Generation of an inducible mouse ES cell lines deficient for Argonaute proteins.

Argonautes (Agos) are core effectors of RNA silencing. In several nonmammalian organisms, multiple Agos are known to exhibit specialized functions for distinct RNA silencing pathway. Mammals have four closely related Agos.

Selective leukemia cell death by activation of the double-stranded RNA-dependent protein kinase PKR.

Deregulated activity of the BCR-ABL tyrosine kinase encoded by the Bcr-Abl oncogene represents an important therapeutic target for all the chronic myelogenous leukemia (CML) phases. In this study, we sought to identify targeted PKR activation by Bcr-Abl AS RNA, an anti-sense RNA complementary to the unique mRNA fragments flanking the fusion point of Bcr-Abl, which can be used as an effective anti-leukemia strategy in K562 cells. Moreover, we observed expression of Bcr-Abl AS RNA in K562 cells which resulted in selective apoptosis induction through specific activation of PKR, leading to phosphorylation of eIF2α, global inhibition of protein synthesis, caspase-8 activation and BAX up-regulation.

[Clinical significance of multi-slice spiral CT angiography in radical resection of gastric cancer].

Objectives: To explore the clinical significance of preoperative abdominal multi-slice spiral CT angiography (MSCTA) in radical resection of gastric cancer.

Methods: One hundred and three patients with gastric cancer were divided into two groups according to their desires. Group I( included 57 patients who underwent preoperative MSCTA and group II( included 46 patients who underwent surgery without preoperative MSCTA.

[Modulation of histone acetylation and induction of apoptosis in SMMC-7721 cells by phenylhexyl isothiocyanate].

Objective: To investigate the effect of phenylhexyl isothiocyanate (PHI) on histone acetylation and apoptosis in hepatocellular carcinoma cell line (SMMC-7721) in vitro.

Methods: The viability of SMMC-7721 cells was determined by trypan blue exclusion. Apoptotic cells were assessed by TUNEL assay.

A novel NKX2-5 mutation in familial ventricular septal defect.

Ventricular septal defect (VSD) is the most common cardiovascular malformation and an important contributor to the substantial morbidity and mortality in infancy. Growing evidence suggests that genetic defects play important roles in the pathogenesis of congenital VSD. However, VSD is of great genetic heterogeneity and the genetic basis for VSD in the majority of the patients remains largely unhnown.

Targeted blockage of signal transducer and activator of transcription 5 signaling pathway with decoy oligodeoxynucleotides suppresses leukemic K562 cell growth.

The protein signal transducer and activator of transcription 5 (STAT5) of the JAK/STAT pathway is constitutively activated because of its phosphorylation by tyrosine kinase activity of fusion protein BCR-ABL in chronic myelogenous leukemia (CML) cells. This study investigated the potential therapeutic effect of STAT5 decoy oligodeoxynucleotides (ODN) using leukemia K562 cells as a model. Our results showed that transfection of 21-mer-long STAT5 decoy ODN into K562 cells effectively inhibited cell proliferation and induced cell apoptosis.

PDCD10/CCM3 acts downstream of {gamma}-protocadherins to regulate neuronal survival.

γ-Protocadherins (PCDH-γ) regulate neuronal survival in the vertebrate central nervous system. The molecular mechanisms of how PCDH-γ mediates this function are still not understood. In this study, we show that through their common cytoplasmic domain, different PCDH-γ isoforms interact with an intracellular adaptor protein named PDCD10 (programmed cell death 10).

A recessive genetic screen for components of the RNA interference pathway in mouse embryonic stem cells.

Several key components of the RNA interference (RNAi) pathway were identified in genetic screens performed in nonmammalian model organisms. To identify components of the mammalian RNAi pathway, we developed a recessive genetic screen in mouse embryonic stem (ES) cells. Recessive genetic screens are feasible in ES cells that are Bloom-syndrome protein (Blm-) deficient.

Roquin binds inducible costimulator mRNA and effectors of mRNA decay to induce microRNA-independent post-transcriptional repression.

The molecular mechanism by which roquin controls the expression of inducible costimulator (ICOS) to prevent autoimmunity remains unsolved. Here we show that in helper T cells, roquin localized to processing (P) bodies and downregulated ICOS expression. The repression was dependent on the RNA helicase Rck, and roquin interacted with Rck and the enhancer of decapping Edc4, which act together in mRNA decapping.

Disruption of the clock components CLOCK and BMAL1 leads to hypoinsulinaemia and diabetes.

The molecular clock maintains energy constancy by producing circadian oscillations of rate-limiting enzymes involved in tissue metabolism across the day and night. During periods of feeding, pancreatic islets secrete insulin to maintain glucose homeostasis, and although rhythmic control of insulin release is recognized to be dysregulated in humans with diabetes, it is not known how the circadian clock may affect this process. Here we show that pancreatic islets possess self-sustained circadian gene and protein oscillations of the transcription factors CLOCK and BMAL1.

[Phenylhexyl isothiocyanate (PHI) regulates histone methylation and acetylation and induces apoptosis in SMMC-7721 cells].

Objective: To investigate the effects of PHI on histone acetylation and methylation in hepatocellular carcinoma line SMMC-7721 cells.

Methods: Apoptosis was measured by TUNNEL assay. Histone methylation and acetylation were detected by Western blot.

Fibronectin promotes tyrosine phosphorylation of paxillin and cell invasiveness in the gastric cancer cell line AGS.

Aims And Background: Paxillin is a central protein within the focal adhesion and serves as a critical transducer of signals from fibronectin. Although abnormal expression of fibronectin and paxillin is often observed during the development of human malignancies, the relationship between paxillin and cell invasion in gastric cancer is still unclear. The current study was designed to investigate the potential role and mechanisms of fibronectin in tyrosine phosphorylation of paxillin and in the invasiveness of gastric cancer cells.

Gamma-protocadherins regulate the functional integrity of hypothalamic feeding circuitry in mice.

The hypothalamic neuronal circuits that modulate energy homeostasis become mature and functional during early postnatal life. However, the molecular mechanism underlying this developmental process remains largely unknown. Here we use a mouse genetic approach to investigate the role of gamma-protocadherins (Pcdh-gammas) in hypothalamic neuronal circuits.

Proteomics analysis reveals overlapping functions of clustered protocadherins.

The three tandem-arrayed protocadherin (Pcdh) gene clusters, namely Pcdh-alpha, Pcdh-beta, and Pcdh-gamma, play important roles in the development of the vertebrate central nervous system. To gain insight into the molecular action of PCDHs, we performed a systematic proteomics analysis of PCDH-gamma-associated protein complexes. We identified a list of 154 non-redundant proteins in the PCDH-gamma complexes.

PiggyBac transgenic strategies in the developing chicken spinal cord.

The chicken spinal cord is an excellent model for the study of early neural development in vertebrates. However, the lack of robust, stable and versatile transgenic methods has limited the usefulness of chick embryos for the study of later neurodevelopmental events. Here we describe a new transgenic approach utilizing the PiggyBac (PB) transposon to facilitate analysis of late-stage neural development such as axon targeting and synaptic connection in the chicken embryo.

Competitive priming PCR: a versatile method to generate cohesive terminus.

In the post-genomic era, providing a detailed description of protein functions poses a formidable challenge. To gain functional insights, we have to construct many kinds of expression vectors. DNA recombination based on polymerase chain reaction (PCR) and digestion followed by ligation is the preferred method for vector construction.

Fibronectin promotes invasiveness and focal adhesion kinase tyrosine phosphorylation of human colon cancer cell.

Background/aims: The study was designed to investigate a potential role and mechanisms of fibronectin in tyrosine phosphorylation of focal adhesion kinase (FAK) and invasiveness of colon cancer cells.

Methodology: A colorectal cancer cell line, Colo320, was stimulated by fibronectin with gradient concentrations. Phosphorylation of FAK tyrosine 397 (tyr-397), was detected by immunoprecipitation and western-blotting.

A genetic screen for components of the mammalian RNA interference pathway in Bloom-deficient mouse embryonic stem cells.

Genetic screens performed in model organisms have helped identify key components of the RNA interference (RNAi) pathway. Recessive genetic screens have recently become feasible through the use of mouse embryonic stem (ES) cells that are Bloom's syndrome protein (Blm) deficient. Here, we developed and performed a recessive genetic screen to identify components of the mammalian RNAi pathway in Blm-deficient ES cells.

Essential and overlapping functions for mammalian Argonautes in microRNA silencing.

MicroRNA (miRNA) silencing fine-tunes protein output and regulates diverse biological processes. Argonaute (Ago) proteins are the core effectors of the miRNA pathway. In lower organisms, multiple Agos have evolved specialized functions for distinct RNA silencing pathways.

WITHDRAWN: Fem1b interacts with Ankrd37 in mouse testis and induces its degradation by ubiquitin-mediated proteolysis pathway.

This article has been withdrawn at the request of the authors. The Publisher apologises for any inconvenience that this may cause. The full Elsevier Policy on Article Withdrawal can be found at http://www.

[The effect of IL-10 on proliferation of primary cultured hepatocytes].

Aim: To investigate the effect of IL-10 on proliferation of rat primary cultured hepatocytes.

Methods: Rat hepatocytes were isolated from rat liver by in situ digestion of collagenase IV and cryopreserved, resuscitated, cultured in vitro. Reverse-transcription polymerase chain reaction (RT-PCR) was used to characterize the purity of hepatocytes and analyze IL-10/IL10Ralpha mRNA from freshly isolated cells.

alpha- and gamma-Protocadherins negatively regulate PYK2.

Genetic studies demonstrate that gamma-protocadherins (PCDH-gamma) are required for the survival and synaptic connectivity in neuronal subpopulations of the central nervous system. However, the intracellular signaling mechanisms for PCDH-gamma are poorly understood. Here, we show that PCDH-gamma binds two tyrosine kinases, PYK2 and focal adhesion kinase (FAK), and interaction with PCDH-gamma inhibits kinase activity.

A differential developmental pattern of spinal interneuron apoptosis during synaptogenesis: insights from genetic analyses of the protocadherin-gamma gene cluster.

Although the role of developmental apoptosis in shaping the complement and connectivity of sensory and motoneurons is well documented, the extent to which cell death affects the 13 cardinal classes of spinal interneurons is unclear. Using a series of genetic manipulations in vivo, we demonstrate for the first time a differential pattern of developmental apoptosis in molecularly identified spinal interneuron populations, and implicate the adhesion molecule family encoded by the 22-member protocadherin-gamma (Pcdh-gamma) gene cluster in its control. In constitutive Pcdh-gamma null mouse embryos, many interneuron populations undergo increased apoptosis, but to differing extents: for example, over 80% of En1-positive V1 neurons are lost, whereas only 30% of Chx10-positive V2a neurons are lost and there is no reduction in the number of V1-derived Renshaw cells.

gamma-Protocadherins regulate neuronal survival but are dispensable for circuit formation in retina.

Twenty-two tandemly arranged protocadherin-gamma (Pcdh-gamma) genes encode transmembrane proteins with distinct cadherin-related extracellular domains and a common intracellular domain. Genetic studies have implicated Pcdh-gamma genes in the regulation of neuronal survival and synapse formation. Because mice lacking the Pcdh-gamma cluster die perinatally, we generated conditional mutants to analyze roles of Pcdh-gamma genes in the development and function of neural circuits.