC), and is attributable to an enhancement of its degradation. Skp2, an F-box protein necessary for DNA replication, is required for the ubiquitinylation and subsequent degradation of p27(Kip1). In the present study, we examined the expression of Skp2 and its correlation with the expression of p27(Kip1) protein or p27(Kip1) degradation in OSCC. Using immunohistochemistry, we found that high expression of Skp2 was present in 49% of OSCCs and only 20% of epithelial dysplasias. Significantly, high expression of Skp2 was correlated with poor prognosis of OSCC patients. We also found an inverse correlation between the expression of Skp2 and p27 by immunohistochemical analysis. A similar correlation was observed in OSCC cell lines and OSCC tissues by Western blot analysis. Interestingly, OSCC tissues with Skp2 expression had high p27(Kip1) degradation activity. These findings indicate that (a) Skp2 may play an important role for the development of OSCC, (b) Skp2 can be a novel target for OSCC treatment as well as a strong prognostic marker, and (c) the reduction in p27(Kip1) protein may be brought about by enhancement of its degradation mediated by increased levels of Skp2 protein.

Magnetic resonance imaging in hemifacial hyperplasia

We describe a case of hemifacial hyperplasia due to a combination of lipoma and lipomatosis. The contribution of MRI to the diagnosis of hemifacial hyperplasia and to monitoring growth and development in this condition is demonstrated.

Cytokine expression in rat molar gingival periodontal tissues after topical application of lipopolysaccharide

It is well known that proinflammatory cytokines produced by host cells play an important role in periodontal tissue destruction. However, the localization of the cytokines in in vivo periodontal tissues during development of periodontal disease has not been determined. Immunohistochemical expression of proinflammatory cytokines including IL-1alpha, IL-1beta, and TNF-alpha was examined at 1 and 3 h, and 1, 2, 3, and 7 days after topical application of lipopolysaccharide (LPS; 5 mg/ml in physiological saline) from E. coli into the rat molar gingival sulcus. In the normal periodontal tissues, a small number of cytokine-positive epithelial cells were seen in the junctional epithelium (JE), oral sulcular and oral gingival epithelium, in addition to macrophages infiltrating in the subjunctional epithelial area and osteoblasts lining the alveolar bone surface. Epithelial remnants of Malassez existing throughout periodontal ligament were intensely positive for IL-1beta but negative for the other two cytokines. At 3 h after the LPS treatment, almost all cells in the JE were strongly positive for the cytokines examined. In addition, several cytokine-positive cells, including neutrophils, macrophages, and fibroblasts, were seen in the subjunctional epithelial connective tissue. At day 2, expression of the cytokines in the JE gradually decreased, while cytokine-positive cells in the connective tissue increased in number. Positive staining of the cytokines was seen in osteoclasts and preosteoclasts which appeared along the alveolar bone margin in this period. The number of cytokine-positive cells decreased by day 7. These findings indicate that, in addition to macrophages, neutrophils, and fibroblasts, the JE cells are a potent source of TNF-alpha, IL-1alpha, and IL-1beta reacting to LPS application, and suggest that JE cells may play an important role in the first line of defense against LPS challenge, and the proinflammatory cytokines transiently produced by various host cells may be involved in the initiation of inflammation and subsequent periodontal tissue destruction.

Reduced expression of CD44 variant 9 is related to lymph node metastasis and poor survival in squamous cell carcinoma of tongue

Expression of CD44v9 was immunohistochemically studied in 120 biopsy specimens from primary squamous cell carcinoma (SCC) of the tongue and correlated with clinicopathological findings of the SCCs. The tumors were classified into three groups according to immunostaining pattern of CD44v9; 53 cases with distinct positivity in all cancer cells except for those in the central part of nests (Group 1, non-reduced group), 42 cases with reduced expression in peripheral cells of nests (Group 2, reduced group), and 25 cases with complete disappearance of the expression in one or more nests (Group 3, negative group). Nineteen of 25 (76%) tumors in Group 3 and 14 of 42 (33%) in Group 2 exhibited lymph node metastasis, compared with only 8 of 53 (15%) in Group 1. The average survival time in Groups 1, 2 and 3 was 4496+/-204, 3866+/-379 and 2719+/-359 days, respectively and became shorter with the reduction of CD44v9 expression. These results suggest that the down-regulation of CD44v9 in SCC of the tongue may relate to the detachment of tumor cells from primary lesions, establishment of lymph node metastasis and consequently the death of patients.

Prevention of coronary arterial renarrowing by continuous 3-day infusion of tissue plasminogen activator after successful percutaneous transluminal coronary angioplasty: a randomized, double-blind, placebo-controlled study

Vascular injury resulting from percutaneous transluminal coronary angioplasty (PTCA) and subsequent thrombus formation are important factors in the pathogenesis of coronary arterial restenosis. The present study was undertaken to determine whether infusions of tissue plasminogen activator (tPA), beginning immediately after PTCA, would decrease the renarrowing of the coronary arterial lumen. Patients were randomized and divided into two groups: one group (15 patients, 16 lesions) received continuous, 3-day, intravenous infusions of tPA (0.25 mg/kg/day in 0.9% saline), beginning immediately after successful PTCA, while the other group (17 patients, 17 lesions) received saline alone. Coronary angiography was performed before, immediately after, 24 hours after, and 3 months after PTCA. Coronary stenosis (%), reference diameters, and minimum luminal diameters were measured by quantitative coronary angiography. The incidence of restenosis tended to be lower in the tPA group than in the placebo group (tPA group, 13%; placebo group, 41%; NS), although diameter stenoses before and immediately after PTCA were not significantly different in the two groups. Three months later, however, diameter stenoses were significantly smaller in the tPA group (35.6 +/- 13.3 vs 47.7 +/- 18.9%; P<0.05). Thus, intravenous tPA infusion beginning immediately after successful PTCA may inhibit renarrowing of the coronary arterial lumen.

Reduced expression of p27(Kip1) correlates with an early stage of cancer invasion in oral squamous cell carcinoma

Down-regulation of p27(Kip1) has been reported to correlate with poor survival of various carcinoma patients including oral squamous cell carcinomas (OSCCs). It is still unclear, however, at what stage of oral carcinogenesis the down-regulation of this protein occurs. In this study, therefore, we evaluated immunoexpression of p27(Kip1) protein in 17 cases of oral epithelial dysplasia and succeeding invasive OSCC in the same patient. We reported here that 88% cases showed high p27(Kip1) expression in dysplastic lesions, whereas 82% cases of succeeding invasive OSCC exhibited reduced expression. The reduction of p27(Kip1) expression was also observed in 16 of 19 (84%) early invasive lesions and well correlated with Ki-67 expression which is good indicator of cell proliferation. We also investigated immunoexpression of p53 protein of which abnormality has been known to occur during the early stage of OSCC development. Overexpression of p53 protein was demonstrated in 29% of dysplastic lesions, 42% of early invasive and 71% of invasive OSCCs. These findings suggest that abnormalities of both p53 and p27(Kip1) are involved in the carcinogenesis of OSCC, but they seem to play their role at different stages of oral cancer development, respectively. Reduced expression of p27(Kip1) may concern the cancer invasion directly or indirectly as well as abnormal proliferation.

Immunoexpression of transforming growth factor beta in desmoplastic ameloblastoma

Desmoplastic ameloblastoma (DA) is an unusual subtype of ameloblastoma histologically characterized by the pronounced collagenized stroma. In the present study, the immunolocalization of transforming growth factor beta (TGF-beta), one of the most potent local factors for modulating extracellular matrix formation, was observed in DA in order to study its participation in the stromal desmoplasia. Seven cases of DA, including a "hybrid" lesion, were studied together with ten cases of ordinary follicular and plexiform ameloblastomas as the control. In contrast to ordinary ameloblastomas, marked immunoexpression was observed in all DAs but one. In the "hybrid" lesion, TGF-beta was not expressed in the area of follicular ameloblastoma but in that of DA. These results show that TGF-beta produced by tumor cells of DA plays a part in the desmoplastic matrix formation.

p27Kip1 accumulation by inhibition of proteasome function induces apoptosis in oral squamous cell carcinoma cells

Ubiquitin-mediated proteolysis controls intracellular levels of various cell cycle regulatory proteins, and its inhibition has been shown to induce apoptosis in proliferating cells. In the present study, we examined induction of apoptosis in oral squamous cell carcinoma (OSCC) cells by treatment with specific proteasome inhibitors, carbobenzoxy-L-leucyl-L-leucyl-L-norvalinal and lactacystin. In all three OSCC cell lines examined, apoptotic changes such as apoptotic body formation and DNA fragmentation were observed at various degrees after 24 h of the carbobenzoxy-L-leucyl-L-leucyl-L-norvalinal or lactacystin treatment. HSC2 cells showed the most prominent apoptotic changes among the cell lines examined and demonstrated the highest level of accumulation of p27Kip1 protein after the treatment with proteasome inhibitor. Reduced expressions of cyclin D1 and phospho pRb were also observed after the treatment with proteasome inhibitor. Moreover, 12 h of treatment with the proteasome inhibitor inhibited cdk2/cyclin E kinase activity and increased the ratio of the cell cycle population at the G1 phase. The proteasome inhibitor led to inhibition of cell cycle progression. In addition, activation of CPP32 and reduced expression of Bcl-2 were observed. Because apoptosis induced by the proteasome inhibitor was inhibited by treatment with antisense p27Kip1 oligonucleotide, accumulation of the p27Kip1 protein might play an important role in the apoptosis induced by proteasome inhibitor. The present results suggest that inhibition of proteasome function may be used as a possible target of novel therapy for OSCC.

Prevention of left ventricular remodeling by percutaneous transluminal coronary angioplasty performed 24 hours after the onset of acute myocardial infarction

It remains controversial whether percutaneous transluminal coronary angioplasty (PTCA) performed 24 hours after the onset of acute myocardial infarction (AMI) in coronary arteries with 99% stenosis is useful in preserving left ventricular function. We investigated the effectiveness of PTCA in preventing left ventricular remodeling when it was performed 24 hours after the onset of AMI in infarct-related coronary arteries (IRCAs) having 99% stenosis and thrombolysis in myocardial infarction (TIMI) grade 3 flow. The subjects were 19 patients with AMI (anterior wall, 9 patients; inferior wall, 7 patients; and non-Q, 3 patients) who, within 24 hours of the onset of AMI, underwent coronary angiography and left ventriculography during the acute and/ or chronic phases. The patients were divided into a PTCA group, comprised of patients in whom PTCA was successfully performed 24 hours after the onset of AMI (n = 10), and a non-PTCA group (n = 9). The non-PCTA group included patients who were successfully reperfused by thrombolysis and did not include patients who had spontaneous reperfusion or reperfusion after PTCA. In the non-PTCA group, the left ventricular end-diastolic volume (mean +/- SD) was significantly increased in the chronic phase (86 +/- 23 mL/m(2)) as compared with the acute phase (67 +/- 13 mL/m(2)), whereas in the PTCA group no significant difference was observed between end-diastolic volumes in the acute and chronic phases (67 +/- 26 and 68 +/- 13 mL/m(2), respectively). Left ventricular remodeling is prevented by PTCA when it is performed 24 hours after the onset of AMI in IRCAs with 99% stenosis and TIMI grade 3 flow.

Clinical and histopathological analyses of desmoplastic ameloblastoma

Desmoplastic ameloblastoma (DA) is an unusual subtype of ameloblastoma characterized by pronounced desmoplastic stroma. There is, however, still argument whether DA is a distinct clinicopathologic entity. To enhance knowledge of DA, 7 cases of DA (7.9%) were retrieved from 89 ameloblastomas field in the Department of Oral Pathology, Hiroshima University School of Dentistry and analyzed clinicopathologically and histopathologically. The mean age of the patients with DA and non-DA at the time of the diagnosis was 40.6 +/- 5.9 years and 33.1 +/- 2.0 years, respectively. The male-to-female ratio was 2.5:1 in DA and 1.8:1 in non-DA. Four (57%) DAs were located in the maxilla where only 6% of the non-DA occurred. Interestingly, all DAs arose in the anterior/premolar area of the jaws and 6 cases were located mainly within the alveolus. None of the DA showed typical radiographic features of ameloblastoma. In 5 DAs, scattered radiopacities were observed in the radiolucent lesion and gave preoperative diagnoses of non-ameloblastomatous lesions or even osteosarcoma. All DAs showed pronounced desmoplastic stroma where there were compressed tumor islands usually lacking a peripheral layer of ameloblastic cells and a central zone of stellate reticulum. There was cystic change within the epithelial nests in 3 DAs and true glandular structures with mucus cells in a case of DA. Tumor islands often infiltrated into marrow spaces of surrounding bone. There was no capsule formation. Recurrence rate was 14% in DA and 20% in non-DA. The present study based on data of DA in the Japanese population supports that DA must be considered as a distinct clinicopathologic entity.

Biosynthesis of glycosaminoglycans and aggrecan by tumor cells in salivary pleomorphic adenoma: ultrastructural evidence

The present study attempted to discover the sites of synthesis of various glycosaminoglycans (GAGs) and aggrecan in salivary pleomorphic adenoma (PA) with the use of a highly sensitive and specific post-embedding immunogold-silver staining technique at the ultrastructural level. Silver particles representing various GAGs and aggrecan were found to accumulate frequently in the intercellular spaces of non-luminal cells in the epithelial clusters and were dispersed in the myxoid matrix of the mesenchyme-like areas. Furthermore, the non-luminal epithelial cells were demonstrated to contain immunopositive intracytoplasmic vesicles and vacuoles, some of which were of Golgi complex origin. In contrast, intracellular silver particles for hyaluronic acid were mostly attached to the inner surface of the cell membrane. These observations agree well with the current theories of the biosynthesis of GAGs and proteoglycans and provide direct evidence for the production of various GAGs and aggrecan by tumor epithelial cells of PA. Such findings support the ideas that in PA a loss of epithelium occurs by stromalization following epithelial secretion of extracellular matrix substances and transformation of epithelium to mesenchyme represents the basic principle of the tissue heterogeneity in this tumor.

Bone formation in a carcinoma of the maxillary antrum

Malignant tumors of the paranasal sinuses are rare: about 80% are found in the maxillary sinus123. The presence of dense radiopaque masses in combination with destruction of the bone margins suggests osteosarcoma or aspergillosis4 rather than carcinoma. We present a unique mucoepidermoid carcinoma of the maxillary antrum containing new bone formation and discuss the differential diagnosis.

So-called 'hybrid' lesion of desmoplastic and conventional ameloblastoma: report of a case and review of the literature

So-called 'hybrid' lesion of ameloblastoma, which is composed of desmoplastic ameloblastoma and conventional follicular/plexiform ameloblastoma, is an unusual variant of ameloblastoma and only eight cases of 'hybrid' lesion have been published in the English literature. To enhance knowledge of this interesting tumor, we add a case of 'hybrid' lesion that occurred in the right mandible of a 48-year-old Japanese male. Radiographic examination disclosed a honeycomb appearance at the anterior alveolar region, combined with a unicystic radiolucency in the molar region of the mandibular body. Histologically, the former showed microscopic features of desmoplastic ameloblastoma and the latter those of follicular ameloblastoma with focal granular cell transformation. The lesion was enucleated with curettage of surrounding bone and the lesional cavity was marsupialized. Although tumor tissues reappeared at 3, 5, 7 and 14 months after the surgery, the patient has remained disease free for 11 years after the last vaporization by CO2 laser of the recurred tumor. Many more cases of 'hybrid' lesion are needed to clarify the clinicopathological, histopathological and biological characteristics of this interesting variant of ameloblastoma.

Reduced expression of p27(Kip1) protein in relation to salivary adenoid cystic carcinoma metastasis

BACKGROUND

Adenoid cystic carcinoma (ACC) is a malignant tumor of salivary gland origin. It tends to grow slowly but shows frequent recurrence and metastasis, ultimately with a poor outcome. Reduced expression of a cyclin-dependent kinase inhibitor, p27(Kip1), has been reported to correlate with poor survival for patients with various types of carcinoma. However, there has been no previous study reported of p27(Kip1) expression in ACC, to the authors' knowledge.

METHODS

To evaluate p27(Kip1) as a prognostic marker, the authors examined the immunohistochemical expression of p27(Kip1) protein in 29 ACCs and correlated its expression with clinicopathologic findings. Eleven pleomorphic adenomas (PAs) were also examined to compare the p27(Kip1) expression in benign and malignant salivary gland tumors.

RESULTS

All PAs expressed p27(Kip1) at high levels, whereas 83% of ACCs (24 of 29) showed reduced expression of this protein. Furthermore, the expression levels were significantly lower in ACCs with metastasis than in those without metastasis. The authors also examined the expression of p27(Kip1) in 2 ACC cell lines (ACCh and ACC3) by Northern and Western blot analysis to elucidate the possible mechanism of p27(Kip1) reduction in ACC. Both ACCh and ACC3 expressed p27(Kip1) mRNA, but ACCh did not produce p27(Kip1) protein. In ACCh, the expression of p27(Kip1) protein was induced by treatment with a proteasome inhibitor.

CONCLUSIONS

Overall, these findings suggest that reduced expression of p27(Kip1) may correlate with the development and progression of salivary ACC and can be an indicator of its malignant behavior. They also suggest that increased proteasome-mediated degradation may play an important role in this reduction of p27(Kip1) expression.

Immunohistochemical and histochemical characterization of the mucosubstances of odontogenic myxoma: histogenesis and differential diagnosis

To discuss the dental origin of odontogenic myxoma and to provide further information for the differential diagnosis between this tumor and myxoid malignant fibrous histiocytoma (MFH) which occasionally occurs in jaw bones, the contents of glycosaminoglycans (GAGs) and proteoglycans (PGs) in the mucosubstances of 15 odontogenic myxomas, 5 myxoid MFH and 3 human fetal tooth germs in the bell stage of development were characterized using histochemical and immunohistochemical methods. Histochemical staining of hyaluronic acid (HA) was undertaken using biotinylated HA binding protein (B-HABP), and immunohistochemical detection was done using a panel of antibodies against chondroitin 6-sulfate (CS-6), chondroitin 4-sulfate (CS-4), dermatan sulfate (DS), keratan sulfate (KS), heparan sulfate (HS), aggrecan, PG-M/versican, decorin and biglycan. In odontogenic myxoma, CS-6, HA and PG-M/versican were observed in the myxomatous matrix of all cases, while KS and HS were seen in none. As for CS-4, DS, aggrecan, decorin and biglycan, only irregular and mild stainings were shown. Consistent and strong positive straining for CS-6, HA and PG-M/versican were seen in dental papilla and provided evidence supporting the origin of this tumor from dental papilla. Except for the constant staining for HA, the myxoid matrix was rarely stained for most GAGs and PGs in myxoid MFH. Immunodetection of CS-6 and PG-M/version with the use of monoclonal antibodies 3-B-3 and 2-B-1 is therefore recommended as a useful tool in differentiating odontogenic myoma from myxoid MFH.

Expression of p53 and p21CIP1/WAF1 proteins in oral epithelial dysplasias and squamous cell carcinomas

The expression of tumor suppressor gene, p53 and cyclin-dependent kinase inhibitor, p21 in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC) was examined immunohistochemically and its relationship with clinicopathological findings was analyzed. Among 24 epithelial dysplasias, 4 cases (17%) expressed p53 protein and 23 cases (96%) expressed p21 protein. On the other hand, expression of p53 was observed in 64% of OSCCs, and expression of p21 was observed in 77% of OSCCs. In the analyses of the correlation between the expression of p53 and p21 in epithelial dysplasia and OSCC, 79% of epithelial dysplasias were p53-negative and p21-positive, compared to 25% of the OSCCs. p21 expression did not correlate with p53 expression. These results were also demonstrated in OSCC cell lines by western blot analysis. Cumulative survival rate of the patients p53-negative and p21-positive was higher than those p53-positive and p21-negative, those p53-negative and p21-negative and those p53-positive and p21-positive. These findings suggest that p53 expression and p21 negative expression may involve in neoplastic transformation of oral epithelium. In the present study, we did not observe correlation between the expression of p53 and p21 proteins in OSCC. p21 expression may be regulated by p53-independent pathways as well as p53-dependent ones. However, combination of the p21 and p53 expression may be useful as a prognostic marker.

[Postoperative prophylactic intravesical instillation of tetrahydropyranyl-adriamycin (THP) for superficial bladder cancer]

Intravesical instillation of tetrahydropyranyl-adriamycin (THP) was performed on 51 patients with superficial bladder cancer after transurethral resection (TUR) for prophylaxis of recurrence. The instillation was carried out with 20 mg of THP dissolved in 40 ml of distilled normal saline. Instillation was performed once 24 hours postoperatively, 9 times every 2 weeks, and 8 times every 4 weeks. These drugs were instilled for 30 to 60 minutes. The recurrence-free survival at 1, 2 and 3 years was 74.5%, 64.6% and 58.0%, respectively. Side effects of THP instillation were observed in only 4 cases (7.8%) as slight urinary frequency or micturition pain. Cases involving 5 or more tumors, or tumors measuring 3 cm or larger, more frequently demonstrated recurrence. The cases that did not respond to preoperative intravesical instillation of THP demonstrated a high frequency of recurrence. Intravesical instillation of THP as a prophylaxis against recurrence of superficial bladder cancer was effective in selected patients.

Highly Selective Thioselenation of Vinylcyclopropanes with a (PhS)(2)-(PhSe)(2) Binary System and Its Application to Thiotelluration

A novel, highly selective method for introducing organic sulfur, selenium, and tellurium functions into vinylic cyclopropanes has been developed on the basis of the relative reactivities of organic dichalcogenides and chalcogen-centered radicals. Upon irradiation with the light of wavelength over 300 nm, the reaction of vinylcyclopropanes with diphenyl disulfide and diphenyl diselenide proceeds smoothly to provide the corresponding gamma-(selenoethyl)allylic sulfides regioselectively in good yields. Similarly, vinylcyclopropanes undergo regioselective thiotelluration by use of a novel (PhS)(2)-(PhTe)(2) binary system, affording the corresponding ring-opened thiotelluration product in good yields. Furthermore, the scope and limitations of this (PhS)(2)-(PhTe)(2) binary system are discussed.

Immunohistochemical evaluation of the small and large proteoglycans in pleomorphic adenoma of salivary glands

This study investigated the immunolocalization of small and large proteoglycans (PGs), including decorin, biglycan, PG-M/versican and aggrecan, in salivary pleomorphic adenoma (PA) using monoclonal and polyclonal antibodies. In addition, a polyclonal antibody, A0082, recognizing blood vessels was also used to help identify truly mesenchymal tissues in PA. Decorin reactivity was detected only in tumor capsule and interstitial tissue of non-neoplastic salivary gland, but not in the tumor tissue. Biglycan was frequently revealed throughout the matrix of small chondroid regions and in the peripheral portion of larger chondroid regions. PG-M/versican was mainly localized to the truly mesenchymal tissues in PA and the innermost portion of tumor capsule. On the contrary, aggrecan was extensively expressed in the non-luminal epithelial areas as well as in the myxoid and chondroid areas, but not in the truly mesenchymal tissues. These findings suggest that aggrecan is the most widely distributed PG in PA and may be produced mainly by non-luminal tumor cells. The absence of aggrecan from the truly mesenchymal tissues argues against its origin from this source. Both aggrecan and biglycan may play important roles in the chondroid differentiation and morphogenesis of PA.

Reduced expression of cyclin-dependent kinase inhibitor p27Kip1 is an indicator of malignant behavior in oral squamous cell carcinoma

BACKGROUND

Reduced expression of the cyclin-dependent kinase inhibitor p27Kip1 has been reported to correlate with poor survival in cohorts of breast and colorectal carcinoma patients. Posttranslational ubiquitin-mediated proteasomal proteolysis is related to p27Kip1 protein levels. However, to the authors' knowledge, no previous study has examined the expression of p27Kip1 in oral squamous cell carcinoma (OSCC).

METHODS

To examine the expression of p27Kip1 and its clinicopathologic roles in OSCC, the authors studied the expression of p27Kip1 protein by immunohistochemistry in deparaffinized tissue sections of 20 normal oral mucosa specimens, 22 epithelial dysplasia specimens, and 70 OSCCs, and analyzed its correlation with clinicopathologic parameters. They also studied the expression of p27Kip1 mRNA and protein in six OSCC cell lines by Northern blot and Western blot analysis. To examine the mechanism of reduced expression of p27Kip1, OSCC cell lines were treated with the proteasome inhibitor LLnV.

RESULTS

All the normal oral mucosa specimens and 73% (16 of 22) of the oral epithelial dysplasia specimens expressed p27Kip1 at high levels, whereas 87% of the OSCCs (61 of 70) showed reduced expression of p27Kip1. Furthermore, the levels of expression of this protein were significantly lower in carcinomas with metastasis than those without metastasis. Although OSCC cell lines expressed p27Kip1 mRNA at various levels, most of them expressed p27Kip1 protein at lower or undetectable levels. LLnV induced the expression of p27Kip1 protein in HSC2 cells, in which p27Kip1 protein was originally undetectable.

CONCLUSIONS

These findings suggest that 1) reduced expression of p27Kip1 may correlate with the development and progression of OSCC and can be an indicator of malignant behavior of this neoplasm, and 2) increased proteasome-mediated degradation may play an important role in the reduction of p27Kip1 protein expression.

Proliferative activity of calcifying odontogenic cysts as evaluated by proliferating cell nuclear antigen labeling index

The calcifying odontogenic cyst (COC) presents with diverse histological features; thus, several subclassifications have been proposed. To evaluate the significance of the various histological features and subtypes of COC from the perspective of proliferative activity, the proliferating cell nuclear antigen (PCNA) labeling index (LI; the percentage of positive nuclei) was assessed immunohistochemically in 25 cases of COC (21 benign and four malignant). All of the benign cases were of the cystic variety and further subclassified into non-proliferative subtype (NPS; four cases); proliferative subtype (PS; eight cases); and COC associated with odontoma (COCaO, nine cases). The PCNA LI of the malignant COC (65.2+/-5.6) was significantly higher than that of the benign COC (11.6+/-9.0; P = 0.002). Non-proliferative subtype (6.8+/-2.8) showed the lowest PCNA LI and PS (17.2+/-11.2) the highest of among the three subtypes of benign cystic COC (P = 0.028). In nine cases of COCaO, six showed epithelial lining of the non-proliferative type as NPS and the other three had lining with proliferative features as PS. The PCNA LI of the latter COCaO group (14.3+/-6.6) was significantly higher than that of the former (6.1+/-4.3; P = 0.05), as seen between PS and NPS. These results demonstrate that PCNA LI is a possible parameter for differentiating malignant COC from benign COC and, whatever the subtypes, the proliferative features in the lining are the main factor influencing the proliferating activity of COC.

Three-dimensional appearance of Langerhans cells in human gingival epithelium as revealed by confocal laser scanning microscopy

Detailed three-dimensional morphological information of the cell without distortion due to thin sectioning can be obtained from thick sections using a confocal laser scanning microscope. Here that microscope was used to evaluate human gingival Langerhans cells stained with anti-CD1a antibody. Optical sectioning and reconstruction by laser scanning microscopy revealed not only three-dimensional aspects of Langerhans cells but also spatial information on the distribution of their dendritic processes towards the gingival surface. The orientated configuration of those processes may reflect the reaction of the gingival Langerhans cell to the surrounding moist environment containing antigenic stimuli originating in saliva.

Distribution of macrophage lineage cells in rat gingival tissue after topical application of lipopolysaccharide: an immunohistochemical study using monoclonal antibodies: OX6, ED1 and ED2

To discuss the role of macrophage lineage cells on the periodontal tissue destruction, we immunohistochemically examined the phenotype and the dynamics of macrophage lineage cells 1 or 3 h or 1, 2, 3 or 7 d after topical application of LPS (5 mg/ml in physiological saline) from the rat gingival sulcus using 3 monoclonal antibodies: OX6 (antigen-presenting cells), ED1 (monocytes, macrophages and dendritic cells) and ED2 (resident macrophages). We could detect at least 3 different types of macrophage lineage cells, namely OX6+/ED1+/ED2- dendritic cells and exudate macrophages and ED2+ resident macrophages. After LPS application the majority of macrophage lineage cells accumulated in the subjunctional epithelial area were newly extravasated OX6+/ED1+/ED2- dendritic cells or macrophages. The number of these cells increased progressively with time and reached a maximum level at d 2. On the other hand, number and tissue distribution of ED2+ resident macrophages did not change. These results indicate that several types of macrophage lineage cells exist in rat gingival tissue and suggest that dendritic cells and exudate macrophages transiently accumulated after LPS application are responsible for various host immune response and tissue destruction caused by LPS.

Immunohistochemical demonstration of bone morphogenetic protein-2 and type II collagen in pleomorphic adenoma of salivary glands

Immunohistochemical investigation of bone morphogenetic protein-2 (BMP-2) and type II collagen, two cartilage-associated proteins, was undertaken using monoclonal antibodies in 20 cases of salivary pleomorphic adenoma (PA) in order to explore their possible roles in chondroid differentiation of this tumor. Other salivary gland tumors, including adenoid cystic carcinoma (17 cases), polymorphous low-grade adenocarcinoma (10 cases), basal cell adenoma (3 cases), basal cell adenocarcinoma (1 case), and epithelial-myoepithelial carcinoma (2 cases), were also examined for comparison. In PA, BMP-2 immunoreactivity was detected in the luminal and non-luminal cells of the tubulo-ductal structures, plasmacytoid cells, and other scattered tumor cells in solid areas. In addition, tumor cells in chondroid areas in most cases (14/15), and stellate cells in myxoid areas in many cases (7/19), were also intensely labeled for BMP-2. Furthermore, BMP-2 was also detected in the non-neoplastic ductal cells in salivary glands, whereas no other salivary gland tumors were positively stained for this protein. Type II collagen was localized in the intercellular matrix of chondroid areas and in a few chondroid differentiating cells in myxoid areas, confirming its cartilage-specificity. A proportional relationship was observed between BMP-2 expression and chondroid formation, although BMP-2 was also stained in occasional PAs without chondroid formation. It is speculated that BMP-2 might be secreted by tumor cells and play a role in chondroid formation in PA by inducing some tumor cells to produce type II collagen and other chondroid matrical substances, like glycosaminoglycans. The expression of BMP-2 is specific to PA and may possibly be used as a useful marker in differentiating PA from other salivary gland tumors.

Localization of glycosaminoglycans (GAGs) in pleomorphic adenoma (PA) of salivary glands: an immunohistochemical and histochemical evaluation

The tumor matrix of salivary pleomorphic adenoma (PA) is characteristically rich in glycosaminoglycans (GAGs), which contribute to its complex histoarchitecture. This study evaluated the microscopic localization of various GAGs in 17 PAs, using a panel of anti-GAG monoclonal antibodies and biotinylated hyaluronic acid (HA)-binding protein. Both epithelial and mesenchymal-like tissues were confirmed to contain GAGs. Luminal epithelial cells mostly lacked GAGs, whereas GAGs were seen both in the cytoplasm and cell membrane of non-luminal epithelial cells. In addition, small intercellular accumulations of GAGs were often present in solid epithelial areas, implying the epithelial origin of GAGs. GAGs did not appear to be a main component of the hyaline matrix. The myxoid region was consistently stained for both chondroitin 6-sulfate (CS-6) and HA but variably for chondroitin 4-sulfate (CS-4), dermatan sulfate (DS) and keratan sulfate (KS); heparan sulfate (HS) was not detected. The chondroid region showed increased staining for CS-6 but reduced staining for HA when compared with the myxoid region. In addition, CS-4, DS and KS were seen both in chondroid cells and the territorial matrix, whereas HS was present only in the cells. It is suggested that GAGs in PA are mainly produced by non-luminal cells and influence the proliferation, differentiation, secretory activity and shape of tumor cells, thus contributing to the morphological diversity of this tumor.