Mapping structural variants to rare disease genes using long-read whole genome sequencing and trait-relevant polygenic scores

Recent studies have revealed the pervasive landscape of rare structural variants (rSVs) present in human genomes. rSVs can have extreme effects on the expression of proximal genes and, in a rare disease context, have been implicated in patient cases where no diagnostic single nucleotide variant (SNV) was found. Approaches for integrating rSVs to date have focused on targeted approaches in known Mendelian rare disease genes. This approach is intractable for rare diseases with many causal loci or patients with complex, multi-phenotype syndromes. We hypothesized that integrating trait-relevant polygenic scores (PGS) would provide a substantial reduction in the number of candidate disease genes in which to assess rSV effects. We further implemented a method for ranking PGS genes to define a set of core/key genes where a rSV has the potential to exert relatively larger effects on disease risk. Among a subset of patients enrolled in the Genomic Answers for Kids (GA4K) rare disease program (N=497), we used PacBio HiFi long-read whole genome sequencing (lrWGS) to identify rSVs intersecting genes in trait-relevant PGSs. Illustrating our approach in Autism (N=54 cases), we identified 1,827 deletions, 158 duplications, 619 insertions, and 14 inversions overlapping putative core/key PGS genes. Additionally, by integrating genomic constraint annotations from gnomAD, we observed that rare duplications overlapping putative core/key PGS genes were frequently in higher constraint regions compared to controls (P = 2×10-04). This difference was not observed in the lowest-ranked gene set (P = 0.18). Overall, our study provides a framework for the annotation of long-read rSVs from lrWGS data and prioritization of disease-linked genomic regions for downstream functional validation of rSV impacts. To enable reuse by other researchers, we have made SV allele frequencies and gene associations freely available.

Beyond conduction impairment: Unveiling the profound myocardial injury in left bundle branch block

BACKGROUND

Left bundle branch block (LBBB) represents a frequently encountered conduction system disorder. Despite its widespread occurrence, a continual dilemma persists regarding its intricate association with underlying cardiomyopathy and its pivotal role in the initiation of dilated cardiomyopathy. The pathologic alterations linked to LBBB-induced cardiomyopathy (LBBB-CM) have remained elusive.

OBJECTIVE

This study sought to investigate the chronologic dynamics of LBBB to left ventricular dysfunction and the pathologic mechanism of LBBB-CM.

METHODS

LBBB model was established through main left bundle branch trunk ablation in 14 canines. All LBBB dogs underwent transesophageal echocardiography and electrocardiography before ablation and at 1 month, 3 months, 6 months, and 12 months after LBBB induction. Single-photon emission computed tomography imaging was performed at 12 months. We then harvested the heart from all LBBB dogs and 14 healthy adult dogs as normal controls for anatomic observation, Purkinje fiber staining, histologic staining, and connexin43 protein expression quantitation.

RESULTS

LBBB induction caused significant fibrotic changes in the endocardium and mid-myocardium. Purkinje fibers exhibited fatty degeneration, vacuolization, and fibrosis along with downregulated connexin43 protein expression. During a 12-month follow-up, left ventricular dysfunction progressively worsened, peaking at the end of the observation period. The association between myocardial dysfunction, hypoperfusion, and fibrosis was observed in the LBBB-afflicted canines.

CONCLUSION

LBBB may lead to profound myocardial injury beyond its conduction impairment effects. The temporal progression of left ventricular dysfunction and the pathologic alterations observed shed light on the complex relationship between LBBB and cardiomyopathy. These findings offer insights into potential mechanisms and clinical implications of LBBB-CM.

Rhizosphere bacteria show a stronger response to antibiotic-based biopesticide than to conventional pesticides

The plant microbiota can substantially contribute to various functions related to host health, fitness, and productivity. Therefore, maintaining the integrity of the microbiota is beginning to be seen as a crucial factor in modern agriculture. Here, we evaluated the effects of two chemical pesticides (azoxystrobin and carbendazim) and an antibiotic-based biopesticide (wuyiencin) on the rhizosphere microbiome of tomato plants. It was found that all treatments resulted in changes in the bacterial community structure to varying degrees. The most pronounced changes were observed with the biopesticide, which resulted in an enrichment of Streptomyces in the microbiome. In contrast, the relative abundance of Actinobacteria decreased in samples that were treated with low and high dosages of carbendazim. Clostridia were enriched after the applications of azoxystrobin and wuyiencin. When functioning of the microbiome was assessed, it was shown that genes encoding multidrug efflux pumps and ABC transporters related to nutrient uptake were enriched. This enrichment is likely to overcome potentially negative effects linked to the exposure to the employed substances. The study provides new insights into the potential of different pesticides to modulate native plant microbiomes, and thus highlights the importance to include such evaluations when new active agents are developed.

Enhancing wuyiencin productivity of Streptomyces albulus (CK15) by mutagenesis breeding with atmospheric and room temperature plasma

Streptomyces species are known for their ability to efficiently produce secondary metabolites, including various antibiotics. Wuyiencin, an antibiotic produced by Streptomyces albulus CK15, is commonly used in agriculture to control fungal diseases in crops and vegetables. In this study, we utilized atmospheric and room temperature plasma (ARTP) mutagenesis to generate mutant S. albulus strains with improved fermentation capabilities for wuyiencin production. After mutagenizing the wild-type S. albulus CK15 strain once and conducting two rounds of antimicrobial screening, three genetically stable mutants (M19, M26, and M28) were identified. These mutants showed increased wuyiencin production by 17.4%, 13.6%, and 18.5% in comparison to the CK15 strain in flask culture, respectively. The M28 mutant exhibited the highest wuyiencin activity, producing 1443.0 ± 134.6 U/mL in flask culture and 1673.8 ± 127.4 U/mL in a 5 L fermenter. These results demonstrate that ARTP is an efficient tool for microbial mutation breeding and improving wuyiencin production.

Induced Defense Response in Soybean to Sclerotinia sclerotiorum Using Wuyiencin from Streptomyces albulus CK-15

Sclerotinia sclerotiorum (Lib) de Bary, a destructive fungal pathogen with an extensive host range, causes major economic losses to crop production activities globally. Streptomyces spp. produce secondary metabolites with diverse structures and biological activities with potential applications in the control of crop disease. This study explored the potential application of wuyiencin, a secondary metabolite of Streptomyces albulus CK-15, to induce defense responses in soybean against S. sclerotiorum. Lesion size was reduced by nearly 60% in wuyiencin-treated soybean plants compared with plants infected with S. sclerotiorum only in greenhouse experiments. Wuyiencin induced callose deposition at 6 h postinoculation and increased reactive-oxygen-scavenging enzyme activities, including superoxide dismutase, catalase, and peroxidase. Moreover, wuyiencin inoculated before S. sclerotiorum infection significantly increased polyphenol oxidase, phenylalanine ammonia lyase, chitinase, and β-1,3-glucanase activity, suggesting their involvement in soybean defense responses to S. sclerotiorum. Further, qRT-PCR results showed expression levels of the hormone signaling markers CO11, MYC2, PR4, PR1, NPR1, and ERF1 were upregulated in infected leaves treated with wuyiencin.

LRFN2 binding to NMDAR inhibits the progress of ESCC via regulating the Wnt/β-Catenin and NF-κB signaling pathway

As a neuronal transmembrane protein, leucine-rich repeat and fibronectin type-III domain-containing protein 2 (LRFN2) can recruit and combine with N-methyl-D-aspartic acid receptors (NMDARs) to promote nerve growth. Genetic studies suggest that mutations in LRFN2 are associated with various cancers. However, the role and mechanism of LRFN2 in the progression of esophageal squamous cell carcinoma (ESCC) have not been elucidated. In this study, we demonstrated that LRFN2 was significantly downregulated in ESCC tissues by qRT-PCR and immunohistochemistry. Low LRFN2 expression was an adverse prognostic factor in patients with ESCC. Overexpression of LRFN2 effectively suppressed the proliferation, migration, invasion and epithelial-to-mesenchymal transition in vitro and tumor growth in vivo. Bioinformatics analysis indicated that Wnt/β-catenin signaling regulation was one of the most potential mechanisms and studies confirmed that overexpression of LFRN2 obviously downregulated the expression of β-catenin, c-Myc and cyclin D1 in ESCC cells and tumor tissues. Further studies revealed that LRFN2 plays anti-ESCC role by binding with NMDAR-GRIN2B and this effect can be weakened by NR2B-selective NMDA antagonist-NMDA-IN-1. Moreover, the bioinformatics analysis showed that the interaction of GRIN2B and GSK3β affects the NF-κB pathway, which was demonstrated by western blot experiments. Collectively, our results indicate that LRFN2 binding to NMDARs inhibits the progression of ESCC by regulating the Wnt/β-catenin and NF-κB pathway, which provides a new therapeutic target for improving the prognosis of patients with ESCC.

Field Application of Wuyiencin Against Sclerotinia Stem Rot in Soybean

Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a devastating disease of soybean. Biological control is a potential alternative to chemical fungicides for disease management, and provides broad benefits to the environment, farmers and consumers. Herein, we established a field application technique for biocontrol of Sclerotinia stem rot in soybean using wuyiencin, expanding on a previous study showing biocontrol potential. We used wuyiencin to reduce sclerotia in soybean seed, and disease incidence analysis by seed bioassay revealed an optimal wuyiencin seed soaking concentration of 12.5 μg/mL. We found that different application methods had different effects on soybean plant growth. Soybean pot experiments showed that 100 μg/mL wuyiencin was obtained a significant disease protection effect and promote soybean growth through root irrigation, and the optimal concentration for wuyiencin spraying was 100–200 μg/mL. We tested the efficacy of applying wuyiencin under field conditions, and the protection effect of 200 μg/mL wuyiencin sprayed three times was the best (64.0%), but this was slightly inferior to the protection effect of 200 μg/mL dimethachlon (77.6%).

Effects of ε-Poly-L-Lysine Combined with Wuyiencin as a Bio-Fungicide against Botryris cinerea

This study mainly evaluated the broad-spectrum fungicidal activity of ε-poly L lysine (ε-PL) against 12 pathogenic fungi. We further demonstrated synergistic antifungal activity of ε-PL combined with wuyiencin against Botryris cinerea. The combined bio-fungicide achieved an inhibition rate of 100% for mycelial growth using ε-PL at 500 μg/mL + wuyiencin at 50 μg/mL and for spore germination using ε-PL at 200 μg/mL + wuyiencin at 80 μg/mL in vitro. This synergistic spore and mycelia-damaging effect of the combination was confirmed using scanning electron microscopy. In vivo assays with combined bio-fungicide (1500 μg/mL ε-PL + 60 μg/mL wuyiencin) on detached leaves showed depressed growth and development of the spores of B. cinerea. The synergistic effect was further tested in combinations of ε-PL with wuyiencin by measuring the fractional inhibition concentration index (FICI) value below 0.5. Moreover, ε-PL and wuyiencin inoculation before B. cinerea infection significantly increased the superoxide dismutase, peroxidase, catalase, and phenylalanine ammonia-lyase activities, which suggested their involvement in tomato defense responses to disease to minimize damage to B. cinerea. These findings revealed that a combined bio-fungicide comprising ε-PL and wuyiencin had a good prospect for controlling plant fungal disease.

Effect of toyF on wuyiencin and toyocamycin production by Streptomyces albulus CK-15

Streptomyces albulus CK-15 produces various secondary metabolites, including the antibiotics wuyiencin and toyocamycin, which can reportedly control a broad range of plant fungal diseases. The production of these nucleoside antibiotics in CK-15 is regulated by two biosynthesis gene clusters. To investigate the potential effect of toyocamycin biosynthesis on wuyiencin production, we herein generated S. albulus strains in which a key gene in the toyocamycin biosynthesis gene cluster, namely toyF, was either deleted or overexpressed. The toyF deletion mutant ∆toyF did not produce toyocamycin, while the production of wuyiencin increased by 23.06% in comparison with that in the wild-type (WT) strain. In addition, ΔtoyF reached the highest production level of wuyiencin 4 h faster than the WT strain (60 h vs. and 64 h). Further, toyocamycin production by the toyF overexpression strain was two-fold higher than by the WT strain, while wuyiencin production was reduced by 29.10%. qRT-PCR showed that most genes in the toyocamycin biosynthesis gene cluster were expressed at lower levels in ∆toyF as compared with those in the WT strain, while the expression levels of genes in the wuyiencin biosynthesis gene cluster were upregulated. Finally, the growth rate of ∆toyF was much faster than that of the WT strain when cultured on solid or liquid medium. Based on our findings, we report that in industrial fermentation processes, ∆toyF has the potential to increase the production of wuyiencin and reduce the timeframe of fermentation.

Left ventricular systolic motion pattern differs among patients with left bundle branch block patterns

The study aimed to investigate left ventricular (LV) motion pattern in patients with LBBB patterns including patients with pacemaker rhythm (PM), type B Wolff-Parkinson-White syndrome (B-WPW), premature ventricular complexes originating from the right ventricular outflow tract (RVOT-PVC), and complete left bundle branch block (CLBBB). Two-dimensional speckle tracking was used to evaluate peak value and time to peak value of the LV twist, LV apex rotation, and LV base rotation in patients with PM, B-WPW, RVOT-PVC, and CLBBB with normal LV ejection fraction, and in age-matched control subjects. The LV motion patterns were altered in all patients compared to the control groups. Patients with PM and CLBBB had a similar LV motion pattern with a reduced peak value of LV apex rotation and LV twist. Patients with B-WPW demonstrated the opposite trend in the reduction of LV rotation peak value, which was more dominant in the basal layer. The most impairment in the LV twist/rotation peak value was identified in patients with RVOT-PVC. Compared to the control group, the apical-basal rotation delay was prolonged in patients with CLBBB, followed by those with B-WPW, PM, and RVOT-PVC. The LV motion patterns were different among patients with different patterns of LBBB. CLBBB and PM demonstrated a reduction in LV twist/rotation that was pronounced in the apical layer, B-WPW showed a reduction in the basal layer, and RVOT-PVC in both layers. CLBBB had the most pronounced LV apical-basal rotation dyssynchrony.

Evaluation of the Inhibitory Effects of Wuyiencin, a Secondary Metabolite of Streptomyces albulus CK-15, Against Sclerotinia sclerotiorum In Vitro

Sclerotinia sclerotiorum (Lib.) de Bary, a destructive fungal pathogen with an extensive host range, causes various diseases with the potential to cause huge economic losses to crops worldwide. Streptomyces species produce secondary metabolites with variable structures and biological activities that offer possible control methods for crop diseases. Herein, we evaluated the inhibitory effects of wuyiencin, a secondary metabolite of Streptomyces albulus CK-15, against S. sclerotiorum. The results showed that wuyiencin markedly inhibited mycelial growth and germination and the formation of sclerotia. It also increased cell membrane permeability, resulting in leakage of intracellular substances in pathogen mycelia. Wuyiencin markedly decreased oxalic acid content and the activities of polygalacturonase and pectin methyl-galacturonic enzymes. Moreover, it downregulated Nox1, ITL, pph1, Caf1, and sca1, all genes related to growth and infection. Lesions were smaller and less pronounced on soybean (Glycine max [L.] Merr.) leaves pretreated with wuyiencin in vitro, and the inhibition rate reached 78.36%. The results suggest that wuyiencin holds promise for the management of diseases caused by S. sclerotiorum, and the findings provide clues on the mechanism of action.

Wuyiencin produced by Streptomyces albulus CK-15 displays biocontrol activities against cucumber powdery mildew

AIMS

Wuyiencin is a nucleoside antibiotic produced by Streptomyces albulus CK-15. The aim of this study was to determine whether wuyiencin can be used, as a suitable alternative to chemical pesticides, to protect cucumbers (Cucumis sativus L.) from powdery mildew caused by Sphaerotheca fuliginea. Further, the mechanisms underlying the control of cucumber powdery mildew by S. albulus CK-15 were preliminarily elucidated.

METHODS AND RESULTS

Wuyiencin solutions of different concentrations were used to treat infected cucumber plants under greenhouse conditions. The results indicated that wuyiencin could significantly reduce powdery mildew disease incidence, with a maximum prevention efficacy of 94·38%. Further, scanning electron micrographs and enzyme assays showed that wuyiencin inhibited S. fuliginea spore growth and elicited the activity of plant systemic resistance-related enzymes. Additionally, real-time quantitative reverse transcription PCR suggested that wuyiencin can activate a salicylic acid-dependent plant defence response.

CONCLUSIONS

Wuyiencin produced by S. albulus CK-15 possessed antifungal effects and was able to mitigate cucumber powdery mildew disease via antagonistic action. Wuyiencin also induced defence responses in the plants.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results reinforce the biotechnological potential of wuyiencin as both an antagonistic agent and an inducer of plant systemic resistance.

Effects of Folic Acid and Vitamin B12 Supplementation on Cognitive Impairment and Inflammation in Patients with Alzheimer's Disease: A Randomized, Single-Blinded, Placebo-Controlled Trial

OBJECTIVES

To evaluate the combined action of folic acid and vitamin B12 supplementation on cognitive performance and inflammation in patients with Alzheimer's disease (AD).

DESIGN

This was a randomized, single-blind, placebo-controlled trial.

PARTICIPANTS

Patients (n=120) diagnosed clinically as probable AD and in stable condition from Tianjin Key Laboratory of Cerebrovascular and Neurodegenerative Diseases.

MEASUREMENTS

Individuals were randomly divided into the intervention group (n=60, folic acid 1.2 mg/d + vitamin B12 50 μg/d) and the placebo group (n=60). Cognitive performance, blood folate, vitamin B12, one carbon cycle metabolite, and inflammatory cytokine levels were measured at baseline and after 6 months. The data were analyzed using linear mixed models for repeated measures.

RESULTS

A total of 101 participants (51 in the intervention group and 50 in the placebo group) completed the trial. Folic acid plus vitamin B12 supplementation had a beneficial effect on the MoCA total scores (P=0.029), naming scores (P=0.013), orientation scores (P=0.004), and ADAS-Cog domain score of attention (P=0.008), as compared to those of the control subjects. Moreover, supplementation significantly increased plasma SAM (P<0.001) and SAM/SAH (P<0.001), and significantly decreased the levels of serum Hcy (P<0.001), plasma SAH (P<0.001), and serum TNFα (P<0.001) compared to in the control subjects.

CONCLUSIONS

Folic acid and vitamin B12 supplementation showed a positive therapeutic effect in AD patients who were not on a folic acid-fortified diet. The findings of this study help to delineate nutrient intervention as far as public health management for the prevention of dementia is concerned.

Baduanjin exercise for patients with knee osteoarthritis: A protocol for systematic review and meta-analysis

BACKGROUND

Knee osteoarthritis (KOA) is a common chronic degenerative disorder with an increasingly prevalence among the older individuals and the leading cause of pain in the elderly. Baduanjin, one of the ancient traditional Chinese mind-body exercise routine, has been recognized to have clinical benefits for KOA. We aim to evaluate the efficacy and safety of Baduanjin for patients with KOA through this systematic review and meta-analysis.

METHODS

Four English databases (Cochrane Central Register of Controlled Trials, PubMed, EMBASE, and Web of Science), and 4 Chinese databases (China National Knowledge Infrastructure, Chinese Biomedical Literature Database, Chinese Scientific Journal Database, and Wanfang Database), will be searched from establishment of the database until October 2020. The reference lists and the citation lists of studies meeting the inclusion criteria will also be searched to identify further studies for inclusion. The search languages are English and Chinese. The randomized controlled trials of Baduanjin training for patients with KOA will be included. The primary outcome will be assessed according to the Western Ontario and McMaster Universities Osteoarthritis Index. Meta-analysis will be conducted with the use of RevMan 5.3.

RESULTS

The results of this research will be submitted to a peer-reviewed publications.

CONCLUSION

This systematic review aims to present evidence for whether Baduanjin training is an effective intervention which can improve both physical condition and life quality in patients suffering KOA.

INPLASY REGISTRATION NUMBER

INPLASY202090051.

Genome-wide transcriptomic analysis of the response of Botrytis cinerea to wuyiencin

Grey mould is caused by the ascomycetes Botrytis cinerea in a range of crop hosts. As a biological control agent, the nucleoside antibiotic wuyiencin has been industrially produced and widely used as an effective fungicide. To elucidate the effects of wuyiencin on the transcriptional regulation in B. cinerea, we, for the first time, report a genome-wide transcriptomic analysis of B. cinerea treated with wuyiencin. 2067 genes were differentially expressed, of them, 886 and 1181 genes were significantly upregulated and downregulated, respectively. Functional categorization indicated that transcript levels of genes involved in amino acid metabolism and those encoding putative secreted proteins were altered in response to wuyiencin treatment. Moreover, the expression of genes involved in protein synthesis and energy metabolism (oxidative phosphorylation) and of those encoding ATP-binding cassette transporters was markedly upregulated, whereas that of genes participating in DNA replication, cell cycle, and stress response was downregulated. Furthermore, wuyiencin resulted in mycelial malformation and negatively influenced cell growth rate and conidial yield in B. cinerea. Our results suggest that this nucleoside antibiotic regulates all aspects of cell growth and differentiation in B. cinerea. To summarize, some new candidate pathways and target genes that may related to the protective and antagonistic mechanisms in B. cinerea were identified underlying the action of biological control agents.

iTRAQ-based proteomic analysis reveals the mechanisms of Botrytis cinerea controlled with Wuyiencin

Background

Grey mould is an important plant disease worldwide, caused by Botrytis cinerea, resulting in serious economic loss. Wuyiencin, a low toxicity, high efficiency, and broad-spectrum agricultural antibiotic, has been demonstrated effectiveness against B. cinerea.

Results

Wuyiencin treatment inhibited growth and sporulation of B. cinerea, specifically altering hypha morphology and intracellular structures. These changes were accompanied by differential expression (fold change > 2.0) of 316 proteins identified by iTRAQ-labelling LC-MS/MS analysis (P < 0.05). Up-regulation of 14 proteins, including carbohydrate metabolism proteins and cell wall stabilization proteins, was validated by parallel reaction monitoring (PRM). Down-regulation of 13 proteins was validated by PRM, including regulators of energy metabolism, nucleotide/protein synthesis, and the biosynthesis of mediators of plant stress and decay.

Conclusion

Our results confirm the inhibitory biological effects of wuyiencin on B. cinereal and elaborate on the differentially expressed proteins and associated pathways implicated in the capacity of wuyiencin to debilitate the growth and pathogenicity of grey mould. This study provides validated candidates for further targeted exploration with the goal of optimizing wuyiencin as a safe, low-toxicity agent for biological control.

High-glucose promotes proliferation of human bladder cancer T24 cells by activating Wnt/β-catenin signaling pathway

OBJECTIVE

Bladder cancer is the most prevalent genitourinary malignant disorder worldwide. We aimed to observe effects of high-glucose on bladder cancer proliferation and explore the associated mechanisms.

MATERIALS AND METHODS

Human bladder cancer cell line, T24, was divided into Blank, Control (Ctrl), 10 mmol/l, 20 mmol/l and 30 mmol/l group. T24 cell proliferation was evaluated by using multiple table tournament (MTT) assay and colony formation analysis, respectively. Quantitative Real-time PCR (qRT-PCR) assay was employed to examine mRNA expression of Wnt-5a and β-catenin. Meanwhile, Western blot assay was used to evaluate expression of Wnt-5a and β-catenin protein. The linear regression analysis was utilized to analyze correlation between Wnt-5a/β-catenin expression and T24 cell proliferation.

RESULTS

High-glucose significantly enhanced proliferation of T24 cells compared to that of Blank and Ctrl group (p < 0.05). High-glucose significantly promoted colony formation of T24 cells compared to that of Blank and Ctrl group (p < 0.05). High-glucose significantly up-regulated Wnt-5a mRNA and protein expression compared to that of Blank and Ctrl group (p < 0.01). High-glucose significantly increased β-catenin mRNA and protein expression compared to that of Blank and Ctrl group (p < 0.01). Effects of high-glucose on T24 cell proliferation were increased following with the enhanced glucose concentration. Wnt/β-catenin signaling pathway molecules were correlated with colony formation of T24 cells (p < 0.05).

CONCLUSIONS

High-glucose promoted the proliferation of T24 cells by activating the Wnt/β-catenin signaling pathway. This study would provide the novel targets for bladder cancer therapy.

Indole-3-acetic acid production by Streptomyces fradiae NKZ-259 and its formulation to enhance plant growth

BACKGROUND

Indole-3-acetic acid (IAA) is produced by microorganisms and plants via either tryptophan-dependent or tryptophan-independent pathways. Herein, we investigated the optimisation of IAA production by Streptomyces fradiae NKZ-259 and its formulation as a plant growth promoter to improve economic and agricultural development.

RESULTS

The maximum IAA yield achieved using optimal conditions was 82.363 μg/mL in the presence of 2 g/L tryptophan after 6 days of incubation. Thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC) analysis of putative IAA revealed an RF value of 0.69 and a retention time of 11.842 min, comparable with the IAA standard. Regarding product formulation, kaolin-based powder achieved a suspension rate of 73.74% and a wetting time of 80 s. This carrier exhibited good shelf life stability for NKZ-259, and the cell population did not decrease obviously over 4 months of storage at 4 °C. In vivo analysis of plant growth promotion showed that tomato seedlings treated with kaolin powder containing NKZ-259 cells displayed a significant increase in root and shoot length of 7.97 cm and 32.77 cm, respectively, and an increase in fresh weight and dry weight of 6.72 g and 1.34 g. Compared to controls, plant growth parameters were increased almost it two-fold.

CONCLUSION

Optimising the culture conditions resulted in an almost four-fold increase in IAA secretion by NKZ-259 cells. The results clearly demonstrate that S. fradiae NKZ-259 holds great potential for plant growth promotion and IAA production. Furthermore, kaolin-based powder is an effective carrier for NKZ-259 cells and may be useful for commercial applications.

Identification of wysPII as an Activator of Morphological Development in Streptomyces albulus CK-15

Wuyiencin is produced by Streptomyces albulus var. wuyiensis and used widely in agriculture to control a variety of fungal diseases, such as cucumber downy mildew, strawberry powdery mildew, and tomato gray mold. As an industrially-produced biopesticide, reducing production costs is very important for popularization of this approach. To obtain a rapidly growing strain that effectively shortens the fermentation time, we investigated the effects of knockout and overexpression of the wysPII gene, a member of the LuxR regulatory gene family, in S. albulus strain CK-15. The ΔwysPII mutant exhibited a reduced rate of growth and sporulation. The time taken to reach the greatest mycelial biomass was approximately 18 h shorter in the ooPII (wysPII overexpressing) strain compared with that of the wild-type (WT) strain. In addition, the time to reach the greatest wuyiencin production was 56 h in the ooPII strain compared with 62 h in the WT strain. Furthermore, wysPII was shown to act as an activator of morphological development without affecting wuyiencin production. Thus, the ooPII strain can be used to reduce costs and increase efficiency in industrial fermentation processes for wuyiencin production.

Bacillus methylotrophicus Strain NKG-1, Isolated from Changbai Mountain, China, Has Potential Applications as a Biofertilizer or Biocontrol Agent

Chemical pesticides are widely used in agriculture, which endangers both environmental health and food safety. Biocontrol is an environmentally-friendly and cost-effective green technique in environmental protection and agricultural production; it generally uses selected bioresources, including beneficial microorganisms. We isolated a novel bacterial strain (NKG-1) from the rare dormant volcanic soils of Changbai Mountain in China's Jilin Province. The strain was identified as Bacillus methylotrophicus using morphological, biochemical, physiological, and phylogenetic 16S rDNA sequencing data. This strain was able to suppress mycelial growth and conidial germination of numerous plant pathogenic fungi on solid media. A greenhouse experiment showed that application of NKG-1 fermentation broth prior to inoculation of Botrytis cinerea, the cause of gray tomato mold, inhibited growth of the mold by 60%. Furthermore, application of a 100× dilution of NKG-1 fermentation broth to tomato seedlings yielded a significant increase in seedling fresh weight (27.4%), seedling length (12.5%), and root length (57.7%) compared to the control. When the same dosage was applied in the field, we observed increases in tomato plant height (14.7%), stem diameter (12.7%), crown width (16.3%), and maximum fruit diameter (11.5%). These results suggest that NKG-1 has potential commercial application as a biofertilizer or biocontrol agent.

Robustness of Salmonella loop-mediated isothermal amplification assays for food applications

AIMS

Loop-mediated isothermal amplification (LAMP) assays have been developed recently for Salmonella detection. This study aimed at evaluating the robustness of two Salmonella LAMP assays in comparison with PCR and real-time quantitative PCR for food applications.

METHODS AND RESULTS

Performance of the assays was examined under abusive preparation conditions, running temperatures and pH, and with the addition of various inhibitors and food rinses. LAMP achieved robust detection under abusive assay preparation conditions (holding at 22 and 37°C for up to 30 min) and running temperatures (57-68°C). With a hot-start DNA polymerase, PCR obtained comparable results under these temperature ranges. However, PCR performed markedly poorer under abusive pH. LAMP also showed greater tolerance to potential inhibitors than PCR. When food rinses including meat juice, chicken rinse, egg homogenate and produce homogenate were added at 20% of the reaction mix, PCR amplifications were completely inhibited, but LAMP reactions were not.

CONCLUSIONS

Our results demonstrated that LAMP is a robust alternative to PCR in Salmonella detection for food applications.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study filled important knowledge gaps regarding the robustness of Salmonella LAMP assays. The findings will help bring Salmonella LAMP assays closer to wider applications in food testing.

Population genetic structure and historical demography of Oratosquilla oratoria revealed by mitochondrial DNA sequences

Genetic diversity, population genetic structure and molecular phylogeographic pattern of mantis shrimp Oratosquilla oratoria in Bohai Sea and South China Sea were analyzed by mitochondrial DNA sequences. Nucleotide and haplotype diversities were 0.00409-0.00669 and 0.894-0.953 respectively. Neighbor-Joining phylogenetic tree clustered two distinct lineages. Both phylogenetic tree and median-joining network showed the consistent genetic structure corresponding to geographical distribution. Mismatch distributions, negative neutral test and "star-like" network supported a sudden population expansion event. And the time was estimated about 44000 and 50000 years ago.

Recruitment of Grb2 and SHIP1 by the ITT-like motif of TIGIT suppresses granule polarization and cytotoxicity of NK cells

Activating and inhibitory receptors control natural killer (NK) cell activity. T-cell immunoglobulin and ITIM (immunoreceptor tyrosine-based inhibition motif) domain (TIGIT) was recently identified as a new inhibitory receptor on T and NK cells that suppressed their effector functions. TIGIT harbors the immunoreceptor tail tyrosine (ITT)-like and ITIM motifs in its cytoplasmic tail. However, how its ITT-like motif functions in TIGIT-mediated negative signaling is still unclear. Here, we show that TIGIT/PVR (poliovirus receptor) engagement disrupts granule polarization leading to loss of killing activity of NK cells. The ITT-like motif of TIGIT has a major role in its negative signaling. After TIGIT/PVR ligation, the ITT-like motif is phosphorylated at Tyr225 and binds to cytosolic adapter Grb2, which can recruit SHIP1 to prematurely terminate phosphatidylinositol 3-kinase (PI3K) and MAPK signaling, leading to downregulation of NK cell function. In support of this, Tyr225 or Asn227 mutation leads to restoration of TIGIT/PVR-mediated cytotoxicity, and SHIP1 silencing can dramatically abolish TIGIT/PVR-mediated killing inhibition.

Multiplex PCR assays for simultaneous detection and characterization of Vibrio vulnificus strains

AIMS

Vibrio vulnificus is a major cause of seafood-related deaths in the United States. Several biomarkers, e.g. the virulence-correlated gene (vcg), 16S rRNA, and the capsular polysaccharide operon (CPS) have been used to differentiate virulent- from nonvirulent-type V. vulnificus strains. In this study, we combined the use of these biomarkers with a species-specific V. vulnificus cytolysin/haemolysin gene (vvhA) to develop two pairs of multiplex PCR assays that simultaneously detect and characterize V. vulnificus strains.

METHODS AND RESULTS

The first multiplex PCR pair amplified four genes (vvhA, vcg, 16S rRNA, and CPS), with one for virulent-type and the other one for nonvirulent-type V. vulnificus strains, while the second pair targeted three of those genes excluding CPS. Primer concentration and annealing temperature were optimized for the four multiplex PCR assays. When testing ten V. vulnificus reference strains and 80 field oyster isolates, results from each multiplex PCR matched 100% with known strain characteristics for these target genes.

CONCLUSIONS

The optimized multiplex PCR assays were capable of simultaneously detecting and characterizing V. vulnificus with high specificity and speed.

SIGNIFICANCE AND IMPACT OF THE STUDY

Multiplex PCR assays designed in this study are valuable tools for microbial ecology and epidemiology studies. They may facilitate better control of V. vulnificus risks in oysters, thereby reducing the number of illnesses and deaths because of V. vulnificus in the long run.

Weight gain in breast cancer patients: Tamoxifen versus anastrazole

10544

Background: Weight gain is a common complaint among breast cancer patients, especially those taking tamoxifen. Aromatase inhibitors have been increasingly used in postmenopausal breast cancer patients, and are generally thought to have a more tolerable side-effect profile than selective estrogen receptor modulators (SERM’s). This study specifically addresses weight gain in patients on the SERM, tamoxifen, compared to patients on the aromatase inhibitor, anastrazole. Methods: Ninety-six outpatients with primary breast cancer of any stage received standard doses of adjuvant hormonal therapy. Seventy received tamoxifen (Group T) and 26 anastrazole (Group A). The nursing staff in the clinic weighed all patients at the time of diagnosis, at start of chemotherapy (if received), at start of hormone therapy, and at 3 month intervals for 12 months after starting hormone therapy. Data were gathered in a retrospective manner. Results: Demographic variables were compared between the two groups. In all patients, it was noted that increasing age was correlated with greater weight gain at 3 months after starting hormone therapy (p = 0.0257), but not at any other intervals. No other variables were significantly correlated with weight gain. In Group T, mean weight gain was clinically (>1.8 kgs) and statistically significant at 9 and 12 months (p = 0.0137, p = 0.0003). In Group A, mean weight gain was not clinically significant at any point. Using the Wilcoxon two-sample tests to compare groups T and A, it was shown that there was no statistically significant difference in weight gain between the two groups at any interval (see table). Conclusions: These results are consistent with previous studies that show significant weight gain in breast cancer patients on tamoxifen. This study failed to show a statistically significant difference in weight gain between patients on tamoxifen and patients on anastrazole. Group A did not have statistically significant weight gain at any interval after starting hormone therapy.

[Table: see text]

No significant financial relationships to disclose.

BCL3 is induced by IL-6 via Stat3 binding to intronic enhancer HS4 and represses its own transcription

BCL3 is a proto-oncogene affected by chromosomal translocations in some patients with chronic lymphocytic leukemia. It is an IkappaB family protein that is involved in transcriptional regulation of a number of NF-kappaB target genes. In this study, interleukin (IL)-6-induced BCL3 expression and its effect on survival of multiple myeloma (MM) cells were examined. We demonstrate the upregulation of BCL3 by IL-6 in INA-6 and other MM cell lines. Sequence analysis of the BCL3 gene locus revealed four potential signal transducer and activator of transcription (Stat) binding sites within two conserved intronic enhancers regions: one located within enhancer HS3 and three within HS4. Chromatin immunoprecipitation experiments showed increased Stat3 binding to both enhancers upon IL-6 stimulation. Silencing Stat3 expression by small interfering RNA (siRNA) abrogated BCL3 expression by IL-6. Using reporter gene assays, we demonstrate that BCL3 transcription depends on HS4. Mutation of the Stat motifs within HS4 abolished IL-6-dependent BCL3 induction. Furthermore, BCL3 transcription was inhibited by its own gene product. This repressive feedback is mediated by NF-kappaB sites within the promoter and HS3. Finally, we show that overexpression of BCL3 increases apoptosis, whereas BCL3-specific siRNA does not affect the viability of INA-6 cells suggesting that BCL3 is not essential for the survival of these cells.

Genotyping of Campylobacter spp. from retail meats by pulsed-field gel electrophoresis and ribotyping

AIMS

To determine the genetic relatedness of Campylobacter spp. from retail meat products, and compare the discriminatory power of pulsed-field gel electrophoresis (PFGE) and automatic ribotyping.

METHODS AND RESULTS

A total of 378 Campylobacter isolates recovered from 159 raw meats (130 chicken, 25 turkey, three pork and one beef) sampled from 50 retail grocery stores of four supermarket chains in the Maryland suburban area from August 1999 to July 2000 were analysed by PFGE with SmaI, 120 isolates of which were also characterized by ribotyping with PstI using RiboPrinter system. A total of 148 unique PFGE patterns were identified, 91 of which were present in multiple Campylobacter isolates and 24 in multiple meat samples. Nineteen Campylobacter clones with identical PFGE patterns recurred frequently (up to nine times) throughout the sampling period. Comparing ribotyping with PFGE, we identified 44 PFGE patterns and 22 RiboGroups among the 120 isolates tested. Multiple PFGE patterns within one RiboGroup were commonly observed, as well as multiple RiboGroups within one PFGE pattern.

CONCLUSIONS

Although Campylobacter present in retail meats were genetically diverse, certain clones persisted in poultry meats. PFGE had a greater discriminatory power than ribotyping, and the two methods were complementary in genotyping Campylobacter.

SIGNIFICANCE AND IMPACT OF THE STUDY

Genomic DNA fingerprinting of Campylobacter confirmed diverse and recurrent Campylobacter clones in the retail meats, which provides additional data for a better understanding of the epidemiological aspect of Campylobacter infection.

Effect of nebulized albuterol on blood glucose in patients with diabetes mellitus with and without cystic fibrosis

Over 90% of cystic fibrosis (CF) patients are treated with bronchodilators, and 6% have diabetes. Some with asthma also have diabetes, and most are treated with bronchodilators. Systemic administration of adrenergic agents can cause increases in blood glucose, but the effect of inhaled agents is unclear. A double-blind study was performed on 10 patients with type 1 diabetes mellitus (DM) without CF (3 male, 7 female, mean age 25.5 years) and 9 patients with insulin-dependent CF-related diabetes (CFRD) (8 male, 1 female, mean age 21.9 years). On 2 separate days before 9 AM fasting and the morning dose of insulin, 2.5 mg of albuterol or nebulized placebo were given. Blood glucose was measured by finger stick with a glucose reflectance meter before and 15, 30, 45, and 60 min after treatment. No significant changes from baseline or differences between placebo and albuterol occurred in either group. The mean maximum increase from baseline in DM was 20 mg/dl on placebo, and 38 mg/dl on albuterol; in the CFRD, the respective changes were 7 and 7 mg/dl. Two DM patients had a > 50 mg/dl increase on albuterol vs. placebo; no CFRD patients had differences of such magnitude. DM patients had greater increases from baseline than CFRD patients on placebo and albuterol. Differences reached statistical significance at 30 and 45 min on placebo, and 45 min on albuterol. Albuterol 2.5 mg by nebulizer causes no clinically significant increases in blood glucose in DM or CFRD patients. Diabetes patients without CF have a significantly greater increase of glucose with time (placebo or albuterol) than CFRD patients.

Electrochemistry of immobilized CuZnSOD and FeSOD and their interaction with superoxide radicals

Copper, zinc superoxide dismutase (CuZnSOD) from bovine erythrocytes and iron superoxide dismutase from Escherichia coli (FeSOD) were immobilized on 3-mercaptopropionic acid (MPA)-modified gold electrodes, respectively. The characterization of the SOD electrodes showed a quasi-reversible, electrochemical redox behavior with a formal potential of 47+/-4 mV and -154+/-5 mV (vs. Ag/AgCl, 1 M KCl) for surface adsorbed CuZnSOD and FeSOD, respectively. The heterogeneous electron transfer rate constants were determined to be about 65 and 35/s, respectively. Covalent fixation of both SODs was also feasible with only slight changes in the formal potential. The interaction of superoxide radicals (O(2)(-)) with the SOD electrode was investigated. No catalytic current could be observed. However, due to the fast cyclic redox reaction of SOD with superoxide, the communication of the protein with the electrode was strongly influenced. The amperometric detection of superoxide radicals is discussed.

Identification of Escherichia coli O157:H7 and other enterohemorrhagic serotypes by EHEC- hlyA targeting, strand displacement amplification, and fluorescence polarization

Human disease caused by enterohemorrhagic E. coli O157:H7 and other serotypes (EHEC) has been associated with bovine fecal contamination of food and the environment. The range of serotypes, low infectious dose, and numerous transmission vehicles for EHEC render development of detection methods for this pathogen complex. In this study, the hemolysin gene (EHEC- hly A) was targeted with oligonucleotides, and probe-target hybrids were amplified using strand displacement amplification (SDA). Amplicons were resolved in the complete reaction mix through changes in the fluorescence polarization (FP) of a fluorescein-labeled detector probe hybridized to the amplicons during amplification. Results combining EHEC- hly A, SDA, and FP were obtained within 35 min of reaction initiation. The test specificity was determined on EHEC strains representing 13 serotypes (49 isolates); and control uropathogenic, commensal, and other organisms (10 isolates). Statistical analysis of results indicated a sensitivity in the reaction vessel to 4.3 bacteria (95% confidence interval), and a specificity for EHEC (n=59) at 100% (P=5.11E-17; i.e. P<<0.05). Detection based on combining EHEC- hly A, SDA, and FP was compatible with water sources directly associated with human infection (drinking and recreational supplies), and bovine drinking trough water representing an environmental matrix linked to the maintenance of an EHEC animal reservoir.

Amperometric biosensor based on a functionalized gold electrode for the detection of antioxidants

A method for the electrochemical detection of antioxidants has been developed, which is based on a radical measurement with a cytochrome c modified electrode. A controlled enzymatic production system for superoxide radicals based on xanthine oxidase was used. The addition of antioxidants facilitated the decomposition of the radical in addition to the spontaneous dismutation. The steady-state of superoxide generation and decomposition was thus shifted to a new situation due to the higher decomposition rate after antioxidant addition. This resulted in a decreased current level at the electrode. Antioxidant activity could be quantified from the response of the sensor electrode by the percentage of the signal decrease. The 50% inhibition value (IC(50)) for different antioxidants was calculated and the antioxidant activity of numerous substances was compared. Thus, a hierarchy of superoxide radical scavenging abilities of flavonoids was established: flavanols>flavonols>flavones>flavonones>isoflavonones.

SB203580 promotes EGF-stimulated early morphological differentiation in PC12 cell through activating ERK pathway

MAP kinases have important role in PC12 cell differentiation, since the activities of both extracellular regulated protein kinase (ERK) and p38 have been indicated as necessary signal for PC12 cell differentiation. Epidermal growth factor (EGF) and NGF both activate ERK and p38 in PC12 cells, but only NGF trigger differentiation. It has been proposed that the duration of ERK activation determines the switch from proliferation to differentiation, since EGF causes more transient activation of ERK than NGF in PC12 cells. Here we report that treatment of PC12 cells with EGF in the presence of SB203580, a widely used p38 inhibitor, caused differentiation. The pro-differentiation effect of SB203580 in EGF-treated PC12 cells was found to be independent of its function of p38 inhibition but was through an effect on the ERK pathway that has been recently reported (Kalmes et al. [1999] FEBS Lett. 444: 71-74; Hall-Jackson et al. [1999] Onc. 18: 2047-2054). We found that SB203580 by itself did not affect the activity of ERK1/2 but significantly extended EGF-induced ERK activation in PC12 cells, which resulted in early morphological differentiation. Our data indicated that although both ERK and p38 are required for PC12 cell differentiation, activation of p38 is not required when ERK is superactivated. Our data provided further evidence for the threshold theory that differentiation is determined by the duration of ERK activation.

Prevalence of Campylobacter spp., Escherichia coli, and Salmonella serovars in retail chicken, turkey, pork, and beef from the Greater Washington, D.C., area

A total of 825 samples of retail raw meats (chicken, turkey, pork, and beef) were examined for the presence of Escherichia coli and Salmonella serovars, and 719 of these samples were also tested for Campylobacter spp. The samples were randomly obtained from 59 stores of four supermarket chains during 107 sampling visits in the Greater Washington, D.C., area from June 1999 to July 2000. The majority (70.7%) of chicken samples (n = 184) were contaminated with Campylobacter, and a large percentage of the stores visited (91%) had Campylobacter-contaminated chickens. Approximately 14% of the 172 turkey samples yielded Campylobacter, whereas fewer pork (1.7%) and beef (0.5%) samples were positive for this pathogen. A total of 722 Campylobacter isolates were obtained from 159 meat samples; 53.6% of these isolates were Campylobacter jejuni, 41.3% were Campylobacter coli, and 5.1% were other species. Of the 212 chicken samples, 82 (38.7%) yielded E. coli, while 19.0% of the beef samples, 16.3% of the pork samples, and 11.9% of the turkey samples were positive for E. coli. However, only 25 (3.0%) of the retail meat samples tested were positive for Salmonella. Significant differences in the bacterial contamination rates were observed for the four supermarket chains. This study revealed that retail raw meats are often contaminated with food-borne pathogens; however, there are marked differences in the prevalence of such pathogens in different meats. Raw retail meats are potential vehicles for transmitting food-borne diseases, and our findings stress the need for increased implementation of hazard analysis of critical control point (HACCP) and consumer food safety education efforts.

Manganese superoxide dismutase induction by iron is impaired in Friedreich ataxia cells

Iron-mediated oxidative stress has been implicated in the pathology of the neurodegenerative disease Friedreich ataxia (FRDA). Here, we show that normal upregulation of the stress defense protein manganese superoxide dismutase (MnSOD) fails to occur in FRDA fibroblasts exposed to iron. This impaired induction was observed at iron levels in which increased activation of the redox-sensitive factor NF-kappaB was absent. Furthermore, MnSOD induction could only be partially suppressed by antioxidants. We conclude that an NF-kappaB-independent pathway that may not require free radical signaling is responsible for the reduction of MnSOD induction. This impairment could constitute both a novel defense mechanism against iron-mediated oxidative stress in cells with mitochondrial iron overload and conversely, an alternative source of free radicals that could contribute to the disease pathology.

Liposome-C-erbB2 antisense oligodoxynucleotides in human ovarian cancer cells

OBJECTIVE

To explore the effects of liposome-C-erbB2 antisense phosphorothioate oligodeoxynucleotides (S-ODNs) on C-erbB2 proto-oncogene expression and cell proliferation in human ovarian cancer cells.

METHODS

The effects of liposome-C-erbB2 S-ODNs on C-erbB2 protein expression, cell cycle and cell proliferation in human ovarian cancer cells were studied by means of flow cytometry and 3H-thymidine incorporation.

RESULTS

Liposome-C-erbB2 S-ODNs can specifically reduce C-erbB2 protein expression in human ovarian cancer cells, accompanied by a 30% inhibition of cell proliferation. The effectiveness of liposome-C-erbB2 S-ODNs on the expression of C-erbB2 was about 40 times higher than that of C-erbB2 S-ODNs.

CONCLUSIONS

The data suggest that antisense therapy might be a useful method of gene therapy in ovarian cancer. The effectiveness of C-erbB2 S-ODNs could be greatly increased by adsorption of S-ODNs by liposomes.

Identification and characterization of integron-mediated antibiotic resistance among Shiga toxin-producing Escherichia coli isolates

A total of 50 isolates of Shiga toxin-producing Escherichia coli (STEC), including 29 O157:H7 and 21 non-O157 STEC strains, were analyzed for antimicrobial susceptibilities and the presence of class 1 integrons. Seventy-eight (n = 39) percent of the isolates exhibited resistance to two or more antimicrobial classes. Multiple resistance to streptomycin, sulfamethoxazole, and tetracycline was most often observed. Class 1 integrons were identified among nine STEC isolates, including serotypes O157:H7, O111:H11, O111:H8, O111:NM, O103:H2, O45:H2, O26:H11, and O5:NM. The majority of the amplified integron fragments were 1 kb in size with the exception of one E. coli O111:H8 isolate which possessed a 2-kb amplicon. DNA sequence analysis revealed that the integrons identified within the O111:H11, O111:NM, O45:H2, and O26:H11 isolates contained the aadA gene encoding resistance to streptomycin and spectinomycin. Integrons identified among the O157:H7 and O103:H2 isolates also possessed a similar aadA gene. However, DNA sequencing revealed only 86 and 88% homology, respectively. The 2-kb integron of the E. coli O111:H8 isolate contained three genes, dfrXII, aadA2, and a gene of unknown function, orfF, which were 86, 100, and 100% homologous, respectively, to previously reported gene cassettes identified in integrons found in Citrobacter freundii and Klebsiella pneumoniae. Furthermore, integrons identified among the O157:H7 and O111:NM strains were transferable via conjugation to another strain of E. coli O157:H7 and to several strains of Hafnia alvei. To our knowledge, this is the first report of integrons and antibiotic resistance gene cassettes in STEC, in particular E. coli O157:H7.

Novel promoter polymorphism in insulin-like growth factor-binding protein-3: correlation with serum levels and interaction with known regulators

Insulin-like growth factor (IGF)-binding protein-3 (IGFBP-3) is a major determinant of circulating levels of the IGFs and is clinically useful for the evaluation of GH deficiency and for predicting the response to GH treatment. Recent studies provide evidence that the circulating level of IGFBP-3 is inversely related to the risk of several common cancers, and that antiproliferative agents such as antiestrogens and retinoids act in part by up-regulating IGFBP-3 gene (IGFBP3) expression. Although approximately 50% of the substantial interindividual variability in circulating IGFBP-3 levels is known to have a genetic basis, the specific loci involved are unknown. Direct sequencing of genomic DNA specimens from a multiethnic population identified several single nucleotide polymorphisms in the promoter region of IGFBP3. For the most common single nucleotide polymorphism (nucleotide -202) found to be in Hardy-Weinberg equilibrium, genotype was highly correlated to circulating level of IGFBP-3 in 478 men from the Physicians' Health Study. In vitro, we documented significantly higher promoter activity of the A allele at the -202 locus compared with the C allele, consistent with the relationship observed between genotype and circulating IGFBP-3 (AA > AC > CC). A positive correlation was observed between circulating retinol levels and circulating IGFBP-3 levels; subset analysis by genotype showed that this relationship was only present among individuals carrying an A allele at -202 (AA > AC > CC). Tall individuals or individuals with a body mass index of 27 or greater had levels of circulating IGFBP-3 that were significantly higher when they possessed at least one A allele (AA > AC > CC). The IGFBP3 promoter region deserves investigation as a locus where polymorphic variation occurs frequently and may influence GH responsiveness, somatic growth, and possibly cancer risk.

[The expression and clinical significance of pRB and E(2)F(1) in human neuroendocrine lung tumor]

OBJECTIVE

To investigate the role pRB and E(2)F(1) play in the cell cycle and the oncogenesis of human nemoendocrine lung fumor and the correlation between their expression and the invasiveness and prognosis of human neuroendocrine lung tumor.

METHODS

Immunohistochemistry and in situ hybridization were used to detect the expression of pRB and E(2)F(1) mRNA in the paraffin embedded tissues of 78 cases of human neuroendocrine lung tumor. Statistics was used to analyze the data.

RESULTS

The positive expression rate of pRB in both typical and atypical carcinoid was 87.5% (14/16). However, pRB was not expressed in large cell neuroendocrine carcinoma and small cell lung cancer (P < 0.001). The positive rate of E(2)F(1) mRNA expression in human neuroendocrine lung tumor was 87.2% (68/78). The strength of expression of pRB and E(2)F(1) was obviously correlated with the tumor stage, lymph node metastasis and prognosis (P < 0.05).

CONCLUSION

The loss of pRB and E(2)F(1) overexpression may play a key role in the development of human neuroendocrine lung tumors.