Suppression of androgen receptor-mediated transactivation and cell growth by the glycogen synthase kinase 3 beta in prostate cells

Androgens play important roles in the growth of normal prostate and prostate cancer via binding to the androgen receptor (AR). In addition to androgens, AR activity can also be modulated by selective growth factors and/or kinases. Here we report a new kinase signaling pathway by showing that AR transactivation was repressed by wild type glycogen synthase kinase 3beta (GSK3 beta) or constitutively active S9A-GSK3 beta in a dose-dependent manner. In contrast, the catalytically inactive kinase mutant GSK3 beta showed little effect on the AR transactivation. The suppression of AR transactivation by GSK3 beta was abolished by the GSK3 beta inhibitor lithium chloride. The in vitro kinase assay showed that GSK3 beta prefers to phosphorylate the amino terminus of AR that may lead to the suppression of activation function 1 activity located in the NH(2)-terminal region of AR. GSK3 beta interrupted the interaction between the NH(2) and COOH termini of AR, and overexpression of the constitutively active form of GSK3 beta, S9A-GSK3 beta, reduced the androgen-induced prostate cancer cell growth in stably transfected CWR22R cells. Together, our data demonstrated that GSK3 beta may function as a repressor to suppress AR-mediated transactivation and cell growth, which may provide a new strategy to modulate the AR-mediated prostate cancer growth.     

Developing an <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>-mediated genetic transformation for a selenium-hyperaccumulator <Emphasis Type="Italic">Astragalus racemosus</Emphasis>

Agrobacterium tumefaciens strain LBA4404 containing the plasmid pBI121, carrying the reporter gene uidA and the kanamycin resistance gene nptII, was used for gene transfer experiments in selenium (Se)-hyperaccumulator Astragalus racemosus. The effects of kanamycin on cell growth and division and acetosyringone on transformation efficiency were evaluated. The optimal concentration of kanamycin that could effectively inhibit cell growth and division in non-transgenic tissues was 50 mg l⁻¹ and thus all putative transgenic plants were obtained on induction medium containing 50 mg l⁻¹ kanamycin. The verification of transformants was achieved by both histochemical GUS assay and PCR amplification of nptII gene. Southern blot analysis was performed to further confirm that transgene nptII was stably integrated into the A. racemosus genome. A transformation frequency of approximately 10% was achieved using this protocol, but no beneficial effect from the addition of acetosyringone (50 μM) was observed. This transformation system will be a useful tool for future studies of genes responsible for Se-accumulation in A. racemosus.     

A platform to standardize,store, and visualize proteomics experimental data

With the development of functional genomics research, large-scale proteomics studies are now widespread, presenting significant challenges for data storage, exchange, and analysis. Here we present the Integrated Proteomics Exploring Database （IPED） as a platform for managing proteomics experimental data （both process and result data）. IPED is based on the schema of the Proteome Experimental Data Repository （PEDRo）, and complies with the General Proteomics Standard （GPS） drafted by the Proteomics Standards Committee of the Human Proteome Organization. In our work, we developed three components for the IPED platform： the IPED client editor, IPED server software, and IPED web interface. The client editor collects experimental data and generates an extensible markup language （XML） data file compliant with PEDRo and GPS; the server software parses the XML data file and loads information into a core database; and the web interface displays experimental results, to provide a convenient graphic representation of data. Given software convenience and data abundance, IPED is a powerful platform for data exchange and presents an important resource for the proteomics community. In its current release, IPED is available at http：//www. biosino.org/iped2.     

Improvement and Optimization of Standards for a Preclinical Animal Test Model of Laser Induced Choroidal Neovascularization

Background

As the murine model of laser-induced choroidal neovascularization (CNV) is becoming the most established and commonly utilized model worldwide for studying the pathogenesis of CNV and its response to treatment, specific operating standards are yet to be clarified. The purpose of this study is to compare the lesion size of CNV in mice with different ages, sex, durations of CNV process, and treated positions of laser spots, to make recommendations that may improve and optimize the quality of the model.

Methods and Results

C57/BL6 mice of different ages were treated with diode laser photocoagulation per eye and perfused with PBS containing fluorescein-labeled dextran at different time of observation. Choroid flat mounts, were then examined by fluorescence microscopy for the measurement of CNV area. Messenger-RNA expression levels of several angiogenic cytokines in eye cups of male and female C57BL/6 mice at 5–8 and 16–20 week-old were analyzed by real-time RT-PCR assay. The results showed significantly more CNV area in eyes of female mice compared to male mice with the expression level of several angiogenic cytokines elevated. 16–20-week-old female mice developed the biggest area of CNV. The mean area of CNV increased significantly at the 14^th day after photocoagulation. Laser spots delivered 1PD away from the optic disc induced the biggest area of CNV compared to those 2PD or 3PD away. Interaction of NV was observed in laser spots delivered less than 1PD away from each other.

Conclusion

The current results suggest that 16–20-week-old female C57BL/6 mice developed the most distinct CNV lesion size with laser spots delivered 1PD away from the optic disc. The best time to observe and analyze is the 14^th day after photocoagulation.     

A Modified Delta-Shaped Gastroduodenostomy in Totally Laparoscopic Distal Gastrectomy for Gastric Cancer: A Safe and Feasible Technique

Background

The present study introduced a modified delta-shaped gastroduodenostomy (DSG) technique and assessed the safety, feasibility and clinical results of this procedure in patients undergoing totally laparoscopic distal gastrectomy (TLDG) for gastric cancer (GC).

Materials and Methods

A total of 102 patients with distal GC undergoing TLDG with modified DSG between January 2013 and December 2013 were enrolled. A retrospective study was performed using a prospectively maintained comprehensive database to evaluate the results of the procedure. Univariate and multivariate analyses were performed to estimate the predictive factors for postoperative morbidity.

Results

The mean operation time was 150.6±30.2 min, the mean anastomosis time was 12.2±4.2 min, the mean blood loss was 48.2±33.2 ml, and the mean times to first flatus, fluid diet, soft diet and postoperative hospital stay were 3.8±1.3 days, 5.0±1.0 days, 7.4±2.1 days and 12.0±6.5 days, respectively. Two patients with minor anastomotic leakage after surgery were managed conservatively; no patient experienced any complications around the anastomosis, such as anastomotic stricture or anastomotic hemorrhage. Univariate analysis showed that age, gastric cancer with hemorrhage and cardiovascular disease combined were significant factors that affected postoperative morbidity (P<0.05). Multivariate analysis found that gastric cancer with hemorrhage was the independent risk factor for the postoperative morbidity (P = 0.042). At a median follow-up of 7 months, no patients had died or experienced recurrent or metastatic disease.

Conclusions

The modified DSG was technically safe and feasible, with acceptable surgical outcomes, in patients undergoing TLDG for GC, and this procedure may be promising in these patients.     

酵母菌相关实验的一些改进

高中生物学教学中,与酵母菌相关的实验有多个,如“探究酵母菌的呼吸方式”、“酵母菌的酒精发酵”等。下面就针对这些实验的可操作性,对实验装置进行一些改进,以利于探究实验的顺利进行。     

Reprogramming of sugar transport pathways in Escherichia coli using a permeabilized SecY protein-translocation channel

In the initial step of sugar metabolism, sugar-specific transporters play a decisive role in the passage of sugars through plasma membranes into cytoplasm. The SecY complex (SecYEG) in bacteria forms a membrane channel responsible for protein translocation. The present work shows that permeabilized SecY channels can be used as nonspecific sugar transporters in Escherichia coli. SecY with the plug domain deleted allowed the passage of glucose, fructose, mannose, xylose, and arabinose, and, with additional pore-ring mutations, facilitated lactose transport, indicating that sugar passage via permeabilized SecY was independent of sugar stereospecificity. The engineered E. coli showed rapid growth on a wide spectrum of monosaccharides and benefited from the elimination of transport saturation, improvement in sugar tolerance, reduction in competitive inhibition, and prevention of carbon catabolite repression, which are usually encountered with native sugar uptake systems. The SecY channel is widespread in prokaryotes, so other bacteria may also be engineered to utilize this system for sugar uptake. The SecY channel thus provides a unique sugar passageway for future development of robust cell factories for biotechnological applications.     

MicroPhenoDB Associates Metagenomic Datawith Pathogenic Microbes,Microbial Core Genes,and Human Disease Phenotypes

Microbes play important roles in human health and disease. The interaction between microbes and hosts is a reciprocal relationship, which remains largely under-explored. Current computational resources lack manually and consistently curated data to connect metagenomic data to pathogenic microbes, microbial core genes, and disease phenotypes. We developed the MicroPhenoDB database by manually curating and consistently integrating microbe-disease association data. MicroPhenoDB provides 5677 non-redundant associations between 1781 microbes and 542 human disease phenotypes across more than 22 human body sites. MicroPhenoDB also provides 696,934 relationships between 27,277 unique clade-specific core genes and 685 microbes. Disease phenotypes are classified and described using the Experimental Factor Ontology (EFO). A refined score model was developed to prioritize the associations based on evidential metrics. The sequence search option in MicroPhenoDB enables rapid identification of existing pathogenic microbes in samples without running the usual metagenomic data processing and assembly. MicroPhenoDB offers data browsing, searching, and visualization through user-friendly web interfaces and web service application programming interfaces. MicroPhenoDB is the first database platform to detail the relationships between pathogenic microbes, core genes, and disease phenotypes. It will accelerate metagenomic data analysis and assist studies in decoding microbes related to human diseases. MicroPhenoDB is available through http://www.liwzlab.cn/microphenodb and http://lilab2.sysu.edu.cn/microphenodb.     

Activation of Notch-1 enhances epithelial-mesenchymal transition in gefitinib-acquired resistant lung cancer cells

Despite an initial response to EGFR tyrosine kinase inhibitors (EGFR-TKI) in EGFR mutant lung cancer, most patients eventually become resistant and result in treatment failure. Recent studies have shown that epithelial to mesenchymal transition (EMT) is associated with drug resistance and cancer cell metastasis. Strong multiple gene signature data indicate that EMT acts as a determinant of insensitivity to EGFR-TKI. However, the exact mechanism for the acquisition of the EMT phenotype in EGFR-TKI resistant lung cancer cells remains unclear. In the present study, we showed that the expression of Notch-1 was highly upregulated in gefitinib-resistant PC9/AB2 lung cancer cells. Notch-1 receptor intracellular domain (N1IC), the activated form of the Notch-1 receptor, promoted the EMT phenotype in PC9 cells. Silencing of Notch-1 using siRNA reversed the EMT phenotype and restored sensitivity to gefitinib in PC9/AB2 cells. Moreover, Notch-1 reduction was also involved in inhibition of anoikis as well as colony-formation activity of PC9/AB2 cells. Taken together, these results provide strong molecular evidence that gefitinib-acquired resistance in lung cancer cells undergoing EMT occurs through activation of Notch-1 signaling. Thus, inhibition of Notch-1 can be a novel strategy for the reversal of the EMT phenotype thereby potentially increasing therapeutic drug sensitivity to lung cancer cells.