Metabolic engineering of Halomonas bluephagenesis for production of five carbon molecular chemicals derived from L-lysine

5-Aminovaleric acid (5-AVA), 5-hydroxyvalerate (5HV), copolymer P(3HB-co-5HV) of 3-hydroxybutyrate (3HB) and 5HV were produced from L-lysine as a substrate by recombinant Halomonas bluephagenesis constructed based on codon optimization, deletions of competitive pathway and L-lysine export protein, and three copies of davBA genes encoding L-lysine monooxygenase (DavB) and 5-aminovaleramide amidohydrolase (DavA) inserted into its genome to form H. bluephagenesis YF117ΔgabT1+2, which produced 16.4 g L-1 and 67.4 g L-1 5-AVA in flask cultures and in 7 L bioreactor, respectively. It was able to de novo synthesize 5-AVA from glucose by L-lysine-overproducing H. bluephagenesis TD226. Corn steep liquor was used instead of yeast extract for cost reduction during the 5-AVA production. Using promoter engineering based on Pporin mutant library for downstream genes, H. bluephagenesis YF117 harboring pSEVA341-Pporin42-yqhDEC produced 6 g L-1 5HV in shake flask growth, while H. bluephagenesis YF117 harboring pSEVA341-Pporin42-yqhDEC-Pporin278-phaCRE-abfT synthesized 42 wt% P(3HB-co-4.8 mol% 5HV) under the same condition. Thus, H. bluephagenesis was successfully engineered to produce 5-AVA and 5HV in supernatant and intracellular P(3HB-co-5HV) utilizing L-lysine as the substrate.

Flux optimization using multiple promoters in Halomonas bluephagenesis as a model chassis of the next generation industrial biotechnology

Predictability and robustness are challenges for bioproduction because of the unstable intracellular synthetic activities. With the deeper understanding of the gene expression process, fine-tuning has become a meaningful tool for biosynthesis optimization. This study characterized several gene expression elements and constructed a multiple inducible system that responds to ten different small chemical inducers in halophile bacterium Halomonas bluephagenesis. Genome insertion of regulators was conducted for the purpose of gene cluster stabilization and regulatory plasmid simplification. Additionally, dynamic ranges of the multiple inducible systems were tuned by promoter sequence mutations to achieve diverse scopes for high-resolution gene expression control. The multiple inducible system was successfully employed to precisely control chromoprotein expression, lycopene and poly-3-hydroxybutyrate (PHB) biosynthesis, resulting in colorful bacterial pictures, optimized cell growth, lycopene and PHB accumulation. This study demonstrates a desirable approach for fine-tuning of rational and efficient gene expressions, displaying the significance for metabolic pathway optimization.

Engineering low-salt growth Halomonas Bluephagenesis for cost-effective bioproduction combined with adaptive evolution

Halophilic Halomonas bluephagenesis has been engineered to produce various added-value bio-compounds with reduced costs. However, the salt-stress regulatory mechanism remained unclear. H. bluephagenesis was randomly mutated to obtain low-salt growing mutants via atmospheric and room temperature plasma (ARTP). The resulted H. bluephagenesis TDH4A1B5 was constructed with the chromosomal integration of polyhydroxyalkanoates (PHA) synthesis operon phaCAB and deletion of phaP1 gene encoding PHA synthesis associated protein phasin, forming H. bluephagenesis TDH4A1B5P, which led to increased production of poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxybutyrate-co-4-hydrobutyrate) (P34HB) by over 1.4-fold. H. bluephagenesis TDH4A1B5P also enhanced production of ectoine and threonine by 50% and 77%, respectively. A total 101 genes related to salinity tolerance was identified and verified via comparative genomic analysis among four ARTP mutated H. bluephagenesis strains. Recombinant H. bluephagenesis TDH4A1B5P was further engineered for PHA production utilizing sodium acetate or gluconate as sole carbon source. Over 33% cost reduction of PHA production could be achieved using recombinant H. bluephagenesis TDH4A1B5P. This study successfully developed a low-salt tolerant chassis H. bluephagenesis TDH4A1B5P and revealed salt-stress related genes of halophilic host strains.

Synthetic biology of extremophiles: a new wave of biomanufacturing

Microbial biomanufacturing, powered by the advances of synthetic biology, has attracted growing interest for the production of diverse products. In contrast to conventional microbes, extremophiles have shown better performance for low-cost production owing to their outstanding growth and synthesis capacity under stress conditions, allowing unsterilized fermentation processes. We review increasing numbers of products already manufactured utilizing extremophiles in recent years. In addition, genetic parts, molecular tools, and manipulation approaches for extremophile engineering are also summarized, and challenges and opportunities are predicted for non-conventional chassis. Next-generation industrial biotechnology (NGIB) based on engineered extremophiles promises to simplify biomanufacturing processes and achieve open and continuous fermentation, without sterilization, and utilizing low-cost substrates, making NGIB an attractive green process for sustainable manufacturing.

Advances and trends in microbial production of polyhydroxyalkanoates and their building blocks

With the rapid development of synthetic biology, a variety of biopolymers can be obtained by recombinant microorganisms. Polyhydroxyalkanoates (PHA) is one of the most popular one with promising material properties, such as biodegradability and biocompatibility against the petrol-based plastics. This study reviews the recent studies focusing on the microbial synthesis of PHA, including chassis engineering, pathways engineering for various substrates utilization and PHA monomer synthesis, and PHA synthase modification. In particular, advances in metabolic engineering of dominant workhorses, for example Halomonas, Ralstonia eutropha, Escherichia coli and Pseudomonas, with outstanding PHA accumulation capability, were summarized and discussed, providing a full landscape of diverse PHA biosynthesis. Meanwhile, we also introduced the recent efforts focusing on structural analysis and mutagenesis of PHA synthase, which significantly determines the polymerization activity of varied monomer structures and PHA molecular weight. Besides, perspectives and solutions were thus proposed for achieving scale-up PHA of low cost with customized material property in the coming future.

Effective production of Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by engineered Halomonas bluephagenesis grown on glucose and 1,4-Butanediol

Halomonas bluephagenesis has been engineered to produce flexible copolymers P34HB or poly(3-hydroxybutyrate-co-4-hydroxybutyrate) from glucose and petrol-chemical precursor, γ-butyrolactone. Herein, gene cluster aldD-dhaT was constructed in recombinant H. bluephagenesis for catalyzing 1,4-butanediol (BDO) into 4-hydroxybutyrate, which could grow to 86 g L^-1 dry cell mass (DCM) containing 77 wt% P(3HB-co-14 mol% 4HB) in 7-L bioreactor fed with glucose and bio-based BDO. Furthermore, 4HB monomer ratio could be increased to 16 mol% by engineered H. bluephagenesis TDH4-WZY254 with defected outer-membrane. Upon deletion of 4HB degradation pathway, followed by aldD-dhaT integration, the resulted H. bluephagenesis TDB141ΔAC was grown to 95 g L^-1 DCM containing 79 wt% P(3HB-co-14 mol% 4HB) with a BDO conversion efficiency of 86% under fed-batch fermentation. Notably, 4HB molar ratio can be significantly improved to 21 mol% with negligible effects on cell growth and P34HB synthesis by adding 50% more BDO. This study successfully demonstrated a fully bio-based P34HB effectively produced by H. bluephagenesis.

Engineering an oleic acid-induced system for Halomonas, E. coli and Pseudomonas

Ligand-induced system plays an important role for microbial engineering due to its tunable gene expression control over timings and levels. An oleic acid (OA)-induced system was recently constructed based on protein FadR, a transcriptional regulator involved in fatty acids metabolism, for metabolic control in Escherichia coli. In this study, we constructed a synthetic FadR-based OA-induced systems in Halomonas bluephagenesis by hybridizing the porin promoter core region and FadR-binding operator (fadO). The dynamic control range was optimized over 150-fold, and expression leakage was significantly reduced by tuning FadR expression and positioning fadO, forming a series of OA-induced systems with various expression strengths, respectively. Additionally, ligand orthogonality and cross-species portability were also studied and showed highly linear correlation among Halomonas spp., Escherichia coli and Pseudomonas spp. Finally, OA-induced systems with medium- and small-dynamic control ranges were employed to dynamically control the expression levels of morphology associated gene minCD, and monomer precursor 4-hydroxybutyrate-CoA (4HB-CoA) synthesis pathway for polyhydroxyalkanoates (PHA), respectively, in the presence of oleic acid as an inducer. As a result, over 10 g/L of poly-3-hydroxybutyrate (PHB) accumulated by elongated cell sizes, and 6 g/L of P(3HB-co-9.57 mol% 4HB) were obtained by controlling the dose and induction time of oleic acid only. This study provides a systematic approach for ligand-induced system engineering, and demonstrates an alternative genetic tool for dynamic control of industrial biotechnology.

A Polyhydroxyalkanoates-Based Carrier Platform of Bioactive Substances for Therapeutic Applications

Bioactive substances (BAS), such as small molecule drugs, proteins, RNA, cells, etc., play a vital role in many therapeutic applications, especially in tissue repair and regeneration. However, the therapeutic effect is still a challenge due to the uncontrollable release and instable physico-chemical properties of bioactive components. To address this, many biodegradable carrier systems of micro-nano structures have been rapidly developed based on different biocompatible polymers including polyhydroxyalkanoates (PHA), the microbial synthesized polyesters, to provide load protection and controlled-release of BAS. We herein highlight the developments of PHA-based carrier systems in recent therapeutic studies, and give an overview of its prospective applications in various disease treatments. Specifically, the biosynthesis and material properties of diverse PHA polymers, designs and fabrication of micro- and nano-structure PHA particles, as well as therapeutic studies based on PHA particles, are summarized to give a comprehensive landscape of PHA-based BAS carriers and applications thereof. Moreover, recent efforts focusing on novel-type BAS nano-carriers, the functionalized self-assembled PHA granules in vivo, was discussed in this review, proposing the underlying innovations of designs and fabrications of PHA-based BAS carriers powered by synthetic biology. This review outlines a promising and applicable BAS carrier platform of novelty based on PHA particles for different medical uses.

Tailor-Made Polyhydroxyalkanoates by Reconstructing Pseudomonas Entomophila

Microbial polyhydroxyalkanoates (PHA) containing short- and medium/long-chain-length monomers, abbreviated as SCL-co-MCL/LCL PHAs, generate suitable thermal and mechanical properties. However, SCL-co-MCL/LCL PHAs with carbon chain longer than nine are difficult to synthesize due to the low specificity of PHA synthase PhaC and the lack of either SCL- or MCL/LCL monomer precursor fluxes. This study succeeds in reprogramming a β-oxidation weakened Pseudomonas entomophila containing synthesis pathways of SCL 3-hydroxybutyryl-CoA (3HB) from glucose and MCL/LCL 3-hydroxyalkanoyl-CoA from fatty acids with carbon chain lengths from 9 to 18, respectively, that are polymerized under a low specificity PhaC_61-3 to form P(3HB-co-MCL/LCL 3HA) copolymers. Through rational flux-tuning approaches, the optimized recombinant P. entomophila accumulates 55 wt% poly-3-hydroxybutyrate in 8.4 g L^-1 cell dry weight. Combined with weakened β-oxidation, a series of novel P(3HB-co-MCL/LCL 3HA) copolymers with over 60 wt% PHA in 9 g L^-1 cell dry weight have been synthesized for the first time. P. entomophila has become a high-performing platform to generate tailor-made new SCL-co-MCL/LCL PHAs.

[Preliminary application and efficacy analysis of transumbilical single-incision plus one port robotic total mesorectal excision]

Objective: To investigate the feasibility of transumbilical single-incision plus one port (SIPOP) robotic total mesorectal excision. Methods: Clinical data of a 70-year-old male patient with BMI 22.1 kg/m(2) who successfully underwent transumbilical single-incision plus 1 port robotic total mesorectal resection of upper rectal cancer at the General Surgery Department of Daping Hospital of Army Military Medical University on September 18, 2019 were retrospectively analyzed. Preoperative colonoscopy revealed that the distance of upper rectal cancer to anal edge was 14 cm, and the tumor size was 2.5 cm×1.5 cm×1 cm. Pathological result confirmed rectal moderately differentiated adenocarcinoma. The preoperative abdominal CT showed thickened bowel-wall of upper rectum and the blurred perirectal fat, suggesting tumor infiltration. Results: The operation was successful. There were no conversion to laparotomy or abdominal auxiliary incision, and the mesorectum of the specimen was intact. The operation time was 165 minutes, the blood loss was about 20 ml, and there were no complications such as injury to peripheral organs. Postoperative pathology showed ulcerative moderately differentiated adenocarcinoma of the upper rectum with TNM stage IVA (T4N2b). The postoperative recovery was smooth. Patient ambulated on the 1st day, the catheter was removed on the 7th day, and discharged from the hospital on the 8th day. Conclusion: The transumbilical SIPOP robotic total mesorectal excision is safe, effective and feasible.

Reversible thermal regulation for bifunctional dynamic control of gene expression in Escherichia coli

Genetically programmed circuits allowing bifunctional dynamic regulation of enzyme expression have far-reaching significances for various bio-manufactural purposes. However, building a bio-switch with a post log-phase response and reversibility during scale-up bioprocesses is still a challenge in metabolic engineering due to the lack of robustness. Here, we report a robust thermosensitive bio-switch that enables stringent bidirectional control of gene expression over time and levels in living cells. Based on the bio-switch, we obtain tree ring-like colonies with spatially distributed patterns and transformer cells shifting among spherical-, rod- and fiber-shapes of the engineered Escherichia coli. Moreover, fed-batch fermentations of recombinant E. coli are conducted to obtain ordered assembly of tailor-made biopolymers polyhydroxyalkanoates including diblock- and random-copolymer, composed of 3-hydroxybutyrate and 4-hydroxybutyrate with controllable monomer molar fraction. This study demonstrates the possibility of well-organized, chemosynthesis-like block polymerization on a molecular scale by reprogrammed microbes, exemplifying the versatility of thermo-response control for various practical uses.

Engineering Halomonas bluephagenesis as a chassis for bioproduction from starch

Halomonas bluephagenesis has been successfully engineered to produce multiple products under open unsterile conditions utilizing costly glucose as the carbon source. It would be highly interesting to investigate if H. bluephagenesis, a chassis for the Next Generation Industrial Biotechnology (NGIB), can be reconstructed to become an extracellular hydrolytic enzyme producer replacing traditional enzyme producer Bacillus spp. If successful, cost of bulk hydrolytic enzymes such as amylase and protease, can be significantly reduced due to the contamination resistant and robust growth of H. bluephagenesis. This also allows H. bluephagenesis to be able to grow on low cost substrates such as starch. The modularized secretion machinery was constructed and fine-tuned in H. bluephagenesis using codon-optimized gene encoding α-amylase from Bacillus lichenifomis. Screening of suitable signal peptides and linkers based on super-fold green fluorescence protein (sfGFP) for enhanced expression in H. bluephagenesis resulted in a 7-fold enhancement of sfGFP secretion in the recombinant H. bluephagenesis. When the gene encoding sfGFP was replaced by α-amylase encoding gene, recombinant H. bluephagenesis harboring this amylase secretory system was able to produce poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB), poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), ectoine and L-threonine utilizing starch as the growth substrate, respectively. Recombinant H. bluephagenesis TN04 expressing genes encoding α-amylase and glucosidase on chromosome and plasmid-based systems, respectively, was able to grow on corn starch to approximately 10 g/L cell dry weight containing 51% PHB when grown in shake flasks. H. bluephagenesis was demonstrated to be a chassis for productions of extracellular enzymes and multiple products from low cost corn starch.

[Application value of sedation in colonoscopy]

Objective: To investigate the value of sedation in colonoscopy. Methods: A retrospective cohort study of colonoscopy procedures was performed in our institution. Inclusion criteria: (1) colonoscopy procedures were performed by well-trained gastrointestinal surgeons our institution; (2) medical records were complete and colonoscopy was documented properly by notes, videos, photographs, and traceable pathological reports. Those with incomplete records or performed in other institution were excluded. According to above criteria, clinical data of 49 057 cases of clinic and hospitalization receiving diagnostic or therapeutic colonoscopyat Department of Gastric and Colorectal Surgery, Daping Hospital from July 2007 to February 2017 were collected. Among them, there were 24 638 (50.2%) males and 24 419 females, with mean age of (50.6±14.1) (4 to 98) years. Based on the application of sedation during colonoscopy, patients were divided into the sedation group (39 412 cases, 80.3%) and the non-sedation group (9 645 cases, 19.7%). Clinical characteristics of two groups were compared. Results: The sedation rate increased from 45.6% (369/810) to 94.8% (917/967) from 2007 to 2017. As compared to non-sedation group, a higher proportion of females [51.0% (20 095/39 412) vs. 44.8% (4 324/9 645), χ(2)=117.422, P<0.001] and younger median age (50.0 years vs. 51.0 years, Z=-4.774, P<0.001) were found in the sedation group, whose differences were statistically significant. In all the 9645 cases in the non-sedation group, about 5.5% (534) of them terminated the examination because of unbearable discomfort, including 244 (4.6%) males and 290 (6.7%) females (χ(2)=20.522, P<0.001). Among all the screening population who were ≥50 years old, there was no significant difference in the polyp detection rate (PDR) between the sedation group and the non-sedation group [26.7% (4 737/17 753) vs. 27.4% (1 093/3 984), χ(2)=0.937, P=0.330]. The cecal intubation rate (CIR) in the sedation group was significantly higher than that in the non-sedation group [(85.2% (14 422/16 933) vs. 76.1% (2 803/3 682), χ(2)=180.032, P<0.001]. Five cases in the sedation group developed iatrogenic colonic perforation (ICP), with none in the non-sedation group. Conclusions: The application of sedation in colonoscopy is increasingly popular. Sedation can significantly improve CIR in colonoscopy, while it has no positive influence on PDR. Meanwhile, sedation increases the medical expense and may result in higher ICP rate.

[Clinical analysis of seven cases of H1N1 influenza-associated encephalopathy in children]

Objective: To investigate the clinical manifestations, diagnosis, and treatment of H1N1 influenza A-associated encephalopathy (IAE) in children. Methods: The clinical manifestations, laboratory tests, cranial magnetic resonance imaging (MRI), electroencephalography (EEG) examinations and treatments of seven children with H1N1 IAE hospitalized in Guangzhou Women and Children's Medical Center from December 2018 to January 2019 were retrospectively analyzed. Results: Five of the seven children with H1N1 IAE were female. The age at admission was 4 years and 5 months (range 7 months-9 years). Neurological symptoms occurred simultaneously or early (0-3 days) after the flu-like symptom appeared. The main clinical manifestations of neurological symptoms were seizures (repeated seizures in five cases and status convulsion in two cases, including one case of unexpected fever and repeated seizures in a nine-year old girl) accompanied with altered consciousness (drowsiness in five cases and coma in two cases). Cranial MRI in three cases displayed multifocal lesions, mainly in the bilateral thalamus, brainstem and cerebellar hemisphere. MRI also showed reversible splenial lesion in the corpus callusumin in three cases. EEG tracings were characterized by diffuse slow wave activity in four cases, and status epilepticus was monitored in one case. All the 7 cases were treated with oral oseltamivir. Three cases were treated with pulsed methylprednisolone and intravenous immunoglobulin. One case was treated with intravenous immunoglobulin alone and all the patients received oral oseltamivir. All the patients survived, with three patients had minor neurological sequelae at discharge. Conclusions: The main clinical manifestations of H1N1 IAE are seizures and altered consciousness. Cranial MRI combined with EEG is helpful for early diagnosis. Intravenous immunoglobulin and (or) methylprednisolone should be considered for severe cases.

[Clinical study of S-1 single agent adjuvant chemotherapy in the radical resection of extrahepatic biliary carcinoma]

Objective: To explore the clinical efficacy of S-1 single agent adjuvant chemotherapy for the patients undergoing radical resection of extrahepatic biliary carcinoma. Methods: The clinical data of 108 patients with extrahepatic biliary carcinoma receiving radical resection who were admitted from January 2014 to June 2017 were retrospectively analyzed. There were 62 males(57.4%)and 46 females(42.6%),with a median age of 59 years (range:26 to 79 years),10 cases(9.3%) in stage Ⅱ,85 cases(78.7%) in stage Ⅲ, and 13 cases (12.0%) in stage Ⅳ, 40 cases(37.0%) of hilar cholangiocarcinoma, 8 cases(7.4%) of middle cholangiocarcinoma, 25 cases (23.2%) of distal cholangiocarcinoma, 35 cases(32.4%) of gallbladder carcinoma.After radical resection of extrahepatic biliary carcinoma, 49 patients receiving S-1 single agent chemotherapy and 59 patients receiving non-special treatment were divided into the chemotherapy group and the operation group,respectively. All the dates of the patients were followed up and collected with the overall survival time,tumor-free survival time,1,2 and 3-year survival rate after operation,and the rate of major toxic reaction during chemotherapy of the chemotherapy group. Survival curve was drawn by the Kaplan-Meier method, and survival analysis was done using the Log-rank test. Results: There were no significant differences in the general date of two groups(sex, age, tumor size, tumor site, TNM stages, degree of differentiation). The median overall survival time and the median tumor-free survival time in the chemotherapy group were 27 months and 21 months,respectively,and in the operation group were 21 months and 17 months,respectively. There were differences between the two groups in the overall survival rates(χ(2)=3.967,P<0.05) and the 2 and 3-year survival rate(63.3%,36.6%;41.6%,20.4%;χ(2)=4.510,P<0.05;χ(2)=6.143,P<0.05),but the 1-year overall survival rate (83.4%,79.7%)was not statistically significant(χ(2)=0.286,P>0.05). There were no significant differences in the tumor-free survival time,1,2 and 3-year tumor-free survival rate(77.6%,41.4%,33.1%;62.7%,30.9%,21.2%)between the two groups(χ(2)=0.876,P>0.05;χ(2)=0.252,P>0.05;χ(2)=1.571,P>0.05;χ(2)=3.323,P>0.05,respectively). The main toxic reaction during chemotherapy were dyspepsia(28.6%, 14/49), anemia(26.5%, 13/49), and leukopenia(22.5%, 11/49), all of which were mild. Conclusion: S-1 single agent chemotherapy after radical reseetion of extrahepatic biliary carcinoma could effectly improve the survival of patients and all of the main toxic reaction during chemotherapy were mild.

[Kindlin-2 promotes gallbladder cancer metastasis and invasion by inducing epithelial-mesenchymal transition]

Objective: To investigate the effects of Kindlin-2 on malignant phenotypes of human gallbladder cancer cells and discuss the mechanisms. Methods: The expression level of Kindlin-2 in 30 cases of gallbladder cancer tissues and adjacent non-tumoral tissues collected from the First Affiliated Hospital of Zhengzhou University between September 2012 and May 2013 was assessed by real-time PCR and immunohistochemistry.Lentivirus-mediated Kindlin-2 overexpression was used in gallbladder cancer cell lines GBC-SD and SGC-996.Transwell assay and adhesion assay were investigated to explore the functional role of Kindlin-2 on gallbladder cancer cells.Western Blot was used to test the protein change of epithelial-mesenchymal transition(EMT) characteristics. The t-test was used to analyzed results. Results: The RNA and protein levels of Kindlin-2 in gallbladder cancer tissues were higher than in the non-tumoral tissues (t=4.372, P=0.001; t=7.477, P=0.000). The expression level of Kindlin-2 in gallbladder cancer tissues was correlated with Nevin stage(χ(2)=5.932, P=0.035). Compared with control groups, the cell-matrix adhesion ability of GBC-SD and SGC-996 with Kindlin-2 overexpression was obviously promoted(1.66±0.03 vs. 1.07±0.22, t=2.710, P=0.041; 2.66±0.24 vs. 1.03±0.02, t=6.610, P=0.020). The number of GBC-SD and SGC-996 cells with Kindlin-2 overexpression passing through the Transwell chamber matrix increased significantly compared with the control groups(116.1±13.9 vs. 54.7±8.4, t=3.781, P=0.019; 136.3±7.5 vs. 64.3±6.4, t=7.302, P=0.002). The wound healing rate of GBC-SD with Kindlin-2 overexpression at 12-hour and 24-hour was higher than that of the group ((42.9±2.2)% vs. (29.7±1.7)%, t=4.690, P=0.009; (65.0±2.4)% vs.(40.4±2.0)%, t=7.945, P=0.001). The wound healing rate of SGC-996 with Kindlin-2 overexpression at 12-hour and 24-hour was also higher than that of the group ((32.9±1.3)% vs. (24.1±1.5)%, t=4.518, P=0.011; (51.3±1.1)% vs. (39.2±1.1)%, t=8.001, P=0.001). The characteristics of EMT were induced in gallbladder cancer cells with Kindlin-2 overexpression, including the up-regulation of N-cadherin, Vemintin and the down-regulation of E-cadherin. Conclusion: The expression of Kindlin-2 is up-regulated in gallbladder cancer tissues and Kindlin-2 promoted the malignant phenotypes of gallbladder cancer cells partially by epithelial-mesenchymal transition.

Promoter Engineering for Enhanced P(3HB- co-4HB) Production by Halomonas bluephagenesis

Promoters for the expression of heterologous genes in Halomonas bluephagenesis are quite limited, and many heterologous promoters function abnormally in this strain. P_porin, a promoter of the strongest expressed protein porin in H. bluephagenesis, is one of the few promoters available for heterologous expression in H. bluephagenesis, yet it has a fixed transcriptional activity that cannot be tuned. A stable promoter library with a wide range of activities is urgently needed. This study reports an approach to construct a promoter library based on the P_porin core region, namely, from the -35 box to the transcription start site, a spacer and an insulator. Saturation mutagenesis was conducted inside the promoter core region to significantly increase the diversity within the promoter library. The promoter library worked in both E. coli and H. bluephagenesis, covering a wide range of relative transcriptional strengths from 40 to 140 000. The library is therefore suitable for the transcription of many different heterologous genes, serving as a platform for protein expression and fine-tuned metabolic engineering of H. bluephagenesis TD01 and its derivative strains. H. bluephagenesis strains harboring the orfZ gene encoding 4HB-CoA transferase driven by selected promoters from the library were constructed, the best one produced over 100 g/L cell dry weight containing 80% poly(3-hydroxybutyrate- co-11 mol % 4-hydroxybutyrate) with a productivity of 1.59 g/L/h after 50 h growth under nonsterile fed-batch conditions. This strain was found the best for P(3HB- co-4HB) production in the laboratory scale.

[Clinical analysis of two cases of imported children Zika virus infection in China]

OBJECTIVE

To analyze the clinical characteristics, outcome and diagnosis of two cases of imported children Zika virus infection in China.

METHOD

A retrospective analysis was performed on clinical characteristics, treatment and outcome of two cases of imported children with Zika virus infection in February 2016 in Enping People's Hospital of Guangdong.

RESULT

Two cases of children with imported Zika virus infection resided in an affected area of Venezuela, 8-year-old girl and her 6 year-old brother. The main findings on physical examination included the following manifestations: fever, rash, and conjunctivitis. The rash was first limited to the abdomen, but extended to the torso, neck and face, and faded after 3-4 d. The total number of white blood cells was not high and liver function was normal. The diagnosis of two cases of Zika virus infection was confirmed by the expert group of Guangdong Provincial Center for Disease Control and Prevention, according to the epidemiological history, clinical manifestations and Zika virus nucleic acid detection results.Treatment of Zika virus infection involves supportive care. Two Zika virus infection children had a relatively benign outcome.

CONCLUSION

At present, Zika virus infection in children is an imported disease in China. No specific therapy is available for this disease. Information on long-term outcomes among infants and children with Zika virus disease is limited, routine pediatric care is advised for these infants and children.

Abstract P5-16-03: Influence of radiotherapy boost in patients with ductal carcinoma in situ of breast cancer: A multicenter, retrospective study in Korea (KROG 11-04)

Purpose

We aimed to estimate the effect of boost radiotherapy on local relapse-free survival (LRFS) in patients with ductal carcinoma in situ (DCIS) of breast cancer.

Material and Methods

We included patients from 8 institutions who met the following inclusion criteria: having tumor status Tis, age 18 years or older at diagnosis, having had breast conserving surgery (BCS) and radiotherapy within 12 weeks after surgery. From January 1995 through December 2006, 594 patients with DCIS breast cancer treated with BCS and radiotherapy were analyzed retrospectively in a study by Korean Radiation Oncology Group (KROG). All patients received whole breast radiotherapy (median 5040 cGy) after BCS. Among them, 154 patients (25.9%) received boost radiotherapy (median 1000 cGy) after whole breast radiotherapy. Patients who received boost radiotherapy had higher tumor grade, more comedo pattern and less papillary pattern. Other patients’ or tumor characteristics were not statistically different between boost group and no boost group.

Results

After median follow-up of 89 months (range 26-200), 5 year and 10 year LRFS was 98.3% and 95.6%. There was no statistically significant difference of LRFS between boost group and no boost group.

Local relapse free survival according to boost radiotherpay 5-year LRFS* (%)10-year LRFS (%)p-value**Boost group98.196.20.626No boost group98.495.4 *Local relapse free survival, **Log-rank test

Nineteen (3.2%) patients had ipsilateral breast recurrences, of whom, 12 patients had invasive breast cancer and 7 had DCIS. Positive HER2 receptor was associated with higher invasive recurrences.

Ipsilateral breast recurrences according to HER2 receptor TotalHER2 receptor (+)HER2 receptor (-)p-value*Ipsilateral breast121110.017Invasive8800.023DCIS**4310.642*Fisher's exact test, **Ductal carcinoma in situ

Nine (1.5%) patients developed contralateral breast cancer, of whom, 6 were invasive breast cancer and 3 were DCIS. On multivariate analysis, only margin status was a significant prognostic factor for LRFS.

Conclusion

In the absence of randomized trials, boost radiotherapy could not decrease local recurrence in DCIS of breast cancer after BCS and radiotherapy. In addition, patients with positive HER2 receptor would need further treatment like target agent, trastuzumab. NSABP B-43 study result would answer the question.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P5-16-03.

Huperzine A ameliorates the impaired memory of aged rat in the Morris water maze performance

AIM

To determine the memory-improving properties of huperzine A in aged rats with memory impairments naturally occurring or induced by scopolamine.

METHODS

Morris water maze was used to investigate the effects of huperzine A on the acquisition and memory impairments.

RESULTS

During 7-day acquisition trials, aged rats took longer latency to find the platform. Huperzine A (0.1-0.2 mg/kg, s.c.) could significantly reduce the latency. In the probe trials on the eighth day, huperzine A (0.1, 0.2 and 0.4 mg/kg, s.c.) significantly increased the time in the quadrant where plateform had disappeared in aged rats. In the acute experiment, scopolamine (0.1 mg/kg, i.p.) significantly impaired spatial memory in the trained aged rats. Huperzine A (0.4 mg/kg, s.c.) significantly reversed the memory deficits induced by scopolamine.

CONCLUSION

Huperzine A ameliorates the impaired memory naturally occurring or induced by scopolamine in aged rats.

Improving effects of huperzine A on abnormal lipid peroxidation and superoxide dismutase in aged rats

AIM

To study the effects of huperzine A on lipid peroxidation and superoxide dismutase (SOD) in hippocampus, cerebral cortex, and serum of aged rats.

METHODS

The level of lipid peroxidation was determined by thiobarbituric acid reactive substance method and represented as the concentration of malondialdehyde (MDA) in wet tissue. The activity of SOD was determined by xanthine-xanthine oxidase method and represented as the nitrite unit per gram protein in wet tissue.

RESULTS

The levels of MDA and the manganese-SOD (Mn-SOD) activities in hippocampus, cerebral cortex, and serum of aged male rats were 2.3-2.8 times and 1.8-2.8 times, respectively, higher than those of adult male rats. Huperzine A (0.05 mg/kg, ig) lowered markedly the levels of MDA and the activities of Mn-SOD in aged male rats following 7-14 d consecutive administrations. The MDA levels in hippocampus, cerebral cortex, and serum decreased 44.7-52.8% (7 d) and 52.6-54.7% (14 d). The Mn-SOD activities in hippocampus, cerebral cortex, and serum lowered 25.0 -57.6% (7 d) and 56.0-74.2% (14 d). In adult rats, no marked change was found after 7-14 d consecutive administrations of huperzine A at a dose of 0.05 mg/kg.

CONCLUSION

Huperzine A improved the abnormal free radicals in aged rats.

Improving effects of huperzine A on spatial working memory in aged monkeys and young adult monkeys with experimental cognitive impairment

Our previous studies demonstrated that huperzine A, a reversible and selective acetylcholinesterase inhibitor, exerts beneficial effects on memory deficits in various rodent models of amnesia. To extend the antiamnesic action of huperzine A to nonhuman primates, huperzine A was evaluated for its ability to reverse the deficits in spatial memory produced by scopolamine in young adult monkeys or those that are naturally occurring in aged monkeys using a delayed-response task. Scopolamine, a muscarinic receptor antagonist, dose dependently impaired performance with the highest dose (0.03 mg/kg, i.m.) producing a significant reduction in choice accuracy in young adult monkeys. The delayed performance changed from an average of 26.8/30 trials correct on saline control to an average of 20.2/30 trials correct after scopolamine administration. Huperzine A (0.01-0. 1 mg/kg, i.m.) significantly reversed deficits induced by scopolamine in young adult monkeys on a delayed-response task; performance after an optimal dose (0.1 mg/kg) averaged 25.0/30 correct. In four aged monkeys, huperzine A (0.001-0.01 mg/kg, i.m.) significantly increased choice accuracy from 20.5/30 on saline control to 25.2/30 at the optimal dose (0.001 mg/kg for two monkeys and 0.01 mg/kg for the other two monkeys). The beneficial effects of huperzine A on delayed-response performance were long lasting; monkeys remained improved for about 24 h after a single injection of huperzine A. This study extended the findings that huperzine A improves the mnemonic performance requiring working memory in monkeys, and suggests that huperzine A may be a promising agent for clinical therapy of cognitive impairments in patients with Alzheimer's disease.