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Background: Cognitive impairment has been reported in patients with Major Depressive Disorder (MDD). This study aims to explore the association between lifestyle habits and health-related factors and the presence of cognitive symptoms in MDD patients. Methods: Demographic, clinical, health-related variables and cognitive scores measured with the Cambridge Neuropsychological Test Automated Battery (CANTAB) were compared between 74 patients with current MDD and 68 healthy controls (HC). To test the hypothesis of associated factors to cognitive symptoms, multivariate backward stepwise linear regression models were run. Results: Significant neuropsychological deficits were evident in MDD compared with HC in the global cognitive index (F=8.29; df=1, 140; p=0.005). In the regression analysis performed on MDD and HC, years of schooling (β=-0.11; p=

The antioxidant natural product sulforaphane (SFN) is an oil with poor aqueous and thermal stability. Recent work with SFN has sought to optimize methods of formulation for oral and topical administration. Herein we report the design of new analogs of SFN with the goal of improving stability and drug-like properties. Lead compounds were selected based on potency in a cellular screen and physicochemical properties. Among these, 12 had good aqueous solubility, permeability and long-term solid-state stability at 23 °C. Compound 12 also displayed comparable or better efficacy in cellular assays relative to SFN and had in vivo activity in a mouse cigarette smoke challenge model of acute oxidative stress.

SUMMARY Accelerating cures for children with cancer remains an immediate challenge as a result of extensive oncogenic heterogeneity between and within histologies, distinct molecular mechanisms evolving between diagnosis and relapsed disease, and limited therapeutic options. To systematically prioritize and rationally test novel agents in preclinical murine models, researchers within the Pediatric Preclinical Testing Consortium are continuously developing patient-derived xenografts (PDXs)—many of which are refractory to current standard-of-care treatments—from high-risk childhood cancers. Here, we genomically characterize 261 PDX models from 37 unique pediatric cancers; demonstrate faithful recapitulation of histologies and subtypes; and refine our understanding of relapsed disease. In addition, we use expression signatures to classify tumors for TP53 and NF1 pathway inactivation. We anticipate that these data will serve as a resource for pediatric oncology drug development and will guide rational clinical trial design for children with cancer., Graphical Abstract, In Brief Rokita et. al provide an extensively annotated genomic dataset of somatic oncogenic regulation across 37 distinct pediatric malignancies. The 261 patient-derived xenograft models are available to the scientific community, and the genomic annotations will enable rational preclinical agent prioritization and acceleration of therapeutic targets for early-phase pediatric oncology clinical trials.

SummaryThe ability to propagate embryonic stem cells (ESCs) while maintaining their pluripotency is critical if their potential use in regenerative medicine is to be realized. The mechanisms controlling ESC self-renewal are under intense investigation, and glycogen synthase kinase 3 (GSK-3) has been implicated in regulating both self-renewal and differentiation. To clarify its role in ESCs we have used chemical genetics. We synthesized a series of bisindolylmaleimides, a subset of which inhibit GSK-3 in murine ESCs and robustly enhance self-renewal in the presence of leukemia inhibitory factor (LIF) and serum, but not in the absence of LIF. Importantly, these molecules appear selective for GSK-3 and do not perturb other signaling pathways regulating self-renewal. Our study clarifies the functional importance of GSK-3 in regulation of ESC self-renewal and provides tools for investigating its role further.

Chk1 is an evolutionarily conserved protein kinase that functions to ensure genomic integrity upon genotoxic stress. Studies to date have revealed striking similarities among Chk1 pathways of different organisms. In this review we discuss what is known about Chk1 activation and what downstream factors are regulated by Chk1 to counter replication blocks and DNA damage induced by UV, IR, and other genotoxic agents. Where applicable, we also compare the role of Chk1 with that of the Chk2 protein kinase in the checkpoint responses.

Checkpoints are biochemical pathways that provide the cell with mechanisms to detect DNA damage and respond by arresting the cell cycle to allow DNA repair. The conserved checkpoint kinase Chk1 regulates mitotic progression in response to DNA damage and replication interference by blocking the activation of Cdk1/cyclin B. Chk1 is phosphorylated on Ser-317 and Ser-345 following a checkpoint signal, a process that is regulated by Atr, and by the sensor complexes containing Rad17 and Hus1. We show that Chk1 is associated with chromatin in cycling cells and that the chromatin-associated Chk1 is phosphorylated in the absence of exogenous DNA damage. The UV-induced Ser-345-phosphorylated forms of Chk1 that appear minutes after treatment are predominantly associated with chromatin. The Ser-345 site is in a 14-3-3 consensus binding motif and is required for nuclear retention of Chk1 following an hydroxyurea-induced checkpoint signal; nonetheless, Ser-345 or Ser-317 are not required for the chromatin association of Chk1. Hus1, a member of the proliferating cell nuclear antigen-like damage recognition complex plays a role in the phosphorylation of Chk1 on Ser-345, however, Hus1 is not required for phosphorylation on Ser-317 or for Chk1 localization to chromatin. These results indicate that there is more than one step in Chk1 activation and that the regulation of this checkpoint signaling is achieved at least in part through phosphorylation of Ser-345, which serves to localize Chk1 in the nucleus presumably by blocking Crm1-dependent nuclear export.

The levels of the human checkpoint gene hCHK1 were measured in human cancer cells growing in vitro after treatment with the DNA damaging agent cis-dichlorodiammine platinum(II) (DDP). Treatment of human cancer cell lines with DDP induced a decrease in the hCHK1 protein levels starting 6 h after treatment, with a further decline at 24 and 48 h. A similar decrease in the levels of hCHK1 was found at the mRNA level by using Northern blot analysis. By using isogenic cell systems in which p53 was disrupted either by transfection with HPV-E6 or by targeted homologous recombination, we found that the DNA damage-induced down-regulation of hCHK1 was only observable in wild type p53-expressing cells, with only a minor decline in the hCHK1 levels observable 48 h after treatment in cells with disrupted p53. Similarly, treatment of mutant p53-expressing human cancer cell lines with DDP did not result in changes in the levels of hCHK1. The p53-dependent down-regulation of hCHK1 is likely to be at transcriptional levels, as suggested by the lack of down-regulation of the hCHK1 when transfected under the control of a heterologous viral promoter. In addition, p53 is able to down-regulate the luciferase activity under the control of the 5′ flanking region of the hCHK1 gene. The data suggest a strict link between p53 and hCHK1 governing the activation and repression of the G2 checkpoint in which both proteins participate.

Tyrosinase inhibitory activity of flavonols, galangin, kaempferol and quercetin, was found to come from their ability to chelate copper in the enzyme. In contrast, the corresponding flavones, chrysin. apigenin and luteolin, did not chelate copper in the enzyme. The chelation mechanism seems to be specific to flavonols as long as the 3-hydroxyl group is free. Interestingly, flavonols affect the enzyme activity in different ways. For example, quercetin behaves as a cofactor and does not inhibit monophenolase activity. On the other hand, galangin inhibits monophenolase activity and does not act as a cofactor. Kaempferol neither acts as a cofactor nor inhibits monophenolase activity. However, these three flavonols are common to inhibit diphenolase activity by chelating copper in the enzyme.

Techniques in somatic cell genetics have proven to be very important in the elucidation of genetic mechanisms in cancer and, in particular, the functional definition of tumor suppressor genes. Genetic complementation studies using microcell fusion have allowed the identification of specific chromosomes and particular chromosome regions that contain functional tumor suppressor genes for a variety of human cancers. In this article, the basic strategy for insertion of dominant selectable markers into human chromosomes is described, as are the methods for microcell fusion of tagged chromosomes into malignant cell lines. Molecular cytogenetic characterization protocols for microcell hybrids generated by such strategies are outlined. Finally, novel approaches to the isolation of dominantly tagged subchromosomal fragments for functional assays as well as to the isolation of new tumor suppressor genes are also described.

By bioassay-guided fractionations, quercetin was isolated as the principal tyrosinase inhibitor from the dried flowers of Heterotheca inuloides Cass (Compositae). This flavonol inhibited the oxidation of L-3,4-dihydroxyphenylalanine (L-DOPA) by mushroom tyrosinase (EC 1.14.18.1) with an ID 50 of 22 μg/ml (0.07 mM). Interestingly, quercetin 3-β-glucoside did not inhibit this oxidation up to 1 mg/ml. Kinetic study have found quercetin to be a characteristic competitive inhibitor for the L-DOPA oxidation by the mushroom tyrosinase. Based on the above findings, several related flavonoids were also examined for comparison.

A common feature of early vertebrate embryos is that they are surrounded by a simple protective epithelial cell layer. However, it is currently not well understood how the differentiation of this epithelium is controlled. We present data showing that BMP4 is sufficient to promote differentiation of this epithelium in diverse vertebrates. In mouse embryos the outer epithelium forms the trophectoderm which overlies the pluripotent inner cell mass. Xenopus embryos do not have a trophectoderm or inner cell mass but they do have outer epithelial cells and inner deep cells, which follow distinct fates. We have examined the role of BMP4 in the Xenopus epidermis and found that it is sufficient and required for differentiation of the outer epithelial cells. In contrast, BMP4 inhibits genes normally expressed in the deep cells, arguing that BMP4 specifically promotes differentiation of the outer epithelial cells. We then examined the role of BMP4 signalling in mouse ES cells. We found that in the absence of additional factors BMP4 is able to induce ES cells to form a trophectoderm like cell type. Thus, it appears that BMP4 acts to promote differentiation of the first epithelium in both Xenopus and mouse. Our data also suggest that, despite differences between vertebrates, there are conserved pathways which control differentiation of the first epithelial cells.

A new sesquiterpenoid, inuloidin, isolated from the dried flower of Heterotheca inuloides has been characterized as 2,7-dihydroxy-β-calacoren or 7-hydroxy-5,6,7,8-tetrahydro-3-methyl-8-methylene-5-(1-methylethyl)-2-naphthalenol by means of spectroscopic method. It exhibited plant growth inhibitory activity in lettuce seedling assay.