Salivary gland polymorphous adenocarcinoma: Clinicopathological features and gene alterations in 36 Japanese patients.

BACKGROUND: Polymorphous adenocarcinoma is a common intraoral minor salivary gland carcinoma in Western countries but is extremely rare in Japan. The current study aimed to characterize the clinicopathological features and status of molecular alterations of polymorphous adenocarcinoma-associated genes, such as PRKD1/2/3, ARID1A, and DDX3X, in a large cohort of Japanese patients with polymorphous adenocarcinoma. METHODS: We examined the cases of 36 Japanese patients with salivary gland polymorphous adenocarcinoma and 26 cases involving histopathological mimics. To detect gene splits, fluorescence in situ hybridization was carried out for polymorphous adenocarcinoma-associated genes. Additionally, we applied a SNaPshot multiplex assay to identify PRKD1 hotspot mutations. RESULTS: This study revealed the indolent clinical course of polymorphous adenocarcinoma with a high 10-year overall survival rate (92.9%), accompanied by occasional local recurrences and cervical lymph node metastasis (23.3%). Twenty cases (55.6%) of polymorphous adenocarcinoma (but none of the mimics) exhibited alterations in at least one polymorphous adenocarcinoma-associated gene. Rearrangement of polymorphous adenocarcinoma-associated genes and PRKD1 E710D were identified in 17 (47.2%) and 4 (11.1%) cases, respectively; one case showed coexisting PRKD3 split and PRKD1 E710D. In the multivariate analysis, high clinical stage (p = 0.0005), the presence of prominent nucleoli (p = 0.0003), and ARID1A split positivity (p = 0.004) were independent risk factors for disease-free survival. CONCLUSION: Japanese patients with polymorphous adenocarcinoma showed clinicopathological features similar to those reported in Western countries. This study disclosed that polymorphous adenocarcinoma-associated genetic alterations were common and specific findings in polymorphous adenocarcinomas. The diagnostic role and possible prognostic significance of polymorphous adenocarcinoma-associated genetic alterations in polymorphous adenocarcinomas were suggested.

Improving function of cytotoxic T-lymphocytes by transforming growth factor-ß inhibitor in oral squamous cell carcinoma.

Immunotherapy with immune-checkpoint therapy has recently been used to treat oral squamous cell carcinomas (OSCCs). However, improvements in current immunotherapy are expected because response rates are limited. Transforming growth factor-ß (TGF-ß) creates an immunosuppressive tumor microenvironment (TME) by inducing the production of regulatory T-cells (Tregs) and cancer-associated fibroblasts and inhibiting the function of cytotoxic T-lymphocytes (CTLs) and natural killer cells. TGF-ß may be an important target in the development of novel cancer immunotherapies. In this study, we investigated the suppressive effect of TGF-ß on CTL function in vitro using OSCC cell lines and their specific CTLs. Moreover, TGFB1 mRNA expression and T-cell infiltration in 25 OSCC tissues were examined by in situ hybridization and multifluorescence immunohistochemistry. We found that TGF-ß suppressed the function of antigen-specific CTLs in the priming and effector phases in vitro. Additionally, TGF-ß inhibitor effectively restored the CTL function, and TGFB1 mRNA was primarily expressed in the tumor invasive front. Interestingly, we found a significant negative correlation between TGFB1 mRNA expression and the CD8+ T-cell/Treg ratio and between TGFB1 mRNA expression and the Ki-67 expression in CD8+ T-cells, indicating that TGF-ß also suppressed the function of CTLs in situ. Our findings suggest that the regulation of TGF-ß function restores the immunosuppressive TME to active status and is important for developing new immunotherapeutic strategies, such as a combination of immune-checkpoint inhibitors and TGF-ß inhibitors, for OSCCs.

Porphyromonas gingivalis Components/Secretions Synergistically Enhance Pneumonia Caused by Streptococcus pneumoniae in Mice.

Streptococcus pneumoniae is an important causative organism of respiratory tract infections. Although periodontal bacteria have been shown to influence respiratory infections such as aspiration pneumonia, the synergistic effect of S. pneumoniae and Porphyromonas gingivalis, a periodontopathic bacterium, on pneumococcal infections is unclear. To investigate whether P. gingivalis accelerates pneumococcal infections, we tested the effects of inoculating P. gingivalis culture supernatant (PgSup) into S. pneumoniae-infected mice. Mice were intratracheally injected with S. pneumoniae and PgSup to induce pneumonia, and lung histopathological sections and the absolute number and frequency of neutrophils and macrophages in the lung were analyzed. Proinflammatory cytokine/chemokine expression was examined by qPCR and ELISA. Inflammatory cell infiltration was observed in S. pneumoniae-infected mice and S. pnemoniae and PgSup mixed-infected mice, and mixed-infected mice showed more pronounced inflammation in lung. The ratios of monocytes/macrophages and neutrophils were not significantly different between the lungs of S. pneumoniae-infected mice and those of mixed-infected mice. PgSup synergistically increased TNF-α expression/production and IL-17 production compared with S. pneumoniae infection alone. We demonstrated that PgSup enhanced inflammation in pneumonia caused by S. pneumoniae, suggesting that virulence factors produced by P. gingivalis are involved in the exacerbation of respiratory tract infections such as aspiration pneumonia.

UV-Pre-Treated and Protein-Adsorbed Titanium Implants Exhibit Enhanced Osteoconductivity.

Titanium materials are essential treatment modalities in the medical field and serve as a tissue engineering scaffold and coating material for medical devices. Thus, there is a significant demand to improve the bioactivity of titanium for therapeutic and experimental purposes. We showed that ultraviolet light (UV)-pre-treatment changed the protein-adsorption ability and subsequent osteoconductivity of titanium. Fibronectin (FN) adsorption on UV-treated titanium was 20% and 30% greater after 1-min and 1-h incubation, respectively, than that of control titanium. After 3-h incubation, FN adsorption on UV-treated titanium remained 30% higher than that on the control. Osteoblasts were cultured on titanium disks after 1-h FN adsorption with or without UV-pre-treatment and on titanium disks without FN adsorption. The number of attached osteoblasts during the early stage of culture was 80% greater on UV-treated and FN-adsorbed (UV/FN) titanium than on FN-adsorbed (FN) titanium; osteoblasts attachment on UV/FN titanium was 2.6- and 2.1-fold greater than that on control- and UV-treated titanium, respectively. The alkaline phosphatase activity of osteoblasts on UV/FN titanium was increased 1.8-, 1.8-, and 2.4-fold compared with that on FN-adsorbed, UV-treated, and control titanium, respectively. The UV/FN implants exhibited 25% and 150% greater in vivo biomechanical strength of bone integration than the FN- and control implants, respectively. Bone morphogenetic protein-2 (BMP-2) adsorption on UV-treated titanium was 4.5-fold greater than that on control titanium after 1-min incubation, resulting in a 4-fold increase in osteoblast attachment. Thus, UV-pre-treatment of titanium accelerated its protein adsorptivity and osteoconductivity, providing a novel strategy for enhancing its bioactivity.

A Newly Created Meso-, Micro-, and Nano-Scale Rough Titanium Surface Promotes Bone-Implant Integration.

Titanium implants are the standard therapeutic option when restoring missing teeth and reconstructing fractured and/or diseased bone. However, in the 30 years since the advent of micro-rough surfaces, titanium's ability to integrate with bone has not improved significantly. We developed a method to create a unique titanium surface with distinct roughness features at meso-, micro-, and nano-scales. We sought to determine the biological ability of the surface and optimize it for better osseointegration. Commercially pure titanium was acid-etched with sulfuric acid at different temperatures (120, 130, 140, and 150 °C). Although only the typical micro-scale compartmental structure was formed during acid-etching at 120 and 130 °C, meso-scale spikes (20-50 µm wide) and nano-scale polymorphic structures as well as micro-scale compartmental structures formed exclusively at 140 and 150 °C. The average surface roughness (Ra) of the three-scale rough surface was 6-12 times greater than that with micro-roughness only, and did not compromise the initial attachment and spreading of osteoblasts despite its considerably increased surface roughness. The new surface promoted osteoblast differentiation and in vivo osseointegration significantly; regression analysis between osteoconductivity and surface variables revealed these effects were highly correlated with the size and density of meso-scale spikes. The overall strength of osseointegration was the greatest when the acid-etching was performed at 140 °C. Thus, we demonstrated that our meso-, micro-, and nano-scale rough titanium surface generates substantially increased osteoconductive and osseointegrative ability over the well-established micro-rough titanium surface. This novel surface is expected to be utilized in dental and various types of orthopedic surgical implants, as well as titanium-based bone engineering scaffolds.

UV-Photofunctionalization of Titanium Promotes Mechanical Anchorage in A Rat Osteoporosis Model.

Effects of UV-photofunctionalization on bone-to-titanium integration under challenging systemic conditions remain unclear. We examined the behavior and response of osteoblasts from sham-operated and ovariectomized (OVX) rats on titanium surfaces with or without UV light pre-treatment and the strength of bone-implant integration. Osteoblasts from OVX rats showed significantly lower alkaline phosphatase, osteogenic gene expression, and mineralization activities than those from sham rats. Bone density variables in the spine were consistently lower in OVX rats. UV-treated titanium was superhydrophilic and the contact angle of ddH2O was ≤5°. Titanium without UV treatment was hydrophobic with a contact angle of ≥80°. Initial attachment to titanium, proliferation, alkaline phosphatase activity, and gene expression were significantly increased on UV-treated titanium compared to that on control titanium in osteoblasts from sham and OVX rats. Osteoblastic functions compromised by OVX were elevated to levels equivalent to or higher than those of sham-operated osteoblasts following culture on UV-treated titanium. The strength of in vivo bone-implant integration for UV-treated titanium was 80% higher than that of control titanium in OVX rats and even higher than that of control implants in sham-operated rats. Thus, UV-photofunctionalization effectively enhanced bone-implant integration in OVX rats to overcome post-menopausal osteoporosis-like conditions.

Tuning of Titanium Microfiber Scaffold with UV-Photofunctionalization for Enhanced Osteoblast Affinity and Function.

Titanium (Ti) is an osteoconductive material that is routinely used as a bulk implant to fix and restore bones and teeth. This study explored the effective use of Ti as a bone engineering scaffold. Challenges to overcome were: (1) difficult liquid/cell infiltration into Ti microfiber scaffolds due to the hydrophobic nature of Ti; and (2) difficult cell attachment on thin and curved Ti microfibers. A recent discovery of UV-photofunctionalization of Ti prompted us to examine its effect on Ti microfiber scaffolds. Scaffolds in disk form were made by weaving grade 4 pure Ti microfibers (125 µm diameter) and half of them were acid-etched to roughen the surface. Some of the scaffolds with original or acid-etched surfaces were further treated by UV light before cell culture. Ti microfiber scaffolds, regardless of the surface type, were hydrophobic and did not allow glycerol/water liquid to infiltrate, whereas, after UV treatment, the scaffolds became hydrophilic and immediately absorbed the liquid. Osteogenic cells from two different origins, derived from the femoral and mandibular bone marrow of rats, were cultured on the scaffolds. The number of cells attached to scaffolds during the early stage of culture within 24 h was 3-10 times greater when the scaffolds were treated with UV. The development of cytoplasmic projections and cytoskeletal, as well as the expression of focal adhesion protein, were exclusively observed on UV-treated scaffolds. Osteoblastic functional phenotypes, such as alkaline phosphatase activity and calcium mineralization, were 2-15 times greater on UV-treated scaffolds, with more pronounced enhancement on acid-etched scaffolds compared to that on the original scaffolds. These effects of UV treatment were associated with a significant reduction in atomic carbon on the Ti microfiber surfaces. In conclusion, UV treatment of Ti microfiber scaffolds tunes their physicochemical properties and effectively enhances the attachment and function of osteoblasts, proposing a new strategy for bone engineering.

Novel Osteogenic Behaviors around Hydrophilic and Radical-Free 4-META/MMA-TBB: Implications of an Osseointegrating Bone Cement.

Poly(methyl methacrylate) (PMMA)-based bone cement, which is widely used to affix orthopedic metallic implants, is considered bio-tolerant but lacks osteoconductivity and is cytotoxic. Implant loosening and toxic complications are significant and recognized problems. Here we devised two strategies to improve PMMA-based bone cement: (1) adding 4-methacryloyloxylethyl trimellitate anhydride (4-META) to MMA monomer to render it hydrophilic; and (2) using tri-n-butyl borane (TBB) as a polymerization initiator instead of benzoyl peroxide (BPO) to reduce free radical production. Rat bone marrow-derived osteoblasts were cultured on PMMA-BPO, common bone cement ingredients, and 4-META/MMA-TBB, newly formulated ingredients. After 24 h of incubation, more cells survived on 4-META/MMA-TBB than on PMMA-BPO. The mineralized area was 20-times greater on 4-META/MMA-TBB than PMMA-BPO at the later culture stage and was accompanied by upregulated osteogenic gene expression. The strength of bone-to-cement integration in rat femurs was 4- and 7-times greater for 4-META/MMA-TBB than PMMA-BPO during early- and late-stage healing, respectively. MicroCT and histomorphometric analyses revealed contact osteogenesis exclusively around 4-META/MMA-TBB, with minimal soft tissue interposition. Hydrophilicity of 4-META/MMA-TBB was sustained for 24 h, particularly under wet conditions, whereas PMMA-BPO was hydrophobic immediately after mixing and was unaffected by time or condition. Electron spin resonance (ESR) spectroscopy revealed that the free radical production for 4-META/MMA-TBB was 1/10 to 1/20 that of PMMA-BPO within 24 h, and the substantial difference persisted for at least 10 days. The compromised ability of PMMA-BPO in recruiting cells was substantially alleviated by adding free radical-scavenging amino-acid N-acetyl cysteine (NAC) into the material, whereas adding NAC did not affect the ability of 4-META/MMA-TBB. These results suggest that 4-META/MMA-TBB shows significantly reduced cytotoxicity compared to PMMA-BPO and induces osteoconductivity due to uniquely created hydrophilic and radical-free interface. Further pre-clinical and clinical validations are warranted.

Patients with SATB2-associated syndrome exhibiting multiple odontomas.

Special AT-rich sequence-binding protein 2 (SATB2)-associated syndrome (SAS) is characterized by alterations of SATB2. Its clinical features include intellectual disability and craniofacial abnormalities, such as cleft palate, dysmorphic features, and dental abnormalities. Here, we describe three previously undiagnosed, unrelated patients with SAS who exhibited dental abnormalities, including multiple odontomas. Although isolated odontomas are common, multiple odontomas are rare. Individuals in families 1 and 3 underwent whole-exome sequencing. Patient 2 and parents underwent targeted amplicon sequencing. On the basis of the hg19/GRCh37 reference and the RefSeq mRNA NM_001172517, respective heterozygous mutations were found and validated in Patients 1, 2, and 3: a splice-site mutation (chr2:g.200137396C > T, c.1741-1G > A), a nonsense mutation (chr2:g.200213750G > A, c.847C > T, p.R283*), and a frame-shift mutations (chr2:g.200188589_200188590del, c.1478_1479del, p.Q493Rfs*19). All mutations occurred de novo. The mutations in Patients 1 and 3 were novel; the mutation in Patient 2 has been described previously. Tooth mesenchymal cells derived from Patient 2 showed diminished SATB2 expression. Multiple odontomas were evident in the patients in this report; however, this has not been recognized previously as a SAS-associated phenotype. We propose that multiple odontomas be considered as an occasional manifestation of SAS.

Notch as a Possible Cell Differentiation Factor in Pleomorphic Adenomas.

The expression of Notch in 30 cases of pleomorphic adenoma was examined by immunohistochemistry. Comparing the results of our study with previous literatures, from the partial CK7 expression and substantial Notch expression in ductal epithelial cells as well as the Notch expression in solid tumor nests, it can be inferred that Notch is involved in cell differentiation. CK13 expression was observed in cells undergoing squamous metaplasia and Notch expression was seen in the nucleus of basal and squamous cells. The intense Notch expression in basal cells and weak expression in squamous cells suggests that Notch is involved in the differentiation from basal to squamous cell. Moreover, the loss of nuclear expression on the inner layer would signify that differentiation is about to end or has been terminated. Notch was expressed in the cytoplasm of cartilage cells and in the cell membrane of mucous cells but not in the nucleus indicating that differentiation has been concluded. Notch involvement is suspected in cell differentiation in areas showing ductal structures and squamous metaplasia. In summary, Notch is involved in cell differentiation of ductal cells in PA. Nuclear expression was shown in tumor cells in solid nests and surrounding structures. Moreover, Notch is expressed by basal cells undergoing squamous metaplasia suggesting the participation of Notch in cell differentiation in PA.

Wnt signaling as a possible promoting factor of cell differentiation in pleomorphic adenomas.

There are well known that Wnt signaling was some roles of cell differentiation at the development tissues, especially the oral and maxillofacial regions of some developmental stages. Therefore, to determine Wnt signaling in the pleomorphic adenoma tissues, we examined. The expression of Wnt1 and ß-catenin as well as the distribution of various cytoskeletal proteins CK7 and CK13 was examined in 30 cases of pleomorphic adenoma by immunohistochemistry. Wnt1 was detected in almost all tumor cells. The peripheral columnar cells in squamous metaplasia and small cuboidal cells in duct-like structures were strongly positive to Wnt1. Although ß-catenin was clearly localized on the cell membrane of tumor cells, nuclear translocation was observed in small cuboidal cells and in some basaloid cells. The immunofluorescent staining pattern of Wnt1 and CK7 as well as Wnt1 and CK13 was consistent with IHC results. Thus, in pleomorphic adenoma, Wnt is involved in tumor cell differentiation of peripheral columnar cells forming solid nests and small peripheral columnar cells forming duct-like structures. Moreover, among the three currently known Wnt pathways, ß-catenin is the suggested pathway working during cell differentiation. Furthermore, peripheral columnar cells in solid tumor nests and in squamous metaplasia are governed by another Wnt pathway other than ß-catenin. Therefore, Wnt signaling through ß-catenin pathway may be involved in the 'mixed' differentiation characteristic of pleomorphic adenoma although another pathway may also be possibly working in other parts of the tumor tissue.

Periostin Is a Candidate Regulator of the Host Microenvironment in Regeneration of Pulp and Dentin Complex and Periodontal Ligament in Transplantation with Stem Cell-Conditioned Medium.

Purpose: The microenvironment is required for tissues to maintain their properties in vivo. This microenvironment encompasses the types and three-dimensional arrangement of cells forming the tissues, and their interactions with neighboring cells and extracellular matrices, as represented by the stem cell niche. Tissue regeneration depends not on the original tissue source of the transplanted cells, but on the microenvironment in which they are transplanted. We have previously reported pulp regeneration in a heterotopic root graft model by transplantation of conditioned medium alone, which suggests that host-derived cells expressing receptors for migration factors in conditioned medium migrate into the root canal and cause pulp regeneration. Regenerative medicine is needed to restore the original function of complex tissues. To achieve this, it is necessary to reproduce the changes in the microenvironment of the host tissue that accompany the regenerative response. Therefore, it is important to reproduce the microenvironment in vivo for further development of tissue regeneration therapy. Periostin is also found in the epithelial-mesenchymal junction, with expression sites that differ depending on the mineralized matrix stage, and is involved in regulation of calcification. Methods: We investigate whether periostin contributes to microenvironmental changes in regenerated pulp tissue. Dental pulp stem cells were induced into dentin, and gene expression of DSPP, nestin, DMP1, Runx2, and periostin was analyzed by qPCR and protein expression by IHC. Similarly, gene expression was analyzed using qPCR and protein expression using IHC in regenerated dental pulp obtained by ectopic transplantation. Results: Since these regenerated tissues were observable on the same slice, it was possible to understand changes in the microenvironment within the tissues. Conclusions: Periostin promoted proliferation of pulp stem cells, migration in type I collagen, and calcification in regenerated pulp, which strongly suggests that periostin is a promising candidate as a factor that contributes to the microenvironment of regenerated pulp.

Heat shock protein27 expression and cell differentiation in ameloblastomas.

The expression of HSP27 and some CKs were examined the 40 cases of typical solid/multicystic ameloblastoma using immunohistochemical techniques. In order to examine the relevance of HSP in cell differentiation, we focused on the cytoskeletal expression of CK. CK19 is a marker of typical odontogenic epithelium widely observed in follicular and plexiform types of ameloblastomas. Since staining with CK14 is one of the measures of the differentiation potential of squamous cells and is extensively expressed in both follicular and plexiform types, it implies that squamous differentiation of each type can occur. CK8 was strongly detected in tumor nests in plexiform type but weakly detected in follicular type. It was considered that the expression of HSP27 in plexiform type correlated with the expression of CK8 suggesting that HSP27 might have regulated the expression of CK8.

Vacuum Ultraviolet (VUV) Light Photofunctionalization to Induce Human Oral Fibroblast Transmigration on Zirconia.

Soft tissue adhesion and sealing around dental and maxillofacial implants, related prosthetic components, and crowns are a clinical imperative to prevent adverse outcomes of periodontitis and periimplantitis. Zirconia is often used to fabricate implant components and crowns. Here, we hypothesized that UV treatment of zirconia would induce unique behaviors in fibroblasts that favor the establishment of a soft tissue seal. Human oral fibroblasts were cultured on zirconia specimens to confluency before placing a second zirconia specimen (either untreated or treated with one minute of 172 nm vacuum UV (VUV) light) next to the first specimen separated by a gap of 150 µm. After seven days of culture, fibroblasts only transmigrated onto VUV-treated zirconia, forming a 2.36 mm volume zone and 5.30 mm leading edge. Cells migrating on VUV-treated zirconia were enlarged, with robust formation of multidirectional cytoplastic projections, even on day seven. Fibroblasts were also cultured on horizontally placed and 45° and 60° tilted zirconia specimens, with the latter configurations compromising initial attachment and proliferation. However, VUV treatment of zirconia mitigated the negative impact of tilting, with higher tilt angles increasing the difference in cellular behavior between control and VUV-treated specimens. Fibroblast size, perimeter, and diameter on day seven were greater than on day one exclusively on VUV-treated zirconia. VUV treatment reduced surface elemental carbon and induced superhydrophilicity, confirming the removal of the hydrocarbon pellicle. Similar effects of VUV treatment were observed on glazed zirconia specimens with silica surfaces. One-minute VUV photofunctionalization of zirconia and silica therefore promotes human oral fibroblast attachment and proliferation, especially under challenging culture conditions, and induces specimen-to-specimen transmigration and sustainable photofunctionalization for at least seven days.

A Novel Cell Delivery System Exploiting Synergy between Fresh Titanium and Fibronectin.

Delivering and retaining cells in areas of interest is an ongoing challenge in tissue engineering. Here we introduce a novel approach to fabricate osteoblast-loaded titanium suitable for cell delivery for bone integration, regeneration, and engineering. We hypothesized that titanium age influences the efficiency of protein adsorption and cell loading onto titanium surfaces. Fresh (newly machined) and 1-month-old (aged) commercial grade 4 titanium disks were prepared. Fresh titanium surfaces were hydrophilic, whereas aged surfaces were hydrophobic. Twice the amount of type 1 collagen and fibronectin adsorbed to fresh titanium surfaces than aged titanium surfaces after a short incubation period of three hours, and 2.5-times more fibronectin than collagen adsorbed regardless of titanium age. Rat bone marrow-derived osteoblasts were incubated on protein-adsorbed titanium surfaces for three hours, and osteoblast loading was most efficient on fresh titanium adsorbed with fibronectin. The number of osteoblasts loaded using this synergy between fresh titanium and fibronectin was nine times greater than that on aged titanium with no protein adsorption. The loaded cells were confirmed to be firmly attached and functional. The number of loaded cells was strongly correlated with the amount of protein adsorbed regardless of the protein type, with fibronectin simply more efficiently adsorbed on titanium surfaces than collagen. The role of surface hydrophilicity of fresh titanium surfaces in increasing protein adsorption or cell loading was unclear. The hydrophilicity of protein-adsorbed titanium increased with the amount of protein but was not the primary determinant of cell loading. In conclusion, the osteoblast loading efficiency was dependent on the age of the titanium and the amount of protein adsorption. In addition, the efficiency of protein adsorption was specific to the protein, with fibronectin being much more efficient than collagen. This is a novel strategy to effectively deliver osteoblasts ex vivo and in vivo using titanium as a vehicle.

Melanoma Inhibitory Activity and Melanoma Inhibitory Activity 2 as Novel Immunohistochemical Markers of Oral Epithelial Dysplasia.

Oral potentially malignant disorders are associated with the development of oral squamous cell carcinoma (OSCC). Most OSCCs are diagnosed via histopathology as oral epithelial dysplasia (OED), but the histologic diagnostic criteria remain non-uniform. Accordingly, the establishment of a diagnostic marker to assist in diagnosis could contribute towards cancer prevention. Melanoma inhibitory activity (MIA) and MIA2 are involved in tumor growth, invasion, and lymph node metastasis in various malignancies. The purpose of this study was to clarify the usefulness of MIA and MIA2 as diagnostic markers of oral mucosal lesions. The expression of MIA and MIA2 was analyzed immunohistochemically in 100 specimens (10 specimens with normal oral mucosa (NOM) and 30 specimens each with low-grade epithelial dysplasia (LED), high-grade epithelial dysplasia (HED), and OSCC). Immunohistochemical results were evaluated based on the Allred scoring system. Cytoplasmic expression of MIA and MIA2 increased in the order of LED, HED, and OSCC. All NOM specimens were negative for cytoplasmic expression. Significant differences were observed between the groups (NOM vs. HED, p < 0.05, NOM vs. OSCC, p < 0.001). These results demonstrate that MIA and MIA2 are expressed in the oral mucosa within early neoplastic lesions and suggest that MIA and MIA2 are useful novel immunohistochemical markers for discriminating between normal tissue and OED.

Automatic detection of cervical lymph nodes in patients with oral squamous cell carcinoma using a deep learning technique: a preliminary study.

OBJECTIVE: To apply a deep learning object detection technique to CT images for detecting cervical lymph nodes metastasis in patients with oral cancers, and to clarify the detection performance. METHODS: One hundred and fifty-nine metastatic and 517 non-metastatic lymph nodes on 365 CT images in 56 patients with oral squamous cell carcinoma were examined. The images were arbitrarily assigned to training, validation, and testing datasets. Using the neural network, 'DetectNet' for object detection, the training procedure was conducted for 1000 epochs. Testing image datasets were applied to the learning model, and the detection performance was calculated. RESULTS: The learning curve indicated that the recall (sensitivity) for detecting metastatic and non-metastatic lymph nodes reached 90% and 80%, respectively, while the model performance recall by applying the test dataset was 73.0% and 52.5%, respectively. The recall for detecting level IB and Level II metastatic lymph nodes was relatively high. CONCLUSIONS: A system that has the potential to automatically detect cervical lymph nodes was constructed.

Deep learning object detection of maxillary cyst-like lesions on panoramic radiographs: preliminary study.

OBJECTIVES: This study aimed to examine the performance of deep learning object detection technology for detecting and identifying maxillary cyst-like lesions on panoramic radiography. METHODS: Altogether, 412 patients with maxillary cyst-like lesions (including several benign tumors) were enrolled. All panoramic radiographs were arbitrarily assigned to the training, testing 1, and testing 2 datasets of the study. The deep learning process of the training images and labels was performed for 1000 epochs using the DetectNet neural network. The testing 1 and testing 2 images were applied to the created learning model, and the detection performance was evaluated. For lesions that could be detected, the classification performance (sensitivity) for identifying radicular cysts or other lesions were examined. RESULTS: The recall, precision, and F-1 score for detecting maxillary cysts were 74.6%/77.1%, 89.8%/90.0%, and 81.5%/83.1% for the testing 1/testing 2 datasets, respectively. The recall was higher in the anterior regions and for radicular cysts. The sensitivity was higher for identifying radicular cysts than for other lesions. CONCLUSIONS: Using deep learning object detection technology, maxillary cyst-like lesions could be detected in approximately 75-77%.

Suppression of alveolar bone resorption by salubrinal in a mouse model of periodontal disease.

AIMS: The relationship between stress to endoplasmic reticulum (ER) and periodontitis has been known, and ER stress induced by Porphyromonas gingivalis results in the loss of alveolar bone. Salubrinal is a small synthetic compound and attenuates ER stress through inhibition of de-phosphorylation of eukaryotic translation initiation factor 2 alpha (eIF2α). In this study, we examined whether salubrinal attenuates periodontitis in a mouse model of experimental periodontal disease. MATERIALS AND METHODS: We evaluated loss of alveolar bone and attachment levels in periodontium using micro-computed tomography (µCT) and hematoxylin-eosin (HE) staining, respectively. Furthermore, we measured osteoclast numbers using tartrate-resistant acid phosphatase (TRAP) staining and osteoblast numbers using HE staining for bone resorption and for bone formation, respectively. To examine the inhibitory effects of salubrinal against pro-inflammatory cytokines, we measured TNF-α and IL1-ß score in periodontium using immunohistostaining. KEY FINDINGS: The results revealed that salubrinal suppressed loss of alveolar bone and attachment levels in periodontium induced by periodontitis. It decreased osteoclast numbers and increased osteoblasts. It also suppressed the expression levels of TNF-α in periodontium. SIGNIFICANCE: These results show that salubrinal alleviates periodontitis through suppression of alveolar bone resorption and the pro-inflammatory cytokine, and promotion of the bone formation. Since salubrinal has been shown to have these beneficial effects for periodontal disease, it may provide a novel therapeutic possibility for the disease.

A rare case of odontogenic keratocyst extending into the sphenoid bone from the maxilla.

BACKGROUND: Odontogenic keratocyst (OKC) is the third most common odontogenic cyst which arises from cell rests of dental lamina, and usually observed in the jaws. Because OKC is noted for its high rate of recurrence, there are various treatment strategies. Here, we present a rare case of OKC which occupied the entire maxillary sinus and pterygoid process of the sphenoid bone extending nearly to the skull base. CASE PRESENTATION: The patient was a 21-year-old male and underwent surgical removal of the cyst using the Caldwell-Luc procedure which in this case extended the surgical approach to the pterygoid process of the sphenoid bone via the pterygomaxillary junction. However, we found a recurrent lesion in the posterior wall of the maxillary sinus 20 months after the surgery and subsequently performed a secondary cystectomy. Surgical specimens showed positive bcl-2 staining of OKC and negative cytokeratin-10 on immunohistochemistry for both primary and recurrent lesions. CONCLUSION: OKC rarely occurs in the maxillary sinus and extends to the deep maxillary structure and the skull base. In order to prevent recurrence, it is necessary to recognize the exact location of the entire lesion. Careful examination of preoperative CT images is needed to make a complete surgical planning and to perform a reliable surgical procedure.