胰腺导管内乳头状粘液性肿瘤诊治相关进展

胰腺导管内乳头状黏液瘤（Intraductalpapillarymucinousneoplasm,IPMN）是由胰腺导管内产生粘液的上皮细胞呈乳头状增殖形成的低度恶性肿瘤。其生长缓慢、临床表现多样、命名及分型标准复杂混乱、影像学具有一定的特征且检查手段众多、治疗需采用不同方案。因此,本文从临床特征、病理分型及生物学行为、影像特征及影像诊断方法、治疗及预后等方面就其相关进展进行综述。     

An Increased Total Resected Lymph Node Count Benefits Survival following Pancreas Invasive Intraductal Papillary Mucinous Neoplasms Resection: An Analysis Using the Surveillance,Epidemiology, and End Result Registry Database

Background

The therapeutic effect of lymph node dissection for pancreas invasive intraductal papillary mucinous neoplasms (IPMN) remains unclear. The study investigated whether cancer-specific survival (CSS) and overall survival (OS) rates among invasive IPMN patients improve when more lymph nodes are harvested during surgery.

Study Design

The study cohort was retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. The lymph node count was categorized into quartiles. The relationship between lymph node count and survival was analyzed using Kaplan–Meier curves and a Cox proportional-hazards model. The stage migration was assessed by Chi-square tests. Propensity score matching (PSM) was used to minimize confounding variables between groups.

Results

In total, 1,080 patients with resected invasive IPMNs from 1992 to 2011 were included. Univariate and multivariate Cox models indicated that an increased lymph node count independently improves survival. The Kaplan-Meier and log-rank tests identified 16 nodes as an optimal cut-off value that yielded a significant survival benefit for all invasive IPMN patients. The stage migration effect existed in this cohort. After PSM, the 5-year CSS increased from 36% to 47%, and the median survival rate increased from 30 months to 40 months by increasing the lymph node count to over 16, alone. The 5-year OS rate also provided additional support for this result.

Conclusion

Increased lymph node counts were associated with improved survival in invasive IPMN patients. One cut-off value of lymph node count was 16 for this improvement.     

GNAS and KRAS Mutations are Common in Intraductal Papillary Neoplasms of the Bile Duct

Intraductal papillary neoplasms of the bile duct (IPNB) shows favorable prognosis and is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. Although activating point mutations of GNAS at codon 201 have been detected in approximately two thirds of IPMNs of the pancreas, there have been few studies on GNAS mutations in IPNBs. This study investigates the status of GNAS and KRAS mutations and their association with clinicopathological factors in IPNBs. We examined the status of GNAS mutation at codon 201 and KRAS mutation at codon 12&13, degree of mucin production and immunohistochemical expressions of MUC mucin core proteins in 29 patients (M/F = 15/14) with IPNB in intrahepatic and perihilar bile ducts (perihilar IPNB) and 6 patients (M/F = 5/1) with IPNB in distal bile ducts (distal IPNB). GNAS mutations and KRAS mutations were detected in 50% and 46.2% of IPNBs, respectively. There was no significant correlation between the status of GNAS mutation and clinicopathological factors in IPNBs, whereas, the status of KRAS mutation was significantly inversely correlated with the degree of MUC2 expression in IPNBs (p<0.05). All IPNBs with GNAS mutation only showed high-mucin production. Degree of mucin production was significantly higher in perihilar IPNBs than distal IPNBs (p<0.05). MUC2 and MUC5AC expression was significantly higher in IPNBs with high-mucin production than those with low-mucin production (p<0.01 and p<0.05, respectively). In conclusions, this study firstly disclosed frequent GNAS mutations in IPNBs, similarly to IPMNs. This may suggest a common histopathogenesis of IPNBs and IPMNs. The status of KRAS mutations was inversely correlated to MUC2 expression and this may suggest heterogeneous properties of IPNBs. IPNBs with high-mucin production are characterized by perihilar location and high expression of MUC2 and MUC5AC, irrespective of the status of GNAS and KRAS mutations.     

A Genome-Wide Association Study of the Maize Hypersensitive Defense Response Identifies Genes That Cluster in Related Pathways

Much remains unknown of molecular events controlling the plant hypersensitive defense response (HR), a rapid localized cell death that limits pathogen spread and is mediated by resistance (R-) genes. Genetic control of the HR is hard to quantify due to its microscopic and rapid nature. Natural modifiers of the ectopic HR phenotype induced by an aberrant auto-active R-gene (Rp1-D21), were mapped in a population of 3,381 recombinant inbred lines from the maize nested association mapping population. Joint linkage analysis was conducted to identify 32 additive but no epistatic quantitative trait loci (QTL) using a linkage map based on more than 7000 single nucleotide polymorphisms (SNPs). Genome-wide association (GWA) analysis of 26.5 million SNPs was conducted after adjusting for background QTL. GWA identified associated SNPs that colocalized with 44 candidate genes. Thirty-six of these genes colocalized within 23 of the 32 QTL identified by joint linkage analysis. The candidate genes included genes predicted to be in involved programmed cell death, defense response, ubiquitination, redox homeostasis, autophagy, calcium signalling, lignin biosynthesis and cell wall modification. Twelve of the candidate genes showed significant differential expression between isogenic lines differing for the presence of Rp1-D21. Low but significant correlations between HR-related traits and several previously-measured disease resistance traits suggested that the genetic control of these traits was substantially, though not entirely, independent. This study provides the first system-wide analysis of natural variation that modulates the HR response in plants.     

Antibodies That Distinguish between the Serine-158 Phospho- and Dephospho-Form of Spinach Leaf Sucrose-Phosphate Synthase

Serum antibodies were raised against a synthetic peptide corresponding to the amino acid sequence surrounding the major inactivating phosphorylation site (serine-158) of spinach (Spinacia oleracea) leaf sucrose-phosphate synthase (SPS). The anti-peptide antibodies precipitated highly activated SPS preferentially to ATP-inactivated SPS and interacted only weakly with the sodium dodecyl sulfate-denatured enzyme bound to a membrane. The antibodies blocked phosphorylation but not dephosphorylation of SPS. Highly activated SPS was not entirely dephosphorylated and ATP-inactivated SPS was not completely phosphorylated on serine-158, as indicated by the sensitivities of immunopurified serine-158 phospho- and dephospho-SPS to inhibition by inorganic phosphate. The anti-peptide antibodies can be used to detect changes in the phosphorylation state of serine-158, and they are useful to purify and characterize distinct kinetic forms of SPS.     

Characterization of MicroRNA Expression Profiles and the Discovery of Novel MicroRNAs Involved in Cancer during Human Embryonic Development

MicroRNAs (miRNAs), approximately 22-nucleotide non-coding RNA molecules, regulate a variety of pivotal physiological or pathological processes, including embryonic development and tumorigenesis. To obtain comprehensive expression profiles of miRNAs in human embryos, we characterized miRNA expression in weeks 4-6 of human embryonic development using miRNA microarrays and identified 50 human-embryo-specific miRNAs (HES-miRNAs). Furthermore, we selected three non-conserved or primate-specific miRNAs, hsa-miR-638, -720, and -1280, and examined their expression levels in various normal and tumor tissues. The results show that expression of most miRNAs is extremely low during early human embryonic development. In addition, the expression of some non-conserved or primate-specific miRNAs is significantly different between tumor and the corresponding normal tissue samples, suggesting that the miRNAs are closely related to the pathological processes of various tumors. This study presents the first comprehensive overview of miRNA expression during human embryonic development and offers immediate evidence of the relationship between human early embryonic development and tumorigenesis.     

A Genome-Wide Survey of Sexually Dimorphic Expression of Drosophila miRNAs Identifies the Steroid Hormone-Induced miRNA let-7 as a Regulator of Sexual Identity

MiRNAs bear an increasing number of functions throughout development and in the aging adult. Here we address their role in establishing sexually dimorphic traits and sexual identity in male and female Drosophila. Our survey of miRNA populations in each sex identifies sets of miRNAs differentially expressed in male and female tissues across various stages of development. The pervasive sex-biased expression of miRNAs generally increases with the complexity and sexual dimorphism of tissues, gonads revealing the most striking biases. We find that the male-specific regulation of the X chromosome is relevant to miRNA expression on two levels. First, in the male gonad, testis-biased miRNAs tend to reside on the X chromosome. Second, in the soma, X-linked miRNAs do not systematically rely on dosage compensation. We set out to address the importance of a sex-biased expression of miRNAs in establishing sexually dimorphic traits. Our study of the conserved let-7-C miRNA cluster controlled by the sex-biased hormone ecdysone places let-7 as a primary modulator of the sex-determination hierarchy. Flies with modified let-7 levels present doublesex-related phenotypes and express sex-determination genes normally restricted to the opposite sex. In testes and ovaries, alterations of the ecdysone-induced let-7 result in aberrant gonadal somatic cell behavior and non-cell-autonomous defects in early germline differentiation. Gonadal defects as well as aberrant expression of sex-determination genes persist in aging adults under hormonal control. Together, our findings place ecdysone and let-7 as modulators of a somatic systemic signal that helps establish and sustain sexual identity in males and females and differentiation in gonads. This work establishes the foundation for a role of miRNAs in sexual dimorphism and demonstrates that similar to vertebrate hormonal control of cellular sexual identity exists in Drosophila.     

Yeast Genome-Wide Expression Analysis Identifies a Strong Ergosterol and Oxidative Stress Response during the Initial Stages of an Industrial Lager Fermentation

Genome-wide expression analysis of an industrial strain of Saccharomyces cerevisiae during the initial stages of an industrial lager fermentation identified a strong response from genes involved in the biosynthesis of ergosterol and oxidative stress protection. The induction of the ERG genes was confirmed by Northern analysis and was found to be complemented by a rapid accumulation of ergosterol over the initial 6-h fermentation period. From a test of the metabolic activity of deletion mutants in the ergosterol biosynthesis pathway, it was found that ergosterol is an important factor in restoring the fermentative capacity of the cell after storage. Additionally, similar ERG10 and TRR1 gene expression patterns over the initial 24-h fermentation period highlighted a possible interaction between ergosterol biosynthesis and the oxidative stress response. Further analysis showed that erg mutants producing altered sterols were highly sensitive to oxidative stress-generating compounds. Here we show that genome-wide expression analysis can be used in the commercial environment and was successful in identifying environmental conditions that are important in industrial yeast fermentation.     

Genome-Wide Association Study Identifies That the ABO Blood Group System Influences Interleukin-10 Levels and the Risk of Clinical Events in Patients with Acute Coronary Syndrome

Introduction

Acute coronary syndrome (ACS) is a major cause of mortality worldwide. We have previously shown that increased interleukin-10 (IL-10) levels are associated with poor outcome in ACS patients.

Method

We performed a genome-wide association study in 2864 ACS patients and 408 healthy controls, to identify genetic variants associated with IL-10 levels. Then haplotype analyses of the identified loci were done and comparisons to levels of IL-10 and other known ACS related biomarkers.

Results

Genetic variants at the ABO blood group locus associated with IL-10 levels (top SNP: rs676457, P = 4.4 × 10⁻¹⁰) were identified in the ACS patients. Haplotype analysis, using SNPs tagging the four main ABO antigens (A1, A2, B and O), showed that O and A2 homozygous individuals, or O/A2 heterozygotes have much higher levels of IL-10 compared to individuals with other antigen combinations. In the ACS patients, associations between ABO antigens and von Willebrand factor (VWF, P = 9.2 × 10⁻¹³), and soluble tissue factor (sTF, P = 8.6 × 10⁻⁴) were also found. In the healthy control cohort, the associations with VWF and sTF were similar to those in ACS patients (P = 1.2 × 10⁻¹⁵ and P = 1.0 × 10⁻⁵ respectively), but the healthy cohort showed no association with IL-10 levels (P>0.05). In the ACS patients, the O antigen was also associated with an increased risk of cardiovascular death, all causes of death, and recurrent myocardial infarction (odds ratio [OR] = 1.24–1.29, P = 0.029–0.00067).

Conclusion

Our results suggest that the ABO antigens play important roles, not only for the immunological response in ACS patients, but also for the outcome of the disease.     

Opposite Expression of SPARC between the Liver and Pancreas in Streptozotocin-Induced Diabetic Rats

Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein that regulates several cellular events, including inflammation and tissue remodelling. In this study, we investigated the tissue-specific expression of SPARC in streptozotocin (STZ)-induced diabetes, and found that SPARC was significantly up-regulated in the liver while down-regulated in the pancreas of STZ-induced diabetic rats. Chronic inflammation occurred in the diabetic pancreas accompanied by up-regulation of CCAAT/enhancer-binding protein beta (C/EBPβ) and its targets (TNFα, Il6, CRP, and Fn1) as well as myeloperoxidase (Mpo) and C-X-C chemokine receptor type 2 (Cxcr2). Diabetic liver showed significant up-regulation of Tgfb1 as well as moderately less up-regulated TNFα and reduced Fn1, resulting in elevated fibrogenesis. PARP-1 was not up-regulated during CD95-mediated apoptosis, resulting in restoration of high ATP levels in the diabetic liver. On the contrary, CD95-dependent apoptosis was not observed in the diabetic pancreas due to up-regulation of PARP-1 and ATP depletion, resulting in necrosis. The cytoprotective machinery was damaged by pancreatic inflammation, whereas adequate antioxidant capacity indicates low oxidative stress in the diabetic liver. High and low cellular insulin content was found in the diabetic liver and pancreas, respectively. Furthermore, we identified six novel interacting partner proteins of SPARC by co-immunoprecipitation in the diabetic liver and pancreas, and their interactions with SPARC were predicted by bioinformatics tools. Taken together, opposite expression of SPARC in the diabetic liver and pancreas may be related to inflammation and immune cell infiltration, degrees of apoptosis and fibrosis, cytoprotective machinery, and cellular insulin levels.     

MicroRNA Regulation in Extreme Environments:Differential Expression of MicroRNAs in the Intertidal Snail Littorina littorea During Extended Periods of Freezing and Anoxia

Several recent studies of vertebrate adaptation to environmental stress have suggested roles for microRNAs (miRNAs) in regulating glo- bal suppression of protein synthesis and/or restructuring protein expression patterns. The present study is the first to characterize stress-responsive alterations in the expression of miRNAs during natural freezing or anoxia exposures in an invertebrate species, the intertidal gastropod Littorina littorea. These snails are exposed to anoxia and freezing conditions as their environment constantly fluctuates on both a tidal and seasonal basis. The expression of selected miRNAs that are known to influence the cell cycle, cellular signaling pathways, carbohydrate metabolism and apoptosis was evaluated using RT-PCR. Compared to controls, significant changes in expression were observed for miR-1a-1, miR-34a and miR-29b in hepatopancreas and for miR-1a-1, miR-34a, miR-133a, miR-125b, miR-29b and miR-2a in foot muscle after freezing exposure at 6 °C for 24 h (P < 0.05). In addition, in response to anoxia stress for 24 h, significant changes in expression were also observed for miR-1a-1, miR-210 and miR-29b in hepatopancreas and for miR-1a-1, miR-34a, miR-133a, miR-29b and miR-2a in foot muscle (P < 0.05). Moreover, protein expression of Dicer, an enzyme responsible for mature microRNA processing, was increased in foot muscle during freezing and anoxia and in hepatopancreas during freezing. Alterations in expression of these miRNAs in L. littorea tissues may contribute to organismal survival under freezing and anoxia.     

An Investigation of the Ability of the Glutaraldehyde Test to Distinguish between Acute and Chronic Inflammatory Disease in Horses

The Glutaraldehyde test (GT), a rapid and inexpensive test, has been utilized empirically for many years in bovine practice for diagnosing inflammatory diseases. GT is used primarily to demonstrate increased serum concentrations of fibrinogen and globulin. Glutaraldehyde binds with free amino groups in fibrinogen and immunoglobulin to create a clot in a first degree chemical reaction. The clotting time of the GT estimates the content of proteins produced in response to inflammation. The applicability of GT for diagnosing inflammation in the horse has never been investigated. The objective of this study was to determine the ability of GT to distinguish between acute and chronic inflammatory disease in horses. Thirty-seven horses with suspected inflammatory diseases were evaluated using the GT, history, complete clinical examination and routine blood analysis. GT-times, laboratory results and clinical outcome were compared statistically. Horses that were determined to be acutely affected (based on history, clinical examination and routine blood analysis) tended to have a negative GT (75%). Results of the GT did not correlate with blood fibrinogen concentration. Positive GT also predicted a fatal outcome in 69% of the clinical cases. The results of this trial indicate that GT can be a useful screening test to distinguish between acute and chronic inflammatory disease in horses.     

Genome-Wide Investigation and Expression Analyses of WD40 Protein Family in the Model Plant Foxtail Millet (Setaria italica L.)

WD40 proteins play a crucial role in diverse protein-protein interactions by acting as scaffolding molecules and thus assisting in the proper activity of proteins. Hence, systematic characterization and expression profiling of these WD40 genes in foxtail millet would enable us to understand the networks of WD40 proteins and their biological processes and gene functions. In the present study, a genome-wide survey was conducted and 225 potential WD40 genes were identified. Phylogenetic analysis categorized the WD40 proteins into 5 distinct sub-families (I–V). Gene Ontology annotation revealed the biological roles of the WD40 proteins along with its cellular components and molecular functions. In silico comparative mapping with sorghum, maize and rice demonstrated the orthologous relationships and chromosomal rearrangements including duplication, inversion and deletion of WD40 genes. Estimation of synonymous and non-synonymous substitution rates revealed its evolutionary significance in terms of gene-duplication and divergence. Expression profiling against abiotic stresses provided novel insights into specific and/or overlapping expression patterns of SiWD40 genes. Homology modeling enabled three-dimensional structure prediction was performed to understand the molecular functions of WD40 proteins. Although, recent findings had shown the importance of WD40 domains in acting as hubs for cellular networks during many biological processes, it has invited a lesser research attention unlike other common domains. Being a most promiscuous interactors, WD40 domains are versatile in mediating critical cellular functions and hence this genome-wide study especially in the model crop foxtail millet would serve as a blue-print for functional characterization of WD40s in millets and bioenergy grass species. In addition, the present analyses would also assist the research community in choosing the candidate WD40s for comprehensive studies towards crop improvement of millets and biofuel grasses.     

A Genome-Wide Analysis of the Gene Expression and Alternative Splicing Events in a Whole-Body Hypoxic Preconditioning Mouse Model

Exposure to specific doses of hypoxia can trigger endogenous neuroprotective and neuroplastic mechanisms of the central nervous system. These molecular mechanisms, together referred to as hypoxic preconditioning (HPC), remain poorly understood. In the present study, we applied RNA sequencing and bioinformatics analyses to study HPC in a whole-body HPC mouse model. The preconditioned (H4) and control (H0) groups showed 605 differentially expressed genes (DEGs), of which 263 were upregulated and 342 were downregulated. Gene Ontology enrichment analysis indicated that these DEGs were enriched in several biological processes, including metabolic stress and angiogenesis. The Kyoto Encyclopedia of Genes and Genomes enrichment analysis showed that the FOXO and Notch signaling pathways were involved in hypoxic tolerance and protection during HPC. Furthermore, 117 differential alternative splicing events (DASEs) were identified, with exon skipping being the dominant one (48.51%). Repeated exposure to systemic hypoxia promoted skipping of exon 7 in Edrf1 and exon 9 or 13 in Lrrc45. This study expands the understanding of the endogenous protective mechanisms of HPC and the DASEs that occur during HPC.

     

Menin: A Tumor Suppressor That Mediates Postsynaptic Receptor Expression and Synaptogenesis between Central Neurons of Lymnaea stagnalis

Neurotrophic factors (NTFs) support neuronal survival, differentiation, and even synaptic plasticity both during development and throughout the life of an organism. However, their precise roles in central synapse formation remain unknown. Previously, we demonstrated that excitatory synapse formation in Lymnaea stagnalis requires a source of extrinsic NTFs and receptor tyrosine kinase (RTK) activation. Here we show that NTFs such as Lymnaea epidermal growth factor (L-EGF) act through RTKs to trigger a specific subset of intracellular signalling events in the postsynaptic neuron, which lead to the activation of the tumor suppressor menin, encoded by Lymnaea MEN1 (L-MEN1) and the expression of excitatory nicotinic acetylcholine receptors (nAChRs). We provide direct evidence that the activation of the MAPK/ERK cascade is required for the expression of nAChRs, and subsequent synapse formation between pairs of neurons in vitro. Furthermore, we show that L-menin activation is sufficient for the expression of postsynaptic excitatory nAChRs and subsequent synapse formation in media devoid of NTFs. By extending our findings in situ, we reveal the necessity of EGFRs in mediating synapse formation between a single transplanted neuron and its intact presynaptic partner. Moreover, deficits in excitatory synapse formation following EGFR knock-down can be rescued by injecting synthetic L-MEN1 mRNA in the intact central nervous system. Taken together, this study provides the first direct evidence that NTFs functioning via RTKs activate the MEN1 gene, which appears sufficient to regulate synapse formation between central neurons. Our study also offers a novel developmental role for menin beyond tumour suppression in adult humans.     

A Cytochemical Study on the Pancreas of the Guinea Pig : IV. Chemical and Metabolic Investigation of the Ribonucleoprotein Particles

Five ribonucleoprotein (RNP) fractions were isolated from the postmitochondrial supernatant of the pancreas of the guinea pig. Two were obtained from the microsomes which, by deoxycholate (DOC) treatment, were subdivided into a DOC-soluble and a DOC-insoluble fraction. The latter was taken to represent attached RNP particles. Two other fractions obtained from the microsomal supernatant supposedly represent free RNP particles existing as such in the cytoplasm, while a third fraction resisted sedimentation for 20 hours at 105,000 g and is considered to be a soluble nucleoprotein. These fractions exhibited different RNA/protein ratios and also different RNA turnover patterns, as determined after in vivo labelling with adenine-8-C¹⁴. However, little discernible differences could be detected in the nucleotide composition of the RNA moieties of these RNP fractions. Amino acid-"activating" enzymes were found to occur in the fraction containing the soluble nucleoproteins. The discussion focuses on the relationships between these fractions and protein synthesis in the pancreas, using data given in this and a previous paper, and data contained in the literature.