Cordycepin inhibits cell growth and induces apoptosis in human cholangiocarcinoma.

The purpose of this study was to explore the role of cordycepin in human cholangiocarcinoma (CCA) cell growth and apoptosis. In the present study, colony formation assay, cell-counting kit-8 (CCK-8) assay and tumor xenograft experiment were performed to evaluate the effect of cordycepin on human CCA cell growth in vitro and in vivo; flow cytometric analysis was performed to evaluate the effect of cordycepin on cell apoptosis; quantitative real-time reverse transcription PCR (qRT-PCR) and western blot assays were performed to evaluate the expression levels of Caspase-3, Bcl-2 and Bax. The results showed that cordycepin inhibited cell growth in QBC939 and RBE cells in vitro and it could also inhibit QBC939 cells growth in vivo. Furthermore, the flow cytometric analysis, qRT-PCR and western blot assays showed that cordycepin could trigger QBC939 and RBE cells apoptosis by regulating the expression levels of Caspase-3, Bcl-2 and Bax. And we proposed that cordycepin could inhibit human CCA cell growth in vitro and in vivo, while, this function is related to the induction of cell apoptosis.

Long non-coding RNA MALAT1 promotes cholangiocarcinoma cell proliferation and invasion by activating PI3K/Akt pathway.

Increasing evidence indicated that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) acted as a key regulator in the proliferation and invasion of several cancers. However, the function of MALAT1 in the development of cholangiocarcinoma has not been experimentally established. In the present study, the expression levels of MALAT1 in cholangiocarcinoma cell lines were detected by quantitative real-time PCR. The effects of MALAT1 knockdown on the cell proliferation and invasion of cholangiocarcinoma cells were detected with Cell Counting Kit-8 (CCK-8), colony formation assay and Trans-well assay, respectively. The expressions of epithelial-mesenchymal transition (EMT)-related proteins (E-cadherin, Vimentin) were evaluated to discover whether the process of EMT was involved. We also evaluated the expression of phos-phatidylinositol-3-kinase/serine/threonine kinase (PI3K/Akt) signaling pathway proteins (PI3K, p-PI3K, Akt, p-Akt) to determine the associated molecular mechanism. And we discovered that MALAT1 was up-regulated in cholangiocarcinoma cancer cells. CCK-8, colony formation and trans-well assay showed that the proliferation and invasion of QBC-939 and RBE with MALAT1 knockdown were inhibited. Moreover, MALAT1 could promote EMT in cholangiocarcinoma cells. In addition, MALAT1 may activate PI3K/Akt pathway. These results indicated that MALAT1 promoted cholangiocarcinoma cell proliferation and invasion. The effects of MALAT1 on cholangiocarcinoma cells might be through activating the PI3K/Akt signaling pathway. These investigations may facilitate a better understanding of MALAT1 and it might be a potential therapeutic target for the treatment of cholangiocarcinoma.

Genome-wide identification, characterization, and expression analysis of the MLO gene family in Cucumis sativus.

Mildew resistance locus o (MLO) is a plant-specific seven-transmembrane (TM) gene family. Several studies have revealed that certain members of the MLO gene family mediate powdery mildew susceptibility in three plant species, namely, Arabidopsis, barley, and tomato. The sequenced cucumber genome provides an opportunity to conduct a comprehensive overview of the MLO gene family. Fourteen genes (designated CsMLO01 through CsMLO14) have been identified within the Cucumis sativus genome by using an in silico cloning method with the MLO amino acid sequences of Arabidopsis thaliana and rice as probes. Sequence alignment revealed that numerous features of the gene family, such as TMs, a calmodulin-binding domain, peptide domains I and II, and 30 important amino acid residues for MLO function, are well conserved. Phylogenetic analysis of the MLO genes from cucumber and other plant species reveals seven different clades (I through VII). Three of these clades comprised MLO genes from A. thaliana, rice, maize, and cucumber, suggesting that these genes may have evolved after the divergence of monocots and dicots. In silico mapping showed that these CsMLOs were located on chromosomes 1, 2, 3, 4, 5, and 6 without any obvious clustering, except CsMLO01. To our knowledge, this paper is the first comprehensive report on MLO genes in C. sativus. These findings will facilitate the functional characterization of the MLOs related to powdery mildew susceptibility and assist in the development of disease resistance in cucumber.

MiR-4299 suppresses non-small cell lung cancer cell proliferation, migration and invasion through modulating PTEN/AKT/PI3K pathway.

OBJECTIVE: The aim of the present study was to investigate clinical significances and biological roles of miR-4299 in non-small cell lung cancer (NSCLC) PATIENTS AND METHODS: Expression of miR-4299 in NSCLC tissues and matched non-tumor tissues was determined by quantitative real-time PCR (qRT-PCR). The correlations between miR-4299 expression and clinicopathological characteristics and prognosis were also analyzed. MTT assay and Transwell assay were performed to determine the proliferation, migration and invasion. Western blotting was used to examine the expressing patterns of PTEN/AKT/PI3K signaling pathway-related proteins. RESULTS: We found that the expression level of miR-4299 was downregulated in NSCLC tissues and cell lines. Low miR-4299 expression was positively correlated with TNM stage (p=0.002), histological grade (p=0.002) and lymph node metastasis (p=0.028). Moreover, Kaplan-Meier survival analysis showed that the patients with low miR-4299 expression had shorter survival time than those with high miR-4299 expression (p=0.0011). More importantly, multivariate analysis suggested that decreased miR-4299 expression was a poor independent prognostic predictor for NSCLC patients (p=0.009). Functionally, overexpression of miR-4299 inhibited the proliferation, migration and invasion in A549 cells. Mechanistically, the results of Western blot showed that miR-4299 exhibited its tumor-suppressive role by modulating PTEN/AKT/PI3K signaling pathway. CONCLUSIONS: We firstly indicated that miR-4299 may be a candidate independent marker for NSCLC prognosis and suppressed the progression of NSCLC by modulating the activation of PTEN/AKT/PI3K signaling pathway, suggesting that miR-4299 could be a potential target for developing therapies in treating NSCLC.

TiO2 and Cu1.5Mn1.5O4 co-modified hierarchically porous zeolite Beta for soot oxidation with excellent sulfur-resistance and stability.

TiO2 and spinel Cu1.5Mn1.5O4 co-modified hierarchically porous zeolite Beta (Ti/Cu1.5Mn1.5O4-HBeta) with 3D interpenetrating micro-mesoporosity has been synthesized, which showed highly efficient catalytic activity to the soot oxidation in the presence of O2/NO/N2 due to the rich moderate intensity acidic sites and chemisorbed oxygen species. In the presence of SO2/O2/NO/N2, the SO2 could be preferentially adsorbed on the Ti/Cu1.5Mn1.5O4-HBeta and the resulting sulfates could easily decompose at elevated temperatures, thus leading to significantly improved sulfur-resistance. Furthermore, the excellent water-resistance and cycling stability were achieved on the catalyst Ti/Cu1.5Mn1.5O4-HBeta owing to its crystalline zeolite framework and highly dispersed active components.

Genetic association of HLA-DRB1 multiple polymorphisms with dermatomyositis in Chinese population.

Genetic variation in HLA plays an important role in the pathogenesis of dermatomyositis (DM). The aim of this study was to investigate the association of HLA class II with DM in China. Two hundred and twenty-four DM patients and 300 healthy controls were randomly enrolled at China-Japan Friendship Hospital. High-resolution typing of HLA-DRB1 alleles was performed by sequencing based typing. The HLA-DQA1 and HLA-DQB1 alleles were determined by polymerase chain reaction sequence-specific primers. The frequencies of HLA-DRB1*09:01 (28.6% vs 11.3%, P < .0001, odds ratio, OR = 3.14, 95% confidence interval, CI = 2.47-3.99) and HLA-DRB1*12:01 (29.0% vs 11.0%, P < .0001, OR = 3.30, 95% CI = 2.59-4.20) in DM patients were significantly higher than that in healthy controls. No significant difference was found in HLA-DQA1 or DQB1 alleles between DM patients and healthy controls. Furthermore, DM patients with anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5) had a significantly higher frequency of HLA-DRB1*12:01 compared to that for patients without anti-MDA5 (P < .0001, OR = 4.77, 95% CI: 2.29-9.93). Multivariate binary logistic regression analysis was performed to identify the risk factors for interstitial lung disease. The HLA-DRB1*09:01 allele was a poor prognostic factor (P = .01, OR = 9.21, 95% CI: 1.47-57.50) for DM patients with anti-MDA5 autoantibody. In summary, our findings indicate that HLA-DRB1*09:01 and HLA-DRB1*12:01 alleles may contribute to susceptibility of adult DM in Han Chinese population. In addition, the DRB1*12:01 genotype is significantly associated with the presence of anti-MDA5 antibody in DM patients.

Substrate co-doping modulates electronic metal-support interactions and significantly enhances single-atom catalysis.

Transitional metal nanoparticles or atoms deposited on appropriate substrates can lead to highly economical, efficient, and selective catalysis. One of the greatest challenges is to control the electronic metal-support interactions (EMSI) between the supported metal atoms and the substrate so as to optimize their catalytic performance. Here, from first-principles calculations, we show that an otherwise inactive Pd single adatom on TiO2(110) can be tuned into a highly effective catalyst, e.g. for O2 adsorption and CO oxidation, by purposefully selected metal-nonmetal co-dopant pairs in the substrate. Such an effect is proved here to result unambiguously from a significantly enhanced EMSI. A nearly linear correlation is noted between the strength of the EMSI and the activation of the adsorbed O2 molecule, as well as the energy barrier for CO oxidation. Particularly, the enhanced EMSI shifts the frontier orbital of the deposited Pd atom upward and largely enhances the hybridization and charge transfer between the O2 molecule and the Pd atom. Upon co-doping, the activation barrier for CO oxidation on the Pd monomer is also reduced to a level comparable to that on the Pd dimer which was experimentally reported to be highly efficient for CO oxidation. The present findings provide new insights into the understanding of the EMSI in heterogeneous catalysis and can open new avenues to design and fabricate cost-effective single-atom-sized and/or nanometer-sized catalysts.

Facile synthesis of manganese silicate nanoparticles for pH/GSH-responsive T1-weighted magnetic resonance imaging.

Contrast agents (CAs) play an important role in enhancing the magnetic resonance imaging (MRI) performance for accurate tumor diagnosis, which, however, may give rise to unexceptional issues such as in vivo accumulation and bio-toxicity. Here we report on manganese silicate nanoparticles (denoted as MnSNs) as highly biocompatible and pH/GSH-responsive T1-weighted MRI CAs. The MnSNs were synthesized via a facile, cost-effective and environmentally friendly route based on one-step rapid precipitation between the Mn2+ cation and the SiO3 2- anion in aqueous solution at room temperature without any other additives, and showed excellent dispersion stability in water or PBS for weeks without any surface modification at ambient temperature. The MnSNs present an efficient pH/GSH-responsive T1-MRI feature based on the rapid changes in the relaxation rate in a mildly acidic/reducing environment both in vitro and in vivo, and furthermore, MnSNs showed negligible cellular cytotoxicity in vitro, no distinct tissue toxicity in vivo and fast clearance from the body organs and tissues in 24-72 h. Thus, the MnSNs are able to serve as a novel class of highly promising T1-MRI CAs for clinical cancer diagnosis.

Ultrafast and large third-order nonlinear optical properties of CdS nanocrystals in polymeric film.

We report the ultrafast and large third-order nonlinear optical properties of CdS nanocrystals (NCs) embedded in a polymeric film. The CdS NCs of 2 nm radius are synthesized by an ion-exchange method and highly concentrated in the two layers near the surfaces of the polymeric film. The two-photon absorption coefficient and the optical Kerr coefficient are measured with laser pulses of 250 fs duration at 800 nm wavelength. The one-photon and two-photon figures of merit are determined to be 3.1 and 1.3, respectively, at irradiance of 2 GW/cm(2). The observed nonlinearities have a recovery time of approximately 1 ps. The two-photon-generated free carrier effects have also been observed and discussed. These results demonstrate that CdS NCs embedded in polymeric film are a promising candidate for optical switching applications.

AML1/ETO cooperates with HIF1α to promote leukemogenesis through DNMT3a transactivation.

The mechanisms by which AML1/ETO (A/E) fusion protein induces leukemogenesis in acute myeloid leukemia (AML) without mutagenic events remain elusive. Here we show that interactions between A/E and hypoxia-inducible factor 1α (HIF1α) are sufficient to prime leukemia cells for subsequent aggressive growth. In agreement with this, HIF1α is highly expressed in A/E-positive AML patients and strongly predicts inferior outcomes, regardless of gene mutations. Co-expression of A/E and HIF1α in leukemia cells causes a higher cell proliferation rate in vitro and more serious leukemic status in mice. Mechanistically, A/E and HIF1α form a positive regulatory circuit and cooperate to transactivate DNMT3a gene leading to DNA hypermethylation. Pharmacological or genetic interventions in the A/E-HIF1α loop results in DNA hypomethylation, a re-expression of hypermethylated tumor-suppressor p15(INK4b) and the blockage of leukemia growth. Thus high HIF1α expression serves as a reliable marker, which identifies patients with a poor prognosis in an otherwise prognostically favorable AML group and represents an innovative therapeutic target in high-risk A/E-driven leukemia.

Carbon-13 NMR studies and purification of gluconate pathway enzymes from Schizosaccharomyces pombe.

Evidence is presented to show that D-glucose in Schizosaccharomyces pombe can be metabolized via a new alternative route (gluconate pathway) in addition to the regular D-glucose 6-phosphate route. This gluconate pathway consists of two steps: oxidation of D-glucose to D-gluconate by NADP(+)-dependent glucose dehydrogenase and phosphorylation of D-gluconate to 6-phosphogluconate by gluconate kinase. The formation of D-gluconate and 6-phosphogluconate from D-glucose was monitored by 13C nuclear magnetic resonance spectroscopy using D-[1-13C]glucose and D-[U-13C]glucose. The operation of the gluconate pathway was further substantiated by the purification of its two member enzymes, glucose dehydrogenase and gluconate kinase, from the cell-free extract of the fission yeast. Glucose dehydrogenase has been purified (580-fold) to homogeneity by the combined procedures of ammonium sulfate fractionation, Sephadex gel filtration, cation-exchange chromatography, matrex gel chromatography, and agarose-NADP+ affinity chromatography. The purified enzyme is monomeric with a relative molecular weight of 6.65 x 10(4) Da. Gluconate kinase has been purified (410-fold) to near homogeneity by a combination of chromatographic procedures using Bio-gels, matrex gel, and agarose gels. The purified enzyme is monomeric with a relative molecular weight of 2.4 x 10(4) Da. The gluconate pathway presented here provides an alternative route for the D-glucose metabolism in Sch. pombe. Meanwhile, this paper documents another metabolic difference between the fission and budding yeasts.

Kinetic studies of gluconate pathway enzymes from Schizosaccharomyces pombe.

Glucose dehydrogenase and gluconate kinase which catalyze two-step reactions of the gluconate pathway have been purified from Schizosaccharomyces pombe. Their steady-state kinetic studies were undertaken. The yeast glucose dehydrogenase requires NADP+ as an obligatory coenzyme and mediates the oxidation of D-glucose to D-gluconate via an ordered Bi Bi mechanism with NADP+ as the leading substrate. Kinetic constants for the dehydrogenase reactions have been measured. The yeast gluconate kinase requires Mg2+ as an activator. The phosphorylation catalyzed by the fission yeast gluconate kinase has been studied kinetically at a fixed concentration of Mg2+. The initial velocity and product inhibition results are consistent with a rapid equilibrium random Bi Bi mechanism with the formation of an abortive enzyme-ADP-gluconate complex. Dissociation constants of the two substrates, ATP and D-gluconate from various binary and ternary enzymic complexes, have been determined.

Enzyme activities of D-glucose metabolism in the fission yeast Schizosaccharomyces pombe.

The activities of key enzymes that are members of D-glucose metabolic pathways in Schizosaccharomyces pombe undergoing respirative, respirofermentative, and fermentative metabolisms are monitored. The steady-state activities of glycolytic enzymes, except phosphofructokinase, decrease with a reduced efficiency in D-glucose utilization by yeast continuous culture. On the other hand, the enzymic activities of pentose monophosphate pathway reach the maximum when the cell mass production of the cultures is optimum. Enzymes of tricarboxylate cycle exhibit the maximum activities at approximately the washout rate. The steady-state activity of pyruvate dehydrogenase complex increases rapidly when D-glucose is efficiently utilized. By comparison, the activity of pyruvate decarboxylase begins to increase only when ethanol production occurs. Depletion of dissolved oxygen suppresses the activity of pyruvate dehydrogenase complex but facilitates that of pyruvate decarboxylase. Acetate greatly enhances the acetyl CoA synthetase activity. Similarly, ethanol stimulates alcohol dehydrogenase and aldehyde dehydrogenase activities. Evidence for the existence of alcohol dehydrogenase isozymes in the fission yeast is presented.