A triazine compound S06 inhibits proinvasive crosstalk between carcinoma cells and stromal fibroblasts via binding to heat shock protein 90

Carcinoma-associated fibroblasts (CAFs) promote tumor invasion by secreting soluble factors. A tagged triazine library was screened in our novel transwell coculture model of CAF and oral squamous cell carcinoma (OSCC). We discovered compound S06, which reduced OSCC invasion by inhibiting secretion of CAF-derived proinvasive chemokines. The N-terminus of Hsp90 was found to be the cellular target of S06. Importantly, S06 did not induce hepatic toxicity, a side effect associated with well-known Hsp90 inhibitors. Moreover, S06 inhibited tumor cell migration in a zebrafish xenograft model. Our results demonstrate that Hsp90 is a novel target for stromal-based therapy to modulate proinvasive molecular crosstalk within the tumor microenvironment. Furthermore, S06 represents a new class of Hsp90 inhibitor and is an attractive candidate for anticancer drug development.     

Comparison of arsenic acid with phosphoric acid in the interaction with a water molecule and an alkali/alkaline-earth metal cation

Recently, Wolfe-Simon has discovered a bacterium which is able to survive using arsenic(V) rather than phosphorus(V) in its DNA. Thus it is important to investigate some important structural and chemical similarities and dissimilarities between phosphate and arsenate. We compared the monohydrated structures and the alkali/alkaline-earth metal (Na(+), K(+), Mg(2+) and Ca(2+)) complexes of the arsenic acid/anions with those of the phosphoric acid/anions [i.e., H(m)PO(4)(-(3-m)) vs H(m)AsO(4)(-(3-m)) (m = 1-3)]. We carried out geometry optimization along with harmonic frequency calculations using ab initio calculations. Despite the increased van der Waals radius of As, the hydrated structures of both P and As systems show very close similarity (within 0.25 ? in the P/As···O(water) distance and within a few kJ/mol in binding energy) because of the increased induction energies by more polar arsenic acid/anons and slightly increased dispersion energy by a larger size of the As atom. In the metal complexes, the arsenic acid has a slightly larger binding distance (by 0.07-1.0 ?) and weaker binding energy because the As(V) ion has a slightly larger radius than the P(V) ion, and the electrostatic interaction is the dominating feature in these systems.     

Introduction of the CIITA gene into tumor cells produces exosomes with enhanced anti-tumor effects

Exosomes are small membrane vesicles secreted from various types of cells. Tumor-derived exosomes contain MHC class I molecules and tumor-specific antigens, receiving attention as a potential cancer vaccine. For induction of efficient anti-tumor immunity, CD4+ helper T cells are required, which recognize appropriate MHC class II-peptide complexes. In this study, we have established an MHC class II molecule-expressing B16F1 murine melanoma cell line (B16F1- CIITA) by transduction of the CIITA (Class II transactivator) gene. Exosomes from B16-CII cells (CIITA- Exo) contained a high amount of MHC class II as well as a tumor antigen TRP2. When loaded on dendritic cells (DCs), CIITA-Exo induced the increased expression of MHC class II molecules and CD86 than the exosomes from the parental cells (Exo). In vitro assays using co-culture of immunized splenocytes and exosome-loaded DCs demonstrated that CIITA-Exo enhanced the splenocyte proliferation and IL-2 secretion. Consistently, compared to B16-Exo, CIITA-Exo induced the increased mRNA levels of inflammatory cytokines such as TNF-α, chemokine receptor CCR7 and the production of Th1-polarizing cytokine IL-12. A tumor preventive model showed that CIITA-Exo significantly inhibited tumor growth in a dose-dependent manner. Ex vivo assays using immunized mice demonstrated that CIITA-Exo induced a higher amount of Th1-polarized immune responses such as Th1-type IgG2a antibodies and IFN-γ cytokine as well as TRP2-specific CD8+ T cells. A tumor therapeutic model delayed effects of tumor growth by CIITA-Exo. These findings indicate that CIITA-Exo are more efficient as compared to parental Exo to induce anti-tumor immune responses, suggesting a potential role of MHC class II-containing tumor exosomes as an efficient cancer vaccine.     

Electric detection of target DNA by fabricating gold nanowire bridges on planar nanogap electrodes

For the electrical detection of target DNA (partial avian influenza virus/H1N1/HA sequence) prepared via asymmetric PCR, we fabricated DNA-templated conducting gold nanowire bridges on planar nanogap electrodes using positively charged gold nanoparticles.     

Tubular microporous organic networks bearing imidazolium salts and their catalytic CO2 conversion to cyclic carbonates

Tubular microporous organic networks bearing imidazolium salts (T-IM) were prepared by Sonogashira coupling of tetrakis(4-ethynylphenyl)methane and diiodoimidazolium salts, which showed promising catalytic activities in heterogeneous conversion of CO(2) into cyclic carbonates.     

A highly effective bifunctional ligand for radioimmunotherapy applications

A novel bifunctional ligand (3p-C-NETA) for antibody-targeted radioimmunotherapy (RIT) of β-emitting radioisotopes (90)Y and (177)Lu was efficiently synthesized via an unexpected regiospecific ring opening of an aziridinium ion. 3p-C-NETA instantly formed a very stable complex with (90)Y or (177)Lu. 3p-C-NETA is an excellent bifunctional ligand for RIT.     

Isoconiferoside, a new phenolic glucoside from seeds of Panax ginseng

A new phenolic glucoside, isoconiferoside (1), was isolated from the seeds of Panax ginseng (Araliaceae). The structure was determined to be 9-O-[β-D-glucopyranosyl-(1 --> 6)-β-D-glucopyranosyl]-trans-coniferyl alcohol based on spectroscopic analyses (1H- and 13C-NMR, DEPT, COSY, HMQC, and HMBC) and acid hydrolysis.     

Corydaline inhibits multiple cytochrome P450 and UDP-glucuronosyltransferase enzyme activities in human liver microsomes

Corydaline is a bioactive alkaloid with various antiacetylcholinesterase, antiallergic, and antinociceptive activities found in the medicinal herb Corydalis Tubers. The inhibitory potential of corydaline on the activities of seven major human cytochrome P450 and four UDP-glucuronosyltransferase enzymes in human liver microsomes was investigated using LC-tandem MS. Corydaline was found to inhibit CYP2C19-catalyzed S-mephenytoin-4'-hydroxylatoin and CYP2C9-catalyzed diclofenac 4-hydroxylation, with K(i) values of 1.7 and 7.0 mM, respectively. Corydaline also demonstrated moderate inhibition of UGT1A1-mediated 17b-estradiol 3-glucuronidation and UGT1A9-mediated propofol glucuronidation with K(i) values of 57.6 and 37.3 mM, respectively. In the presence of corydaline, CYP3A-mediated midazolam hydroxylation showed a decrease with increasing preincubation time in a dose-dependent manner with K(i) values of 30.0 mM. These in vitro results suggest that corydaline should be evaluated for potential pharmacokinetic drug interactions in vivo due to potent inhibition of CYP2C19 and CYP2C9.     

Rapid Profiling of Bovine and Human Milk Gangliosides by Matrix-Assisted Laser Desorption/Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Gangliosides are anionic glycosphingolipids widely distributed in vertebrate tissues and fluids. Their structural and quantitative expression patterns depend on phylogeny and are distinct down to the species level. In milk, gangliosides are exclusively associated with the milk fat globule membrane. They may participate in diverse biological processes but more specifically to host-pathogen interactions. However, due to the molecular complexities, the analysis needs extensive sample preparation, chromatographic separation, and even chemical reaction, which makes the process very complex and time-consuming. Here, we describe a rapid profiling method for bovine and human milk gangliosides employing matrix-assisted desorption/ionization (MALDI) Fourier transform ion cyclotron resonance (FTICR) mass spectrometry (MS). Prior to the analyses of biological samples, milk ganglioside standards GM3 and GD3 fractions were first analyzed in order to validate this method. High mass accuracy and high resolution obtained from MALDI FTICR MS allow for the confident assignment of chain length and degree of unsaturation of the ceramide. For the structural elucidation, tandem mass spectrometry (MS/MS), specifically as collision-induced dissociation (CID) and infrared multiphoton dissociation (IRMPD) were employed. Complex ganglioside mixtures from bovine and human milk were further analyzed with this method. The samples were prepared by two consecutive chloroform/methanol extraction and solid phase extraction. We observed a number of differences between bovine milk and human milk. The common gangliosides in bovine and human milk are NeuAc-NeuAc-Hex-Hex-Cer (GD3) and NeuAc-Hex-Hex-Cer (GM3); whereas, the ion intensities of ganglioside species are different between two milk samples. Kendrick mass defect plot yields grouping of ganglioside peaks according to their structural similarities. Gangliosides were further probed by tandem MS to confirm the compositional and structural assignments. We found that only in human milk gangliosides was the ceramide carbon always even numbered, which is consistent with the notion that differences in the oligosaccharide and the ceramide moieties confer to their physiological distinctions.