Long Non-Coding RNAs as Functional Codes for Oral Cancer: Translational Potential,Progress and Promises

Oral cancer is one of the leading malignant tumors worldwide. Despite the advent of multidisciplinary approaches, the overall prognosis of patients with oral cancer is poor, mainly due to late diagnosis. There is an urgent need to develop valid biomarkers for early detection and effective therapies. Long non-coding RNAs (lncRNAs) are recognized as key elements of gene regulation, with pivotal roles in various physiological and pathological processes, including cancer. Over the past few years, an exponentially growing number of lncRNAs have been identified and linked to tumorigenesis and prognosis outcomes in oral cancer, illustrating their emerging roles in oral cancer progression and the associated signaling pathways. Herein, we aim to summarize the most recent advances made concerning oral cancer-associated lncRNA, and their expression, involvement, and potential clinical impact, reported to date, with a specific focus on the lncRNA-mediated molecular regulation in oncogenic signaling cascades and oral malignant progression, while exploring their potential, and challenges, for clinical applications as biomarkers or therapeutic targets for oral cancer.     

Photoisomerization of electroactive polyimide/multiwalled carbon nanotube composites on the effect of electrochemical sensing for ascorbic acid

We present the first investigation of photoisomerization of the azo‐based electroactive polyimide (PI)/amino‐functionalized multiwalled carbon nanotube (MWCNT) composite electrode on the effect of electrochemical sensing for ascorbic acid (AA). First, MWCNTs were grafted with 4‐aminobenzoic acid in a medium of polyphosphoric acid/phosphorous pentoxide to obtain MWCNTs functionalized with 4‐aminobenzoyl groups (AF‐MWCNTs). Subsequently, photoactive and electroactive PI/AF‐MWCNT composites (PEPACCs) were prepared by introducing pendant conjugated oligoaniline (amino‐capped aniline trimer) in the main chain and azobenzene chromophores in the side chain, in the presence of AF‐MWCNTs. Photoactive and electroactive PI (PEPI) and PEPACCs were characterized by ¹H NMR spectra, UV?visible absorption spectra, cyclic voltammetry (CV) and transmission electron microscopy. The CV study shows that the PEPACCs have higher electroactivity than PEPI. The redox and reversible photoisomerization (i.e. cis ? trans) behavior of PEPACCs was analyzed by in situ monitoring through systematic studies of CV and UV?visible spectroscopy. The light of the UV lamp was 365 nm. It should be noted that the sensor constructed from a trans‐PEPACC‐modified carbon‐paste electrode (CPE) demonstrated a higher electrocatalytic activity by 2.75‐fold and 1.12‐fold towards the oxidation of AA compared with those constructed using a PEPI‐ and cis‐PEPACC‐modified CPE, respectively. The detection limit of the trans‐PEPACC‐modified electrode was 1.73‐fold and 1.70‐fold lower than that of PEPI‐ and cis‐PEPACC‐modified CPE. Moreover, the differential pulse voltammetry data showed that the trans‐PEPACC‐modified electrode had high electrochemical sensing ability for the determination of AA, dopamine and uric acid. © 2014 Society of Chemical Industry     

En route to complete design of heterogeneous catalysts

Achieving complete control in the synthesis of the active center of a heterogeneous catalyst, which includes the active site, environment around the active site, and the access path is highly desirable but not attainable yet. However, there has been significant progress in recent years that permits a level of control of these properties that are unachievable before. Some illustrative examples are described to demonstrate this in the synthesis of active sites in metal and oxide catalysts and their surroundings. For the active site synthesis, examples include using polynuclear metal complexes as precursors, cluster beam deposition, and use of dendrimers to generate metallic active sites, protection of coordination unsaturation in the synthesis of oxide active sites, and employing silsesquioxane, and unit-by-unit approach. Exfoliation, use of inverse micelles, molecular and macromolecular templating as techniques to exert control of the environment of the active center are also discussed. The limitations of these synthetic methods and remaining challenges are examined.     

Photolithographically patterned silver nanowire electrodeposition

We report the fabrication of silver nanowires using lithographically patterned nanowire electrodeposition (LPNE). The LPNE synthesis of silver nanowires proceeds by lithographically patterning, and then etching an evaporated nickel film to produce a nickel nanoband 20-80 nm in height. This nanoband, which traces the perimeter of the exposed region, is recessed by ≈500 nm into the photoresist producing a horizontal trench. A silver nanowire, of controlled height and width, is formed within this trench by electrodepositing silver from either of two aqueous solutions at the nickel nanoband. Silver nanowires with controlled widths ranging from 100 to 400 nm were obtained and the height of silver nanowires was independently controllable over the range from 20 to 80 nm. The LPNE process is wafer-scale and continuous silver nanowires millimeters in length are readily obtained. Data for the characterization of these nanowires using AFM, TEM, and XRD is presented.     

Effects of alpha‐tocopherol addition to polymeric coatings on the UV and heat resistance of a fibrous collagen material—chrome‐free leather

The US is the world's 3rd largest hide producing country and currently produces approximately 35 million cattle hides annually. The majority of hides are tanned into leather, which is composed of collagen fibers interwoven into fibrous networks. Most leather products are constantly exposed to outdoor environments, therefore UV and heat resistance are very important qualities, particularly for nonchrome‐tanned (chrome‐free) leather. In recent years, we have focused on using environmentally friendly antioxidants that will improve the UV and heat resistance of chrome‐free leather. Tocopherols are well‐known antioxidants commonly used in the cosmetic and food industries. They are known as potent free radical scavengers and highly protective agents for collagen fibers against UV damage. We have investigated their potential to improve the UV and heat resistance of chrome‐free leather. Experiments were conducted by adding 5–12% α‐tocopherol to the polymeric topcoat on the grain of chrome‐free leather. The treated samples were tested in a weatherometer, where they were exposed to artificial sunlight. Colorfastness and mechanical property tests showed that α‐tocopherol significantly improved UV and heat resistance of leather. Dynamic mechanical tests showed that α‐tocopherol reduced the hardening effects on leather caused by UV irradiation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Methylene Homologues of Artemisone: An Unexpected Structure–Activity Relationship and a Possible Implication for the Design of C10‐Substituted Artemisinins

We sought to establish if methylene homologues of artemisone are biologically more active and more stable than artemisone. The analogy is drawn with the conversion of natural O‐ and N‐glycosides into more stable C‐glycosides that may possess enhanced biological activities and stabilities. Dihydroartemisinin was converted into 10β‐cyano‐10‐deoxyartemisinin that was hydrolyzed to the α‐primary amide. Reduction of the β‐cyanide and the α‐amide provided the respective methylamine epimers that upon treatment with divinyl sulfone gave the β‐ and α‐methylene homologues, respectively, of artemisone. Surprisingly, the compounds were less active in vitro than artemisone against P. falciparum and displayed no appreciable activity against A549, HCT116, and MCF7 tumor cell lines. This loss in activity may be rationalized in terms of one model for the mechanism of action of artemisinins, namely the cofactor model, wherein the presence of a leaving group at C10 assists in driving hydride transfer from reduced flavin cofactors to the peroxide during perturbation of intracellular redox homeostasis by artemisinins. It is noted that the carba analogue of artemether is less active in vitro than the O‐glycoside parent toward P. falciparum, although extrapolation of such activity differences to other artemisinins at this stage is not possible. However, literature data coupled with the leaving group rationale suggest that artemisinins bearing an amino group attached directly to C10 are optimal compounds.     

Expression and characterization of a cytotoxic human-frog chimeric ribonuclease: potential for cancer therapy

Onconase is a cytotoxic ribonuclease with antitumor properties. A semisynthetic gene encoding the entire protein sequence was constructed by fusing oligonucleotides coding for the first 15 and last six of the 104 amino acid residues to a genomic clone that encoded the remaining amino acid residues. Additionally, the 15 N-terminal amino acid residues of onconase were replaced with the first 21 amino acid residues of the homologous human RNase, eosinophil-derived neurotoxin, EDN. Two versions of the hybrid EDN-onconase protein were cloned, expressed and purified. The chimera that contained a glycine in lieu of the aspartic acid present in native onconase (position 26 in the chimera) exhibited enzymatic activity more characteristic of EDN than native onconase and was considerably more active with respect to both RNase activity and cellular cytotoxicity than recombinant onconase. In contrast to native or recombinant onconase, the EDN chimera was recognized by anti-EDN polyclonal antibodies, demonstrating that the chimera also shared structural antigenic determinants to the human enzyme. These results demonstrate that a chimeric ribonuclease has cytotoxicity comparable to onconase in two out of four cell lines tested. The implications with regard to cancer therapy are presented.      

Transition metal-decorated activated carbon catalysts for dehydrogenation of NaAlH4

Dehydrogenation of NaAlH₄ can be greatly facilitated by activated carbon catalysts. The catalytic function can be further enhanced by decorating the carbon with Co, Ni, or Cu nanoparticles. The decomposition temperature was lowered by as much as 100 °C using a 3 wt.% Co or Ni-decorated activated carbon, comparable to a Ti-based catalyst, which were the most effective among the metals tested. The catalytic effect is likely due to a combination of hydrogen spillover effect, high contact area between carbon and the hydride, and confinement of the hydride as nano-sized domains in the pores of the carbon matrix. The catalysts were also effective in facilitating rehydrogenation of NaAlH₄ under moderate pressure (75.8 bar H₂) and low temperature (120 °C), when no rehydrogenation would occur without the catalyst. The fact that this new catalyst system is not specific to any hydride offers many potential applications.     

The effect of delayed ensiling and application of a propionic acid-based additive on the fermentation of barley silage

Prolonged exposure to air can adversely affect the silage fermentation process. To investigate a possible method to overcome this problem, we determined if a buffered propionic acid-based additive, applied to chopped, whole-plant barley exposed to air before ensiling, would affect the subsequent fermentation. Wilted forage was chopped and treated with nothing, or with 0.1% (wt/wt wet forage) of a buffered propionic acid-based additive and ensiled immediately in quadruplicate 20-L laboratory silos. Portions of the chopped forage, untreated and treated, were left in loose piles in a barn for 24 h before ensiling. Another portion of the untreated silage exposed to air for 24 h was also treated with 0.1% of the additive just before ensiling. Prolonged exposure to air before ensiling increased the numbers of yeasts on forages by more than 1,000-fold. The concentrations of water-soluble carbohydrates decreased by more than 50%; the ammonia-N concentrations increased 40%, and pH increased by more than 1 unit as a result of exposure to air. These changes were less in forage that was treated with the additive at chopping. After 60 d, silages of forages that were exposed to air before ensiling had a higher pH, higher concentrations of ammonia-N and butyric acid, and lower concentrations of lactic and acetic acids than silages of forage that had been ensiled immediately after harvest. In situ DM digestibility was lowest in untreated silages that had been exposed to air before ensiling. In contrast, treatment with the additive, applied before or after exposure to air, prevented the reduction in in vitro digestion.