The Tumor Suppressor Gene TUSC2 (FUS1) Sensitizes NSCLC to the AKT Inhibitor MK2206 in LKB1-dependent Manner

TUSC2-defective gene expression is detected in the majority of lung cancers and is associated with worse overall survival. We analyzed the effects of TUSC2 re-expression on tumor cell sensitivity to the AKT inhibitor, MK2206, and explored their mutual signaling connections, in vitro and in vivo. TUSC2 transient expression in three LKB1-defective non-small cell lung cancer (NSCLC) cell lines combined with MK2206 treatment resulted in increased repression of cell viability and colony formation, and increased apoptotic activity. In contrast, TUSC2 did not affect the response to MK2206 treatment for two LKB1-wild type NSCLC cell lines. In vivo, TUSC2 systemic delivery, by nanoparticle gene transfer, combined with MK2206 treatment markedly inhibited growth of tumors in a human LKB1-defective H322 lung cancer xenograft mouse model. Biochemical analysis showed that TUSC2 transient expression in LKB1-defective NSCLC cells significantly stimulated AMP-activated protein kinase (AMPK) phosphorylation and enzymatic activity. More importantly, AMPK gene knockdown abrogated TUSC2-MK2206 cooperation, as evidenced by reduced sensitivity to the combined treatment. Together, TUSC2 re-expression and MK2206 treatment was more effective in inhibiting the phosphorylation and kinase activities of AKT and mTOR proteins than either single agent alone. In conclusion, these findings support the hypothesis that TUSC2 expression status is a biological variable that potentiates MK2206 sensitivity in LKB1-defective NSCLC cells, and identifies the AMPK/AKT/mTOR signaling axis as an important regulator of this activity.     

Adipogenetic effects of retrofractamide A derivatives in 3T3-L1 cells

In a previous study, retrofractamide A from the fruit of Piper chaba was shown to promote adipogenesis in 3T3-L1 cells. In the present study, retrofractamide A and its derivatives were synthesized, and their adipogenetic effects in 3T3-L1 cells were examined. Among the tested compounds, an amide composed of 9-(3′,4′-methylenedioxyphenyl)-nona-2E,4E,8E-trienoic acid and an n-butyl or n-pentyl amine showed strongest activity. Moreover, the amide with the n-pentyl amine moiety significantly increased the uptake of 2-deoxyglucose into the cells, and also increased the mRNA levels of adiponectin, peroxisome proliferator-activated receptor γ2 (PPARγ2), glucose transporter 4 (GLUT4), fatty acid-binding protein (aP2), and CCAAT/enhancer-binding protein (C/EBP) α and β in a similar manner as the PPARγ agonist troglitazone, although it had less agonistic activity against PPARγ.     

Biological Status and Dietary Intakes of Iron,Zinc and Vitamin A among Women and Preschool Children in Rural Burkina Faso

Background

Food-based approaches such as biofortification are meant to sustainably address micronutrient deficiencies in poor settings. Knowing more about micronutrient intakes and deficiencies is a prerequisite to designing and evaluating interventions.

Objective

The objectives of the study were to assess biological status and dietary intakes of iron, zinc and vitamin A among women and children aged 36–59 months in rural Burkina Faso and to study relationships between intake and status to better inform future food-based interventions.

Design

A cross-sectional survey was carried out in two rural provinces of Burkina Faso on a random cluster sample of 480 mother-child pairs. Dietary data was obtained by 24-hour recalls repeated on a random sub-selection of 37.5% of subjects to allow calculation of nutrient’s probability of adequacy (PA). Biomarkers were measured on a sub-sample of 180 mother-child pairs. Blood samples were analyzed for hemoglobin, serum ferritin, soluble transferrin receptors (sTfR), C-reactive protein, alpha-1-glycoprotein, serum zinc concentration (SZnC) and retinol. For each micronutrient the relationship between biomarker and dietary intake was investigated by multiple linear regression models accounting for inflammatory biomarkers.

Results

Mean PA for iron, zinc and vitamin A was 0.49, 0.87 and 0.21 among women and 0.61, 0.95 and 0.33 among children, respectively. Prevalence of anemia, corrected low serum ferritin and high sTfR was 37.6%, 4.0% and 77.5% among women and 72.1%, 1.5% and 87.6% among children, respectively. Prevalence of low SZnC and corrected low serum retinol was 39.4% and 12.0% among women and 63.7% and 24.8% among children, respectively. There was a tendency for a positive relationship between vitamin A intakes and serum retinol among women (β = 0.0003, P = 0.06). Otherwise, no link was found between micronutrients biomarkers and intakes.

Conclusion

Our study depicted different images of micronutrient deficiencies when based on dietary intakes or biomarkers results, thus highlighting the need for more suitable biomarkers and more precise measures of absorbable micronutrient intakes at the individual level. It thus points to challenges in the design and evaluation of future biofortification or other food-based interventions in rural areas of Burkina Faso.     

Effective biofertilizer Trichoderma spp. isolates with enzymatic activity and metabolites enhancing plant growth

International Microbiology - Trichoderma species have been widely recognized as biofertilizer fungi for their ability to produce phytohormones and enhance plant growth. In our current study,...     

Self-incompatibility genotypes in almond re-evaluated by PCR,stylar ribonucleases,sequencing analysis and controlled pollinations

As part of the almond breeding programme at IRTA, we investigated the S genotypes of several cultivars using a combination of RNase zymograms, testcrosses, pollen-tube growth analysis and molecular identification by PCR analysis. For some of the cultivars examined, discrepancies appeared between their S alleles as reported in the literature and those found in this investigation, leading to a re-evaluation of their S genotypes. Analysis of the stylar ribonucleases (RNases), which are known to correlate with S alleles, of cvs. Achaak, Ardechoise, Desmayo Largueta, Ferrastar, Gabaix, Garbí, Glorieta, Languedoc, Primorskiy and Texas revealed inconsistencies with respect to the S₅ and S₁₀ alleles. However, PCR with the conserved primer pair AS1II/AmyC5R failed to detect any of these inconsistencies. When the S alleles from Desmayo Largueta, Gabaix, Primorskiy and Texas were sequenced, Texas and Primorskiy were found to carry the reported S₅ allele, while Desmayo Largueta and Gabaix carried a new allele, which has been tentatively denoted as S₂₅ This new S allele, previously reported to be S₁₀, was also identified in Achaak, Ardechoise and Ferrastar. The proposed new S genotypes are Achaak (S₂S₂₅), Ardechoise (S₁S₂₅), Desmayo Largueta (S₁S₂₅), Ferrastar (S₂S₂₅) and Gabaix (S₁₀S₂₅). The S alleles of Garbí, Glorieta, Languedoc, Texas and Primorskiy remain as reported in the literature. Testcrosses in the field and laboratory confirmed the new S genotypes. One cultivar (Gabaix) could be assigned to the existing cross-incompatibility group O of unique genotypes, and two new groups were established (XVI and XVII) consisting of two cultivars each. The clarification of these S alleles will be useful in almond breeding programmes and for planning new commercial orchards in the future.     

Lipid raft-dependent and -independent signaling through HLA-DR molecules

Lipid rafts are plasma membrane microdomains that are highly enriched in signaling molecules and that act as signal transduction platforms for many immune receptors. The involvement of these microdomains in HLA-DR-induced signaling is less well defined. We examined the constitutive presence of HLA-DR molecules in lipid rafts, their possible recruitment into these microdomains, and the role of these microdomains in HLA-DR-induced responses. We detected significant amounts of HLA-DR molecules in the lipid rafts of EBV(+) and EBV(-) B cell lines, monocytic cell lines, transfected HeLa cells, tonsillar B cells, and human monocytes. Localization of HLA-DR in these microdomains was unaffected by the deletion of the cytoplasmic domain of both the alpha and beta chains. Ligation of HLA-DR with a bivalent, but not a monovalent, ligand resulted in rapid tyrosine phosphorylation of many substrates, especially Lyn, and activation of ERK1/2 MAP kinase. However, the treatment failed to induce further recruitment of HLA-DR molecules into lipid rafts. The HLA-DR-induced signaling events were accompanied by the induction of cell-cell adhesion that could be inhibited by PTK and Lyn but not ERK1/2 inhibitors. Disruption of lipid rafts by methyl-beta-cyclodextrin (MbetaCD) resulted in the loss of membrane raft association with HLA-DR molecules, inhibition of HLA-DR-mediated protein tyrosine phosphorylation and cell-cell adhesion. MbetaCD did not affect the activation of ERK1/2, which was absent from lipid rafts. These results indicate that although all the HLA-DR-induced events studied are dependent on HLA-DR dimerization, some require the presence of HLA-DR molecules in lipid rafts, whereas others do not.     

Design and synthesis of acyclic nucleoside analogs with chlorinated imidazo[1,2-a]pyridine bases

A series of acyclic C-nucleoside analogs of 2,6-dichloro- and 2,6,7-trichloroimidazo[1,2-a]pyridine were synthesized and tested for antiviral activity. The appropriate hydroxymethyl-substituted heterocycles were treated successively with thionyl chloride, an appropriate nucleophile, then diisopropylethylamine to obtain the desired acyclic nucleoside analogs. These compounds were evaluated for activity against human cytomegalovirus and herpes simplex virus, type 1. Two of the dichloro analogs, but none of the trichloro analogs demonstrated slight antiviral activity (IC50's = 20-45 microM) at non-cytotoxic concentrations.     

Mek2 is dispensable for mouse growth and development

MEK is a dual-specificity kinase that activates the extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP) kinase upon agonist binding to receptors. The ERK/MAP kinase cascade is involved in cell fate determination in many organisms. In mammals, this pathway is proposed to regulate cell growth and differentiation. Genetic studies have shown that although a single Mek gene is present in Caenorhabditis elegans, Drosophila melanogaster, and Xenopus laevis, two Mek homologs, Mek1 and Mek2, are present in the mammalian cascade. The inactivation of the Mek1 gene leads to embryonic lethality and has revealed the unique role played by Mek1 during embryogenesis. To investigate the biological function of the second homolog, we have generated mice deficient in Mek2 function. Mek2 mutant mice are viable and fertile, and they do not present flagrant morphological alteration. Although several components of the ERK/MAP kinase cascade have been implicated in thymocyte development, no such involvement was observed for MEK2, which appears to be nonessential for thymocyte differentiation and T-cell-receptor-induced proliferation and apoptosis. Altogether, our findings demonstrate that MEK2 is not necessary for the normal development of the embryo and T-cell lineages, suggesting that the loss of MEK2 can be compensated for by MEK1.     

Cdk1/cyclin B1 controls Fas-mediated apoptosis by regulating caspase-8 activity

Caspase activation is a hallmark of apoptosis. However, the molecular mechanisms underlying the regulation of caspase-8 activation within the extrinsic death pathway are not well understood. In this study, we demonstrate that procaspase-8 is phosphorylated in mitotic cells by Cdk1/cyclin B1 on Ser-387, which is located at the N terminus of the catalytic subunit p10. This phosphorylation of procaspase-8 on Ser-387 occurs in cancer cell lines, as well as in primary breast tissues and lymphocytes. Furthermore, RNA interference-mediated silencing of cyclin B1 or treatment with the Cdk1 inhibitor RO-3306 enhances the Fas-mediated activation and processing of procaspase-8 in mitotic cells. A nonphosphorylatable procaspase-8 (S387A) facilitates Fas-induced apoptosis during mitosis. Our findings suggest that Cdk1/cyclin B1 activity shields human cells against extrinsic death stimuli and unravel the molecular details of the cross talk between cell cycle and extrinsic apoptotic pathways. Finally, this new mechanism may also contribute to tumorigenesis.     

Biological performance of quercetin on the cotton leaf-worm larvae, Spodoptera littoralis Boisd. (Lep., Noctuidae) and prevailing natural enemies in the Egyptian cotton fields

The Egyptian cotton (Gossypium barbadense L.) accounts for 65 % of the world production of long stable cultivars. Taking into consideration the competition of other cotton producing countries, it should be of great importance to control pests, which attack the cotton plants to improve the yield and its quality. The main objective of this study is to develop new approaches for the management of the cotton leafworm Spodoptera littoralis Boisd. within an IPM program, that include synthetic insecticides rationalization, and maximiziation the role of the biological control agents. Sunflower plants Helianthus annuus (Asterales: Asteraceae) raised in rows surrounding plots of cotton were used as trap plants to attract some biological agents, which subsequently lead to check the build-up of the cotton leafworm population. This scientific phenomenon was attributed to the main chemical constituent of sunflower plants, which has been proved to be the polyhydroxy flavone "quercetin". Field data of the two successive seasons 2004 and 2005 revealed that: (a) the total number of insect predators, Coccinella undecimpunctata, Paederus alfierli, Chrysopa vulgaris, Orius laevigatus, Scymnus synacus, and true spiders in the cotton plots surrounded by either one or two rows of sunflower plants significantly exceeded the corresponding numbers in the cotton plots without sunflower plants., (b) the least number of cotton leafworm Spodoptera littorolis larvae infestation was recorded simultaneously in the cotton plots surrounded by sunflower plants. Moreover, laboratory studies assured the antifeeding properties of quercetin against the 4th instar larvae of Spodoptera littoralis. Quercetin at a concentration rate of 4000 ppm, showed abnormal behaviour represented in feeding stop, growth inhibition and development retardation. Deformation of pupae, moths, and reduction up to 50% in egg laying was also noticed after quercetin application to the larvae.