Three new discovery effector proteins from Candidatus Liberibacter asiaticus psy62 inhibit plant defense through interaction with AtCAT3 and AtGAPA.

KEY MESSAGE: We identify three SDEs that inhibiting host defence from Candidatus Liberibacter asiaticus psy62, which is an important supplement to the pathogenesis of HLB. Candidatus Liberibacter asiaticus (CLas) is the main pathogen of citrus Huanglongbing (HLB). 38 new possible sec-dependent effectors (SDEs) of CLas psy62 were predicted by updated predictor SignalP 5.0, which 12 new SDEs were found using alkaline phosphate assay. Among them, SDE4310, SDE4435 and SDE4955 inhibited hypersensitivity reactions (HR) in Arabidopsis thaliana (Arabidopsis, At) and Nicotiana benthamiana leaves induced by pathogens, which lead to a decrease in cell death and reactive oxygen species (ROS) accumulation. And the expression levels of SDE4310, SDE4435, and SDE4955 genes elevated significantly in mild symptom citrus leaves. When SDE4310, SDE4435 and SDE4955 were overexpressed in Arabidopsis, HR pathway key genes pathogenesis-related 2 (PR2), PR5, nonexpressor of pathogenesis-related 1 (NPR1) and isochorismate synthase 1 (ICS1) expression significantly decreased and the growth of pathogen was greatly increased relative to control with Pst DC3000/AvrRps4 treatment. Our findings also indicated that SDE4310, SDE4435 and SDE4955 interacted with AtCAT3 (catalase 3) and AtGAPA (glyceraldehyde-3-phosphate dehydrogenase A). In conclusion, our results suggest that SDE4310, SDE4435 and SDE4955 are CLas psy62 effector proteins that may have redundant functions. They inhibit ROS burst and cell death by interacting with AtCAT3 and AtGAPA to negatively regulate host defense.

Salicylic acid accelerates carbon starvation-induced leaf senescence in Arabidopsis thaliana by inhibiting autophagy through Nonexpressor of pathogenesis-related genes 1.

In plants, leaf senescence is regulated by several factors, including age and carbon starvation. The molecular mechanism of age-regulated developmental leaf senescence differs from that of carbon starvation-induced senescence. Salicylic acid (SA) and Nonexpressor of pathogenesis-related genes 1 (NPR1) play important roles in promoting developmental leaf senescence. However, the relationship between SA signaling and carbon starvation-induced leaf senescence is not currently well understood. Here, we used Arabidopsis thaliana as material and found that carbon starvation-induced leaf senescence was accelerated in the SA dihydroxylase mutants s3hs5h compared to the Columbia ecotype (Col). Exogenous SA treatment significantly promoted carbon starvation-induced leaf senescence, especially in NPR1-GFP. Increasing the endogenous SA and overexpression of NPR1 inhibited carbon starvation-induced autophagy. However, mutation of NPR1 delayed carbon starvation-induced leaf senescence, increased autophagosome production and accelerated autophagic degradation of the Neighbor of BRCA1 gene 1 (NBR1). In conclusion, SA promotes carbon starvation-induced leaf senescence by inhibiting autophagy via NPR1.

Gold nanoparticles (AuNPs) can rapidly deliver artificial microRNA (AmiRNA)-ATG6 to silence ATG6 expression in Arabidopsis.

KEY MESSAGE: We establish a fast and efficient transient silencing system that facilitates functional studies of some genes, whose knockout leads to plant lethality. In plants, the generation of loss-of-function mutants is crucial for studying gene function. Artificial microRNA (AmiRNA) technology is a more targeted and effective tool for gene silencing. Gold nanoparticles (AuNPs) can bind nucleic acids and deliver them into animal cells. Here, AuNPs are used in combination with AmiRNA technology in plants. We found that AmiRNA-autophagy-related proteins (ATG6) can be delivered to cells by AuNPs to achieve the effect of ATG6 silencing. It is worth noting that on the 10th day there is still a silencing effect. Similar to the atg5 lines, silencing of ATG6 significantly reduced plant resistance to Pseudomonas syringae pv.maculicola (Psm) ES4326/AvrRpt2. Interestingly, ATG6 silencing and ATG5 mutation in NPR1-GFP (nonexpressor of pathogenesis-related genes) lines significantly reduced plant resistance to Psm ES4326/AvrRpt2, suggesting that autophagy is also involved in NPR1-regulated plant immune responses. In summary, we establish a fast and efficient transient silencing system that facilitates functional studies of some genes, whose knockout leads to plant lethality.

Expression of PEI-coated gold nanoparticles carrying exogenous gene in periwinkle mesophyll cells and its practice in huanglongbing research.

Huanglongbing (HLB) is a devastating disease of citrus, which is mostly caused by Candidatus Liberibacter asiaticus (CLas). To realize the specific application of nano-transgenic technology in HLB, AuNPs-PEI (Gold Nanoparticles-Polyethylenimine) was used to carry foreign genes into the leaves of periwinkle (Catharanthus roseus) by infiltration. Here, we demonstrated that NPR1-GFP protein expression was observed from the 12th hour to the 10th day after infiltrating AuNPs-PEI-pNPR1 (Arabidopsis thaliana nonexpressor of pathogenesis-related gene 1)-GFP. Fluorescence of mCherry was observed 6 h after AuNPs-PEI-pNLS (nuclear localization signal sequence)-mCherry infiltration and fluorescence of FAM was observed in the nucleus 4 h after AuNPs-PEI-FAM-siRNA NPR1 infiltration. In addition, NPR1-GFP expression in CLas-infected periwinkle leaves was significantly higher than that in healthy periwinkle leaves after infiltration. Our work confirmed that the expression of exogenous NPR1-GFP could reduce the CLas titers by promoting the expression of PR (pathogenesis related) genes and ICS (isochorismate synthase) gene.

Efficient Transient Expression of Plasmid DNA Using Poly (2-(N,N-Dimethylamino) Ethyl Methacrylate) in Plant Cells.

Nanomaterials have been widely studied for their potential to become the new generation of nanocarriers in gene transfection, yet it remains still difficult to apply them efficiently and succinctly to plant cells. Poly (2-(N,N-dimethylamino) ethyl methacrylate) (PDMAEMA), which possesses temperature and pH dual-sensitivity, has largely been applied in animal cells, but it is rarely involved in plant cells. As a proof of concept, PDMAEMA as a gene carrier is incubated with plasmid GFP (pGFP) to explore its transfection ability in plants, and cationic polymer polyethylenimine (PEI) is used as a control. pGFP was efficiently condensed into the nanostructure by electrostatic interactions at an N/P (amino group from cationic polymers/phosphate group from plasmid DNA (pDNA)) ratio of 15; after complexation into nanocarriers, pGFP was protected from endonuclease degradation according to the DNase I digestion assay. After incubation with protoplasts and leaves, GFP was observed with confocal microscopy in plant cells. Western blot experiments confirmed GFP expression at the protein level. Toxicity assay showed PDMAEMA had a lower toxicity than PEI. These results showed that transient expression of pGFP was readily achieved in Arabidopsis thaliana and Nicotiana benthamiana. Notably, PDMAEMA showed lower cytotoxicity than PEI upon incubation with Nicotiana benthamiana leaves. PDMAEMA exhibited great potency for DNA delivery in plant cells. This work provides us with new ideas of more concise and more effective methods for plant transformation.

Research Progress of ATGs Involved in Plant Immunity and NPR1 Metabolism.

Autophagy is an important pathway of degrading excess and abnormal proteins and organelles through their engulfment into autophagosomes that subsequently fuse with the vacuole. Autophagy-related genes (ATGs) are essential for the formation of autophagosomes. To date, about 35 ATGs have been identified in Arabidopsis, which are involved in the occurrence and regulation of autophagy. Among these, 17 proteins are related to resistance against plant pathogens. The transcription coactivator non-expressor of pathogenesis-related genes 1 (NPR1) is involved in innate immunity and acquired resistance in plants, which regulates most salicylic acid (SA)-responsive genes. This paper mainly summarizes the role of ATGs and NPR1 in plant immunity and the advancement of research on ATGs in NPR1 metabolism, providing a new idea for exploring the relationship between ATGs and NPR1.

Transcriptome profiling reveals histone deacetylase 1 gene overexpression improves flavonoid, isoflavonoid, and phenylpropanoid metabolism in Arachis hypogaea hairy roots.

BACKGROUND: The peanut (Arachis hypogaea) is a crop plant of high economic importance, but the epigenetic regulation of its root growth and development has not received sufficient attention. Research on Arabidopsis thaliana has shown that histone deacetylases (HDACs) are involved in cell growth, cell differentiation, and stress response. Few studies have focused on the role of HDACs in the root development of other plants, particularly crop plants. In earlier studies, we found large accumulations of A. hypogaea histone deacetylase 1 (AhHDA1) mRNA in peanut roots. However, we did not explore the role of AhHDA1 in peanut root development. METHODS: In this paper, we investigated the role of the peanut AhHDA1 gene and focused on the effect of altered AhHDA1 expression in hairy roots at both the phenotypic and transcriptional levels. We analyzed the transformation of A. hypogaea hairy roots using Agrobacterium rhizogenes and RNA sequencing to identify differentially expressed genes that were assigned to specific metabolic pathways. Transgenic hairy roots were used as experimental material to analyze the downstream genes expression and histone acetylation levels. To thoroughly understand AhHDA1 function, we also simultaneously screened the AhHDA1-interacting proteins using a yeast two-hybrid system. RESULTS: AhHDA1-overexpressing hairy roots were growth-retarded after 20 d in vitro cultivation, and they had a greater accumulation of superoxide anions and hydrogen peroxide than the control and RNAi groups. AhHDA1 overexpression in hairy roots accelerated flux through various secondary synthetic metabolic pathways, as well as inhibited the primary metabolism process. AhHDA1 overexpression also caused a significant upregulation of genes encoding the critical enzyme chalcone synthase (Araip.B8TJ0, CHS) in the flavonoid biosynthesis pathway, hydroxyisoflavanone synthase (Araip.0P3RJ) in the isoflavonoid biosynthesis pathway, and caffeoyl-CoA O-methyltransferase (Aradu.M62BY, CCoAOMT) in the phenylpropanoid biosynthesis pathway. In contrast, ferredoxin 1 (Araip.327XS), the polypeptide of the oxygen-evolving complex of photosystem II (Araip.N6ZTJ), and ribulose bisphosphate carboxylase (Aradu.5IY98) in the photosynthetic pathway were significantly downregulated by AhHDA1 overexpression. The expression levels of these genes had a positive correlation with histone acetylation levels. CONCLUSION: Our results revealed that the relationship between altered gene metabolism activities and AhHDA1 overexpression was mainly reflected in flavonoid, isoflavonoid, and phenylpropanoid metabolism. AhHDA1 overexpression retarded the growth of transgenic hairy roots and may be associated with cell metabolism status. Future studies should focus on the function of AhHDA1-interacting proteins and their effect on root development.

ATG4 Mediated Psm ES4326/AvrRpt2-Induced Autophagy Dependent on Salicylic Acid in Arabidopsis Thaliana.

Psm ES4326/AvrRpt2 (AvrRpt2) was widely used as the reaction system of hypersensitive response (HR) in Arabidopsis. The study showed that in npr1 (GFP-ATG8a), AvrRpt2 was more effective at inducing the production of autophagosome and autophagy flux than that in GFP-ATG8a. The mRNA expression of ATG1, ATG6 and ATG8a were more in npr1 during the early HR. Based on transcriptome data analysis, enhanced disease susceptibility 1 (EDS1) was up-regulated in wild-type (WT) but was not induced in atg4a4b (ATG4 deletion mutant) during AvrRpt2 infection. Compared with WT, atg4a4b had higher expression of salicylic acid glucosyltransferase 1 (SGT1) and isochorismate synthase 1 (ICS1); but less salicylic acid (SA) in normal condition and the same level of free SA during AvrRpt2 infection. These results suggested that the consumption of free SA should be occurred in atg4a4b. AvrRpt2 may trigger the activation of Toll/Interleukin-1 receptor (TIR)-nucleotide binding site (NB)-leucine rich repeat (LRR)-TIR-NB-LRR-to induce autophagy via EDS1, which was inhibited by nonexpressor of PR genes 1 (NPR1). Moreover, high expression of NPR3 in atg4a4b may accelerate the degradation of NPR1 during AvrRpt2 infection.

Fosaprepitant versus aprepitant in the prevention of chemotherapy-induced nausea and vomiting in patients receiving cisplatin-based chemotherapy: a multicenter, randomized, double-blind, double-simulated, positive-controlled phase III trial.

BACKGROUND: To establish the role of antiemetic therapy with neurokinin-1 (NK-1) receptor antagonists (RAs) in Chinese patients associated with cisplatin-base chemotherapy regimens, this study evaluated the efficacy and safety of single-dose intravenous fosaprepitant-based triple antiemetic regimen to a 3-day orally aprepitant-based antiemetic triplet schedule for the prevention of chemotherapy-induced nausea and vomiting (CINV). METHODS: A randomized, double-blind, positive-control design was used to test the noninferiority of fosaprepitant towards aprepitant. Patients receiving cisplatin-base (≥50 mg/m2) chemotherapy were administrated palonosetron and dexamethasone with a single-dose fosaprepitant (150 mg on day 1) or a standard aprepitant regimen (125 mg on day 1, 80 mg on day 2 and day 3). The primary endpoint was complete response (CR) during overall phase (OP). Secondary endpoints include CR during acute phase (AP) and delayed phase (DP), no vomiting and no significant nausea during OP, AP and DP. Accrual of 324 patients per treatment arm was planned to confirm noninferiority with expected CR of 75% and noninferiority margin of minus 10 percentage points. RESULTS: A total of 648 patients were randomly assigned, and 644 were evaluable for efficacy and safety. Antiemetic efficacy of CR during the OP with fosaprepitant and aprepitant was equivalent (71.96% versus 69.35%, P=0.4894). And a between-group difference of 2.61 percentage points was finally achieved (95% CI, -4.42 to 9.64) within predefined bounds for noninferiority (primary end point achieved). Both regimens were well tolerated and commonly reported adverse events (≥1%) were similar between these two group. CONCLUSIONS: Single-dose intravenous fosaprepitant (150 mg) combined with palonosetron and dexamethasone was well tolerated and demonstrated noninferior control of CINV to aprepitant-based triple regimen in Chinese patients treating with cisplatin-base chemotherapy.

AhHDA1-mediated AhGLK1 promoted chlorophyll synthesis and photosynthesis regulates recovery growth of peanut leaves after water stress.

Peanut (Arachis hypogaea L.) is an important crop that is adversely affected by drought. Post-drought growth is essential for improving peanut productivity and quality. Previous studies demonstrated that AhGLK1 (Arachis hypogaea L. Golden2-like 1) activates the expression of AhPORA to stimulate chlorophyll biosynthesis, and that AhGLK1 physically interacts with AhHDA1 (Arachis hypogaea L. histone deacetylase 1). However, the roles of the AhGLK1/AhHDA1 interaction in post-drought recovery remain to be elucidated. Herein, we report that AhHDA1 binds to AhGLK1 promoter and alters histone deacetylation levels to inhibit AhGLK1 expression. RNA-seq confirms that chlorophyll synthesis and photosynthesis-related genes are induced in AhGLK1-overexpressing, but reduced in AhGLK1 RNAi hairy roots. Furthermore, ChIP-seq shows that AhCAB (Arachis hypogaea L. chlorophyll A/B binding protein) is a target of both AhHDA1 and AhGLK1. Transactivation assays reveal that AhGLK1 activates AhCAB expression, while AhHDA1 inhibits the effect of AhGLK1 on AhCAB and AhPORA transcription. ChIP-qPCR shows that AhHDA1 and AhGLK1 bind to the promoters of AhCAB and AhPORA to regulate their expression during water stress and recovery. We propose that AhHDA1 and AhGLK1 consist of an ON/OFF switch for AhCAB and AhPORA expression during water stress and recovery. AhGLK1 activates, whereas AhHDA1 suppresses the expression of AhCAB and AhPORA.

Construction of gold-siRNA NPR1 nanoparticles for effective and quick silencing of NPR1 in Arabidopsis thaliana.

In recent years, gold nanoparticles (AuNPs) have been widely used as gene silencing agents and therapeutics for treatment of cancers due to their high transfection efficiency and lack of cytotoxicity, but their roles in gene silencing in plants have not yet been reported. Here, we report synthesis of AuNPs-branched polyethylenimine and its integration with the small interfering RNAs (siRNA) of NPR1 to form a AuNPs-siRNA NPR1 compound. Our results showed that AuNPs-siRNA NPR1 was capable of infiltrating into Arabidopsis cells. AuNPs-siRNA NPR1 silenced 80% of the NPR1 gene in Arabidopsis. Bacteriostatic and ion leakage experiments suggest that the NPR1 gene in Arabidopsis leaves was silenced by AuNPs-siRNA NPR1 . In Columbia-0 plants, compared with the control group treated with buffer solution, the AuNPs-siRNA NPR1 treatment significantly increased the number of colonies and cell death, and the leaves turned yellow, similar to the phenotype of the npr1 leaves. These results indicated this AuNPs-siRNA NPR1 silencing the NPR1 gene method is simple, effective and quick (3 days), and a powerful tool to study gene functions in plants.

Expression of AhDREB1, an AP2/ERF Transcription Factor Gene from Peanut, Is Affected by Histone Acetylation and Increases Abscisic Acid Sensitivity and Tolerance to Osmotic Stress in Arabidopsis.

Drought stress negatively affects plant growth and development. An increasing number of reports have revealed the involvement of APETALA2/Ethylene Responsive Factor (AP2/ERF) transcription factors (TFs) in biotic and abiotic stress regulation in plants. However, research on these TFs in the peanut plant (Arachis hypogaea) has been limited. Here, we isolated a full-length coding sequence (CDS) of the AP2/ERF family gene AhDREB1 from the peanut plant and showed that its expression was induced by Polyethylene Glycol (PEG) 6000 and exogenous abscisic acid (ABA) treatment. When overexpressed in Arabidopsis, AhDREB1 increased both ABA levels and ABA sensitivity, affected the ABA signaling pathway and increased the expression of downstream drought stress-related genes RD29A, P5CS1, P5CS2 and NCED1. These results demonstrate that AhDREB1 can improve tolerance to drought via the ABA-dependent pathway in Arabidopsis. In the peanut plant, the specific histone deacetylases (HDACs) inhibitor trichostatin A (TSA) promotes AhDREB1 transcription and the enrichment level of H3ac was increased in regions of the AhDREB1 gene during TSA and PEG treatment. In summary, histone acetylation can affect the expression of AhDREB1 under osmotic stress conditions, thereby improving plant drought resistance.

AhGLK1 affects chlorophyll biosynthesis and photosynthesis in peanut leaves during recovery from drought.

Peanut is an important edible oil crop plant whose quality and yield are greatly affected by drought. The process and molecular mechanisms of recovery from drought are also critical to its productivity, but are currently poorly characterized. Here, we investigate the involvement of peanut AhGLK1 in recovery from drought, and in particular its relationship with AhPORA, which encodes a key enzyme in chlorophyll biosynthesis. We found that chlorophyll content, chlorophyll fluorescence, AhPORA protein level and genes related to chlorophyll biosynthesis and photosynthesis declined markedly under drought conditions, but all increased during recovery. Consistent with this, AhGLK1 expression decreased during water stress and increased when the stress was removed. When AhGLK1 was transformed into Arabidopsis glk1glk2 mutant, it increased the survival rate of the mutant during recovery from drought and fully rescued the mutant's pale-green phenotype. In addition, chlorophyll content and fluorescence, and the expression of genes related to chlorophyll biosynthesis and photosynthesis, were all increased. Bioinformatics analysis and experimental evidence suggested that AhGLK1 augments the expression of AhPORA by binding to its promoter. Our findings confirm that AhGLK1 plays a role as a transcription factor that upregulates expression of AhPORA during post-drought recovery, thereby stimulating chlorophyll biosynthesis and photosynthesis.

Advantages with prophylactic PEG-rhG-CSF versus rhG-CSF in breast cancer patients receiving multiple cycles of myelosuppressive chemotherapy: an open-label, randomized, multicenter phase III study.

BACKGROUND: PEG-rhG-CSF reduces neutropenia and improves chemotherapy safety. In China's registration trial (CFDA: 2006L01305), we assessed its efficacy and safety against rhG-CSF, and prospectively explored its value over multiple cycles of chemotherapy. METHODS: In this open-label, randomized, multicenter phase 3 study, breast cancer patients (n = 569) were randomized to receive PEG-rhG-CSF 100 µg/kg, PEG-rhG-CSF 6 mg, or rhG-CSF 5 µg/kg/d after chemotherapy. The primary endpoints were the incidence and duration of grade 3/4 neutropenia during cycle 1. Secondary endpoints included the incidence and duration of grade 3/4 neutropenia during cycles 2-4, the incidence of febrile neutropenia, and the safety. RESULTS: A once-per-cycle PEG-rhG-CSF at either 100 µg/kg or 6 mg was not different from daily injections of rhG-CSF for either incidence or duration of grade 3/4 neutropenia. Interestingly, a substantial difference was noted during cycle 2, and the difference became bigger over cycles 3-4, reaching a statistical significance at cycle 4 in either incidence (P = 0.0309) or duration (P = 0.0289) favoring PEG-rhG-CSF. A significant trend toward a lower incidence of all-grade adverse events was noted at 129 (68.98%), 142 (75.53%), and 160 (82.47%) in the PEG-rhG-CSF 100 µg/kg and 6 mg and rhG-CSF groups, respectively (P = 0.0085). The corresponding incidence of grade 3/4 drug-related adverse events was 2/187 (1.07%), 1/188 (0.53%), and 8/194 (4.12%), respectively (P = 0.0477). Additionally, PFS in metastatic patients preferred PEG-rhG-CSF to rhG-CSF despite no significance observed by Kaplan-Meier analysis (n = 49, P = 0.153). CONCLUSIONS: PEG-rhG-CSF is a more convenient and safe formulation and a more effective prophylactic measure in breast cancer patients receiving multiple cycles of chemotherapy.

[A multicenter, randomized, controlled, phase â ¢ clinical study of PEG-rhG-CSF for preventing chemotherapy-induced neutropenia in patients with breast cancer and non-small cell lung cancer].

OBJECTIVE: To explore the safety and efficacy of pegylated recombinant human granulocyte colony-stimulating factor (PEG-rhG-CSF) in preventing chemotherapy-induced neutropenia in patients with breast cancer and non-small cell lung cancer (NSCLC), and to provide the basis for clinical application. METHODS: According to the principle of open-label, randomized, parallel-group controlled clinical trial, all patients were randomized by 1∶1∶1 into three groups to receive PEG-rhG-CSF 100 µg/kg, PEG-rhG-CSF 6 mg, or rhG-CSF 5 µg/kg, respectively. The patients with breast cancer received two chemotherapy cycles, and the NSCLC patients received 1-2 cycles of chemotherapy according to their condition. All patients were treated with the combination chemotherapy of TAC (docetaxel+ epirubicin+ cyclophosphamide) or TA (docetaxel+ epirubicin), or the chemotherapy of docetaxel combined with carboplatin, with a 21 day cycle. RESULTS: The duration of grade 3-4 neutropenia in the PEG-rhG-CSF 100 µg/kg and PEG-rhG-CSF 6 mg groups were similar with that in the rhG-CSF 5 µg/kg group (P>0.05 for all). The incidence rate of grade 3-4 neutropenia in the PEG-rhG-CSF 100 µg/kg group, PEG-rhG-CSF 6 mg group, and G-CSF 5 µg/kg group were 69.7%, 68.4%, and 69.5%, respectively, with a non-significant difference among the three groups (P=0.963). The incidence rate of febrile neutropenia in the PEG-rhG-CSF 100 µg/kg group, PEG-rhG-CSF 6 mg group and G-CSF 5 µg/kg group were 6.1%, 6.4%, and 5.5%, respectively, showing no significant difference among them (P=0.935). The incidence rate of adverse events in the PEG-rhG-CSF 100 µg/kg group, PEG-rhG-CSF 6 mg group and G-CSF 5 µg / kg group were 6.7%, 4.1%, and 5.5%, respectively, showing a non-significant difference among them (P=0.581). CONCLUSIONS: In patients with breast cancer and non-small cell lung cancer (NSCLC) undergoing TAC/TA chemotherapy, a single 100 µg/kg injection or a single fixed 6 mg dose of PEG-rhG-CSF at 48 hours after chemotherapy show definite therapeutic effect with a low incidence of adverse events and mild adverse reactions. Compared with the continuous daily injection of rhG-CSF 5 µg/kg/d, a single 100 µg/kg injection or a single fixed 6 mg dose of PEG-rhG-CSF has similar effect and is more advantageous in preventing chemotherapy-induced neutropenia.

Association between the MTHFR C677T polymorphism and gastric cancer susceptibility: A meta-analysis of 5,757 cases and 8,501 controls.

Current data regarding the association between the methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism and the risk of developing gastric cancer are insufficient to draw definite conclusions. Therefore, the present meta-analysis was conducted to achieve a more precise estimation of the association. MEDLINE, EMBASE and Wanfang database searches resulted in the identification of 28 eligible studies describing 5,757 cases and 8,501 controls. The strength of the association between the MTHFR C677T polymorphism and gastric cancer risk were evaluated using crude odds ratios (ORs), with 95% confidence intervals (CIs). The pooled ORs were determined using homozygous (TT vs. CC), heterozygous (CT vs. CC), dominant (TT+CT vs. CC) and recessive (TT vs. CC+CT) models. When all studies were pooled into the meta-analysis, significant associations were identified between the MTHFR C677T polymorphism and the risk of gastric cancer (homozygous model: OR, 1.39; 95% CI, 1.20-1.62; heterozygous model: OR, 1.18; 95% CI, 1.05-1.32; dominant model: OR, 1.23; 95% CI, 1.10-1.38; recessive model: OR, 1.26; 95% CI, 1.12-1.42). Stratification of the data by ethnicity identified a statistically significantly elevated risk of gastric cancer in Asian MTHFR C677T polymorphism populations (homozygous model: OR, 1.64; 95% CI, 1.43-1.90; heterozygous model: OR, 1.30; 95% CI, 1.16-1.45; dominant model: OR, 1.39; 95% CI, 1.25-1.54; recessive model: OR, 1.41; 95% CI, 1.25-1.51), but not in Caucasian populations (homozygous model: OR, 1.15; 95% CI, 0.89-1.48; heterozygous model: OR, 1.03; 95% CI, 0.84-1.25; dominant model: OR, 1.05; 95% CI, 0.86-1.28; recessive model: OR, 1.09; 95% CI, 0.91-1.31). Following adjustment for heterogeneity, the current meta-analysis demonstrated that the MTHFR C677T polymorphism was not associated with the risk of gastric cancer in Caucasian individuals. Furthermore, no evidence of publication bias was observed. Thus, the current meta-analysis indicates that the MTHFR C677T allele may be a low-penetrant risk factor for the development of gastric cancer in Asian populations.

[Effect of Nogo-66 on retinal microglia in chronic ocular hypertension rats].

OBJECTIVE: To study the effect of protein Nogo-66 on the expression of CD11b and MHC-II in retinal microglia of chronic ocular hypertension SD rats and the effects of protein Nogo-66 on the immunogenicity of injured retinal tissues. METHODS: It was a control experimental study. Chronic ocular hypertension rat model was established by laser photocoagulation on the anterior chamber angle and superficial vein of the sclera. One ml of Nogo-66 (0.01%) in PBS was injected subcutaneously on the day of laser treatment and 0.005% Nogo-66 PBS solution was injected into the vitreous 7 days and 1 month latter. PBS without Nogo-66 was injected in the control group. The expression of cell surface antigen CD11b and MHC-II were detected by immunohistochemistry 1 month and 1 day after the establishment of hypertension model. The difference of average IOP among groups was analyzed by variance analysis. The difference of expression of CD11b and MHC-II between the experimental and control groups was analyzed by t-test. RESULTS: The intraocular pressure (IOP) of experimental groups rised from the seventh day after model-building and the highest IOP was (24.16 ± 2.70) mm Hg (1 mm Hg = 0.133 kPa) 1 month later while that in the control groups was (15.93 ± 3.28) mm Hg. The difference between them was statistically significant (F = 2.10, P < 0.05). Expression of CD11b was (1.78 ± 0.63)% and MHC-II was (3.92 ± 1.03)% in Nogo-66 with hypertension groups, these results was significantly lower than those in Nogo-66 with normal intraocular pressure groups in which the expression of CD11b was (8.15 ± 1.97)% (t = 2.35, P < 0.05) and MHC-II was (11.45 ± 1.97)% (t = 2.14, P < 0.05). CONCLUSIONS: Protein Nogo-66 activated the cell surface antigen CD11b in nerve fiber layer of retina and induced antigen presenting molecules (MHC-II). This indicates that Nogo has the center immunogenicity and this protein could activate antigen-presenting cells to present injury antigen.

A new staging system is more discriminant than conventional staging systems for unresectable hepatocellular carcinoma.

BACKGROUND: Prediction of the life expectancy of a patient with unresectable hepatocellular carcinoma (HCC) remains difficult. The aims of the study were to construct a new staging scheme for patients with unresectable HCC and to compare the discriminatory ability of the staging scheme with the Okuda and CLIP score and TNM staging system in a cohort of patients with unresectable HCC. METHODS: A retrospective analysis of unresectable HCC cases from 1999 to 2003 was performed. The Cox model was used for multivariate analyses. The final model was derived from 10 randomly chosen training samples and the prognostic validity of the new staging scheme was assessed on the corresponding testing samples. Moreover, 54 cases with unresectable HCC were enrolled and prospectively followed up. The new staging, named the China integrated score (CIS), Okuda, TNM and CLIP systems were determined for each case. Comparisons of the survival rate between each stage were performed to evaluate their discriminatory ability. RESULTS: A simple scoring system was constructed, assigning linear scores (0/1/2) to the three covariates (TNM, alpha-fetoprotein and Child-Pugh) of the final model. The CIS system was more discriminant than the Okuda or TNM staging system, as confirmed by the Kaplan-Meier comparison of survival curves and by the Cox's regression analysis, with a median survival rate of 9.0, 2.3, 2.1 and 0.6 months in patients with CIS 2, 3, 4 and 5, respectively. The CIS system was performed as well as the CLIP score. CONCLUSION: The new staging system, accounting for both liver function and tumor characteristics, can accurately identify patients with different prognoses, particularly in the advanced phases of HCC. It should be useful as the only tool that can be applied for patients with unresectable HCC.

[Construction of a therapeutic effect evaluation system for patients with primary liver cancer based on syndrome differentiation in traditional Chinese medicine].

OBJECTIVE: To construct a system of therapeutic effect evaluation for patients with primary liver cancer according to the theory of syndrome differentiation in traditional Chinese medicine (TCM), and to examine its reliability. METHODS: Analytic hierarchy process and 100 mm surveyor's rod method were applied to obtain bottom layer and top level syndromes, which were used to construct the method of therapeutic effect evaluation, and its reliability was verified in clinical practice by comparing with some evaluation criteria in Western medicine, such as cancer severity scale; Karnofsky performance scale; Child-Pugh classification, cancer staging classification, and quality of life scale, etc. RESULTS: A system of therapeutic effect evaluation was constructed, and it could reflect the progress of tumor, changes of hepatic function and constitution. The evaluation scores acquired from the system were highly associated with the quality of life of the patients. CONCLUSION: The system of therapeutic effect evaluation can reflect the severity of disease and the characteristics of TCM treatment.

[Clinical application of Lishengsu for treatment of leukopenia induced by chemotherapy].

The efficacy and safety of Lishengsu (a rhG-CSF preparation) were evaluated for treatment of chemotherapy-induced leukopenia. 327 cases of leukopenia with grade I-IV induced by chemotherapy were subcutaneously administered at 2.5 - 5.0 micro g/(kg x d) of Lishengsu, and hemogram and the side effects were observed. The results showed that Lishengsu had satisfactory effect to cure leukopenia after chemtherapy, with an effective rate of 99.4% (325/327), the side effects were quite slight. It is concluded that Lishengsu is efficient and safe for patients with leukopenia, and can be used as an adjuvant drug for treatment of leukopenia after chemotherapy.