Resveratrol Inhibits Proliferation and Induces Autophagy by Blocking SREBP1 Expression in Oral Cancer Cells.

Resveratrol is a polyphenolic antioxidant found in grapes, red wine, and peanuts and has been reported to have anti-neoplastic effects on various cancer types. However, the exact mechanism of its anti-cancer effects in oral cancer is not fully understood and remains controversial. Resveratrol exhibits strong hypolipidemic effects; therefore, we examined its effect on lipid metabolism in oral cancer. Resveratrol significantly reduced cell viability and induced autophagic cell death in oral cancer cells but not in normal cells. This selective effect was accompanied by significantly reduced lipogenesis, which is caused by downregulation of the transcription factor sterol regulatory element-binding protein 1 (SREBP1) gene, followed by downregulation of the epidermal fatty acid-binding protein (E-FABP). It was strongly suggested that resveratrol-induced autophagy resulted from the inhibition of SREBP1-mediated cell survival signaling. Luciferase reporter assay further indicated that resveratrol has a potent and specific inhibitory effect on SREBP1-dependent transactivation. Importantly, resveratrol markedly suppressed the growth of oral cancer cells in an animal xenograft model, without exhibiting apparent cytotoxicity. In conclusion, resveratrol induces autophagy in oral cancer cells by suppressing lipid metabolism through the regulation of SREBP1 expression, which highlights a novel mechanism of the anti-cancer effect of resveratrol.

A Case of Buccal Clear Cell Carcinoma Caused by Rare Fusion Gene: EWSR1-CREM.

Clear cell carcinoma (CCC) is a rare entity in the salivary gland tumor. So far, only 10 cases of primary CCC of the buccal mucosa have been reported. Here, we first report an extremely rare case of buccal CCC with the EWSR1-CREM fusion gene. The patient, a 69-year-old woman, presented with a painless mass in the right buccal mucosa. The tumor, which had been present for about 10 years, measured approximately 15 mm in diameter and was pedunculated, elastic hard, smooth, and mobile. Histopathological examination revealed proliferating tumor cells with vacuolated and clear cytoplasm partially surrounded by hyalinized stroma. The tumor was not encapsulated, and no contact with the overlying epithelium was evident. Duct-like structures were occasionally observed in the tumor nests composed of clear cells. The tumor had invaded into surrounding muscle and adipose tissues. Immunohistochemical examination revealed that the clear cells were positive for epithelial cell markers, and myoepithelial markers were negative. Fluorescence in situ hybridization (FISH), performed to search for genetic abnormalities, demonstrated split positivity for EWSR1, and fusion with CREM was confirmed. These findings suggested a diagnosis of CCC.

Down-regulation of Glutathione Peroxidase 4 in Oral Cancer Inhibits Tumor Growth Through SREBP1 Signaling.

BACKGROUND/AIM: This study aimed to elucidate the role of glutathione peroxidase 4 (GPX4) on the sterol regulatory element binding proteins (SREBPs)-proliferation pathway in oral cancer cells, and determine its protein expression in oral cancer tissues. MATERIALS AND METHODS: Quantitative RT-PCR and immunoblot analysis were carried out. Cell viability assay, apoptosis detection assay, immunohistochemistry and GPX4 knockdown were performed. RESULTS: The levels of both GPX4 mRNA and protein were highest in SAS cells. GPX4 knockdown in SAS cells, a human oral squamous cell carcinoma cell line, using GPX4 siRNA resulted in a reduction in cell number, which appeared to be due to non-apoptotic cell death such as ferroptosis. Furthermore, SREBP was clearly down-regulated by GPX4 knockdown in SAS cells. Immunopositivity for GPX4 was revealed on the membrane of human oral squamous cell carcinoma cells, and this was correlated with p53 immunoreactivity. CONCLUSION: GPX4 appears to play an important role in oral cancer proliferation.

[A CASE OF RENAL CELL CARCINOMA WITH INFERIOR VENA CAVAL TUMOR THROMBUS WHICH THE REDUCTION OF TUMOR IN SPITE OF DRUG DISCONTINUANCE AFTER THE FULMINANT HEPATITIS ONSET WITH THE SUNITNIB].

A 70-year-old man presented with right renal cell carcinoma with inferior vena caval tumor thrombus into the right atrium. CT Scan presented local invasion and lymph node metastasis. We estimated inoperative case, so he was started sunitinib. After 5 month he had general fatigue and admitted to our hospital. He diagnosed serious adverse events of fulminant hepatitis and left ventricular systolic dysfunction and discontinued sunitnib. After drug discontinuance reduction of tumor and tumor thrombus were detected. 7-months later, we showed the increase of tumor and the improvement of the left ventricular systolic dysfunction. We performed right renal nephrectomy and it passes now in 14 months after surgery, but doses not show a recurrence, metastasis.

Periostitis Ossificans Arising in the Mandibular Bone of a Young Patient: Report of an Unusual Case and Review of the Literature.

Periostitis ossificans, also known as Garré osteomyelitis, is a specific type of chronic osteomyelitis that forms new bone under the periosteum resulting from a periosteal reaction to chronic inflammation or infections. It commonly affects the mandible secondary to odontogenic infection. The therapeutic approach involves eliminating the infectious cause and antibiotic administration. This report describes an unusual case of periostitis ossificans arising from the mandible of an 11-year-old boy. The cause of infection was correlated with a lower right unerupted third molar, which had no obvious connection with the oral cavity. The histologic diagnosis was chronic osteomyelitis with proliferative periostitis. The patient has been followed for 1 year, without any evidence of recurrence. Periostitis ossificans can be diagnostically problematic, and various conditions must be considered in the differential diagnosis.

Development and regression of the thyroglossal duct in mice.

The thyroid anlage develops in the foramen caecum area of the tongue, and migrates through the anterior neck towards its final position in front of the laryngeal cartilages. During migration, the thyroglossal duct, a temporary structure connecting the thyroid anlage and the foramen caecum, is recognized. In the present study, chronological changes and apoptosis in the thyroglossal duct of mice were investigated histochemically using an antibody against Nkx2-1, initially identified as a thyroid transcription factor 1 (TTF1), and the TUNEL reaction in consecutive serial sagittal sections. At embryonic day 10.00 (E10.00), the thyroid anlage was Nkx2-1-immunoreactive and located just below the foramen caecum. As the thyroid anlage descended, the thyroglossal duct was formed at E10.25, being less than 10µm in diameter. By E10.75, the Nkx2-1-positive thyroglossal duct had progressively elongated up to 100µm. At E11.00 the thyroglossal duct began to disappear, beginning in its mid-portion, and finally became invisible at E11.50. At E11.00-12.00, apoptotic cells were found in an area where the thyroglossal duct was partially discontinuous. After E12.00, cartilaginous tissue of the hyoid bone anlage developed in the mid-portion of the area where the thyroglossal duct had regressed. Immunoreactivity for thyroglobulin, a marker of differentiated thyroid endocrine cells, was detected at E13.00. These results strongly suggest that the mouse thyroglossal duct disappears as a result of apoptosis before differentiation of the endocrine thyroid.

Expression of epidermal fatty acid binding protein (E-FABP) in septoclasts in the growth plate cartilage of mice.

n-3 Polyunsaturated fatty acids play a role in regulating the growth of the long bones. Fatty acid-binding proteins (FABPs) bind and transport hydrophobic long-chain fatty acids intracellularly, and epidermal-type FABP (E-FABP) has an affinity for n-3 fatty acids. This study aimed to clarify the localization of E-FABP in the growth plate of the mouse tibia. At the chondro-osseous junction (COJ) of the growth plate, E-FABP-immunoreactivity was exclusively localized in mononuclear, spindle-shaped cells with several long processes. These E-FABP-immunoreactive cells were identified as being septoclasts, i.e., cells that resorb uncalcified transverse septa. The processes of these immunoreactive septoclasts terminated between the longitudinal and transverse septa. E-FABP-immunoreactivity was found in the entire cytoplasm and on the mitochondrial outer membrane. In ontogeny, immunoreactive septoclasts were observed immediately after emergence of the primary ossifying center and were distributed not only at the COJ but also in the metaphysis near the COJ. The number of septoclasts increased at the postnatal age of 1 week (P1w)-P2w, and thereafter gradually decreased; and the cells became concentrated at the COJ after P3w-P4w. The immunoreactivity for peroxisome proliferator-activated receptor (PPAR)ß/δ was detected in these E-FABP-immunoreactive septoclasts. The present results suggest that fatty acids, preferably n-3 ones, are intracellularly transported by E-FABP to various targets, including mitochondria and nucleus, in which PPARß/δ may play functional roles in the transcriptional regulation of genes involved in the endochondral ossification.

Localization of heat shock protein 27 (hsp27) in the rat gingiva and its changes with tooth eruption.

Heat shock protein 27 kDa (Hsp27) functions as a molecular chaperon to prevent apoptosis as well as to contribute to the regulation of cell proliferation and differentiation during development. In the present study, the localization of Hsp27 in the oral epithelium of rats and its expression change during formation of the gingiva with the tooth eruption were examined immunohistochemically to elucidate the roles of Hsp27 in the oral mucosa.In adult rats, Hsp27-immunoreactivity was localized in the prickle and granular layers but absent in the basal and horny layers of the oral epithelium. On the other hand, in the outer and sulcular epithelia of the free gingival, Hsp27-immunoreactivity was detected in the whole layers, while it was not found in the proliferation zone of the junctional epithelium immunoreactive for Ki67. In immature rats on 10th postnatal day, Hsp27-immunoreactivity was intense in the prickle and granular layers of the oral epithelium, but was not detected in its basal layer. In rats at the eruptive phase on 15th postnatal day, Hsp27-immunoreactivity was detected in sites of the basal layer adjacent to where the dental cusps penetrated through the oral epithelium. Although the immunoreactivity for Ki67 was found in the basal layer of the oral epithelium, it was not localized in the Hsp27-immunopositive sites of tooth-penetration in the basal layer. Just after the tooth-eruption on 20th postnatal day, Hsp27-immunoreactivity was not found in the stratified squamous epithelium at the dentogingival junction, whereas it was intense in a single layer of cuboidal epithelial cells attached to the tooth neck. Ki67-positive cells were scattered in the stratified squamous epithelium at the dentogingival junction, whereas no positive cells were found in the portion of a single layer of cuboidal epithelial cells.These findings suggest that the outer and sulcular epithelia of the free gingiva have a relatively slower rate of proliferation than other gingival and oral epithelia, and that Hsp27 might inhibit the proliferation of the basal cells. Such specific phenomenon in the free gingiva occurred immediately after the dental cusps were exposed to the oral cavity.

Analysis of nanoplankton community structure using flow sorting and molecular techniques.

We developed a method for the separate and simultaneous analysis of the community structure of heterotrophic nanopkankton (HNP) and autotrophic nanoplankton (ANP). This method consists of three steps. First, nanoplankton cells were concentrated using a cross-flow filtration system because cell densities in natural seawater are usually too low for genetic studies. Second, HNP and ANP were separated by flow cytometric sorting ("flow sorting") on the basis of the presence or absence of chlorophyll. Finally, the community structure was analyzed using denaturing gradient gel electrophoresis targeting 18S rRNA gene. The newly developed method was applied to the coastal surface water of Aburatsubo Inlet, Japan, in July 2008. The separation of nanoplankton into HNP and ANP was validated by phylogenetic analysis, and the trophic mode of uncultured nanoplankton was confirmed (e.g. Marine Alveolata group II [MALV II] and Marine Stramenopile clade-2 [MAST-2]). This new method involving cell concentration, flow sorting and phylogenetic analysis is a potentially powerful tool for evaluating the population dynamics and ecology of marine protozoa.

Separation of marine bacteria according to buoyant density by use of the density-dependent cell sorting method.

The purpose of this study was to test whether some phylogenetic groups of natural marine bacteria have unique buoyant densities that allow them to be separated by the density-dependent cell sorting (DDCS) method. We first concentrated a natural bacterial assemblage to collect sufficient numbers of cells. They were separated into three fractions by DDCS, and the community structure in each was clarified by fluorescence in situ hybridization. The cells of Archaea tended to appear in the high-density fraction, whereas those of Cytophaga-Flavobacterium-Bacteroides were in the low-density fraction. We also calculated the sedimentation velocities of three typical marine bacteria (low density, middle density, and high density) using their buoyant density. The sedimentation velocities were approximately 10, 20, and 30 microm h(-1); these velocities have ecological implications when the heterogeneity of bacteria is considered at a microscale. To our knowledge, this is the first report on the buoyant density of natural marine bacteria.

Indium(III) chloride-sodium borohydride system: a convenient radical reagent for an alternative to tributyltin hydride system.

The indium hydride generated from NaBH4 and InCl3, is a promising candidate of alternative to Bu3SnH. In particular, the catalytic performance of InCl3 in the dehalogenation of alkyl and aryl halides, intramolecular cyclization and intermolecular coupling reaction are noteworthy.