Involvement of integrin up‐regulation in RANKL/RANK pathway of chondrosarcomas migration

Invasion of tumor cells is the primary cause of therapeutic failure in malignant chondrosarcomas treatment. Receptor activator of nuclear factor‐κB ligand (RANKL) and its receptor, RANK, play a key roles in osteoclastogenesis and tumor metastasis. We found that the RANKL and RANK expression in human chondrosarcoma tissues was higher than that in normal cartilage. We also found that RANKL directed the migration and increased cell surface expression of β1 integrin in human chondrosarcoma cells (JJ012 cells). Pretreatment of JJ012 cells with MAPK kinase (MEK) inhibitors, PD98059 or U0126, inhibited the RANKL‐induced migration and integrin expression. Stimulation of cells with RANKL increased the phosphorylation of MEK and extracellular signal‐regulating kinase (ERK). In addition, NF‐κB inhibitor (PDTC) or IκB protease inhibitor (TPCK) also inhibited RANKL‐induced cells migration and integrin up‐regulation. Taken together, these results suggest that the RANKL acts through MEK/ERK, which in turn activates IKKα/β and NF‐κB, resulting in the activation of β1 integrin and contributing to the migration of human chondrosarcoma cells. J. Cell. Biochem. 111: 138–147, 2010. © 2010 Wiley‐Liss, Inc.     

A Novel Monoterpene?Stilbene Adduct with a 4,4‐Dimethyl‐2,3‐diphenylchromane Skeleton from Artocarpus xanthocarpus

Artoxanthochromane ( 1 ), a Diels? Alder‐type conjugation product of 4‐isopropenylresorcinol and oxyresveratrol, was isolated from the heartwood of Artocarpus xanthocarpus and characterized. The structure of 1 was elucidated as 2‐(2,4‐dihydroxyphenyl)‐3‐(3,5‐dihydroxyphenyl)‐7‐hydroxy‐4,4‐dimethylchromane by 1D‐ and 2D‐NMR spectroscopy, and other spectral evidences. A plausible metabolic mechanism was proposed to illustrate the biosynthetic pathway of artoxanthochromane. This compound exhibited mild mushroom tyrosinase inhibitory, and weak free radical‐scavenging activities on ABTS^+. and superoxide anion (O ) free radicals.     

Functional plasticity of mitochondrion-rich cells in the skin of euryhaline medaka larvae (Oryzias latipes) subjected to salinity changes

A noninvasive technique, the scanning ion-selective electrode technique (SIET) was applied to measure Na(+) and Cl(-) transport by the yolk-sac skin and individual mitochondrion-rich cells (MRCs) in intact medaka larvae (Oryzias latipes). In seawater (SW)-acclimated larvae, significant outward Na(+) and Cl(-) gradients were measured at the yolk-sac surface, indicating secretions of Na(+) and Cl(-) from the yolk-sac skin. With Na(+) pump immunostaining and microscopic observation, two groups of MRCs were identified on the yolk-sac skin of SW-larvae. These were single MRCs (s-MRCs), which do not have an accompanying accessory cell (AC), and multicellular complex MRCs (mc-MRCs), which usually consist of an MRC and an accompanying AC. The percentage of mc-MRC was ～60% in 30 parts per thousand of SW, and it decreased with the decrease of external salinity. By serial SIET probing over the surface of the MRCs and adjacent keratinocytes (KCs), significant outward fluxes of Na(+) and Cl(-) were detected at the apical opening (membrane) of mc-MRCs, whereas only outward Cl(-) flux, but not Na(+) flux, was detected at s-MRCs. Treatment with 100 μM ouabain or bumetanide effectively blocked the Na(+) and Cl(-) secretion. Following freshwater (FW) to SW transfer, Na(+) and Cl(-) secretions by the yolk-sac skin were fully developed in 5 h and 2 h, respectively. In contrast, both Na(+) and Cl(-) secretions downregulated rapidly after SW to FW transfer. Sequential probing at individual MRCs found that Na(+) and Cl(-) secretions declined dramatically after SW to FW transfer and Na(+)/Cl(-) uptake was detected at the same s-MRCs and mc-MRCs after 5 h. This study provides evidence demonstrating that ACs are required for Na(+) excretion and MRCs possess a functional plasticity in changing from a Na(+)/Cl(-)-secreting cell to a Na(+)/Cl(-)-absorbing cell.     

Wolbachia infections in world populations of bean beetles (Coleoptera: Chrysomelidae: Bruchinae) infesting cultivated and wild legumes

Wolbachia endosymbionts are widespread among insects and other arthropods, often causing cytoplasmic incompatibility and other reproductive phenotypes in their hosts. Recently, possibilities of Wolbachia-mediated pest control and management have been proposed, and the bean beetles of the subfamily Bruchinae are known as serious pests of harvested and stored beans worldwide. Here we investigated Wolbachia infections in bean beetles from the world, representing seven genera, 20 species and 87 populations. Of 20 species examined, Wolbachia infections were detected in four species, Megabruchidius sophorae, Callosobruchus analis, C. latealbus and C. chinensis. Infection frequencies were partial in M. sophorae but perfect in the other species. In addition to C. chinensis described in the previous studies, C. latealbus was infected with two distinct Wolbachia strains. These Wolbachia strains from the bean beetles were phylogenetically not closely related to each other. Among world populations of C. chinensis, some Taiwanese populations on a wild leguminous plant, Rhynchosia minima, exhibited a peculiar Wolbachia infection pattern, suggesting the possibility that these populations comprise a distinct host race or a cryptic species.     

Discriminating Hepatocellular Carcinoma in Rats Using a High-Tc SQUID Detected Nuclear Resonance Spectrometer in a Magnetic Shielding Box

In this study, we report the spin-lattice relaxation rate of hepatocellular carcinoma (HCC) and normal liver tissue in rats using a high-T_c superconducting quantum interference device (SQUID) based nuclear magnetic resonance (NMR) spectrometer. The resonance spectrometer used for discriminating liver tumors in rats via the difference in longitudinal relaxation time in low magnetic fields was set up in a compact and portable magnetic shielding box. The frequency-domain NMR signals of HCC tissues and normal liver tissues were analyzed to study their respective longitudinal relaxation rate T₁ ⁻¹. The T₁ ⁻¹ of liver tissues for ten normal rats and ten cancerous rats were investigated respectively. The averaged T₁ ⁻¹ value of normal liver tissue was (6.41±0.66) s⁻¹, and the averaged T₁ ⁻¹ value of cancerous tissue was (3.38±0.15) s⁻¹. The ratio of T₁ ⁻¹ for normal liver tissues and cancerous liver tissues of the rats investigated is estimated to be 1.9. Since this significant statistical difference, the T₁ ⁻¹ value can be used to distinguish the HCC tissues from normal liver tissues. This method of examining liver and tumor tissues has the advantages of being convenient, easy to operate, and stable.     

Improved candidate biomarker detection based on mass spectrometry data using the Hilbert-Huang transform

Mass spectrometry biomarker discovery may assist patient's diagnosis in time and realize the characteristics of new diseases. Our previous work built a preprocess method called HHTmass which is capable of removing noise, but HHTmass only a proof of principle to be peak detectable and did not tested for peak reappearance rate and used on medical data. We developed a modified version of biomarker discovery method called Enhance HHTMass (E-HHTMass) for MALDI-TOF and SELDI-TOF mass spectrometry data which improved old HHTMass method by removing the interpolation and the biomarker discovery process. E-HHTMass integrates the preprocessing and classification functions to identify significant peaks. The results show that most known biomarker can be found and high peak appearance rate achieved comparing to MSCAP and old HHTMass2. E-HHTMass is able to adapt to spectra with a small increasing interval. In addition, new peaks are detected which can be potential biomarker after further validation.