Difference between Keratinized- and Non-Keratinized-Originating Epithelium in the Process of Immune Escape of Oral Squamous Cell Carcinoma.

Immune checkpoint inhibitors (ICIs), including anti-programmed cell death 1 ligand 1 (PD-L1) antibodies, are significantly changing treatment strategies for human malignant diseases, including oral cancer. Cancer cells usually escape from the immune system and acquire proliferative capacity and invasive/metastatic potential. We have focused on the two immune checkpoints, PD-1/PD-L1 and CD47/SIRPα, in the tumor microenvironment of oral squamous cell carcinoma (OSCC), performed a retrospective analysis of the expression of seven immune-related factors (PD-L1, PD-1, CD4, CD8, CD47, CD56 and CD11c), and examined their correlation with clinicopathological status. As a result, there were no significant findings relating to seven immune-related factors and several clinicopathological statuses. However, the immune checkpoint-related factors (PD-1, PD-L1, CD47) were highly expressed in non-keratinized epithelium-originated tumors when compared to those in keratinized epithelium-originated tumors. It is of interest that immunoediting via immune checkpoint-related factors was facilitated in non-keratinized sites. Several researchers reported that the keratinization of oral mucosal epithelia affected the immune response, but our present finding is the first study to show a difference in tumor immunity in the originating epithelium of OSCC, keratinized or non-keratinized. Tumor immunity, an immune escape status of OSCC, might be different in the originating epithelium, keratinized or non-keratinized.

Primary syphilis with a tongue ulcer mimicking tongue cancer: a case report.

The main symptom in primary syphilis is a small, painless, sore or ulcer called a chancre on the penis, vagina, or around the anus, although chancres can sometimes appear in the mouth or on the lips, fingers, or buttocks. We present the case of a man in his early 60 s with a chief complaint of a painful tongue ulcer. An ulcerated, indurated, and hemorrhagic lesion (23 × 14 mm) was found on the ventral tongue surface, near the oral floor. Palpation identified several swollen, mobile, elastic cervical lymph nodes, with no tenderness. We initially diagnosed tongue cancer; however, during a subsequent detailed examination for a malignant tumor, including biopsy and obtaining additional history, his disease was finally identified as primary syphilis with multiple swollen cervical lymph nodes. Oral amoxicillin and probenecid were started, and after 14 days, there was partial reduction in the size of the submandibular lymph nodes and the ulcer on the left tongue margin. The number of patients with syphilis in Japan increased by eight times from 2012 to 2018. We suggest that dentists consider primary syphilis as a differential diagnosis for oral refractory ulcer with induration and obtain a detailed patient history.

The mutational spectrum in whole exon of p53 in oral squamous cell carcinoma and its clinical implications.

Mutations in p53 are common in human oral squamous cell carcinoma (OSCC). However, in previous analyses, only detection of mutant p53 protein using immunohistochemistry or mutations in some exons have been examined. Full length mutant p53 protein in many cases shows a loss of tumor suppressor function, but in some cases possibly shows a gain of oncogenic function. In this study, we investigate relationships of outcomes with the mutational spectrum of p53 (missense and truncation mutations) in whole exon in OSCC. Specimens from biopsy or surgery (67 cases) were evaluated using next-generation sequencing for p53, and other oncogenic driver genes. The data were compared with overall survival (OS) and disease-free survival (DFS) using univariate and multivariate analyses. p53 mutations were detected in 54 patients (80.6%), 33 missense mutations and 24 truncation mutations. p53 mutations were common in the DNA-binding domain (43/52) and many were missense mutations (31/43). Mutations in other regions were mostly p53 truncation mutations. We detected some mutations in 6 oncogenic driver genes on 67 OSCC, 25 in NOTCH1, 14 in CDKN2A, 5 in PIK3CA, 3 in FBXW7, 3 in HRAS, and 1 in BRAF. However, there was no associations of the p53 mutational spectrum with mutations of oncogenic driver genes in OSCC. A comparison of cases with p53 mutations (missense or truncation) with wild-type p53 cases showed a significant difference in lymph node metastasis. DFS was significantly poorer in cases with p53 truncation mutations. Cases with p53 truncation mutations increased malignancy. In contrast, significant differences were not found between cases with p53 missense mutations and other mutations. The p53 missense mutation cases might include cases with mostly similar function to that of the wild-type, cases with loss of function, and cases with various degrees of gain of oncogenic function.

A novel cell-based transplantation method using a Rho kinase inhibitor and a specific catheter device for the treatment of salivary gland damage after head and neck radiotherapy.

Radiotherapy (RT) for head and neck cancer results in irreversible damage to salivary glands (SGs) and decreases saliva production, leading to a dry mouth. To date, there are no satisfactory therapies to solve this problem. We recently established a novel culturing method using a Rho kinase inhibitor (RI), Y-27632, that maintained cellular morphology and function for a prolonged period of time. In the present study, we investigated whether cell-based transplantation using our culturing method ameliorated the dysfunction of irradiated SGs. First, rat SG cells were cultured in a medium with RI. Cells were characterized by morphological findings and mRNA expression analysis. We also assessed features of SG cells in three-dimensional (3-D) culture by scanning electron microscopy and immunohistochemistry (IHC). The RI-containing medium led to higher cell proliferation of rat SG cells with preservation of cell morphology and higher alpha-amylase (AMY) expression in both 2-D and 3-D culture systems. To establish the atrophic-SG models, external RT at a dose of 15 Gy was delivered to the head and neck fields of nude rats. The SG cells derived from GFP-rats were cultured in medium with RI, after which they were transplanted into the submandibular glands of atrophic-SG rats using a catheter placed into Wharton's duct. IHC and salivary flow rate (SFR) analyses were measured 12 weeks after the transplantation. Following transplantation, donor cells (GFP-SG cells) were primarily located in the ductal region of the SG, and AMY expression in SGs and the SFR were increased in the SG cell transplantation group compared with the control. Those data indicated that cell-based therapy using RI-treated SG cells could restore salivary hypofunction of irradiated SGs by direct integration of the donor cells in the duct of SGs. We propose that these data support future clinical plans in which SG cells would be excised from the labial minor SGs of the patients with head and neck cancers prior to RT, cultured during RT, and auto-transplanted into SGs using a catheter into the Wharton's duct. We believe that our culturing and transplantation methods can be applied to SG cells, constituting a therapeutic approach for the treatment of patients with dry mouth after not only RT but also aging and Sjögren's syndrome.

Diversity of the Origin of Cancer Stem Cells in Oral Squamous Cell Carcinoma and Its Clinical Implications.

Oral squamous cell carcinoma (OSCC) histopathologically accounts for ≥90% of oral cancer. Many clinicopathological risk factors for OSCC have also been proposed, and postoperative therapy is recommended in guidelines based on cancer stage and other risk factors. However, even if the standard treatment is provided according to the guidelines, a few cases rapidly recur or show cervical and distant metastasis. In this review article, we focus on the diversity of the origin of OSCC. We also discuss cancer stem cells (CSCs) as a key player to explain the malignancy of OSCC. CSCs are a subset of cancer cells that occupy a very small portion of the cancer mass and have characteristics of stem cells. When gene abnormalities accumulate in somatic stem cells, those cells transform into CSCs. CSCs as the origin of cancer then autonomously grow and develop into cancer. The histopathological phenotype of cancer cells is determined by the original characteristics of the somatic stem cells and/or surrounding environment. OSCC may be divided into the following three categories with different malignancy based on the origin of CSCs: cancer from oral epithelial stem cell-derived CSCs, cancer from stem cells in salivary gland-derived CSCs, and cancer from bone marrow-derived stem cell-derived CSCs.

Surveillance for Patients with Oral Squamous Cell Carcinoma after Complete Surgical Resection as Primary Treatment: A Single-Center Retrospective Cohort Study.

BACKGROUND: The surveillance methods oral squamous cell carcinoma (OSCC) patients may be chosen by considering the risk for recurrence, and it is important to establish appropriate methods during the period in which latent/dormant cancer cells become more apparent. To investigate the appropriate surveillance of patients with OSCC based on the individual risk for recurrence and/or metastasis, we performed a retrospective cohort study after the complete surgical resection of OSCC as the primary treatment. METHODS: The study was performed in 324 patients with OSCC who had been primarily treated with surgery from 2007 to 2020 at our hospital. We investigated the period, timing, and methods (visual examination, palpation and imaging using FDG-PET/CT or CECT) for surveillance in each case that comprised postsurgical treatment. RESULTS: Regarding the time to occurrence of postsurgical events, we found that half of cases of local recurrence, cervical lymph node metastasis, and distant metastasis occurred within 200 days, and 75% of all of these events occurred within 400 days. However, the mean time for second primary cancer was 1589 days. The postsurgical events were detected earlier by imaging examinations than they were by visual examination and palpation. CONCLUSIONS: For the surveillance of patients with OSCC after primary surgery, it is desirable to perform FDG-PET/CT within 3-6 months and at 1 year after surgery and to consider CECT as an option in between FDG-PET/CT, while continuing history and physical examinations for about 5 years based on individual risk assessment.

Identification of Binding Proteins for TSC22D1 Family Proteins Using Mass Spectrometry.

TSC-22 (TGF-ß stimulated clone-22) has been reported to induce differentiation, growth inhibition, and apoptosis in various cells. TSC-22 is a member of a family in which many proteins are produced from four different family genes. TSC-22 (corresponding to TSC22D1-2) is composed of 144 amino acids translated from a short variant mRNA of the TSC22D1 gene. In this study, we attempted to determine the intracellular localizations of the TSC22D1 family proteins (TSC22D1-1, TSC-22 (TSC22D1-2), and TSC22(86) (TSC22D1-3)) and identify the binding proteins for TSC22D1 family proteins by mass spectrometry. We determined that TSC22D1-1 was mostly localized in the nucleus, TSC-22 (TSC22D1-2) was localized in the cytoplasm, mainly in the mitochondria and translocated from the cytoplasm to the nucleus after DNA damage, and TSC22(86) (TSC22D1-3) was localized in both the cytoplasm and nucleus. We identified multiple candidates of binding proteins for TSC22D1 family proteins in in vitro pull-down assays and in vivo binding assays. Histone H1 bound to TSC-22 (TSC22D1-2) or TSC22(86) (TSC22D1-3) in the nucleus. Guanine nucleotide-binding protein-like 3 (GNL3), which is also known as nucleostemin, bound to TSC-22 (TSC22D1-2) in the nucleus. Further investigation of the interaction of the candidate binding proteins with TSC22D1 family proteins would clarify the biological roles of TSC22D1 family proteins in several cell systems.

Morphometric and histomorphometric evaluations of high-purity macro/microporous beta-tricalcium phosphate in maxillary sinus floor elevation: preliminary results on a retrospective, multi-center, observational study.

BACKGROUND: The present study examined the effectiveness of high-purity macro/microporous beta-tricalcium phosphate (HPMM ß-TCP) as a bone grafting material for maxillary sinus floor elevation by morphometric, histopathological, and histomorphometric evaluations. METHODS: Ten unilateral maxillary sinus floor elevation procedures using 100% HPMM ß-TCP were performed in 10 patients. Morphometric evaluation was carried out by computed tomography (CT) imaging immediately after augmentation and prior to dental implant placement 7 months later. Histopathological and histomorphometric evaluations were carried out by bone biopsy retrieval at the time of dental implant placement 7 months after sinus floor elevation. RESULTS: All 10 sinus floor elevations were successful. Morphometric evaluation by CT showed that the vertical height and volume gained by sinus floor elevation decreased 7 months after surgery. Histopathological evaluation of bone biopsy retrieval specimens showed no signs of inflammation at the newly formed bone area and the native alveolar bone area. New bone formation was observed at the cranial side from the native alveolar bone. The newly formed bone had a trabecular structure and was in intimate contact with the HPMM ß-TCP material. Histomorphometric evaluation of bone biopsy retrieval specimens showed an average new bone volume of 33.97% ± 2.79% and an average residual HPMM ß-TCP volume of 15.81% ± 4.52%. CONCLUSIONS: In this study, HPMM ß-TCP showed osteoconductive properties for vertical augmentation of the atrophied maxilla by means of a maxillary sinus floor elevation procedure allowing subsequent dental implant placement after a 7-month healing period.

Oral squamous cell carcinoma may originate from bone marrow-derived stem cells.

Molecules that demonstrate a clear association with the aggressiveness of oral squamous cell carcinoma (OSCC) have not yet been identified. The current study hypothesized that tumor cells in OSCC have three different origins: Epithelial stem cells, oral tissue stem cells from the salivary gland and bone marrow (BM) stem cells. It was also hypothesized that carcinomas derived from less-differentiated stem cells have a greater malignancy. In the present study, sex chromosome analysis by fluorescence in situ hybridization and/or microdissection PCR was performed in patients with OSCC that developed after hematopoietic stem cell transplantation (HSCT) from the opposite sex. OSCC from 3 male patients among the 6 total transplanted patients were considered to originate from donor-derived BM cells. A total of 2/3 patients had distant metastasis, resulting in a poor prognosis. In a female patient with oral potentially malignant disorder who underwent HSCT, there were 10.7% Y-containing cells in epithelial cells, suggesting that some epithelial cells were from the donor. Subsequently, gene expression patterns in patients with possible BM stem cell-derived OSCC were compared with those in patients with normally developed OSCC by microarray analysis. A total of 3 patients with BM stem cell-derived OSCC exhibited a specific pattern of gene expression. Following cluster analysis by the probes identified on BM stem cell-derived OSCC, 2 patients with normally developed OSCC were included in the cluster of BM stem cell-derived OSCC. If the genes that could discriminate the origin of OSCC were identified, OSCCs were classified into the three aforementioned categories. If diagnosis can be performed based on the origin of the cancer cells, a more specific therapeutic strategy may be implemented to improve prognosis. This would be a paradigm shift in diagnostic and therapeutic strategies for OSCC.

Effectiveness of cetuximab as preemptive postsurgical therapy for oral squamous cell carcinoma patients with major risk: a single-center retrospective cohort study.

A retrospective cohort study was performed to investigate the effectiveness of preemptive postsurgical therapy with cetuximab for patients with a major risk of recurrence or metastasis after clinical complete resection of primary oral squamous cell carcinoma (OSCC). The study period was from 2007 to 2019 for patients treated at the Department of Oral and Maxillofacial Surgery, Dokkyo Medical University School of Medicine. OSCC patients with major risk (n = 88) in the follow-up period were divided into groups with no postsurgical treatment (NP group), with standard postsurgical treatment (SP group), and with postsurgical treatment including cetuximab (CP group), and prognosis were compared among those groups. The 5-year overall survival rate was significantly higher in patients who received postsurgical treatment with cetuximab (CP) compared to that in the other two groups ((CP vs. NP, p = 0.028; CP vs. SP, p = 0.042). Furthermore, we performed multivariate analysis to evaluate the effects of the main components of the treatment. Among CDDP, radiotherapy, and cetuximab, only cetuximab significantly contributed to improved survival by univariate analysis (crude HR:0.228, 95%CI:0.05-0.968, p = 0.045). cetuximab also showed the same tendency in multivariate analysis, although p value did not reach significant level (Adjusted HR: 0.233, 95%CI: 0.053-1.028, p = 0.054). The results suggest that the postsurgical treatment with cetuximab as a preemptive postsurgical therapy after complete surgical resection of a visible tumor is considerably effective for OSCC patients with major risk, in other words, invisible dormant metastasis.

Clinical characteristics, treatment methods and prognoses of patients with oral squamous cell carcinoma in Japanese population: a single institution retrospective cohort study.

BACKGROUND: The status of oral cancer therapy in elderly patients in Japan, where ageing is rapidly progressing, may serve as a model for other countries with similar demographics. There is controversy over what kind of treatment should be applied and how aggressively it should be applied to very elderly patients who have exceeded the average life expectancy. Given that 85 years is approximately the overall Japanese life expectancy at birth, we considered a threshold of 85 years and hypothesized that the prognosis of oral squamous cell carcinoma (SCC) patients aged ≥85 years was not inferior to that of those < 85 years. The aim of the present study was to investigate the clinical characteristics, treatment methods, and prognoses of Japanese oral SCC patients aged ≥85 years. METHODS: A retrospective cohort study was performed. The data of patients with primary oral SCC (n = 358) from 2005 to 2018 in our institute were extracted from electronic medical records. A total of 358 patients with oral SCC were divided into two groups (≥85 years group [n = 26] and < 85 years group [n = 332]) based on the age threshold of 85 years at the first visit. Kaplan-Meier survival analyses and Cox proportional hazard models were used to analyse overall survival (OS) and hazard ratios (HRs) according to age group, treatment, and TNM classification. RESULTS: There was no difference in the 5-year OS rate between the ≥85 years and < 85 years groups (80.8% vs. 82.2%, P = 0.359). This finding was the same in the operative (94.7% vs. 85.8%, P = 0.556) and non-operative (42.9% vs. 33.2%, P = 0.762) groups, indicating that age did not affect prognosis. Mortality was lower in the operative group than in the non-operative group (adjusted HR: 0.276, 95% CI: 0.156-0.489, P < 0.001), suggesting that surgery is a superior method. However, non-surgical treatment was selected at a higher rate in the ≥85 years group (26.9% vs. 11.1%, P = 0.028). CONCLUSIONS: This study suggests the prognosis of ≥85-year-old patients was not inferior to that of < 85-year-old patients. We recommend that surgery as the first choice treatment for ≥85-year-old patients with oral SCC who can tolerate surgery should be performed.

Whole Exome Sequencing of SMO, BRAF, PTCH1 and GNAS in Odontogenic Diseases.

BACKGROUND/AIM: Odontogenic diseases are diagnosed based on clinical course, imaging, and histopathology. However, a definitive diagnosis is not always possible. PATIENTS AND METHODS: We analyzed whole exons of SMO, BRAF, PTCH1 and GNAS using next-generation sequencing (NGS) in 18 patients. RESULTS: Of the 6 patients with ameloblastoma, 2 patients had the same missense mutation in BRAF, and 1 patient with peripheral ameloblastoma had a missense mutation in PTCH1. Of the 7 patients with odontogenic keratocyst, 4 patients had a missense mutation in PTCH1, 2 patients had missense mutations in BRAF, and 1 patient had a missense mutation in SMO. The patient with odontoma had missense mutations in SMO, BRAF and PTCH1. One patient with cement-osseous dysplasia had missense mutations in SMO and PTCH1. The patient with adenomatoid odontogenic tumor had missense mutations in SMO. CONCLUSION: Whole exome sequencing of the above genes by NGS would be useful for the differential diagnosis of odontogenic diseases.

Paclitaxel Potentiates the Anticancer Effect of Cetuximab by Enhancing Antibody-Dependent Cellular Cytotoxicity on Oral Squamous Cell Carcinoma Cells In Vitro.

Administration of cetuximab (C-mab) in combination with paclitaxel (PTX) has been used for patients with head and neck squamous cell carcinoma (SCC) clinically. In this study, we attempted to clarify the molecular mechanisms of the enhancing anticancer effect of C-mab combined with PTX on oral SCC cells in vitro. We used two oral SCC cells (HSC4, OSC19) and A431 cells. PTX alone inhibited cell growth in all cells in a concentration-dependent manner. C-mab alone inhibited the growth of A431 and OSC19 cells at low concentrations, but inhibited the growth of HSC4 cells very weakly, even at high concentrations. A combined effect of the two drugs was moderate on A431 cells, but slight on HSC4 and OSC19 cells. A low concentration of PTX enhanced the antibody-dependent cellular cytotoxicity (ADCC) induced by C-mab in all of the cells tested. PTX slightly enhanced the anticancer effect of C-mab in this ADCC model on A431 and HSC4 cells, and markedly enhanced the anticancer effect of C-mab on OSC19 cells. These results indicated that PTX potentiated the anticancer effect of C-mab through enhancing the ADCC in oral SCC cells.

Troglitazone, a Selective Ligand for PPARγ, Induces Cell-cycle Arrest in Human Oral SCC Cells.

AIM: We attempted to clarify the role of Peroxisome proliferator-activated receptor γ (PPARγ) and its ligand, troglitazone (TRO) on oral squamous cell carcinoma (SCC). MATERIALS AND METHODS: The expression of PPARγ gene was examined in 47 human oral SCC tissues and two human oral SCC cell lines, CA9-22 and HSC-4. The effects of TRO on the growth and cell-cycle progression of human oral SCC cells were examined. RESULTS: PPARγ mRNA was detected in 20 of 47 oral SCC tissues and two human oral SCC cells. TRO significantly suppressed the growth of the cells, but did not induce apoptosis. CA9-22 cells treated with TRO showed an increased fraction in the G1 phase and decreased fractions in the S and G2-M phases. CONCLUSION: TRO did not induce apoptosis in oral SCC cells, but did inhibit the growth of the cells by arresting the cell cycle at G1 phase.

Cavin-2 in oral cancer: A potential predictor for tumor progression.

Cavin-2 (CVN2) affects formation of large caveolae, which are membrane-rich cholesterol domains associated with several functions in signal transduction. Accumulating evidence suggests that CVN2 is present in many cellular types; however, the molecular mechanisms of CVN2 in cancers and its clinical relevance are unknown. We proposed a mechanism by which CVN2 regulates caveolin-1 expression leading to slow cellular proliferation by inactivation of the extracellular regulated kinase (ERK) pathway. Quantitative reverse transcriptase-polymerase chain reaction and immunoblot analyses were used to assess the CVN2 regulation mechanism in oral squamous cell carcinoma (OSCC). Immunohistochemistry (IHC) was performed to analyze the correlation between CVN2 expression and clinical behavior in 115 patients with OSCC. A CVN2 overexpressed model of OSCC cells (oeCVN2 cells) was used for functional experiments. CVN2 expression was down-regulated significantly (P < 0.05) in OSCCs compared with normal counterparts in vitro and in vivo. In addition to the findings that a serum deprivation culture induced up-regulation of CVN2 and slowed cellular proliferation, oeCVN2 cell growth decreased because of cell-cycle arrest at the G1 phase resulting from up-regulated cyclin-dependent kinase inhibitors (p21(Cip1) and p27(Kip1) ) and down-regulated cyclins (cyclin D1, cyclin E) and cyclin-dependent kinases (CDK2, CDK4, and CDK6). Interestingly, CVN2 overexpression facilitated caveolin-1 recruitment and colocalization with each other. We also found decreased ERK phosphorylation levels, an upstream event in cell-cycle arrest. Clinically, IHC data from primary OSCCs showed high tumoral progression in CVN2-negative patients with OSCC. CVN2 may be a possible key regulator of OSCC progression via the CVN2/caveolin-1/ERK pathway and a potential therapeutic target for developing new treatments for OSCCs. © 2015 Wiley Periodicals, Inc.

Lysophosphatidylcholine acyltransferase1 overexpression promotes oral squamous cell carcinoma progression via enhanced biosynthesis of platelet-activating factor.

BACKGROUND: The relevance of lysophosphatidylcholine acyltransferase1 (LPCAT1), a cytosolic enzyme in the remodeling pathway of phosphatidylcholine metabolism, in oral squamous cell carcinoma (OSCC) is unknown. We investigated LPCAT1 expression and its functional mechanism in OSCCs. METHODS: We analyzed LPCAT1 mRNA and protein expression levels in OSCC-derived cell lines. Immunohistochemistry was performed to identify correlations between LPCAT1 expression levels and primary OSCCs clinicopathological status. We established LPCAT1 knockdown models of the OSCC-derived cell lines (SAS, Ca9-22) for functional analysis and examined the association between LPCAT1 expression and the platelet-activating factor (PAF) concentration and PAF-receptor (PAFR) expression. RESULTS: LPCAT1 mRNA and protein were up-regulated significantly (p<0.05) in OSCC-derived cell lines compared with human normal oral keratinocytes. Immunohistochemistry showed significantly (p<0.05) elevated LPCAT1 expression in primary OSCCs compared with normal counterparts and a strong correlation between LPCAT1-positive OSCCs and tumoral size and regional lymph node metastasis. In LPCAT1 knockdown cells, cellular proliferation and invasiveness decreased significantly (p<0.05); cellular migration was inhibited compared with control cells. Down-regulation of LPCAT1 resulted in a decreased intercellular PAF concentration and PAFR expression. CONCLUSION: LPCAT1 was overexpressed in OSCCs and correlated with cellular invasiveness and migration. LPCAT1 may contribute to tumoral growth and metastasis in oral cancer.

Treatment of an extensive maxillary cyst using nasal airway and balloon catheter devices.

Introduction. Large maxillary cysts occasionally expand into the maxilla and erode the maxillary sinus and nasal cavity. The Caldwell-Luc procedure is the recommended treatment for large maxillary sinus cysts. However, it is hard to preserve the nasal space in the case of large maxillary sinus cysts that penetrate into the nasal cavity. Methods. A 22-year-old man who had large maxillary sinus cysts was referred to our department for a surgical treatment. After removing the cyst from the maxillary sinus using the Caldwell-Luc procedure, we used nasal airway and balloon catheter devices to preserve the space of the inferior nasal meatus and maxillary sinus. These devices were removed 10 days postoperatively. Insertion and removal of both devices were simple and painless. Findings. The nasal airway and balloon catheter devices were useful for performing maxillary sinus surgery to remove large cysts. Our method was satisfactorily safe and was an effective minimally invasive treatment that preserved the space of the inferior nasal meatus and maxillary sinus.

WWP2 is overexpressed in human oral cancer, determining tumor size and poor prognosis in patients: downregulation of WWP2 inhibits the AKT signaling and tumor growth in mice.

The WW domain containing E3 ubiquitin protein ligase 2 (WWP2) encodes a member of the Nedd4 family of E3 ligases, which catalyzes the final step of the ubiquitination cascade. WWP2 is involved in tumoral growth with degradation of the tumor suppressor phosphatase and tensin homologue deleted on chromosome TEN (PTEN). However, little is known about the mechanisms and roles of WWP2 in human malignancies including oral squamous cell carcinomas (OSCCs). We found frequent WWP2 overexpression in all OSCC-derived cell lines examined that was associated with cellular growth by accelerating the cell cycle in the G1 phase via degradation of PTEN and activation of the PI3K/AKT signaling pathway. Our in vivo data of WWP2 silencing showed dramatic inhibition of tumoral growth with increased expression of PTEN. Our 104 primary OSCCs had significantly higher expression of WWP2 than their normal counterparts. Moreover, among the clinical variables analyzed, enhanced WWP2 expression was correlated with primary tumoral size and poor prognosis. These data suggested that WWP2 overexpression contributes to neoplastic promotion via the PTEN/PI3K/AKT pathway in OSCCs. WWP2 is likely to be a biomarker of tumoral progression and prognosis and a potential therapeutic target for development of anticancer drugs in OSCCs.

Glutamate acid decarboxylase 1 promotes metastasis of human oral cancer by ß-catenin translocation and MMP7 activation.

BACKGROUND: Glutamate decarboxylase 1 (GAD1), a rate-limiting enzyme in the production of γ-aminobutyric acid (GABA), is found in the GABAergic neurons of the central nervous system. Little is known about the relevance of GAD1 to oral squamous cell carcinoma (OSCC). We investigated the expression status of GAD1 and its functional mechanisms in OSCCs. METHODS: We evaluated GAD1 mRNA and protein expressions in OSCC-derived cells using real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and immunoblotting analyses. To assess the critical functions of GAD1, i.e., cellular proliferation, invasiveness, and migration, OSCC-derived cells were treated with the shRNA and specific GAD1 inhibitor, 3-mercaptopropionic acid (3-MPA). GAD1 expression in 80 patients with primary OSCCs was analyzed and compared to the clinicopathological behaviors of OSCC. RESULTS: qRT-PCR and immunoblotting analyses detected frequent up-regulation of GAD1 in OSCC-derived cells compared to human normal oral keratinocytes. Suppression of nuclear localization of ß-catenin and MMP7 secretion was observed in GAD1 knockdown and 3-MPA-treated cells. We also found low cellular invasiveness and migratory abilities in GAD1 knockdown and 3-MPA-treated cells. In the clinical samples, GAD1 expression in the primary OSCCs was significantly (P < 0.05) higher than in normal counterparts and was correlated significantly (P < 0.05) with regional lymph node metastasis. CONCLUSIONS: Our data showed that up-regulation of GAD1 was a characteristic event in OSCCs and that GAD1 was correlated with cellular invasiveness and migration by regulating ß-catenin translocation and MMP7 activation. GAD1 might play an important role in controlling tumoral invasiveness and metastasis in oral cancer.