IL-1beta suppresses prolonged Akt activation and expression of E2F-1 and cyclin A in breast cancer cells

Cell cycle aberrations occurring at the G(1)/S checkpoint often lead to uncontrolled cell proliferation and tumor growth. We recently demonstrated that IL-1beta inhibits insulin-like growth factor (IGF)-I-induced cell proliferation by preventing cells from entering the S phase of the cell cycle, leading to G(0)/G(1) arrest. Notably, IL-1beta suppresses the ability of the IGF-I receptor tyrosine kinase to phosphorylate its major docking protein, insulin receptor substrate-1, in MCF-7 breast carcinoma cells. In this study, we extend this juxtamembrane cross-talk between cytokine and growth factor receptors to downstream cell cycle machinery. IL-1beta reduces the ability of IGF-I to activate Cdk2 and to induce E2F-1, cyclin A, and cyclin A-dependent phosphorylation of a retinoblastoma tumor suppressor substrate. Long-term activation of the phosphatidylinositol 3-kinase/Akt signaling pathway, but not the mammalian target of rapamycin or mitogen-activated protein kinase pathways, is required for IGF-I to hyperphosphorylate retinoblastoma and to cause accumulation of E2F-1 and cyclin A. In the absence of IGF-I to induce Akt activation and cell cycle progression, IL-1beta has no effect. IL-1beta induces p21(Cip1/Waf1), which may contribute to its inhibition of IGF-I-activated Cdk2. Collectively, these data establish a novel mechanism by which prolonged Akt phosphorylation serves as a convergent target for both IGF-I and IL-1beta; stimulation by growth factors such as IGF-I promotes G(1)-S phase progression, whereas IL-1beta antagonizes IGF-I-induced Akt phosphorylation to induce cytostasis. In this manner, Akt serves as a critical bridge that links proximal receptor signaling events to more distal cell cycle machinery.     

Helicobacter pylori (H. pylori) molecular signature in conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma

Conjunctival mucosa-associated lymphoid tissue (MALT) lymphoma is an extranodal marginal zone B-cell lymphoma that is characterized by an exaggerated clonal expansion of B cells, which implicate a pathological proliferative response to antigen(s) including bacteria. Helicobacter pylori (H. pylori) infection is recognized as one of the causative agents of gastric MALT lymphoma; however, it has not been reported in extra gastric MALT lymphoma. We studied 5 patients (4 adults and 1 child) with salmon-colored conjunctival lesions. One patient also had a history of abnormal bone marrow biopsy a year earlier with lymphoid aggregates involving 5% of the overall bone marrow. The conjunctival lesions of the 5 patients were biopsied. Histopathological diagnoses were consistent with conjunctival MALT lymphoma. Lymphoma and normal conjunctival cells were microdissected using laser capture microscopy or manual techniques. DNA was extracted and subjected to PCR amplification using H. pylori gene-specific primers from the urease B and vac/m2 gene. Cells from chronic conjunctivitis (normal lymphocytes), conjunctival human T-cell lymphotropic virus type-1/adult T-cell leukemia/lymphoma (HTLV-1/ATL), and orbital B-cell lymphoma were also microdissected, processed and analyzed. PCR amplification and Southern blot hybridization demonstrated H. pylori DNA in the conjunctival MALT lymphoma cells of 4/5 cases. The negative case was the one with a history of abnormal bone marrow. In contrast, H. pylori gene was not detected in normal conjunctival cells from the cases of MALT lymphoma or the lymphocytes, ATL and orbital B-lymphoma cells from the controls. These data suggest that H. pylori may play a role in conjunctival MALT lymphoma.     

应用RACE法克隆鸽恒定链基因的研究

为比较禽类恒定链的结构和功能, 应用RACE (Rapid Amplification of cDNA Ends) 技术首次克隆并鉴定了鸽恒定链基因。首先用一对含高度保守的DNA片段的简并引物, 从鸽脾细胞RNA扩增部分恒定链片段, 接着测序并设计新引物分别从5′和3′RACE扩增延长该片段。最后根据全基因的序列设计上、下游引物,获得大小为1 050 bp的全长cDNA。比较核苷酸序列, 鸽与鸡的Ii链同源性达到82.8％, 而与人等其它动物的同源性则在52.0％以上; 其中633 bp的开放阅读框编码211个氨基酸残基的前体蛋白。推导和分析氨基酸序列表明, 分子结构与鸡恒定链相似, 其中有些氨基酸残基表现出较高的保守性。     

Characterization and mapping of a new male sterility mutant of anther advanced dehiscence （t） in rice

Anther dehiscence is very important for pollen maturation and release.The mutants of anther dehiscence in rice (Oryza sativa L.) arefew,and related research remains poor.A male sterility mutant of anther dehiscence in advance,add(t),has been found in Minghui 63 and its sterility is not sensitive to thermo-photo.To learn the character of sterilization and the function of the add(t) gene,the morphological and cytological studies on the anther and pollen,the ability of the pistil being fertilized,inheritance of the mutant,and mapping of add(t)gene have been conducted.The anther size is normal but the color is white in the mutant against the natural yellow in the wild-type.The pollen is malformed,unstained,and small in the KI-I2 solution.The anther dehiscence is in advance at the bicellular pollen stage.A crossing test indicated that the grain setting ratio of the add(t) is significantly lower than that of the CMS line 2085A.The ability of the pistil being fertilized is most probably decreased by the add(t) gene.The male sterility is controlled by a single recessive gene of add(t).This gene is mapped between the markers of R02004 (InDel) and RM300 (SSR) on chromosome 2,and the genetic distance from the add(t) gene to these markers is 0.78 cM and 4.66 cM,respectively.     

Epigenetic regulation of sensory neurogenesis in the dorsal root ganglion cell line ND7 by folic acid

The epigenetic mechanism of folic acid (FA) action on dorsal root ganglion (DRG) cell proliferation and sensory neuron differentiation is not well understood. In this study, the ND7 cell line, derived from DRG cells, was used to elucidate this mechanism. In ND7 cells differentiated with dbcAMP and NGF, Hes1 and Pax3 levels decreased, whereas Neurog2 levels showed a modest increase. Chromatin immunoprecipitation (ChIP) assays examining epigenetic marks at the Hes1 promoter showed that FA favored increased H3K9 and H3K19 acetylation and decreased H3K27 methylation. Hence, FA plays a positive role in cell proliferation. In differentiated ND7 cells, H3K27 methylation decreased, whereas H3K9 and H3K18 acetylation increased at the Neurog2 promoter. FA did not favor this phenotypic outcome. Additionally, in differentiated ND7 Neurog2 associated with the NeuroD1 promoter, FA decreased this association. The results suggest that the switch from proliferation to sensory neuron differentiation in DRG cells is regulated by alterations in epigenetic marks, H3K9/18 acetylation and H3K27 methylation, at Hes1 and Neurog2 promoters, as well as by Neurog2 association with NeuroD1 promoter. FA although positive for proliferation, does not appear to play a role in differentiation.     

Emergy evaluation of the impact of waste exchanges on the sustainability of industrial systems

Emergy evaluation provided global performance indicators that were used to assess the impact of waste exchanges on the sustainability of a sulfuric acid production system (SAPS) and a titanium dioxide production system (TDPS) in Pan-zhi-hua City, China. Impact of emissions was quantified in terms of emergy and integrated into the classic emergy-based indicators. Results show that waste exchanges improve the sustainability of the two systems, although the SAPS benefits more from the waste exchanges than the TDPS from an economic perspective however, the impact of emissions reduces their sustainability to some degree. This study creates awareness and brings new insight to the gains achieved with resource recovery from waste in the interrelated industrial systems, which is derived from the mutualism relationship existing in natural ecosystems. Finally, this paper puts forward some corresponding suggestions.     

Electrogenerated chemiluminescence of ruthenium complex immobilized in a highly cross‐linked polymer and its analytical applications

Electrogenerated chemiluminescence (ECL) of a ruthenium complex polymer modified carbon paste electrode and its analytical applications were investigated. The ruthenium complex polymer was prepared using bis(2,2‐bipyridine) (4,4‐dicarboxy‐2,2‐bipyridine) ruthenium(II). The ECL behaviours of ruthenium complex polymer modified carbon paste electrode were investigated in the absence and presence of tripropylamine (TPA). The modified carbon paste electrode exhibited long‐term stability and fine reproducibility. The ECL intensity of the modified carbon paste electrode was linear with the concentration of TPA in the range 2.0 × 10^–6–3.8 × 10^–3 mol/L, with a detection limit (S:N = 3) of 6 × 10^–7 mol/L. It was also found that raceanisodamine could enhance the ECL intensity of the modified electrode. The ECL intensity of the modified carbon paste electrode was linear with the concentration of raceanisodamine in the range 1.1 × 10^–5–6.0 × 10^–4 mol/L, with a detection limit (S:N = 3) of 6 × 10^–6 mol/L. This work demonstrates that the entrapment of ruthenium complex in a highly cross‐linked polymer is a promising approach to construct an ECL modified electrode with long‐term stability and fine reproducibility. The modified electrode designed has a potential application in the ECL detector. Copyright © 2008 John Wiley & Sons, Ltd.     

中国水华蓝藻的新记录属——拟浮丝藻属(Planktothricoides)

在近年来对水华蓝藻的调查中,确定了我国一水华蓝藻新记录属——拟浮丝藻属Planktothricoides(WoIoszyńska) Suda et Watanabe 2002。文中对该属及该属一个新记录种的主要形态学特征进行了描述,并对其相近属浮丝藻属Planktothrix进行了形态学比较研究。