Granular cell ameloblastoma: case report of a particular ameloblastoma histologically resembling oncocytoma.

Granular cell ameloblastoma is classified as a histological subtype of solid/multicystic ameloblastoma. Usual granular cell ameloblastoma is histologically characterized by granular changes of stellate-like cells located in the inner portion of the epithelial follicles. Here we report a case of another type of granular cell ameloblastoma, showing predominant anastomosing double-stranded trabeculae of granular cells. This type of granular cell ameloblastoma is extremely rare, and the World Health Organization classification does not contain the entity. We tentatively termed it 'anastomosing granular cell ameloblastoma' in this report. The present case suggests the importance of differential diagnosis because the histology of 'anastomosing granular cell ameloblastoma' resembles that of salivary gland oncocytoma rather than that of usual granular cell ameloblastoma. The trabeculae observed in our case continued to the peripheral cells of a small amount of epithelial sheets of plexiform ameloblastoma, and the tumor cells were positive for CK19, which is regarded as an immunohistochemical marker of odontogenic epithelium. Similar to usual granular cell ameloblastoma, the tumor cells had CD68-positive granules. For precise diagnosis of this condition, immunohistochemistry using CK19 and CD68, as well as detailed histological observation, are recommended.

Metabolomics of Salivary Biomarkers in Yusho Patients.

Yusho patients had many symptoms, and mouth dryness was one of the important oral symptoms. Presently, some Yusho patients complain of mouth dryness. In the present study, we measured mouth dryness by using an oral moisture checking device and examined metabolites of saliva by using metabolome analysis. We found no difference between Yusho patients and controls in terms of mouth dryness. Concerning metabolomes of saliva, there were some metabolites in Yusho patients that were not in controls.

[A clinical study of TMJ arthrosis in Yusho patients].

In the present study, we clarified the TMJ symptoms of Yusho patients. An epidemiologic examination was carried out to identify TMJ arthrosis in patients with Yusho. The patients were collected during annual Yusho examinations in 2012. Nine of 187 patients had TMJ symptoms. The symptoms were pain, trismus, and a clicking sound of the TMJ. We diagnosed these patients with TMJ arthrosis. The rate of TMJ arthrosis in Yusho patients was 4.8%, being similar to the rate of TMJ arthrosis in general. The PCB concentration in the blood of these 9 patients was 2.76 ppb, and the average blood PCB concentration of all patients was 2.98 ppb. We identified no relationship between the blood PCB concentration and TMJ arthrosis.

Efficacy and toxicity of S-1 plus cisplatin combination neoadjuvant chemotherapy in patients with oral cancer.

S-1 is a newly developed oral fluoropyrimidine derivative that is now widely used as a chemotherapeutic agent in the treatment of various carcinomas. This study was performed to assess the efficacy and safety profile of the combination of S-1 and cisplatin(S-1/CDDP)in patients with oral cancer as neo-adjuvant chemotherapy. We reviewed our experience of 12 patients diagnosed with oral carcinoma, who were treated with S-1/CDDP. S-1 was administered orally at a dose of 50mg twice a day for 21 consecutive days, followed by a 14-day rest period. CDDP(60mg/m2)in 500 mL physiological saline was administered by intravenous drip as a 120-min infusion on day 8, together with standard premedications and hydration. Seven partial responders were obtained. The median follow-up duration was 54. 8 months, and all patients were alive excluding one case. This regimen was well tolerated, with only one case of grade 3 thrombocytopenia, and no grade 4 patient. No treatment-related death was observed. Moreover, we evaluated immunohistochemical expressions of thymidylate synthase (TS), dihydropyrimidine dehydrogenase(DPD), and orotate phosphoribosyl transferase(OPRT)which are associated with chemosensitivity to 5-FU-based therapies. We investigated the relation between the immunohistochemical score and clinicopathological factors, however we could not clarify the relationship between the efficacy of chemotherapy and results of immunohistochemistry.

Clinicopathological and Prognostic Analysis of PD-L1 and PD-L2 Expression in Surgically Resected Primary Tongue Squamous Cell Carcinoma.

BACKGROUND/AIM: The expression of tumor-associated programmed death-ligand 1 (PD-L1) predicts clinical responses to PD-1-directed immunotherapy. The expression levels of PD-L2, another PD-1 ligand, and its relationship with responses to PD-1-targeting therapy in oral squamous cell carcinoma (OSCC) remain unclear. Furthermore, the clinicopathological characteristics and prognostic effects of the expression of PD-L1 and PD-L2 in OSCC have not yet been elucidated. MATERIALS AND METHODS: The expression of PD-L1 and PD-L2 was immunohistochemically examined in 98 tongue carcinomas. Furthermore, the expression levels of PD-L1 and PD-L2 in OSCC cell lines and their relationships with those of MMP2 and MMP9 were assessed. RESULTS: The expression levels of PD-L1 and PD-L2 correlated with those of MMP2 and MMP9. The expression of PD-L1 and/or PD-L2 was detected in OSCC cells, and their levels correlated with those of MMP9. The prognosis of patients with PD-L1- and PD-L2-positive tumors was significantly worse. CONCLUSION: PD-L1 and PD-L2 status is potentially a novel predictor of the prognosis of OSCC and provides a rationale for the development of novel immunotherapies.

[Immunohistochemical and clinicopathological study of thymidylate synthase, dihydropyrimidine dehydrogenase, and orotate phosphoribosyl transferase expression in oral cancer patients responding to UFT].

Thymidylate synthase(TS), dihydropyrimidine dehydrogenase(DPD), and orotate phosphoribosyl transferase(OPRT)are initial key enzymes in the 5-fluorouracil(5-FU)metabolic pathway. In this study, we investigated clinicopathological and immunohistochemical expressions of TS, DPD, and OPRT in oral cancer patients who showed a complete response(CR)to UFT. We also evaluated patients showing a partial response(PR)and stable disease(SD)following UFT. The numbers of CR, PR, and SD cases were 3, 5, and 10, respectively. Pathologically, all CR and PR cases were the well-differentiated type, and 5 out of 10 SD cases were of the moderately or poorly-differentiated type. Three out of the 5 cases of moderately or poorlydifferentiated type were DPD-negative. Most cases of CR and PR were DPD-positive. OPRT expression showed no difference with the UFT response. We suggest that UFT affects high DPD patients with the well-differentiated type, but may not influence low DPD patients with the moderately or poorly-differentiated type.

Effect of dioxin-related compounds on oral pigmentation in patients affected by the Yusho incident.

BACKGROUND/AIM: Toxins such as polychlorinated biphenyls (PCBs) and dioxins dramatically affect patients even decades after exposure. Patients with Yusho, a condition caused by exposure to PCBs and dioxins, have diverse mental and physical complaints, even though it is almost 50 years since the Yusho incident. Oral pigmentation is one of the major symptoms in Yusho patients. PATIENTS AND METHODS: A total of 183 participants in the Yusho health study were examined. Oral examinations, including recording the prevalence of oral pigmentation, were performed by two oral surgeons. Demographic and clinical characteristics, including blood concentration of PCB and 2,3,4,7,8-pentachlorodibezofuran (2,3,4,7,8-PeCDF), which are the major causes of Yusho, were obtained from the results of recent surveys conducted by the Yusho Study Group. RESULTS: The mean serum PCB and 2,3,4,7,8-PeCDF levels of the 183 Yusho patients were 1.59 ± 1.25 ppb and 29.0 ± 42.9 pg/g lipid, respectively. There was a significant correlation between the levels of PCB and 2,3,4,7,8-PeCDF (r = 0.64, p < 0.01). The rate of oral pigmentation in Yusho patients (25.7%) was significant higher than among potential victims of Yusho (13 of 183, 7.1%) (p < 0.05). CONCLUSION: The prevalence of oral pigmentation was still significantly higher in Yusho patients, even 50 years after exposure, although blood PCB levels have decreased in that time.

Prognostic Significance of Pretreatment Lymphocyte-to-Monocyte Ratio in Patients with Tongue Cancer.

BACKGROUND/AIM: Low pre-operative lymphocyte-to-monocyte ratio (LMR) is associated with worse outcomes in several malignancies. The aim of this study was to determine the prognostic value of LMR in tongue cancer. MATERIALS AND METHODS: A total of 103 patients with pathologically-proven tongue cancer were retrospectively analyzed. The peripheral LMR and the ratio of CD8-positive to CD14-positive (CD8+/CD14+) tumor-infiltrating cells were determined by immunohistochemical staining. Receiver operating characteristic curve analysis, log-rank test, and Cox proportional hazards regression models were used for statistical analysis. RESULTS: There was a significant difference in overall survival (OS) between low LMR and high LMR, and low CD8+/CD14+ tumor-infiltrating cells and high CD8+/CD14+ tumor infiltrating cells. For the clinical analysis, multivariate analysis showed that clinical ocular inspection type and low LMR were independent predictors for poor OS. Concerning the immunohistochemical analysis, monocyte count was independent predictor of poor OS. CONCLUSION: Pre-operative LMR and CD8+/CD14+ tumor-infiltrating cells serve as independent prognostic biomarkers.

Clinical Study of Reconstruction Plates Used in the Surgery for Mandibular Discontinuity Defect.

BACKGROUND/AIM: Postresective mandibular reconstruction is common in cases of oral and mandibular tumors. However, complications such as plate fracture and/or plate exposure can occur. The purpose of this study was to analyze complications and survival of reconstructive plates used to correct mandibular defects caused by oral cancer. PATIENTS AND METHODS: Clinical and radiological data from 34 patients were analyzed. Only discontinuous mandibular defect cases were included in this study. All cases were classified using the Hashikawa's CAT and Eichner's classification methods. Then, we determined whether these classifications and clinical treatment methods were significantly related to complications. RESULTS: Complications after mandibular reconstruction occurred in 10 of 34 patients, specifically, two plate fractures, one screw fracture, and seven plate exposures occurred. The plate fractures occurred 5 and 6 months after operation, and the screw fracture occurred 39 months after operation. Using the Hashikawa's CAT classification, the two cases of plate fracture were one of AT type and the other of T type, and the screw fracture was AT type. Using Eichner's classification, all three cases of plate and screw fractures were B2 type. CONCLUSION: We suggest that plate and screw fractures were caused by the type of mandibular defect and bite force.

mTORC1 and mTORC2 Expression Levels in Oral Squamous Cell Carcinoma: An Immunohistochemical and Clinicopathological Study.

BACKGROUND/AIM: Mammalian target of rapamycin (mTOR) plays a critical role in the regulation of tumor cell motility, invasion and cancer cell metastasis. mTOR consists of two separate multi-protein complexes, mTOR complex (mTORC) 1 and mTORC2. MATERIALS AND METHODS: We investigated the expression levels of mTORC1 and mTORC2 immunohistochemically in oral squamous cell carcinoma (OSCC). RESULTS: mTORC1 and mTORC2 were more highly expressed in tumors than in normal oral mucosa. mTORC1 expression was correlated with T classification, N classification, and survival rate (p<0.05), whereas mTORC2 expression was only correlated with T classification (p<0.05). Histologically, the expression levels of mTORC1 and mTORC2 correlated with cancer cell invasion and the expression of proliferating cell nuclear antigen (p<0.05), respectively. Expression levels of vascular endothelial growth factors and hypoxia-inducible factor 1 in the mTORC1 (-)/ mTORC2 (+) group were significantly lower than those in other groups. CONCLUSION: These findings suggested that mTORC1 and mTORC2 could be promising anti-tumor targets in OSCC, and mTORC1 (-)/mTORC2 (+) may have a correlation with the malignant potential of OSCC.

Clinicopathologic significance of EpCAM expression in squamous cell carcinoma of the tongue and its possibility as a potential target for tongue cancer gene therapy.

Epithelial adhesion molecule (EpCAM) is a transmembrane glycoprotein involved in intercellular adhesion. In particular, EpCAM appears to be overexpressed by the majority of human epithelial carcinomas, including colorectal, breast, head and neck, and hepatic carcinomas. We therefore hypothesized that EpCAM would be a good molecular target for cancer gene therapy. EpCAM protein expression in 48 primary tongue cancers and 10 normal oral mucosa was evaluated using anti-EpCAM immunohistochemistry, and correlation was examined with the clinicopathologic factors. In four human tongue cancer cell lines (SAS, HSC-2, OSC19 and OSC20), we investigated EpCAM expression by reverse transcription-polymerase chain reaction (RT-PCR). The invasive potential of cancer cells was evaluated using Matrigel invasion assay. Moreover, the effect of EpCAM inhibition was analyzed using RNA interference (RNAi). EpCAM overexpression was detected in 30 of 48 tongue cancers (62.5%), and was significantly higher in primary squamous cell carcinoma (SCC) of the tongue than in normal oral mucosa. The expression of EpCAM was significantly associated with tumor size, regional lymph node metastasis, histological differentiation and invasion pattern. Cancer cell lines with higher EpCAM expression had more invasive potential. Moreover, RNAi-mediated EpCAM reduction decreased the invasion potential and proliferation activity. These results indicated that the overexpression of EpCAM was correlated with a more aggressive phenotype of tongue cancer. Moreover, we suggested that EpCAM could be a molecular target, and that RNAi targeting EpCAM could be useful for tongue cancer gene therapy.

Orotate phosphoribosyl transferase mRNA expression in oral squamous cell carcinoma and its relationship with the dihydropyrimidine dehydrogenase expression and the clinical effect of 5-fluorouracil.

In this study, we investigated whether orotate phosphoribosyl transferase (OPRT) correlates with the clinicopathological features and effect of 5-fluorouracil (5-FU) in human oral carcinoma. We examined the expression of OPRT mRNA by in situ hybridization in surgical specimens of oral squamous cell carcinoma. The expression of OPRT mRNA in oral carcinoma was observed in all specimens and such expression was higher than that seen in normal control tissue specimens. There was no correlation between the expression of OPRT mRNA and clinical factors, but the expression of OPRT mRNA was significantly associated with histological differentiation. The expression of OPRT mRNA showed correlation with effect of 5-FU for oral carcinoma in either in vivo or in vitro. These results suggest that the OPRT expressions may therefore be a prognostic factor of 5-FU efficacy in patients with oral squamous cell carcinoma.

Silencing of the p53R2 gene by RNA interference inhibits growth and enhances 5-fluorouracil sensitivity of oral cancer cells.

The p53R2 gene encodes the ribonucleotide reductase (RR) small subunit 2 homologue, and is induced by several stress signals activating p53, such as DNA-damaging agents. The p53R2 gene product causes an increase in the deoxynucleotide triphosphate (dNTP) pool in the nucleus, which facilitates DNA repair and synthesis. We hypothesized that p53R2 would be a good molecular target for cancer gene therapy. In this study, three human oral cancer cell lines (SAS, HSC-4 and Ca9-22), a human breast cancer cell line MCF-7, and a normal human fibroblast cell line NHDF were tested. We silenced the expression of p53R2 with the highly specific post-transcriptional suppression of RNA interference (RNAi). We investigated p53R2 expression with the reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. The sensitivity to anticancer agents was evaluated by a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The expression of p53R2 showed no association with the mutational status of p53. The cancer cell lines with higher p53R2 expression were more resistant to 5-FU. RNAi-mediated p53R2 reduction selectivity inhibited growth and enhanced chemosensitivity in cancer cell lines but not in normal fibroblasts. These results suggest that basal transcription of p53R2 could be associated with the sensitivity to anticancer agents. Moreover, we assessed the possibility that p53R2 would be a good molecular target, and report that RNAi targeting of p53R2 could be useful for oral cancer gene therapy.

Anti-tumor effect of the mammalian target of rapamycin inhibitor everolimus in oral squamous cell carcinoma.

The mammalian target of rapamycin (mTOR) has recently emerged as a promising target for therapeutic anti-cancer interventions in several human tumors. In present study, we investigated the expression of mTOR, and subsequently examined its relationship with clinicopathological factors and the anti-tumor effect of everolimus (also known as RAD001) in oral squamous cell carcinoma (OSCC). The expression of phosphorylated mTOR (p-mTOR) was immunohistochemically evaluated in specimens obtained from 70 OSCC patients who underwent radical surgery. The relationships between the expression of p-mTOR and clinicopathological factors and survival were determined. We also investigated the effect of everolimus on the OSCC cell lines, SAS, HSC-2, HSC-3, HSC-4, OSC-20, SCC25 and Ca9-22 by the MTT assay. We further evaluated whether mTOR contributed to cell functions by blocking its activity with everolimus, and confirmed the direct target by the Matrigel invasion assay, wound healing assay and Western blotting. p-mTOR was overexpressed in 37 tumors (52.8 %), and correlated with the T classification, N classification, and survival rate (P < 0.05). The treatment with everolimus significantly inhibited cell growth, and significantly reduced the expression of p-mTOR, downstream signaling proteins, and hypoxic related proteins as well as invasion and migration potentials (P < 0.05). The results of the present study suggest that everolimus may represent an attractive approach for the future treatment of OSCC.

Lipomas of the oral cavity: clinicopathological and immunohistochemical study of 24 cases and review of the literature.

Although lipomas are common soft tissue tumors, few cases of lipoma or its variants have been reported in the oral cavity. We here described the clinical, histological, and immunohistochemical features of 24 cases of oral lipoma obtained from medical records at Nagasaki University Hospital between 1977 and 2010, and also retrospectively reviewed 603 cases of oral lipoma reported in the English literatures. The patients examined comprised 11 men and 13 women with a mean age of 59 years, ranging from 31 to 90 years. The main sites involved were the buccal mucosa (n = 9), followed by the tongue (n = 4), lip and retromolar area (n = 3), floor of the mouth (n = 2), and gingiva (n = 1). The mean tumor size was 2.0 cm, ranging from 0.2 to 5 cm. Histological analysis revealed 20 cases of lipoma, 2 cases of fibrolipoma, and one case each of intramuscular lipoma and spindle cell lipoma. Twenty-three cases were treated surgically while one case underwent biopsy and follow-up. Recurrence was not observed in any case. We reviewed the English literatures, and similar results were obtained. In immunohistochemical analysis, PCNA and ki-67 expression indices were higher in intramuscular lipoma cases than in its variants. Especially, it showed that a long time follow-up may be necessary in ki-67 positive cases.

Expression of p53R2, newly p53 target in oral normal epithelium, epithelial dysplasia and squamous cell carcinoma.

Recently, the p53R2 gene has been isolated and shown to play a crucial role in DNA repair after DNA damage. The p53R2 gene encodes the p53 inducible ribonucleotide reductase small subunit 2 homologue, which is part of the p53 pathway. However, the function of p53R2 in human cancer is still unclear. We investigated p53R2 mRNA expression in human oral normal epithelium, epithelial dysplasias and squamous cell carcinomas (SCCs). Surgical or biopsy-proven specimens of 10 normal epithelium, 48 epithelial dysplasias and 63 SCCs were collected in our department. Then, p53R2 was identified by in situ hybridization to visualize and localize the expression of specific mRNAs. The authors examined the p53 gene mutation by polymerase chain reaction-single strand conformation polymorphism analysis. p53, mdm2, p21(WAF1/CIP1) and Ki-67 expression was detected by immunohistochemistry. p53R2 expression was detected in none of ten normal epithelium (0%), ten of 48 dysplasias (20.8%) and 33 of 63 SCCs (52.4%). In oral SCC, the expression of p53R2 was significantly associated with tumor size, lymph node metastasis and histological differentiation (P=0.014, 0.046 and 0.022, respectively). p53R2 expression was significantly associated with p53 abnormality in epithelial dysplasia and SCC (P=0.034 and 0.009, respectively). Of 63 patients, 37 received preoperative radiochemotherapy. p53R2 mRNA expression was significantly associated with the pathologic response to radiochemotherapy (P=0.031). This study suggested that p53R2 expression could be associated with oral carcinogenesis. The presence of p53R2 mRNA expression would be a predictive factor for tumor development, tumor cell differentiation and the sensitivity to radiochemotherapy in oral SCC.

Cathepsin expression in oral squamous cell carcinoma: relationship with clinicopathologic factors.

OBJECTIVE: Proteases are involved in the invasion and metastasis of carcinoma cells. In vivo, oral carcinoma cells easily invade the bone tissue and metastasize to the submandibular and neck lymph nodes. Cathepsin expression has been shown in some neoplastic tissues and serves as a prognostic indicator. The purpose of this study was to investigate the relationship between clinicopathohistologic grades and cathepsin expressions in oral squamous cell carcinoma and to investigate which cathepsin provides prognostic information for patients with oral carcinoma. STUDY DESIGN: Immunohistochemical studies were performed on 78 carcinoma samples with monoclonal antibodies against cathepsins B, H, and L, and a polyclonal antibody against cathepsin D. Serial sections were stained by hematoxylin-eosin staining and classified by Anneroth's classification. Cathepsin B, H, L and D activities of blood serum were determined. Positive results indicative of the presence of cathepsin were investigated to determine any correlation between a particular cathepsin and histologic malignancy grades, tumor cell growth, serum cathepsin activities, and clinical factors. RESULTS: Cathepsins B, H, L, and D were positive in every case. Although the labeling indices for cathepsins B (CB-LI), H (CH-LI), and D (CD-LI) for the cancer cases showed significant differences from those of controls, cathepsin L (CL-LI) of cancer cases showed no difference from that of controls (P <.05). A close correlation was found between CD-LI and T categories of TNM classification (P <.05), and between CD-LI and PCNA-LI (P <.05). Furthermore, a close correlation was found between CD-LI and N categories in TNM classification (P <.05). Pathologically, a close correlation was found between CB-LI or CD-LI and the pattern and/or stage of invasion (P <.05). CONCLUSION: Cathepsin D and B expression were closely correlated with carcinoma invasion and progression. These proteases may be useful in determining the prognoses of patients with oral carcinoma.

p53, mdm2, and p21 expression in oral squamous cell carcinomas: relationship with clinicopathologic factors.

OBJECTIVE: The purpose of this study was to clarify the correlation of expression of cell cycle-associated gene proteins with clinicopathologic factors in oral squamous cell carcinoma (SCC). STUDY DESIGN: Formalin-fixed paraffin-embedded tissues from 69 oral SCC cases and 10 normal mucosa cases were stained by immunohistochemistry (IHC) for p53, mdm 2, and p21 proteins. RESULTS: We found p53, mdm 2, and p21 expression in 44 of 69 (63.8%), 25 of 69 (36.2%), and 37 of 69 (53.6%) oral SCCs, respectively. Ki-67-labeling index of combined p53(+)/mdm 2(+) expression cases was significantly higher than those that lacked combined expression (P =.004). Combined p53(+)/p21(+) expression showed a significant association with lymph node metastasis (P =.019). In survival analysis, combined p53(+)/p21(+) and p53(+)/mdm 2(+)/p21(+) expression was associated with poor clinical outcome (P =.018 and.012, respectively). CONCLUSION: Combined p53/mdm 2 expression was associated with tumor proliferation in oral SCC. Combined p53/p21 and p53/mdm 2/p21 expression may be a predictive factor in lymph node metastasis.