鵜澤 一弘

Background: Adenosine A2b receptor (ADORA2B) encodes an adenosine receptor that is a member of the G protein-coupled receptor superfamily. This integral membrane protein stimulates adenylate cyclase activity in the presence of adenosine. Little is known about the relevance of ADORA2B to human malignancy including oral squamous cell carcinoma (OSCC). We aimed to characterize the expression state and function of ADORA2B in OSCC. Methods: The ADORA2B expression levels in nine OSCC-derived cells were analyzed by quantitative reverse transcriptase-polymerase chain reaction and immunoblotting analyses. Using an ADORA2B knockdown model, we assessed cellular proliferation and expression of hypoxia-inducible factor1 alpha (HIF-1 alpha). We examined the adenosine receptor expression profile under both normoxic and hypoxic conditions in the OSCC-derived cells. In addition to in vitro data, the clinical correlation between the ADORA2B expression levels in primary OSCCs (n = 100 patients) and the clinicopathological status by immunohistochemistry (IHC) also was evaluated. Results: ADORA2B mRNA and protein were up-regulated significantly (p < 0.05) in seven OSCC-derived cells compared with human normal oral keratinocytes. Suppression of ADORA2B expression with shRNA significantly (p < 0.05) inhibited cellular proliferation compared with the control cells. HIF-1 alpha also was down-regulated in ADORA2B knockdown OSCC cells. During hypoxia, ADORA2B expression was induced significantly (p < 0.05) in the mRNA and protein after 24 hours of incubation in OSCC-derived cells. IHC showed that ADORA2B expression in primary OSCCs was significantly (p < 0.05) greater than in the normal oral counterparts and that ADORA2B-positive OSCCs were correlated closely (p < 0.05) with tumoral size. Conclusion: Our results suggested that ADORA2B controls cellular proliferation via HIF-1a activation, indicating that ADORA2B may be a key regulator of tumoral progression in OSCCs.

Angiopoietin-like 3 (ANGPTL3), which is involved in new blood vessel growth and stimulation of mitogen-activated protein kinase (MAPK), is expressed aberrantly in several types of human cancers. However, little is known about the relevance of ANGPTL3 in the behavior of oral squamous cell carcinoma (OSCC). In this study, we evaluated ANGPTL3 mRNA and protein in OSCC-derived cell lines (n=8) and primary OSCCs (n=109) and assessed the effect of ANGPTL3 on the biology and function of OSCCs in vitro and in vivo. Significant (P<0.05) ANGPTL3 upregulation was detected in the cell lines and most primary OSCCs (60%) compared with the normal counterparts. The ANGPTL3 expression level was correlated closely (P<0.05) with tumoral size. In patients with T3/T4 tumors, the overall survival rate with an ANGPTL3-positive tumor was significantly (P<0.05) lower than that of ANGPTL3-negative cases. In vitro, cellular growth in ANGPTL3 knockdown cells significantly (P<0.05) decreased with inactivated extracellular regulated kinase (ERK) and cell-cycle arrest at the G1 phase resulting from upregulation of the cyclin-dependent kinase inhibitors, including p21(Cip1) and p27(Kip1). We also observed a marked (P<0.05) reduction in the growth in ANGPTL3 knockdown-cell xenografts with decreased levels of phosphorylated ERK relative to control-cell xenografts. The current data indicated that ANGPTL3 may play a role in OSCCs via MAPK signaling cascades, making it a potentially useful diagnostic/therapeutic target for use in patients with OSCC.

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.

47歳男。飼育作業のため牛舎に入ったところ、突然ウシの襲撃を受けて下顎骨折を含む多発外傷を受傷し救急搬送され、精査の結果、正中下顎骨骨折、右側耳介不完全断裂、会陰部裂傷、および直腸損傷の疑いと臨床診断した。搬送後は破傷風トキソイドおよび抗破傷風ヒト免疫グロブリンを筋注し、口腔内の骨折部より持続的な出血を認めたため、両側下顎中切歯を利用し応急的に0.5mm歯科用ステンレス鋼線で歯牙結紮を行った。また同日、外科および形成外科により会陰部裂創に対する処置、右側耳介不完全断裂に対する右側耳介再建が施行された。治療後は抗菌薬投与を開始し、受傷8日目に全身麻酔下に正中下顎骨骨折に対する観血的整復固定術を施行した。経過良好で16日目に退院し、退院後、外来にて歯牙欠損部に対し部分床義歯による咬合再建を施行した。

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.

We reported previously that decorin (DCN) is significantly up-regulated in chemoresistant cancer cell lines. DCN is a small leucine-rich proteoglycan that exists and functions in stromal and epithelial cells. Accumulating evidence suggests that DCN affects the biology of several types of cancer by directly/indirectly targeting the signaling molecules involved in cell growth, survival, metastasis, and angiogenesis, however, the molecular mechanisms of DCN in chemoresistance and its clinical relevance are still unknown. Here we assumed that DCN silencing cells increase chemosusceptibility to S-1, consisted of tegafur, prodrug of 5-fluorouracil. We first established DCN knockdown transfectants derived from oral cancer cells for following experiments including chemosusceptibility assay to S-1. In addition to the in vitro data, DCN knockdown zenografting tumors in nude mice demonstrate decreasing cell proliferation and increasing apoptosis with dephosphorylation of ART after S-1 chemotherapy. We also investigated whether DCN expression predicts the clinical responses of neoadjuvant chemotherapy (NAC) using S-1 (S-1 NAC) for oral cancer patients. Immunohistochemistry data in the preoperative biopsy samples was analyzed to determine the cut-off point for status of DCN expression by receiver operating curve analysis. Interestingly, low DCN expression was observed in five (83%) of six cases with complete responses to S-1 MAC, and in one (10%) case of 10 cases with stable/progressive disease, indicating that S-1 chemosensitivity is dramatically effective in oral cancer patients with low DCN expression compared with high DCN expression. Our findings suggest that DCN is a key regulator for chemoresistant mechanisms, and is a predictive immunomarker of the response to S-1 NAC and patient prognosis. (C) 2014 Elsevier Inc. All rights reserved.

Myofibroma is a benign tumor characterized by the proliferation of spindle cells originating from myofibroblasts. This tumor, common in infants, rarely occurs in the oral cavity of adults. Owing to its clinical and pathological characteristics, myofibroma has often been misdiagnosed, leading to inappropriate treatment choices. We report here a rare case of a myofibroma occurring in the maxillary bone of a 57-year-old woman. A rapidly growing mass was observed in the anterior maxilla. Imaging examinations revealed a radiolucent, tumor-like solitary lesion. Nuclear medicine scans revealed hyperintense accumulations at the anterior maxilla. Myofibroma was strongly suggested and no malignant finding was observed on biopsy. Since the lesion was solitary, it was excised completely by surgery. The histopathological findings indicated that the lesion mainly comprised bundles of spindle cells with a central hemangiopericytoma-like vascular pattern. Immunohistochemical staining showed the lesion to be positive for vimentin, α-smooth muscle actin and S-100 and negative for desmin. Thus, a definitive diagnosis of myofibroma was made. No recurrence was observed at the 2-year postoperative follow-up. The present case suggests that pathological examination including immunohistochemical analysis is essential for definitive diagnosis and for avoiding misdiagnosis and the consequent unnecessary therapies.

Odontogenic myxoma (OM) is a rare benign neoplasm with locally aggressive behavior. We present an unusual case of OM as a rapidly expanding lesion in the mandible of a 62-year-old woman who underwent segmental mandibulectomy and primary mandibular reconstruction using a titanium plate. Histologically, we observed stellate and spindle-shaped cells lying loosely in abundant mucoid stroma. Immunohistochemical staining was positive for smooth muscle actin and vimentin and negative for desmin and p53. The patient was followed up for 24 months without a recurrence. Long-term follow-up is required due to the high risk of recurrence.

Multiple myeloma is a malignant neoplasm of plasma cells characterized by proliferation of a single clone of abnormal immunoglobulin-secreting plasma cells. Since the amount of hemopoietic bone marrow is decreased in the maxilla, oral manifestations of multiple myeloma are less common in the maxilla than in the mandible. We report the case of 33-year-old Japanese man who presented with a mass in the right maxillary alveolar region. Computed tomography and magnetic resonance images showed a soft tissue mass in the right maxilla eroding the anterior and lateral walls of the maxillary sinus and extending into the buccal space. The biopsy results, imaging, and laboratory investigations led to the diagnosis of multiple myeloma. This case report suggests that oral surgeons and dentists should properly address oral manifestations as first indications of multiple myeloma.

Sarcomatoid renal cell carcinoma (SRCC) is a rare kidney tumor with rapid growth and a poor prognosis. Here we report a case of metastatic SRCC of the right masseter region with trismus as an initial symptom from SRCC of kidney. Computed tomography imaging presented masses in the right masseter region and right kidney. Positron emission tomography also showed widespread 18F-fluorodeoxyglucose uptake masses in their regions with other organs and lymph nodes. Fine-needle aspiration (FNA) cytology for the right masseter mass showed suspicious findings of glandular cell tumor. We then took a biopsy sample from right kidney and diagnosed the specimen as SRCC histopathologically. Since FNA samples were similar to the SRCC, the right masseter region was predicted to be metastatic tumor from the SRCC of right kidney. Although the patient underwent systemic chemotherapy for SRCC with several anticancer agents, such as sunitinib, gemcitabine, and doxorubicin for SRCC, he died of respiratory failure 10 months after the initial chemotherapy.

根治的手術を行った口腔扁平上皮癌患者156例(男85例、女71例)を対象に、血清SCC抗原値のスクリーニングあるいは予後予測因子としての有用性について検討した。術前SCC抗原の中央値は0.83ng/mlで、一般的な基準値の1.5ng/mlを下回り、SCC抗原陽性は35例(真陽性率22%)であった。臨床病理学的因子別にみると、T3+T4例はT1+T2例に、N2+N3例はN1例に、Stage III+IV例はI+II例に比較して術前SCC抗原値が有意に高値であった。また非再発/非転移群は再発/転移群に比較して術前SCC抗原値が有意に高値で、ROC曲線より求めた再発/転移リスクのカットオフ値は1.34ng/ml(正診率0.724)であった。再発/転移群における再発/転移確認直前のSCC抗原値は、術前陰性・陽性例とも術後平均値に比較して有意に高値で、再発/転移の指標となる術後SCC抗原値のカットオフ値は1.40ng/ml(正診率0.882)であった。

The human kallikrein-related peptidase family is comprised of 15 serine protease genes on chromosome 19q13.4 [1]. Our previous microarray analyses showed that the gene kallikrein-related peptidase 13 (KLK13) was down-regulated in oral squamous cell carcinoma (OSCC) cell lines. We evaluated the expression status of KLK13 in primary OSCCs and performed functional molecular experiments in OSCC cell lines. In 102 primary tumors studied, KLK13 expression significantly (P < 0.05) decreased compared with matched normal counterparts. Interestingly, KLK13-negative cases correlated significantly (P < 0.05) with regional lymph node metastasis. In vitro, cells overexpressing KLK13 (oeKLK13) had decreased invasiveness and motility and up-regulation of adhesion molecules (E-cadherin, alpha-catenin, beta-catenin, junction plakoglobin, plakophilin4, desmocollin2, desmoglein3, and desmoplakin) compared with control cells. A rescue experiment that transfected oeKLK13 cells with siRNA against KLK13 restored invasiveness and migration activities with down-regulated adhesion molecules. Based on our results, we concluded that KLK13 may play an important role in regulating cellular migration and invasiveness, making the loss of KLK13 a potential biomarker for early detection of lymph node metastasis in OSCCs. (C) 2013 Wiley Periodicals, Inc.

Purpose: The aim was to evaluate the efficacy of endoscopy-assisted surgery for treating a foreign body (fish bone) deeply embedded in the parotid duct. Patients and Methods: We report the case of a 67-year-old man with diffuse swelling of the cheek and the discharge of pus from the parotid duct orifice caused by a fish bone that had penetrated into the parotid duct. The preoperative examination using ultrasonography and computed tomography showed a linear foreign body. Results: The fish bone was thought to be embedded deeply in the parotid duct; therefore, we used a combined approach (endoscopy with open surgery), because we anticipated difficulties with endoscopic removal of the fish bone. The endoscopic view showed that the fish bone had partially penetrated the soft tissue in the parotid duct wall, but the fish bone could not be removed endoscopically. With endoscopic assistance, the impacted fish bone was removed using an intraoral surgical approach. The clinical outcome was satisfactory during a 10-month follow-up period, with no evidence of complications. Conclusions: The combined surgical and endoscopic approach resulted in the safe and effective removal of a foreign body from the salivary duct that could not be removed using sialendoscopy alone. (C) 2014 American Association of Oral and Maxillofacial Surgeons

In the oral and maxillofacial regions, epidermoid cysts usually develop in the floor of the mouth and rarely in other sites. We describe a case of an epidermoid cyst arising in the right maxillary sinus. A 27-year-old man was referred to our department for swelling in the right buccal region. Computed tomography showed a dense soft-tissue mass that extended widely into the maxillary sinus, resulting in thinning of the cortical bone of the exterior wall of the maxillary sinus. The cyst was enucleated via the intraoral approach with the patient under general anesthesia. Histopathologically, the wall was lined with a thin layer of keratinizing squamous epithelium and fibroma connective tissue with no skin appendages. The diagnosis was an epidermoid cyst. There has been no evidence of recurrence during the 3-year follow-up. © 2012 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI.

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.

Background: LIM and SH3 protein 1 (LASP-1) is a specific focal adhesion protein involved in several malignant tumors. However, its role in oral squamous cell carcinoma (OSCC) is unknown. The aim of this study was to characterize the role and molecular status/mechanism of LASP-1 in OSCC. Methods: We evaluated LASP-1 mRNA and protein expressions in OSCC-derived cell lines and primary OSCCs. Using an shRNA system, we analyzed the effect of LASP-1 on the biology and function of the OSCC cell lines, HSC-3 and Ca9-22. The cells also were subcutaneously injected to evaluate tumor growth in vivo. Data were analyzed by the Fisher's exact test or the Mann-Whitney U test. Bonferroni correction was used for multiple testing. Results: Significant up-regulation of LASP-1 was detected in OSCC-derived cell lines (n = 7, P<0.007) and primary OSCCs (n = 50, P<0.001) compared to normal controls. LASP-1 knockdown cells significantly inhibited cellular proliferation compared with shMock-transfected cells (P<0.025) by arresting cell-cycle progression at the G2 phase. We observed dramatic reduction in the growth of shLASP-1 OSCC xenografts compared with shMock xenografts in vivo. Conclusion: Our results suggested that overexpression of LASP-1 is linked closely to oral tumourigenicity and further provide novel evidence that LASP-1 plays an essential role in tumor cellular growth by mediating G2/M transition.

Background: Kinesin family member 4A (KIF4A), a microtubule-based motor protein, was implicated in regulation of chromosomal structure and kinetochore microtubule dynamics. Considering the functions of KIF4A, we assumed that KIF4A is involved in progression of oral squamous cell carcinomas (OSCCs) via activation of the spindle assembly checkpoint (SAC). However, little is known about the relevance of KIF4A in the behavior of OSCC. We investigated the KIF4A expression status and its functional mechanisms in OSCC. Methods: The KIF4A expression levels in seven OSCC-derived cells were analyzed by quantitative reverse transcriptase-polymerase chain reaction and immunoblotting analyses. Using a KIF4A knockdown model, we assessed the expression of (SAC)-related molecules (BUB1, MAD2, CDC20, and cyclin B1), cell-cycle, and cellular proliferation. In addition to in vitro data, the clinical correlation between the KIF4A expression levels in primary OSCCs (n = 106 patients) and the clinicopathologic status by immunohistochemistry (IHC) also were evaluated. Results: KIF4A mRNA and protein were up-regulated significantly (P < 0.05) in seven OSCC-derived cells compared with human normal oral keratinocytes. In the KIF4A knockdown cells, SAC activation was observed via increased BUB1 expression on the kinetochores, appropriate kinetochore localization of MAD2, down-regulation of CDC20, up-regulation of cyclin B1, and cell-cycle arrested at G2/M phase. The results showed that cellular proliferation of KIF4A knockdown cells decreased significantly (P < 0.05) compared with control cells. IHC showed that KIF4A expression in primary OSCCs was significantly (P < 0.05) greater than in the normal oral counterparts and that KIF4A-positive OSCCs were correlated closely (P < 0.05) with tumoral size. Conclusions: Our results proposed for the first time that KIF4A controls cellular proliferation via SAC activation. Therefore, KIF4A might be a key regulator for tumoral progression in OSCCs.

Protein O-fucosyltransferase 1 (POFUT1) is the enzyme that adds O-fucose through O-glycosidic linkage to conserved serine or threonine residues in the epidermal growth factor-like repeats of a number of cellular surface and secreted proteins. Our previous study using microarray technology showed that significant upregulation of POFUT1 occurs in oral squamous cell carcinoma (OSCC)-derived cell lines compared to human normal oral keratinocytes. The aim of the present study was to examine the status of POFUT1 mRNA and protein expression in OSCC-derived cell lines and human primary OSCCs. POFUT1 mRNA was upregulated significantly (P<0.05 for both comparisons) in five OSCC-derived cell lines and primary OSCCs using quantitative reverse transcriptase-polymerase chain reaction. Immunohistochemistry data indicated that POFUT1 protein expression levels were consistent with mRNA expression status in OSCC-derived cell lines and primary OSCCs. Furthermore, POFUT1 expression status was correlated significantly (P=0.048) with the primary tumor size. The proliferation of POFUT1 knockdown cells was inhibited significantly compared with that of control cells. These results indicated that POFUT1 expression can contribute to cancer progression and that POFUT1 may serve as a diagnostic marker and a therapeutic target for OSCCs.

20歳男。両側停留精巣、両四肢合指症、硬膜下水腫、肝良性腫瘍、腸回転異常の経過観察を行っていた。右側頬部腫脹および鼻閉感の増悪を認め、両側上顎洞内に埋伏歯および嚢胞様病変を指摘された。両側上顎洞部含歯性嚢胞と診断した。患者の事情により、初診から3ヵ月後に全身麻酔下に両側上顎洞部含歯性嚢胞摘出術、抜歯術、両側下鼻道への対孔形成術を施行した。死腔と術後出血防止のため、対孔より両側上顎洞へバルーンカテーテル、左側上顎洞へアクロマイシン軟膏付タンポンガーゼを挿入した。術後10日目にバルーンカテーテルおよびタンポンガーゼを抜去し、術後14日日に軽快退院となった。術後のCTでは、嚢胞により圧排されていた鼻道の改善および上顎洞の含気を認めた。現在術後42ヵ月経過しているが、再発や鼻閉感を認めず経過良好である。

過去数十年の研究成果によって、がん患者の循環血液中にみられる腫瘍由来細胞(circulating tumor-derived cells:CTCs)あるいは末梢循環腫瘍由来核酸(circulating tumor-derived nucleic acids:ctNAs)が微小転移の兆候であり、それゆえ重要な予後因子であることが広く受け入れられてきた。これらは免疫細胞化学的あるいは分子生物学的分析法によって検出でき、さらに実際の患者においてもシステミックでリアルタイムなCTCs/ctNAsのモニタリングが可能となりつつある。本稿では、口腔がんにおける基礎から臨床応用へのCTCs/ctNAs研究の変遷について、われわれの最近の研究成果と併せて解説する。(著者抄録)

症例は14歳女児で、右側顎下部の腫脹の増大で近歯科より紹介受診した。右側顎下部に弾性軟で無痛性腫脹を認め、口腔内所見では口底部に腫脹は認めなかった。造影MRIで右側顎下腺前方と顎舌骨筋外側にT1強調で低信号、T2強調で高信号を呈する内部均一で境界明瞭な46×35×24mm大の病変が認められた。Plunging ranula疑いで全身麻酔下に右側舌下腺摘出術を行った。摘出後に顎下部を圧迫すると顎舌骨筋裂隙より血性で粘張度の高い唾液様液体が排出され、十分に吸引後洗浄して創面を一時閉鎖した。術後は口腔外から圧迫ガーゼで顎下部を圧迫し、経過良好で術後7日目に退院し、術後6ヵ月経過で再発は認めていない。病理所見では、摘出舌下腺は辺縁部に嚢胞状に拡張した導管様構造を認め、同部に粘液が充満し、上皮の裏装を欠いていた。周囲には中等度の炎症性細胞浸潤を伴い、小葉は局所的に萎縮しており、舌下腺由来のガマ腫と考えられた。

症例は59歳女性で、嚥下時の違和感を主訴に受診し、疼痛もないため、経過観察されたが改善がみられず、紹介受診となった。栄養状態は良好で、顔貌左右対称、特記すべき異常所見はなかった。右側下顎枝前内方に桜実大で弾性硬、可動性の腫瘤が認められた。右側上下第三大臼歯は20年以上前に抜歯され、抜歯窩相当部は正常粘膜に覆われていた。パノラマX線では歯および骨に異常所見を認めなかった。CTでは右側下顎枝前内方部に一部造影効果を伴う腫瘤が認められた。MRIでは右側下顎枝前内方部にT1強調像で筋肉と同程度の信号、STIRおよびT2強調像で高信号の内部不均一な分葉構造を示す腫瘤が認められた。良性唾液腺腫瘍と診断し、全身麻酔下に全切除生検を行った。腫瘍は下顎枝内斜線と翼突下顎縫線の間で粘膜直下に存在していた。周囲の正常脂肪組織を含め腫瘍を一塊として切除し、術中の骨および舌神経の露出は認めなかった。摘出標本は弾性硬であった。創部の治癒経過は良好で、術後2年6ヵ月のCT所見で再発はなく、術後3年9ヵ月現在異常所見は認められない。病理組織学的診断は叢状型周辺性エナメル上皮腫であった。

Background: MicroRNAs (miRNAs) are involved in essential biological activities, and have been reported to exhibit differential expression profiles in various cancers. Our previous study demonstrated that intercellular adhesion molecule-2 (ICAM2) inhibition induces radiosensitisation in oral squamous cell carcinoma (OSCC) cells. Thus, we hypothesised that certain miRNAs play crucial roles in radioresistance in OSCC by regulating ICAM2 expression. Methods: Because predicted target gene analyses revealed that microRNA-125b (miR-125b) potentially regulates ICAM2 mRNA expression, we examined the association between miR-125b and radioresistance. The expression of miR-125b was investigated by real-time quantitative reverse transcriptase-PCR. For a functional analysis, miR-125b was transfected to OSCC-derived cells. Results: A downregulated expression of miR-125b was found in OSCC-derived cell lines and OSCC samples. The miR-125b-transfected cells showed a decreased proliferation rate, enhanced radiosensitivity to X-ray irradiation and diminished ICAM2 mRNA expression. Moreover, miR-125b expression correlated with OSCC tumour staging and survival. Conclusion: These findings suggested that the downregulated miR-125b expression was associated with proliferation and radioresistance mechanisms, probably through ICAM2 signalling. Thus, controlling the expression or activity of miR-125b might contribute to suppressing proliferation and overcoming radioresistance in OSCC.

PURPOSE: Sec8, a component of the exocyst complex, has been implicated in tethering of secretory vesicles to specific regions on the plasma membrane. To investigate the involvement of Sec8 in oral squamous-cell carcinoma (OSCC), we evaluated the expression status and effect of Sec8 in OSCC cell lines. METHODS: Sec8 mRNA and protein expressions in human OSCC cell lines were assessed by quantitative reverse transcriptase-polymerase chain reaction and immunoblotting. Functional analyses, proliferation assay, invasiveness assay, and gelatin zymography in Sec8 knockdown cells were performed. Also the correlation between Sec8 expression and the clinicopathological features in 98 primary OSCCs samples was evaluated by immunohistochemistry. RESULTS: Sec8 mRNA and protein expression were significantly up-regulated in all cell lines (p < 0.05). Sec8 knockdown cells were characterized by reduced cellular proliferation, invasiveness, and secretion of matrix metalloproteinases (MMPs) (MMP-2, proMMP-2, and proMMP-9). Sec8 protein expression in primary OSCCs also was significantly (p < 0.05) greater than in normal counterparts, and higher Sec8 expression was correlated with tumor size (p = 0.03). CONCLUSIONS: Our results suggested for the first time that Sec8 might play a specific role in OSCC progression by mediating MMP secretion.

ALY, an essential mRNA export factor, is dysregulated in a wide variety of human malignancies. However, little is known about the relevance of ALY to oral squamous cell carcinoma (OSCC). The purpose of this study was to investigate ALY expression and its functional mechanisms in OSCCs. ALY mRNA and protein expression in seven OSCC-derived cell lines (Sa3, HO-1-u-1, KON, Ca9-22, HSC-2, HSC-3, and HSC-4) and primary OSCCs were analyzed by quantitative reverse transcriptase-polymerase chain reaction, immunoblotting, and immunohistochemistry. We evaluated cellular invasiveness, migration, and the expression levels of metastasis modulators, ribosomal RNA processing 1 homolog B (RRP1B) and CD82, in ALY knockdown cells. ALY was frequently up-regulated in OSCC-derived cell lines and primary OSCCs compared with normal counterparts at both the mRNA and protein expression levels. ALY-positive expression was correlated significantly (P &lt; 0.05) with a higher risk of regional lymph node metastasis. Furthermore, ALY knockdown cells caused a significant (P &lt; 0.05) decrease in cellular invasiveness and migration with up-regulation of RRP1B and CD82 compared with the control cells. Our results showed that ALY is linked to regional lymph node metastasis by regulating cellular invasiveness and migration. Therefore, ALY might be a potential biomarker for early detection of lymph node metastasis in OSCCs.

The aim of the present study was to identify a target molecule that could predict the efficacy of radiotherapy in oral squamous cell carcinoma (OSCC). We used DNA microarray analysis to identify differences in gene expression after X-ray irradiation. We compared the gene expression profiles between X-ray (8 Gy)-irradiated Ca9-22 cells (an OSCC-derived cell line) and unirradiated Ca9-22 cells. A total of 167 genes with a 2-fold higher level of expression induced by X-ray irradiation were identified. Lipocalin-2 (LCN2) had the greatest increase in expression after X-ray irradiation, and it was categorized in a network that has cancer-related functions with the Ingenuity Pathway Analysis tool. Upregulated expression of LCN2 mRNA was validated by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis. When the LCN2 gene was knocked down in OSCC cells (Ca9-22 and HSC-2) and lung cancer cells (A549) by using small interfering RNA, the radiosensitivity of these cells was enhanced. Our findings suggest that the overexpression of LCN2 is likely associated with radioresistance in oral cancer and lung cancer cells, and that LCN2 expression levels could be used to predict radioresistance. Thus, regulating the expression or function of LCN2 could enhance the radiation response, resulting in a favorable outcome of radiotherapy.

Cell division cycle associated 2 (CDCA2) recruits protein phosphatase 1 to chromatin to antagonize activation of ataxia telangiectasia mutated (ATM)-dependent signal transduction. ATM kinase plays a critical role in the DNA damage response and its phosphorylation cascade to inhibit the p53-MDM2 interaction, which releases p53 to induce p21 and G1 cell-cycle arrest. However, the relevance of CDCA2 to human malignancy including oral squamous cell carcinoma (OSCC) is unknown. In the current study, we found that CDCA2 expression was up-regulated in OSCC cell lines. Functional studies with shRNA system showed that knockdown of CDCA2 significantly (P&lt;0.05) inhibited cellular proliferation compared with the control cells by arresting cell-cycle progression at the G1 phase and up-regulating the cyclin-dependent kinase inhibitors (p21(Cip1), p27(Kip1), p15(INK4B), and p16(INK4A)). CDCA2 knockdown also promoted apoptosis after treatment with the DNA damage reagent, cisplatin. In clinical samples, the CDCA2 protein expression level in primary OSCCs was significantly (P&lt;0.05) greater than in matched normal oral tissues (67/85, 79%). Furthermore, CDCA2-positive cases were correlated significantly (P&lt;0.05) with high cancer progression. Our results showed for the first time that CDCA2 frequently is overexpressed in OSCCs and might be associated closely with OSCC progression by preventing cell-cycle arrest and apoptosis.

We previously reported that human squamous cell carcinoma (SCC) cell lines refractory to cis-diaminedichloro-platinum II (cisplatin [CDDP]) had significant upregulation of the phosphodiesterase 3B gene (PDE3B), suggesting that inhibiting PDE3B suppresses CDDP resistance. shRNA-mediated PDE3B depletion in CDDP-resistant cells derived from SCC cells and Hela cells and induced CDDP sensitivity and inhibited tumor growth with elevated cyclic GMP induction resulting in upregulation of the multidrug-resistant molecule, but this did not occur in the 5-fluorouracil-resistant hepatocellular carcinoma cell lines. Furthermore, the antitumor growth effect of the combination of a PDE3B inhibitor (cilostazol) and CDDP in vivo was also greater than with either cilostazol or CDDP alone, with a significant increase in the number of apoptotic and cell growth-suppressive cancer cells in CDDP-resistance cell lines. Our results provided novel information on which to base further mechanistic studies of CDDP sensitization by inhibiting PDE3B in human cancer cells and for developing strategies to improve outcomes with concurrent chemotherapy.

Background: Myoepithelioma, a generally benign tumor comprised of myoepithelial cells, is an uncommon salivary gland tumor. Among four morphologic variants of myoepithelioma, epithelioid type has not been reported in the oral and maxillofacial region. Case report: A 61-year-old man first noticed the mass 3 years previously. The oral examination revealed a firm, non-tender, and well-circumscribed mass in the middle of the hard palate. A magnetic resonance imaging scan showed a well-circumscribed mass with low signal intensity (T1-weighted image) or increased signal intensity (T2-weighted image). Discussion: Immunohistochemically, the tumor cells in the present case reacted to the epithelial (CK HMW and CAM5. 2) and the mesenchymal (vimentin) markers. However, myoepithelial markers (S-100 protein, α-smooth muscle actin, glial fibrillary acidic protein, and calponin), except p63, were not expressed in the tumor cells. These results indicated that the epithelial myoepithelioma cells differentiated into epithelial cells rather than myoepithelial cells. We believe that epithelioid myoepithelioma of the palate is a distinctive subtype of myoepithelioma that should be included in the differential diagnosis of tumors of the palate. © 2012 Springer-Verlag.

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). 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). TPP2 mRNA and protein were significantly (P &lt; 0.05) up-regulated in OSCC-derived cells compared with human normal oral keratinocytes. Suppression of TPP2 expression with shRNA significantly (P &lt; 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 &lt; 0.001) greater than that in the normal oral counterparts, and the TPP2-positive cases were significantly (P &lt; 0.05) correlated with tumor size. The current study showed that overexpression of TPP2 occurs frequently during oral carcinogenesis and might be associated with OSCC progression via SAC activation.

The four and a half LIM domains 1 (FHL1) gene has been related to carcinogenesis. However, the expression status of FHL1 in human oral squamous cell carcinoma (OSCC) remains unclear and the detailed mechanism of gene silencing is poorly understood. The aim of this study was to examine the FHL1 expression level and its regulatory mechanism in OSCCs. Quantitative reverse-transcriptase-polymerase chain reaction (PCR) and western blotting showed significant downregulation of FHL1 in all OSCC-derived cell lines (Sa3, HSC-2, HSC-3, HSC-4, HO-1-u-1, HO-1-N-1, KON and Ca9-22) compared to human normal oral keratinocytes. We also found that FHL1 mRNA expression was frequently downregulated (P<0.01) in 51 (86.4%) of 59 primary OSCCs compared with the corresponding normal oral tissues, while there was no significant difference between the status of the FHL1 protein expression in OSCCs and the clinicopathological features. Using methylation-specific PCR, we detected methylated FHL1 in all cell lines and treatment with the DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine restored the FHL1 expression. However, no significant restoration of FHL1 expression was observed using sodium butyrate, an inhibitor of histone deacetylase and chromatin immunoprecipitation showed that histone H3 lysine 9 in the FHL1 promoter region was significantly acetylated. In addition, no mutation in the entire coding region of the FHL1 gene was found. Therefore, our data suggested that inactivation of the FHL1 gene is a frequent event during oral carcinogenesis and that the mechanism of FHL1 downregulation in OSCCs is through DNA methylation of the promoter region rather than histone deacetylation or mutation.

Fork-head box protein A1 (FOXA1) is a "pioneer factor" that is known to bind to the androgen receptor (AR) and regulate the transcription of AR-specific genes. However, the precise role of FOXA1 in prostate cancer (PC) remains unknown. In this study, we report that FOXA1 plays a critical role in PC cell proliferation. The expression of FOXA1 was higher in PC than in normal prostate tissues (P = 0.0002), and, using immunohistochemical analysis, we found that FOXA1 was localized in the nucleus. FOXA1 expression levels were significantly correlated with both PSA and Gleason scores (P = 0.016 and P = 0.031, respectively). Moreover, FOXA1 up-regulation was a significant factor in PSA failure (P = 0.011). Depletion of FOXA1 in a prostate cancer cell line (LNCaP) using small interfering RNA (siRNA) significantly inhibited AR activity, led to cell-growth suppression, and induced G0/G1 arrest. The anti-proliferative effect of FOXA1 siRNA was mediated through insulin-like growth factor binding protein 3 (IGFBP-3). An increase in IGFBP-3, mediated by depletion of FOXA1, inhibited phosphorylation of MAPK and Akt, and increased expression of the cell cycle regulators p21 and p27. We also found that the anti-proliferative effect of FOXA1 depletion was significantly reversed by simultaneous siRNA depletion of IGFBP-3. These findings provide direct physiological and molecular evidence for a role of FOXA1 in controlling cell proliferation through the regulation of IGFBP-3 expression in PC.

While circulating tumor-derived molecules have been identified in a variety of malignant tumors, it is sometimes difficult to detect the molecular targets due to the lower serum concentration. We report that evaluation of circulating tumor-derived mitochondrial DNA (mtDNA) seems to have novel efficiency for detecting tumoral micrometastasis. In murine xenografting human oral cancer cells, human mtDNAs could be quantitatively detected from multiple organs and blood samples whereas human nucleic DNAs could not. We also determined if this mtDNA blood test was relevant for patients with oral cancer with no histologic evidence of tumoral cells in their surgical margins. For this, mtDNA from normal and tumorous tissues and serum mtDNA obtained pre and postoperatively was examined at three different regions including the displacement loop, 12S-rRNA, and 16S-rRNA. All recurring patients had significantly higher amounts of mutant mtDNAs in the tumoral tissues compared with the non-recurring group. More importantly, on the blood test with the cut-off point by receiver operating characteristic (ROC) curve analysis, while the vast majority of serum mtDNA samples obtained postoperatively in the recurring cases maintained significantly higher amounts of mutant mtDNAs, the non-recurring cases did not, and they showed good prognosis. This is the first report of this approach for managing patients after resection of oral tumors, and may have substantial diagnostic potential for other tumoral types.

Background: Cell division cycle associated 3 (CDCA3), part of the Skp1-cullin-F-box (SCF) ubiquitin ligase, refers to a trigger of mitotic entry and mediates destruction of the mitosis inhibitory kinase. Little is known about the relevance of CDCA3 to human malignancy including oral squamous cell carcinoma (OSCC). We aimed to characterize the expression state and function of CDCA3 in OSCC. Methods: We evaluated CDCA3 mRNA and protein expression in both OSCC derived cell lines and primary OSCCs and performed functional analyses of CDCA3 in OSCC-derived cells using the shRNA system. Results: The CDCA3 expression at both the mRNA and protein levels was frequently up-regulated in all cell lines examined and primary tumors (mRNA, 51/69, 74 %; protein, 79/95, 83 %) compared to normal controls (p &lt; 0.001). In contrast, no significant level of CDCA3 protein expression was seen in oral premalignant lesions (OPLs) (n = 20) compared with the expression in OSCCs. Among the clinical variables analyzed, the CDCA3 expression status was closely related to tumor size (p &lt; 0.05). In addition, suppression of CDCA3 expression with shRNA significantly (p &lt; 0.05) inhibited cellular proliferation compared with the control cells by arresting cell-cycle progression at the G1 phase. Further, there was up-regulation of the cyclin-dependent kinase inhibitors (p21(Cip1), p27(Kip1), p15(INK4B), and p16(INK4A)) in the knockdown cells. Conclusion: The current results showed that overexpression of CDCA3 occurs frequently during oral carcinogenesis and this overexpression might be associated closely with progression of OSCCs by preventing the arrest of cell-cycle progression at the G1 phase via decreased expression of the cyclin-dependent kinase inhibitors.

Dermatopontin (DPT), a component of the extracellular matrix (ECM), is involved in promotion of cellular adhesion and ECM assembly activities. However, the role of DPT in the pathogenesis of carcinoma is unclear. We evaluated DPT expression in human oral cancer and its possible roles including cellular adhesion and invasiveness. We first investigated the DPT mRNA and protein expression status in human oral squamous cell carcinoma (OSCC)-derived cells. Real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and immunoblotting analysis detected frequent downregulation of DPT in OSCC-derived cells compared to human normal oral keratinocytes. To assess the epigenetic regulation of DPT, OSCC-derived cells were treated with a histone deacetylase inhibitor, sodium butyrate (NaB). NaB restored the DPT expression in OSCC-derived cells. DPT-overexpressed cells were examined whether DPT could contribute to cellular adhesion and invasiveness. Markedly, increased adhesion and decreased invasiveness in DPT-overexpressed cells were found compared to mock-transfected cells. Adhesion of DPT-overexpressed cells was inhibited by a3 beta 1 integrin functional blocking antibody. OSCC-derived cells treated with NaB also decreased invasiveness. The expression status of DPT in primary OSCCs (n = 97) was analyzed and compared to clinicopathological behavior. DPT expression in primary OSCCs was significantly lower (p &lt; 0.05) than in the normal counterparts and was correlated significantly (p &lt; 0.05) with regional lymph node metastasis. Our data provided strong evidence that downregulation of DPT is a characteristic event in OSCCs and that DPT was correlated with cellular adhesion and invasiveness. Therefore, DPT might play an important role in regulating tumor invasion and metastasis.

ADAMs are a disintegrin and metalloproteinase family of membrane-associated metalloproteinases characterized by their multidomain structure, and have been reported to be associated with various malignant tumors. The aim of this study was to identify crucial members of the ADAM family in oral squamous cell carcinoma (OSCC), and to reveal their biological function and clinical significance. To clarify whether ADAM family genes are involved in OSCC, changes in the expression profile were investigated by real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis and immunohistochemical analysis. Functional analysis was performed by comparing cellular proliferation of siADAM-transfected cell lines and parental cell lines. Real-time qRT-PCR analysis identified significantly upregulated expression of ADAM12 in OSCC-derived cell lines. This was validated in OSCC samples using real-time qRT-PCR and immunohistochemical staining. ADAM12 expression was correlated with TNM classification; significantly greater expression of ADAM12 was observed in tumors with higher T classification and more advanced stages. Moreover, siADAM12-transfected cells showed both a suppressed proliferation rate and increased transforming growth factor (TGF)-1 beta 3 expression. Our data indicate that ADAM12 is overexpressed in OSCC and might accelerate cellular proliferation. Its function may be associated with TGF-beta signaling. This study suggests that controlling the expression or activity of ADAM12 could be a useful strategy in the development of an effective cure for OSCC.

Purpose: Family with sequence similarity 3, member B (FAM3B), also known as PANcreatic DERived factor (PANDER), is an islet-specific cytokine predominantly expressed in both pancreatic α- and β-cells. FAM3B is known to induce apoptosis in pancreatic cells, and may therefore be able to regulate apoptosis in other cell types, including cancer cells. However, the role of FAM3B in carcinogenesis is unknown. We previously performed global gene screening using DNA microarray analysis to identify crucial molecules in oral squamous cell carcinoma (OSCC). The results showed significant down-regulation of FAM3B in OSCC-derived cell lines, as compared with human normal oral keratinocytes (HNOKs). The aim of the present study was to clarify the association between FAM3B and OSCCs. Results: Expression profiles of FAM3B in OSCC-derived cell lines and human primary OSCCs were examined by real-time quantitative reverse transcriptase-polymerase chain reaction and Western blot analysis. Significantly decreased expression of FAM3B mRNA and FAM3B protein were observed in five OSCC-derived cell lines, as compared with HNOKs. Moreover, immunohistochemical analysis revealed down-regulated FAM3B protein expression in primary OSCC samples. In order to examine whether microRNA (miRNA) potentially regulates FAM3B expression, miRNA microarray analysis was performed with OSCC-derived cell lines. miRNA microarray data showed that miR-181a, miR-181b, miR-200b, and miR-200c, which can induce imperfect base pairing with the 3'-untranslated region of FAM3B mRNA, were up-regulated in all cell lines examined. Conclusions: These results indicate that decreased FAM3B expression is able to promote OSCC progression and that certain miRNAs may be correlated with the altered expression of FAM3B. © 2012 Japanese Stomatological Society.

5-Fluorouracil (5-FU) chemotherapy is the first choice treatment for advanced hepatocellular carcinoma (HCC), and resistance is the major obstacle to successful treatment. Recent studies have reported that epithelial-to-mesenchymal transition (EMT) is associated with chemoresistance in cancers. We speculated that EMT and 5-FU metabolism are related to the mechanism of 5-FU resistance. First, two 5-FU-resistant cell lines, HLF-R4 and HLF-R10, were established from the HLF undifferentiated human HCC cell line. Whereas cell growth was similar in the HLF and HLF-R cell lines, HLF-Rs are about 4- and 10-fold more resistant compared with the HLF cells; thus, we named these cell lines HLF-R4 and HLF-R10, respectively. The terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling assay also showed a dramatically decreased number of apoptotic cells in the HLF-Rs after treatment with 5-FU. We next assessed the characteristics of the HLF, HLF-R4 and HLF-R10 cells. Consistent with our hypothesis, the HLF-Rs had typical morphologic phenotypes of EMT, loss of cell-cell adhesion, spindle-shaped morphology and increased formation of pseudopodia. Real-time quantitative reverse transcriptase polymerase chain reaction data showed downregulated E-cadherin and upregulated Twist-1 and also indicated that EMT changes occurred in the HLF-Rs. We also found decreased ribonucleotide reductase and increased multidrug resistance protein 5 genes in the HLF-R cells. Our results suggested that the metabolism of EMT and 5-FU has important roles in 5-FU chemoresistance in the HLF-R cells, and that the HLF-R cells would be useful in vitro models for understanding the 5-FU-resistant mechanisms in HCC.