Long-term culture of human odontoma-derived cells with a Rho kinase inhibitor.

Because of cellular senescence/apoptosis, no effective culture systems are available to maintain replication of cells from odontogenic tumors especially for odontoma, and, thus, the ability to isolate human odontoma-derived cells (hODCs) for functional studies is needed. The current study was undertaken to develop an approach to isolate hODCs and fully characterize the cells in vitro. The hODCs were cultured successfully with a Rho-associated protein kinase inhibitor (Y-27632) for an extended period with stabilized lengths of the telomeres to sustain a similar phenotype/property as the primary tumoral cells. While the hODCs showed stable long-term expansion with expression of major dental epithelial markers including dentin sialophosphoprotein (DSPP) even in the three-dimensional microenvironment, they lack the specific markers for the characteristics of stem cells. Moreover, cells from dental pulp showed significant up-regulation of DSPP when co-cultured with the hODCs, while control fibroblasts with the hODCs did not. Taken together, we propose that the hODCs can be isolated and expanded over the long term with Y-27632 to investigate not only the development of the hODCs but also other types of benign human tumors.

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.

Persephin: A potential key component in human oral cancer progression through the RET receptor tyrosine kinase-mitogen-activated protein kinase signaling pathway.

Persephin (PSPN) is a neurotrophic factor of the glial cell line-derived neurotrophic factor (GDNF) family that promotes survival of multiple populations of neurons. Little is known about the relevance of PSPN in human malignancy including oral squamous cell carcinoma (OSCC). This study was undertaken to evaluate PSPN mRNA and protein expression by analyzing cellular proliferation and the cell cycle in PSPN knockdown cells in vitro. PSPN mRNA and protein were significantly (P < 0.05) up-regulated in OSCC-derived cells compared with human normal oral keratinocytes (n = 7). Cellular proliferation decreased significantly (P < 0.05) in PSPN knockdown cells with reduced receptor tyrosine kinase (RTK) signaling, and cell-cycle arrest at the G1 phase resulted from up-regulation of the cyclin-dependent kinase inhibitors (p21(Cip1) , p27(Kip1) , p15(INK4B) , and p16(INK4A) ). Furthermore, the PSPN protein expression in 101 primary OSCCs was significantly (P < 0.05) higher than in normal counterparts. Among the clinical variables analyzed, overexpression of PSPN also was related closely (P < 0.05) to tumoral size. Our results suggested that PSPN is a possible key regulator of OSCC progression via PSPN-RET-mitogen-activated protein kinase activation and that PSPN overexpression may have diagnostic potential for OSCC.

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.

Overexpression of Translocation Associated Membrane Protein 2 Leading to Cancer-Associated Matrix Metalloproteinase Activation as a Putative Metastatic Factor for Human Oral Cancer.

Translocation associated membrane protein 2 (TRAM2) has been characterized as a component of the translocon that is a gated channel at the endoplasmic reticulum (ER) membrane. TRAM2 is expressed in a wide variety of human organs. To date, no information is available regarding TRAM2 function in the genesis of human cancer. The purpose of this study was to investigate the status of the TRAM2 gene in oral squamous cell carcinoma (OSCC) cells and clinical OSCC samples. Using real-time quantitative reverse transcriptase-polymerase chain reaction, Western blotting analysis, and immunohistochemistry, we detected accelerated TRAM2 mRNA and protein expression levels both in OSCC-derived cell lines and primary tumors. Moreover, TRAM2-positive OSCC tissues were correlated closely (P<0.05) with metastasis to regional lymph nodes and vascular invasiveness. Of note, knockdown of TRAM2 inhibited metastatic phenotypes, including siTRAM2 cellular migration, invasiveness, and transendothelial migration activities with a significant (P<0.05) decrease in protein kinase RNA(PKR) - like ER kinase (PERK) and matrix metalloproteinases (MMPs) (MT1-MMP, MMP2, and MMP9). Taken together, our results suggested that TRAM2 might play a pivotal role in OSCC cellular metastasis by controlling major MMPs. This molecule might be a putative therapeutic target for OSCC.

Enhancement of SPHK1 in vitro by carbon ion irradiation in oral squamous cell carcinoma.

PURPOSE: The purpose of this study was to assess the gene expression changes in oral squamous cell carcinoma (OSCC) cells after carbon ion irradiation. METHODS AND MATERIALS: Three OSCC cell lines (HSC2, Ca9-22, and HSC3) were irradiated with accelerated carbon ion beams or X-rays using three different doses. The cellular sensitivities were determined by clonogenic survival assay. To identify genes the expression of which is influenced by carbon ion irradiation in a dose-dependent manner, we performed Affymetrix GeneChip analysis with HG-U133 plus 2.0 arrays containing 54,675 probe sets. The identified genes were analyzed using the Ingenuity Pathway Analysis Tool to investigate the functional network and gene ontology. Changes in mRNA expression in the genes were assessed by real-time reverse transcriptase-polymerase chain reaction. RESULTS: We identified 98 genes with expression levels that were altered significantly at least twofold in each of the three carbon-irradiated OSCC cell lines at all dose points compared with nonirradiated control cells. Among these, SPHK1, the expression of which was significantly upregulated by carbon ion irradiation, was modulated little by X-rays. The function of SPHK1 related to cellular growth and proliferation had the highest p value (p = 9.25e-7 to 2.19e-2). Real-time reverse transcriptase-polymerase chain reaction analysis showed significantly elevated SPHK1 expression levels after carbon ion irradiation (p < 0.05), consistent with microarray data. Clonogenic survival assay indicated that carbon ion irradiation could induce cell death in Ca9-22 cells more effectively than X-rays. CONCLUSIONS: Our findings suggest that SPHK1 helps to elucidate the molecular mechanisms and processes underlying the biologic response to carbon ion beams in OSCC.

Overexpression of PAX5 in oral carcinogenesis.

The oncogenic transcription factor PAX5 is an important developmental regulator and is implicated in the pathogenesis of several malignancies. The PAX5 gene is involved in medulloblastoma, non-Hodgkin's lymphoma, transitional cell carcinoma of the bladder, neuroblastoma, breast cancer and SCC. In the current study, to determine the potential involvement of PAX5 in oral squamous-cell carcinoma (OSCC) and leukoplakias, we evaluated the status of PAX5 mRNA and protein expression in OSCC cell lines, human primary OSCCs, and leukoplakias by real-time quantitative reverse transcriptase-polymerase chain reaction, Western blot analysis, and immunohistochemistry. A significant increase in PAX5 expression was observed in all OSCC-derived cell lines examined compared to human normal oral keratinocytes (HNOKs). In immunohistochemistry, 78% of tumors and 42% of leukoplakias examined were positive for PAX5, while no immunoreaction was observed in corresponding normal tissues. The results suggest that PAX5 plays an important role during oral carcinogenesis, especially in the early stage, and that the gene may have potential as a biomarker and therapeutic target for OSCC.

WISP-2 expression in human salivary gland tumors.

This study was designed to disclose detailed genetic mechanisms in salivary gland tumors (SGTs) for development of novel independent marker. We constructed an in-house cDNA microarray carrying 2,201 cDNA clones derived from SGT and oral squamous cell carcinoma cDNA libraries. Four cell lines that originated from the SGT-derived cell lines were analyzed using this microarray system. The genes identified by our microarray system were further analyzed at the mRNA or protein expression level in other types of human cancer cell lines and clinical samples (ten normal salivary glands [NSGs], eleven pleomorphic adenomas, ten adenoid cystic carcinomas and three adenocarcinomas). Two up-regulated genes and six down-regulated genes were identified in common when compared with the control RNA. Of the up-regulated genes, WISP-2, which plays an important role in breast carcinogenesis, was selected for further analyses. We found a higher expression of the WISP-2 gene in the SGT-derived cell lines compared with other types of human cancer cell lines. Furthermore, WISP-2 mRNA and protein expression levels in NSGs were significantly higher than those in SGTs. These results suggest that WISP-2 could be a reliable independent marker and that down-regulation or loss of the WISP-2 gene may be associated with the development of SGTs.

ARNT2 Regulates Tumoral Growth in Oral Squamous Cell Carcinoma.

Aryl hydrocarbon receptor nuclear translocator (ARNT) 2 is a transcriptional factor related to adaptive responses against cellular stress from a xenobiotic substance. Recent evidence indicates ARNT is involved in carcinogenesis and cancer progression; however, little is known about the relevance of ARNT2 in the behavior of oral squamous cell carcinoma (OSCC). In the current study, we evaluated the ARNT2 mRNA and protein expression levels in OSCC in vitro and in vivo and the clinical relationship between ARNT2 expression levels in primary OSCCs and their clinicopathologic status by quantitative reverse transcriptase-polymerase chain reaction, immunoblotting, and immunohistochemistry. Using ARNT2 overexpression models, we performed functional analyses to investigate the critical roles of ARNT2 in OSCC. ARNT2 mRNA and protein were down-regulated significantly (P < 0.05 for both comparisons) in nine OSCC-derived cells and primary OSCC (n=100 patients) compared with normal counterparts. In addition to the data from exogenous experiments that ARNT2-overexpressed cells showed decreased cellular proliferation, ARNT2-positive OSCC cases were correlated significantly (P < 0.05) with tumoral size. Since von Hippel-Lindau tumor suppressor, E3 ubiquitin protein ligase, a negative regulator of hypoxia-inducible factor (HIF1)-α, is a downstream molecule of ARNT2, we speculated that HIF1-α and its downstream molecules would have key functions in cellular growth. Consistent with our hypothesis, overexpressed ARNT2 cells showed down-regulation of HIF1-α, which causes hypofunctioning of glucose transporter 1, leading to decreased cellular growth. Our results proposed for the first time that the ARNT2 level is an indicator of cellular proliferation in OSCCs. Therefore, ARNT2 may be a potential therapeutic target against progression of OSCCs.

Overexpression of TMOD1 is associated with enhanced regional lymph node metastasis in human oral cancer.

Tropomodulin1 (TMOD1), which regulates the length and depolymerization of actin filaments by binding to the pointed end of the actin filament, has been reported to be a powerful diagnostic marker for ALK-negative anaplastic large-cell lymphoma; however, little is known about the relevance of TMOD1 in the behavior of oral squamous cell carcinoma (OSCC). We evaluated TMOD1 expression in OSCC-derived cell lines and primary OSCC samples (n=200) using quantitative reverse transcriptase-polymerase chain reaction, immunoblotting and semi-quantitative immunohistochemistry. We also analyzed the clinical correlation between TMOD1 expression status and clinical parameters in patients with OSCC and performed a prospective study using 40 primary OSCC samples. TMOD1 expression was upregulated significantly (p<0.05) in OSCC in vitro and in vivo compared with normal counterparts. TMOD1 expression also was correlated significantly (p=0.0199 and p=0.0064, respectively) with regional lymph node metastasis (RLNM) and 5-year survival rates. This prospective study also showed that high TMOD1 expression was seen in 12 (75%) of 16 cases in RLNM-positive patients and 9 (37.5%) of 24 cases in RLNM-negative patients. The current data provide the first evidence that TMOD1 expression is a critical biomarker for RLNM and prognosis of patients with OSCC.

Identification of differentially expressed proteins in oral squamous cell carcinoma using a global proteomic approach.

A number of protein markers for oral cancer are still not applicable in large populations. Proteomic technologies provide excellent tools for rapid screening of a large number of potential biomarkers in malignant cells. To gain insight into the molecular mechanisms of carcinogenesis and to identify potential biomarkers for oral squamous cell carcinomas (OSCCs), we performed proteomic profiling between human normal oral keratinocytes (HNOKs) and OSCC-derived cell lines (HSC-2 and HSC-3) using fluorescent two-dimensional difference in-gel electrophoresis. Proteins with a > or =2-fold change in expression were considered significant. The spots of interest were digested and identified by matrix-assisted laser desorption/ionization time-of-flight peptide mass finger-printing. Twenty-two proteins were identified as differentially expressed between the HNOKs and OSCC-derived cell lines. Of these, 9 spots were up-regulated and 13 were down-regulated in OSCC-derived cell lines compared to the HNOKs. These spots included the cancer-related proteins; annexin A1, heat shock protein 27, lamin A/C, interleukin 1 receptor antagonist, serine proteinase inhibitor clade B5, stathmin 1, and superoxide dismutase 2. Our results are a first step toward identifying a protein profile of HNOKs and OSCC-derived cell lines. The identified proteins in this experiment may be used in future studies of carcinogenesis or as diagnostic markers and therapeutic targets for OSCC.

Identification of candidate radioresistant genes in human squamous cell carcinoma cells through gene expression analysis using DNA microarrays.

Radiation therapy is currently the standard adjuvant approach for oral squamous cell carcinoma (OSCC) patients. Individual OSCCs display a wide range of radiosensitivity (RS). To identify genes associated with radioresistance (RR) of OSCC and establish a useful method of predicting radio-therapeutic effectiveness, we examined the gene expression patterns of OSCC cell lines that exhibited different responses to ionizing radiation (IR) by clonogenic survival assay using an in-house cDNA microarray consisting of 2,201 human genes and quantitative reverse transcriptase-polymerase chain reaction (QRT-PCR). Microarray analysis showed overexpression of 7 genes in the radioresistant cell line, HSC2, and 2 genes in the radiosensitive cell line, HSC3. The changes in expression levels in 7 of 9 genes (Cytokeratin18, DTNBP1, ASNA1, Tcp20, Cyclophilin F, KIAA0218, and HBp17) were confirmed with QRT-PCR. Of these, the genetic alterations of Tcp20, whose expression was remarkably elevated in radioresistant HSC2 cells after IR, were investigated. The escalation of X-ray doses resulted in an enhanced Tcp20 expression level in HSC2 cells compared to radiosensitive HSC3 cells (P<0.05, Mann-Whitney U test). These results suggest that the identified genes, which include Tcp20, may play an important role in conferring RR to OSCC, and could also be useful in identifying cases of OSCC with more radioresistance.

Down-Regulation of Nucleolar and Spindle-Associated Protein 1 (NUSAP1) Expression Suppresses Tumor and Cell Proliferation and Enhances Anti-Tumor Effect of Paclitaxel in Oral Squamous Cell Carcinoma.

BACKGROUND: Nucleolar and spindle-associated protein 1 (NUSAP1) is an important mitotic regulator. In addition to its crucial function in mitosis, NUSAP1 has recently received attention due to the interesting roles in carcinogenesis. The aim of this study was to reveal functional mechanisms of NUSAP1 in oral squamous cell carcinoma (OSCC). METHODS: mRNA and protein expression levels of NUSAP1 in 9 OSCC-derived cells were analyzed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and immunoblotting analyses. The correlation between the NUSAP1 expression profile and the clinicopathological factors was evaluated by immunohistochemistry (IHC) in clinical OSCC samples (n = 70). The NUSAP1 knockdown cells were established with short hairpin RNA (shRNA) in OSCC cells, and functional assays were performed using these cells. In addition to the evaluation of cellular proliferation and cell cycle, we also investigated the potential role of NUSAP1 in paclitaxel (PTX)-induced cellular responses. RESULTS: mRNA and protein expression of NUSAP1 were significantly up-regulated in OSCC-derived cells compared with human normal oral keratinocytes (P < 0.05). IHC revealed that NUSAP-1 expression is closely associated with primary advanced T stage (P<0.05). Suppression of NUSAP1 expression levels led to significant (P < 0.05) inhibition of cellular proliferation. Furthermore, apoptosis induced by PTX was enhanced in NUSAP1 knockdown OSCC cells. CONCLUSIONS: NUSAP1 may be a crucial biomarker for OSCC. Moreover, down-regulated NUSAP1 expression suppresses tumor proliferation and also enhances anti-tumor effect of PTX by activating apoptotic pathways. Thus, the present study strongly suggests that regulating NUSAP1 expression should contribute to the therapy for OSCC.

Kinesin family member 14 in human oral cancer: A potential biomarker for tumoral growth.

Kinesin family member 14 (KIF14), a microtubule-based motor protein, plays an important role in chromosomal segregation, congression, and alignment. Considerable evidence indicates that KIF14 is involved in cytokinesis, although little is known about its role in oral squamous cell carcinomas (OSCCs). In the current study, we functionally and clinically investigated KIF14 expression in patients with OSCC. Quantitative reverse transcriptase-polymerase chain reaction and immunoblotting analyses were used to assess the KIF14 regulatory mechanism in OSCC. Immunohistochemistry (IHC) was performed to analyze the correlation between KIF14 expression and clinical behavior in 104 patients with OSCC. A KIF14 knockdown model of OSCC cells (shKIF14 cells) was used for functional experiments. KIF14 expression was up-regulated significantly (P<0.05) in OSCCs compared with normal counterparts in vitro and in vivo. In addition, shKIF14 cells inhibited cellular proliferation compared with control cells by cell-cycle arrest at the G2/M phase through up-regulation of G2 arrest-related proteins (p-Cdc2 and cyclin B1). As expected, IHC data from primary OSCCs showed that KIF14-positive patients exhibited significantly (P<0.05) more larger tumors compared with KIF14-negative patients. The current results suggest for the first time that KIF14 is an indicator of tumoral size in OSCCs and that KIF14 might be a potential therapeutic target for development of new treatments for OSCCs.

Quantitative detection of circulating tumor-derived mitochondrial NADH subunit variants as a potential prognostic biomarker for oral cancer.

Circulating tumor cells (CTCs) and/or their relating molecules are promising determinants during the course of cancer treatment, especially for post-therapeutic monitoring. We recently reported the clinical relevance of detecting circulating tumor-associated mutant mitochondrial DNAs (mut-mtDNAs) at three different regions including the displacement loop, 12S-rRNA and 16S-rRNA in oral squamous cell carcinomas (OSCCs). In the present study, to further investigate if the other mut-mtDNAs have novel efficiency for detecting potential tumoral micrometastasis, mut-mtDNAs on the ND2 and ND3 regions of the genome in 240 clinical samples from patients with OSCC were assessed in vitro and in vivo by quantitative real-time PCR combined with high-resolution melting curve analysis. Furthermore, the clinical relevance was evaluated by the area under the receiver operating characteristic curve (AUC) analysis. Three discrete sequence variations were identified in OSCC derived cell lines at the regions of ND2 (T:A to C:G at position 5108) and ND3 (A:T to G:C at position 10397 and C:G to T:A at position 10400), whereas no mutation was observed in normal control human normal oral keratinocytes. In OSCC patients examined, the presence of mut-mtDNAs in serum during the postoperative period accurately predicted poor prognoses (ND2 AUC, 0.761; ND3 AUC, 0.704). The data presented here provide a novel approach for detecting the circulating mut-mtDNAs that are promising molecular markers for evaluating tumoral micrometastasis in OSCCs.

Interleukin-1 receptor antagonist (IL1RN) is associated with suppression of early carcinogenic events in human oral malignancies.

Inflammatory abnormalities have been implicated in the pathogenesis of various human diseases, including cancer. Interleukin-1 receptor antagonist (IL1RN) is a potent anti-inflammatory molecule that modulates the biological activity of the proinflammatory cytokine, interleukin-1. The aim of this study was to examine the expression of IL1RN in oral squamous cell carcinomas (OSCCs), and to determine its clinical significance. Expression levels of IL1RN in matched normal and tumor specimens from 39 OSCCs were evaluated using real-time quantitative polymerase chain reaction methods, and immunohistochemical analysis. Protein expression of IL1RN was also examined in 18 oral premalignant lesions (OPLs). Expression of IL1RN mRNA was significantly downregulated in OSCCs compared with normal tissues. Decreased expression of IL1RN protein was also observed in OPLs and OSCCs. The IL1RN expression level was lower in the OPL cases with severe dysplasia compared to those with mild/moderate dysplasia. Significantly downregulated IL1RN expression was observed in all OSCC lesion sites examined when compared with the matched normal tissues. However, the decreased level of IL1RN expression did not correspond with tumor progression. Noteworthy, IL1RN expression was higher in the advanced OSCC cases (T3/T4) compared to early cases (T1/T2). Among OSCC samples, relatively higher IL1RN expression was associated with active tumor development in the OSCCs occurring in the buccal mucosa, oral floor, fauces and gingiva, but not the tongue. These data suggest that IL1RN may exhibit opposing characteristics in oral malignancies depending on the stage of cancer development, suppressing early carcinogenic events, yet promoting tumor development in some lesion sites. Thus, IL1RN could represent a reliable biomarker for the early diagnosis of OSCCs. Furthermore, IL1RN may possess unknown and complex functions in the developed OSCC.

Controlling distant metastasis and surgical treatment are crucial for improving clinical outcome in uncommon head and neck malignancies, such as non-squamous cell carcinoma.

The objective of this study was to elucidate the clinical characteristics of uncommon head and neck malignancies, such as non-squamous cell carcinoma (SCC), in order to improve patient outcomes. A total of 463 head and neck malignancies were retrospectively analyzed, with 43 cases (9.3%) diagnosed as non-SCC. The overall survival rate of patients with adenoid cystic carcinoma was significantly worse compared to that of patients with SCC. The 5-year survival rates were <50% for patients with malignant melanoma, adenocarcinoma, small-cell carcinoma and sarcomas. Distant metastasis to the lung was frequently observed in cases with a poor outcome. Non-SCC malignancies treated without surgery were associated with a worse outcome. Some non-SCC patients had a poor prognosis and distant metastasis was associated with an unsatisfactory outcome. Timely treatment and control of distant metastasis are essential and surgical treatment should be prioritized in non-SCC cases to improve patient outcomes.

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.

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.

Tripeptidyl peptidase II in human oral squamous cell carcinoma.

PURPOSE: Tripeptidyl peptidase II (TPP2), a member of the family of eukaryotic serine peptidase, has been implicated in DNA repair, cellular division, and apoptosis. The aim of this study was to examine TPP2 expression and its functional mechanisms in oral squamous cell carcinoma (OSCC). METHODS: TPP2 mRNA and protein expression in seven OSCC-derived cells (Ca9-22, HSC-2, HSC-3, HSC-4, HO-1-N-1, H1, and Sa3) was analyzed by quantitative reverse transcriptase-polymerase chain reaction and immunoblotting analyses. Since previous studies indicated that TPP2 might control chromosomal division, we investigated cellular proliferation and spindle assembly checkpoint (SAC) molecules, MAD2 and CCNB1. In addition, we evaluated the correlation between TPP2 expression levels in primary OSCCs (n = 108 specimens) and the clinicopathologic status by immunohistochemistry (IHC). RESULTS: TPP2 mRNA and protein were significantly (P < 0.05) up-regulated in OSCC-derived cells compared with human normal oral keratinocytes. Suppression of TPP2 expression with shRNA significantly (P < 0.05) inhibited cellular proliferation compared with the control cells. In addition, appropriate localization of MAD2 and up-regulation of CCNB1 were observed in TPP2 knockdown OSCC cells. IHC showed that TPP2 expression in primary OSCCs was significantly (P < 0.001) greater than that in the normal oral counterparts, and the TPP2-positive cases were significantly (P < 0.05) correlated with tumor size. CONCLUSION: The current study showed that overexpression of TPP2 occurs frequently during oral carcinogenesis and might be associated with OSCC progression via SAC activation.