Loop-mediated isothermal amplification (LAMP): A novel rapid detection platform for pathogens

Foodborne bacterial infections and diseases have been considered to be a major threat for public health in the worldwide. Increased incidence of human diseases caused by foodborne pathogens have been correlated with growing world population and mobility. Loop-mediated isothermal amplification (LAMP) has been regarded as an innovative gene amplification technology and emerged as an alternative to PCR-based methodologies in both clinical laboratory and food safety testing. Nowadays, LAMP has been applied to detection and identification on pathogens from microbial diseases, as it showed significant advantage in high sensitivity, specificity and rapidity. The high sensitivity of LAMP enables detection of the pathogens in sample materials even without time consuming sample preparation. An overview of LAMP mainly containing the development history, reaction principle and its application to four kind of foodborne pathogens detection are presented in this paper. As concluded, with the advantages of rapidity, simplicity, sensitivity, specificity and robustness, LAMP is capable of applications for clinical diagnosis as well as surveillance of infection diseases. Moreover, the main purpose of this paper is to provide theoretical basis for the clinical application of LAMP technology.

Comparative Biochemistry and In Vitro Pathway Reconstruction as Powerful Partners in Studies of Metabolic Diversity

There are estimated to be >300,000 plant species, producing >200,000 metabolites. Many of these metabolites are restricted to specific plant lineages and are referred to as "specialized" metabolites. These serve varied functions in plants including defense against biotic and abiotic stresses, plant-plant and plant-microbe communication, and pollinator attraction. These compounds also have important applications in agriculture, medicine, skin care, and in diverse aspects of human culture. The specialized metabolic repertoire of plants can vary even within and between closely related species, in terms of the number and classes of specialized metabolites as well as their structural variants. This phenotypic variation can be exploited to discover the underlying variation in the metabolic enzymes. We describe approaches for using the diversity of specialized metabolites and variation in enzyme structure and function to identify novel enzymatic activities and understand the structural basis for these differences. The knowledge obtained from these studies will provide new modules for the synthetic biology toolbox.

Abstract P3-05-11: The evolution of the estrogen receptor (ER) complex conformation governs estrogen-induced apoptosis in antihormone-resistant breast cancer cells

Over the past decade new insights have been gained into the acquired resistance to tamoxifen and the Aromatase Inhibitors (AIs) with the discovery of the new biology of estrogen-induced apoptosis. However, it has also been learned that estrogens can be classified into planar class I and angular class II estrogens. Using model systems of long-term estrogen-deprived breast cancer cells in vitro (MCF-7:5C), it was previously shown that class I estrogens cause immediate apoptosis over a 3-4 day period. Paradoxically, class II estrogens actually block apoptosis caused by planar class I estrogens. To gain insight into this paradox we have successfully crystallized an angular class II triphenylethylene (TPE) estrogen bound to the ligand binding domain (LBD) of the ER and derived a new conformation for the TPE:ER complex (code 3Q97 in the PDB). Surprisingly, Helix 12 seals the LBD with the class II estrogen, but not the same conformation is observed with the planar class I estrogen 17β-estradiol (E2). There would seem to be no reason why the 3Q97 complex would not cause immediate apoptosis. To address this issue we have used Western blot analysis for protein and qRT-PCR for mRNA levels for the ER. ER parameters were monitored for up to 72 hours and results compared and contrasted between E2, the Class II estrogens, 4-hydroxytamoxifen (4OHT) and endoxifen (Endox). ER protein and mRNA levels with 4OHT or Endox accumulated and remained high throughout the study period. In contrast, the planar estrogen E2 produced a rapid decline in the protein and mRNA levels for the ER complex. The angular class II estrogens initially produced an accumulation of the ER protein complex, which decreased with time. Using a chromatin immunoprecipitation (ChIP) technique we demonstrated that the class II estrogens recruit only half of the ER to the estrogen-responsive genes promoters (TFF1 And BREB1) and less than half co-activator binding compared to E2. The TPEs were only partial agonists compared to planar estrogen. These results explain why the Class II estrogens induce delayed apoptosis. We conclude that, for the first time, we have observed the binding of a ligand to a receptor that changes conformation against time and evolves from an antagonist to an agonist conformation to trigger apoptosis. These observations have current relevance to the decryption of the protective effects of estrogen alone therapy against breast cancer incidence in the Women's Health Initiative (WHI) trial. This work was supported by the Susan G. Komen for the Cure Foundation award SAC100009.

Citation Format: Maximov PY, Sengupta S, Fernandes DJ, Fan P, Curpan RF, Rajan SS, Greene GL, Jordan VC. The evolution of the estrogen receptor (ER) complex conformation governs estrogen-induced apoptosis in antihormone-resistant breast cancer cells. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-05-11.

Supplemental lipoic acid relieves post-weaning diarrhoea by decreasing intestinal permeability in rats

Lipoic acid (LA) is a naturally existing substance which widely distributed in the cellular membranes and cytosol of animal cells. Its intracellular functions include quenching of free radicals and repairing oxidized proteins. The purpose of this study was to evaluate the effects of LA on post-weaning diarrhoea using a rat model. Sixty weaned rats were fed either a basal diet or a LA-supplemented diet, or a zinc oxide (ZnO)-supplemented diet as a positive control. Rats in the LA and ZnO groups had better performance and reduced incidence of diarrhoea (p < 0.05). Both LA and ZnO treatments enhanced intestinal homeostatic and architecture, significantly decreased urinary lactulose to mannitol ratios (p < 0.05) and increased the expression of the intestinal mucosal tight junction proteins occludin (OCLN) and zonula occludens protein-1 (ZO-1) (p < 0.05). LA significantly increased the activities of antioxidant enzymes, and reduced glutathione while decreasing the levels of oxidative glutathione and malondialdehyde in the intestinal mucosa (p < 0.05). Furthermore, an in vitro study indicated that supplementation with LA in IEC-6 intestinal epithelial cells significantly enhanced the expression of OCLN and ZO-1 under hydrogen peroxide-induced oxidative stress. Collectively, these results suggest that LA relieves post-weaning diarrhoea by reducing intestinal permeability and improving antioxidant indices.

1,25(OH)2D3 prolongs islet graft survival by inflammatory inhibition

OBJECTIVE

This study aimed to determine the protective effect of 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) against islet graft loss.

METHODS

Proliferation of tumor necrosis factor (TNF)-α-induced macrophages was determined in vitro after treatment with different concentrations of 1,25-(OH)2D3. Intraportal islet transplantation (IPIT) was performed with islets harvested from the Sprague-Dawley rats and transplanted to the diabetic rats. The transplanted rats were assigned to receive 1,25-(OH)2D3 or propylene glycol (control). Islet graft survival; inflammatory cytokine (TNF-α and interleukin [IL]-1); numbers and percentages of macrophages, CD4(+), and CD8(+) T cells in bloods; and expression of nuclear factor (NF)-κB and TNF-α were analyzed. Hematoxylin and eosin staining was performed.

RESULTS

We found 100 mg/mL 1,25-(OH)2D3 per day to have the strongest inhibitory effect on macrophages. Survival time of islet grafts significantly increased in the rats receiving 1,25-(OH)2D3. There were fewer infiltrated inflammatory cells in both islet graft and adjacent tissue in the drug-treated rats with lower serum IL-1 and TNF-α. Furthermore, percentage of macrophages and expression of p-NF-κB p65 and TNF-α in graft sites were significantly lower in the treated rats.

CONCLUSION

Our results demonstrated that 1,25(OH)2D3 prolongs islet graft survival by decreasing nonspecific inflammation in syngeneic IPIT through inhibiting TNF-α/NF-κB pathway and macrophage infiltration.

Enrichment of c-Met+ tumorigenic stromal cells of giant cell tumor of bone and targeting by cabozantinib

Giant cell tumor of bone (GCTB) is a very rare tumor entity, which is little examined owing to the lack of established cell lines and mouse models and the restriction of available primary cell lines. The stromal cells of GCTB have been made responsible for the aggressive growth and metastasis, emphasizing the presence of a cancer stem cell population. To identify and target such tumor-initiating cells, stromal cells were isolated from eight freshly resected GCTB tissues. Tumorigenic properties were examined by colony and spheroid formation, differentiation, migration, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, immunohistochemistry, antibody protein array, Alu in situ hybridization, FACS analysis and xenotransplantation into fertilized chicken eggs and mice. A sub-population of the neoplastic stromal cells formed spheroids and colonies, differentiated to osteoblasts, migrated to wounded regions and expressed the metastasis marker CXC-chemokine receptor type 4, indicating self-renewal, invasion and differentiation potential. Compared with adherent-growing cells, markers for pluripotency, stemness and cancer progression, including the CSC surface marker c-Met, were enhanced in spheroidal cells. This c-Met-enriched sub-population formed xenograft tumors in fertilized chicken eggs and mice. Cabozantinib, an inhibitor of c-Met in phase II trials, eliminated CSC features with a higher therapeutic effect than standard chemotherapy. This study identifies a c-Met⁺ tumorigenic sub-population within stromal GCTB cells and suggests the c-Met inhibitor cabozantinib as a new therapeutic option for targeted elimination of unresectable or recurrent GCTB.

Early assessment of chronic kidney dysfunction using contrast-enhanced ultrasound: a pilot study

OBJECTIVE

We performed a prospective study to evaluate the value of contrast-enhanced (CE) ultrasound in quantitative evaluation of renal cortex perfusion in patients with chronic kidney dysfunction (CKD Stage I-II).

METHODS

The present study was approved by the institutional ethics committee. The study focused on 41 consecutive patients (males, 32; females, 9; mean age, 55.0 ± 5.0 years) with clinical suspicion of CKD (Stages I-II). For both kidneys, CE ultrasound was performed after intravenous bolus injection of 1.0 ml SonoVue® (Bracco Imaging S.p.A., Milan, Italy). Time-intensity curves (TICs) and quantitative indexes were created with Qlab software (Philips, Bothell, WA). 45 healthy volunteers were included as control group. All statistical analyses were performed with SPSS® v. 15.0 software package (SPSS, Chicago, IL). A difference was considered statistically significant with p < 0.05.

RESULTS

Patients with CKD (Stages I-II) had no obvious change in the shape of TICs. Among all quantitative indexes, the changes of area under the curve (AUC), derived peak intensity (DPI) and slope rate of elevation curve (A) were statistically significant (p < 0.05). DPI <12 dB, A >2 and AUC >1300 dB s had high utility in the evaluation of CKD, with 81%, 73% and 78% specificities and 76%, 73% and 77% sensitivities.

CONCLUSION

CE ultrasound might be valuable in the early evaluation of CKD. AUC, A and DPI might be valuable quantitative indexes.

ADVANCES IN KNOWLEDGE

Quantitative CE ultrasound analysis can be used for the standardized and early evaluation of renal dysfunction.

Roles of Wnt/β-catenin signaling in the gastric cancer stem cells proliferation and salinomycin treatment

The Wnt1 protein, a secreted ligand that activates Wnt signaling pathways, contributes to the self-renewal of cancer stem cells (CSCs) and thus may be a major determinant of tumor progression and chemoresistance. In a series of gastric cancer specimens, we found strong correlations among Wnt1 expression, CD44 expression, and the grade of gastric cancer. Stable overexpression of Wnt1 increased AGS gastric cancer cells' proliferation rate and spheroids formation, which expressed CSC surface markers Oct4 and CD44. Subcutaneous injection of nude mice with Wnt1-overexpressing AGS cells resulted in larger tumors than injection of control AGS cells. Salinomycin, an antitumor agent, significantly reduced the volume of tumor caused by Wnt1-overexpressing AGS cells in vivo. This is achieved by inhibiting the proliferation of CD44+Oct4+ CSC subpopulation, at least partly through the suppression of Wnt1 and β-catenin expression. Taken together, activation of Wnt1 signaling accelerates the proliferation of gastric CSCs, whereas salinomycin acts to inhibit gastric tumor growth by suppressing Wnt signaling in CSCs. These results suggest that Wnt signaling might have a critical role in the self-renewal of gastric CSCs, and salinomycin targeting Wnt signaling may have important clinical applications in gastric cancer therapy.

Proteomic analysis of tomato (Lycopersicum esculentum var. cerasifarm) expressing the HBsAg gene by 2-dimensional difference gel electrophoresis

In a previous study, an HBsAg gene-bearing transgenic tomato line was made available and it exhibited notable physiological alterations compared with the non-transgenic tomato (control). In particular, leaves of the transgenic plants were fleshy and dark. We hypothesized that a change in leaf proteins of the transgenic plants account for the observed phenotypes. In this study, total protein content in leaves of the transgenic plants was analyzed by 2-dimensional difference gel electrophoresis. A total number of 700 protein spots were detected on silver-stained gels, of which 368 protein spots were matched between the control and sample gels. Among these matched proteins, the expression levels of 122 proteins in the transgenic plants were upregulated while those of the rest were downregulated. In addition, 25 abundant proteins (value ratio > 2.0) on silver-stained gels were analyzed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Sixteen differentially expressed proteins were identified, of which 13 were predicted to be involved in cell division, energy metabolism, protein synthesis and processing. The possible roles of these proteins in the transgenic tomato strain have been discussed. Taken together, our data indicate that significant alterations in protein expression occur in transgenic tomatoes bearing the HBsAg gene. Our findings will help broaden our knowledge of the mechanism by which exogenously expressed genes lead to phenotypic alterations in transgenic plants.

Simultaneous optimization of spin fluctuations and superconductivity under pressure in an iron-based superconductor

We present a high-pressure NMR study of the overdoped iron pnictide superconductor NaFe0.94Co0.06As. The low-energy antiferromagnetic spin fluctuations in the normal state, manifest as the Curie-Weiss upturn in the spin-lattice relaxation rate 1/(75)T1T, first increase strongly with pressure but fall again at P>Popt=2.2  GPa. Neither long-ranged magnetic order nor a structural phase transition is encountered up to 2.5 GPa. The superconducting transition temperature Tc shows a pressure dependence identical to the spin fluctuations. Our observations demonstrate that magnetic correlations and superconductivity are optimized simultaneously as a function of the electronic structure, thereby supporting very strongly a magnetic origin of superconductivity.

Regulation of epidermal growth factor receptor signaling by plasmid-based microRNA-7 inhibits human malignant gliomas growth and metastasis in vivo

MicroRNAs are endogenous, non-coding RNAs of approximately 20-22 nucleotides that regulate genes expression by binding to the 3' untranslated region (UTR) of targets mRNAs and play critical roles in cancer pathways. Malignant glioma is the most common and highly lethal central nervous system tumor for which little effective treatment is available over several decades. The purpose of this study was to explore the therapeutic potential of plasmid-based microRNA-7 (miR-7) for gliomas in vivo. Enhancing miR-7 levels in vitro could significantly induce cell apoptosis, and inhibit cell proliferation, cell migration and invasion. Western blotting analysis was performed, which indicated that miR-7 directly inhibited epidermal growth factor receptor (EGFR) and further antagonized the downstream protein kinases including ERK, Akt and Stat3. Furthermore, systemic administration of miR-7 encapsulated in cationic liposome resulted in glioma xenografts growth arrest and the metastatic nodules decrease effectively in a sequence-specific manner. In this study, miR-7 was applied in glioma treatment for the first time in vivo. Our findings suggested that the plasmid-mediated gene therapy with miR-7 appeared to be a promising candidate for the development of new antitumor and anti-metastasis treatment for human glioma.

Enhanced chemosensitivity to CPT-11 in colorectal carcinoma xenografts by small hairpin RNA interference targeting PLK1

Commonly used drugs for the treatment of colon{} cancer patients like CPT-11 shows severe side effects or induces resistance in clinical settings. Thus, we analyzed a combination of PLK1 (polo-like kinase 1)-specific short hair RNA (shRNA), a potent tool to destroy mitosis in cancer cells, together with CPT-11 to enhance drug sensitivity. Cellular proliferation and apoptosis were determined in SW620 colorectal carcinoma cells. Knockdown of cellular PLK1 led to the decreased mRNA and PLK1 protein in RT-PCR and western blot assay. The viability declined (p<0.001) in MTT assay and colony formation assay, and the number of apoptotic cells was clearly increased (p<0.01) in flow cytometric analysis and Hoechst 33258 staining compared with control cells after incubation with PLK1-specific shRNA and SN-38. We found the level of cleaved PARP was also increased in vitro. In vivo, employment of shRNA targeting PLK1 improved the sensitivity to treat SW620 nude mouse model toward CPT-11. The combination therapy inhibited cellular proliferation and promoted apoptosis observed at the percentage of PCNA and caspase3 by immunohistochemistry, accompanied with TUNEL assay. As we expect, the combination treatment delayed tumor growth (p<0.01) and simultaneously reduced tumor weight (p<0.01) compared with control group. Taken together, combination of PLK1-specific shRNA interference with low-dose CPT-11 triggered a antitumor efficacy and represented a potential strategy to treat colon cancer.

Clinical efficacy of chemotherapy combined with verapamil in metastatic colorectal patients

In order to determine the clinical efficacy and adverse reactions of chemotherapy and verapamil infusion through a target artery to treat colorectal cancer patients with metastasis after failure with previous conventional treatments. Patients with metastatic colon cancer (n = 36) received an infusion of verapamil, interleukin-2, oxaliplatin (or hydroxy camptothecin or irinotecan hydrochloride), fluorouracil and calcium folinate through target artery using the Seldinger puncture technique. From the second day of infusion, the patients were treated with fluorouracil and calcium folinate via systematic intravenous injection for 2-3 days. Efficacy was evaluated after at least two treatment courses. The objective response including complete or partial response was 58.3% in the 36 patients; clinical benefit rate, evaluated by Karnofsky Performance Status score was 91.7%; by weight was 83.3%; by the amount of painkiller consumed was 80.6%. No patient experienced side effects associated with heart function. Post-treatment, the P-R period, Q-T period, QRS, and heart rate were not significantly different than before treatment. Liver function was significantly improved. Side effects of chemotherapy were minor in comparison to those observed with intravenous chemotherapy. Infusion of verapamil and chemotherapy directly into pelvic tumor tissue can increase treatment efficacy and has been shown to be a relatively safe technique.

Study on the effects of c-erbB-2-specific antisense oligonucleotides on c-erbB-2 overexpressing breast cancer cells

10724

Background: Overexpression of c-erbB2 oncoprotein was always correlated with bad prognostic. In this study, we will research on the effects of c-erbB-2-specific antisense oligonucleotides (ODNs) on c-erbB-2 expression, cell proliferation and apoptosis of c-erbB-2 over-expressing breast cancer TM40D cells, and to further study the effects of c-erbB-2-specific oligonucleotides on breast cancer xenografts in Balb/c mice. Methods: Balb/c mouse derived breast cancer cell line TM40D was incubated with liposome-mediated ODNs for 4 h and cultured for another 72 h, then the effects of ODNs on c-erbB-2 expression, cell proliferation and activation of apoptosis were examined by western blot, MTT assay and flow cytometry. Twenty-six mice with breast cancer xenografts were randomized into three groups—9 in control group, 9 in lipsome group and 8 in therapy group, which were injected hypodermically with 0.1 ml serum-free RPMI-1640 culture-medium, lipsome (10 ug/ml) solution, and the mixture of lipsome solution (10 ug/ml) and anti-sense ODN (1 uM) weekly for consecutive 6 weeks, respectively. After the therapy, the incidence of skin ulcer was recorded, the lumps were removed and weighted, and part of them were used for Flow Cytometry. Results: Western Blotting showed treatment of TM40D cells with c-erbB-2-specific antisense ODNs resulted in inhibition of c-erbB-2 expression. The effects of antisense ODNs on c-erbB-2 protein levels correlated with their effects on cell proliferation. MTT Assay showed antisense ODNs inhibited cell growth by about 50%. Flow cytometry analysis revealed that antisense ODNs increased cell apoptosis by38.5%, compared with cultured cells group 9.13% and liposome group 9.29%. The weight of lumps in the therapy group was significantly lower than that of in the other two groups. Flow Cytometry showed that in the therapy group the ratio of G0/G1 cells in cell cycles was 87.18%, which is higher compared with the other two and proliferation index was lower. Conclusions: Antisense ODNs reduced c-erbB-2 expression, inhibited cell proliferation and induced cell apoptosis. Anti-sense ODNs can inhibit the growth of c-erbB2-overexpressing breast cancer xenogarfts in Balb/c mice.

No significant financial relationships to disclose.

Paraoxonase (Pon1) Q192R polymorphism and serum Pon1 activity in diabetic patients on maintenance hemodialysis

Patients with diabetic nephropathy have an increased risk of coronary heart disease (CHD). Paraoxonase (Pon1) is a high-density lipoprotein- (HDL) associated enzyme that protects low-density lipoprotein from oxidation and also protects against atherosclerosis. We investigated the relationship of serum Pon1 activity, Pon1 Q192R polymorphism and HDL-C level to type 2 diabetes mellitus (DM) in patients on maintenance hemodialysis (HD). DM patients (n = 56, F/M = 17/39, aged 64.5 +/- 7.5 years) and non-DM patients (n = 89, F/M = 28/61, aged 62.7 +/- 8.3 years) under HD were included in this study. Salt-stimulated serum Pon1 activities were measured using paraoxon as a substrate. Pon1 Q192R polymorphism was detected by the mutagenically separated polymerase chain reaction. DM patients on HD had significantly lower HDL-C levels and serum Pon1 activities than non-DM patients on HD (657 +/- 277 vs. 763 +/- 257 IU/l, p < 0.01). The distribution of Pon1 Q 192R genotypes in all subjects did not differ from that predicted from the Hardy-Weinberg equilibrium. Serum Pon1 activities in both DM and non-DM patients on HD were regulated by Pon1 Q192R polymorphism: RR > QR > QQ. However, the reduced Pon1 activities in DM patients on HD were related to DM independent of the Pon1 genotype: reduced Pon1 activity was related to DM in RR carriers. Serum Pon1 activities were positively correlated with HDL-C levels. The association between HDL-C and DM in hemodialyzed patients was independent of Pon1 activity as assessed by an analysis of variance. But the relation between Pon1 activity and DM was modified by HDL-C levels: significantly when HDL-C was below 50 mg/dl, but not significantly when HDL-C was above 50 mg/dl. The results of a logistic regression analysis show that reduced serum Pon1 activities and low HDL-C levels were additively associated with DM. In conclusion, Pon1 status and HDL levels are independently associated with DM in patients on hemodialysis and may contribute to the increased risk of CHD in diabetic nephropathy.