Who is who in oral cancer?

Great attention has been attached to explore the association between oral bacteria and oral cancer. Recently, four common inhabitants of oral cavity, Porphyromonas gingivalis, Fusobacterium nucleatum, Treponema denticola and Streptococcus anginosus, have been identified as potential etiologic bacterial agents for oral carcinogenesis. They might promote the oncogenesis and progression of oral cancer by induction of chronic inflammation, enhancement of migration and invasiveness, inhibition of cell apoptosis, augment of cell proliferation, suppression of immune system and production of carcinogenic substances. Thus, this review will focus on the possible mechanisms of these oral bacteria contributing to occurrence and development of oral cancer, and the potential clinical implications of utilizing oral bacteria on the diagnosis, prevention and treatment of oral cancer will be discussed.

Multiple Treatment Meta-Analysis of Intra-Articular Injection for Temporomandibular Osteoarthritis.

PURPOSE: The purpose of the present study was to compare the efficacy of intra-articular injections of different agents for temporomandibular osteoarthritis (TMJOA) using a network meta-analysis. MATERIALS AND METHODS: A comprehensive search strategy was performed in multiple English and Chinese language electronic databases. Randomized controlled trials comparing the effect of intra-articular injections of different agents to treat TMJOA were included in accordance with the inclusion and exclusion criteria. The bias of risk in each study was assessed, with data extraction performed independently by 2 reviewers. The primary outcomes included pain intensity and maximal mouth opening. RESULTS: A total of 11 trials were included in the present study, and 10 different agents (ie, hyaluronic acid, dexamethasone, prednisolone, betamethasone, betamethasone plus hyaluronic acid, morphine, tramadol, platelet-derived growth factor [PDGF], placebo, arthrocentesis alone) administered using intra-articular injections were assessed. The evidence from the direct comparisons showed that arthrocentesis plus sodium hyaluronate resulted in significantly better pain relief outcomes compared with arthrocentesis alone. Also, the visual analog scale score was further reduced to 1.27 by PDGF injection after arthrocentesis (arthrocentesis plus PDGF) compared with arthrocentesis alone. Morphine and tramadol had a high probability of being the best treatment for pain control, with PDGF ranked third. When considering pain relief, arthrocentesis plus sodium hyaluronate resulted in a better outcome than arthrocentesis alone, and arthrocentesis plus PDGF was better than arthrocentesis plus placebo. PDGF injections had the greatest probability of being the best treatment for improving joint opening, followed by sodium hyaluronate. CONCLUSIONS: Tramadol, morphine, and PDGF injections after arthrocentesis were effective in the treatment of TMJOA with excellent effects in reducing pain and improving joint opening. Hyaluronic acid injections were effective for improving the maximal mouth opening of patients with TMJOA in the short-term. The combination of a corticosteroid and hyaluronic acid injection reduced the symptoms of TMJOA more than corticosteroid injections alone, but not of hyaluronic acid alone.

Biodegradation of alkali lignin by a newly isolated Rhodococcus pyridinivorans CCZU-B16.

Based on the Prussian blue spectrophotometric method, one high-throughput screening strategy for screening lignin-degrading microorganisms was built on 24-well plate at room temperature. One high activity of alkali lignin-degrading strain Rhodococcus pyridinivorans CCZU-B16 was isolated from soil. After the optimization of biodegradation, 30.2% of alkali lignin (4 g/L) was degraded under the nitrogen-limited condition (30/1 of C/N ratio; g/g) at 30 °C for 72 h. It was found that syringyl (S) units and guaiacyl (G) in lignin decreased after biodegradation. Moreover, the accumulated lipid in cells had a fatty acid profile rich in C16 and C18 with four major constituent fatty acids including palmitic acid (C16:0; 22.4%), palmitoleic acid (C16:1; 21.1%), stearic acid (C18:0; 16.2%), and oleic acid (C18:1; 23.1%). In conclusion, Rhodococcus pyridinivorans CCZU-B16 showed high potential application in future.

Docking-guided rational engineering of a macrolide glycosyltransferase glycodiversifies epothilone B.

Glycosyltransferases typically display acceptor substrate flexibility but more stringent donor specificity. BsGT-1 is a highly effective glycosyltransferase to glycosylate macrolides, including epothilones, promising antitumor compounds. Here, we show that BsGT-1 has three major regions significantly influencing the glycodiversification of epothilone B based on structural molecular docking, "hot spots" alanine scanning, and site saturation mutagenesis. Mutations in the PSPG-like motif region and the C2 loop region are more likely to expand donor preference; mutations of the flexible N3 loop region located at the mouth of the substrate-binding cavity produce novel epothilone oligosaccharides. These "hot spots" also functioned in homologues of BsGT-1. The glycosides showed significantly enhanced water solubility and decreased cytotoxicity, although the glycosyl appendages of epothilone B also reduced drug permeability and attenuated antitumor efficacy. This study laid a foundation for the rational engineering of other GTs to synthesize valuable small molecules.

The maintenance of an oral epithelial barrier.

Oral epithelial barrier consists of closely controlled structure of the stratified squamous epithelium, which is the gateway to human bodies and encounters a huge burden of microbial, airborne and dietary antigens, as well as masticatory damage. Once this barrier is destroyed, it will trigger bone loss, tissue damage and microbial dysbiosis and lead to diseases, such as periodontitis, oral mucosal diseases and oral cancer. Recently, increasing evidences showed that different factors including microorganism, saliva, proteins and immune components have been considered to play a critical role in the disruption of oral epithelial barrier. Herein, we discussed mechanisms governing the maintenance of oral epithelial barrier. Besides, the role of oral epithelial barrier failure in oral carcinogenesis will also be talked about.

Porphyromonas gingivalis Promotes 4-Nitroquinoline-1-Oxide-Induced Oral Carcinogenesis With an Alteration of Fatty Acid Metabolism.

Microbiota has been widely considered to play a critical role in human carcinogenesis. Human papilloma virus, hepatitis B and C virus, and Helicobacter pylori are implicated in the pathogenesis of cancer of uterine cervix, liver, and stomach, respectively. However, whether Porphyromonas gingivalis (P. gingivalis), a common Gram negative oral bacteria, is associated with oral carcinogenesis still remains unclear and its underlying mechanism needs to be addressed. Here, we established a combined experimental system of 4NQO-induced oral carcinoma model and chronic periodontitis model and investigated the effects of P. gingivalis infection on oral carcinogenesis and fatty acid metabolism during oral carcinogenesis. The data showed that in this animal model, P. gingivalis infection induced mice periodontitis, increased the tongue lesion size and multiplicity of each mouse and promoted oral cancer development. P. gingivalis treatment significantly increased the level of free fatty acids and altered the fatty acid profile in tongue tissues and the serum of mice. And P. gingivalis induced the formation of fatty liver of the mice. Besides, immunohistochemical analysis and qRT-PCR showed that the expression of fatty-acid synthase and acetyl-CoA carboxylase 1 were increased in the tongue and liver tissues of 4NQO-treated mice infected with P. gingivalis. These results showed that P. gingivalis promoted oral carcinogenesis and aggravated disturbance of fatty acid metabolism, indicating a close association among P. gingivalis, lipid metabolic and oral carcinogenesis.

Enzymatic in situ saccharification of sugarcane bagasse pretreated with low loading of alkalic salts Na2SO3/Na3PO4 by autoclaving.

Sugarcane bagasse (SCB) is an abundant, renewable and inexpensive agricultural byproduct for the production of biofuel and other biobased products. To effectively saccharify SCB with cellulases, combination with dilute alkali salts Na2SO3/Na3PO4 (0.4% Na3PO4, 0.03% Na2SO3) at 7.5% sulfidity and hot water (DASHW) in "one-pot" pretreatment media by autoclaving at 110°C for 40min was attempted to pretreat SCB in this study. Furthermore, FT-IR, XRD and SEM were employed to characterize the changes in the cellulose structural characteristics (porosity, morphology, and crystallinity) of the pretreated Na2SO3/Na3PO4-SCB solid residue, which indicated that combination pretreatment could effectively remove lignin and hemicellulose for enhancing enzymatic saccharification. After 72h, the reducing sugars and glucose from the enzymatic in situ hydrolysis of 50g/L Na2SO3/Na3PO4-SCB in dilute Na2SO3/Na3PO4 (0.27% Na3PO4, 0.02% Na2SO3) media were obtained at 33.8 and 21.8g/L, respectively. Finally, the SCB-hydrolysates containing 20g/L glucose were used for ethanol fermentation in the presence of dilute alkali salts. After 48h, the ethanol yield was 0.42g ethanol/g glucose, which represents 82.1% of the theoretical yield. In conclusion, this study provided an effective pretreatment strategy for enhancing SCB's saccharification, which has potential application of other lignocellulosic materials.

Enzymatic saccharification of sugarcane bagasse by N-methylmorpholine-N-oxide-tolerant cellulase from a newly isolated Galactomyces sp. CCZU11-1.

Based on the enrichment culture strategy, a novel N-methylmorpholine-N-oxide (NMMO)-tolerant cellulase-producing strain Galactomyces sp. CCZU11-1 was isolated from soil samples. After the optimization of culture condition, the highest FPA (13.4 U/mL) and CMCase (24.5 U/mL) were obtained. In both culture and reaction media containing NMMO 25% (w/v), the cellulase from Galactomyces sp. CCZU11-1 still had good activity. Furthermore, high saccharification rate was obtained in aqueous-NMMO media. Moreover, the fermentability of the hydrolyzates, obtained after enzymatic in situ saccharification of the NMMO-pretreated sugarcane bagasse, was evaluated using Saccharomyce scerevisiae. In conclusion, Galactomyces sp. CCZU11-1 is a promising candidate as high NMMO-tolerant cellulase producer and has potential application in future.