Notch1 induces cell cycle arrest and apoptosis in human cervical cancer cells: involvement of nuclear factor kappa B inhibition

Notch signaling can serve as a tumor suppressor or tumor promoter in the same kind of cancer, such as human papillomavirus-positive cervical cancer cells. However, the exact mechanisms remain poorly characterized. Our studies demonstrated that constitutively overexpressed active Notch1 via stable transfection with exogenous intracellular domain of Notch1 (ICN) resulted in growth inhibition of the human cervical cancer cell line HeLa by inducing G(2)-M arrest and apoptosis. Moreover, the growth inhibition was correlated with inhibition of nuclear factor kappa B (NF-kappaB) p50 activation, accompanied by a decrease in the nuclear expression of NF-kappaB p50 and an increase in the cytosolic expression of IkappaBalpha. Consistent with these results, downregulation of cyclin D1 and Bcl-2, which are both the downstream genes of NF-kappaB, were observed in ICN-overexpressed cells. Overall, our results suggest that NF-kappaB inhibition may contribute partially to cell cycle arrest and apoptosis induced by Notch1 activation in human cervical cancer cells.

Quantifying the contribution of cross-correlation in stimulus feature discrimination in an ensemble of retinal ganglion cells

Based on Poisson variability, the strength of cross-correlation of two spike trains was quantified by a cross-correlation index (CCI). Discriminant analysis with CCI was used to quantify the contribution of cross-correlation in stimulus feature discrimination in an ensemble of retinal ganglion cells. Compared with simulated Poisson cell pair, it was found that cross-correlation carried useful information for stimulus feature discrimination and with the cross-correlation included in the analysis, the color and the intensity discrimination ability of a cell pair increase 4.2% and 2.7%, respectively.

Low-temperature in situ large strain plasticity of ceramic SiC nanowires and its atomic-scale mechanism

Large strain plasticity is phenomenologically defined as the ability of a material to exhibit an exceptionally large deformation rate during mechanical deformation. It is a property that is well established for metals and alloys but is rarely observed for ceramic materials especially at low temperature ( approximately 300 K). With the reduction in dimensionality, however, unusual mechanical properties are shown by ceramic nanomaterials. In this Letter, we demonstrated unusually large strain plasticity of ceramic SiC nanowires (NWs) at temperatures close to room temperature that was directly observed in situ by a novel high-resolution transmission electron microscopy technique. The continuous plasticity of the SiC NWs is accompanied by a process of increased dislocation density at an early stage, followed by an obvious lattice distortion, and finally reaches an entire structure amorphization at the most strained region of the NW. These unusual phenomena for the SiC NWs are fundamentally important for understanding the nanoscale fracture and strain-induced band structure variation for high-temperature semiconductors. Our result may also provide useful information for further studying of nanoscale elastic-plastic and brittle-ductile transitions of ceramic materials with superplasticity.

Enhanced T-cell immunity induced by dendritic cells with phagocytosis of heat shock protein 70 gene-transfected tumor cells in early phase of apoptosis

The dual role of heat shock protein 70 (HSP70), as antigenic peptide chaperone and danger signal, makes it especially important in dendritic cell (DC)-based vaccination. In this study, we investigated the impacts of apoptotic transgenic MCA/HSP tumor cells expressing HSP70 on DC maturation, T-cell stimulation and vaccine efficacy. We found that DCs with phagocytosis of MCA/HSP in early phase of apoptosis expressed more pMHC I complexes, stimulated stronger cytotoxic T lymphocyte (CTL) responses (40% specific killing at an E:T cell ratio of 50) and induced immune protection in 90% of mice against MCA tumor cell challenge, compared with 25% specific CTL killing activity and 60% immune protection seen in mice immunized with DC with phagocytosis of MCA/HSP in late phase of apoptosis (P<0.05). Similar results were confirmed in another EG7 tumor model also expressing HSP70. Taken together, our data demonstrate that HSP70 on apoptotic tumor cells stimulate DC maturation, and DC with phagocytosis of apoptotic tumor cells expressing HSP70 in early phase of apoptosis more efficiently induced tumor-specific CTL responses and immunity than DCs with phagocytosis of apoptotic tumor cells in late phase of apoptosis. These results may have an important impact in designing DC-based antitumor vaccines.

RTD (residence time distribution) predictions in large mechanically aerated lagoons

Mechanically aerated lagoons (used for wastewater treatment in the pulp and paper industry) are typically very large (>500,000 m3) and have complex three-dimensional fluid flow patterns due to mechanical agitation, sludge accumulation, internal baffling, and confined inlet/outlet flow channels. RTD data is frequently used for evaluation of hydraulic performance, however, obtaining accurate data with traditional dye measurements is a difficult and time-consuming process. Moreover, the mixing impact of factors such as aerator positions, sludge accumulation, and internal baffles would require a significant and costly number of local field measurements. Recent applications of CFD to mechanically aerated lagoons have helped engineers to understand the complex flow interactions. This paper provides a practical method for the evaluation of the hydraulic performance of large mechanically aerated lagoons using CFD. A method, based on random-walk Lagrangian particle tracking, has been developed to significantly shorten the computational time needed to produce RTD curves for these lagoons. Comparison of the particle method with the more conventional scalar transport yields excellent results. These methods allow wastewater engineers to combine their existing knowledge and expertise with the established power of CFD. The results quantify the hydraulic impact of different inlet/outlet configurations, aerator configurations, influent flow rates, and bottom sludge profiles.

In vitro expansion of Ag-specific T cells by HLA-A*0201-transfected K562 cells for immune monitoring

BACKGROUND

Development of a practical and sensitive assay for evaluating immune responses against cancer Ag has been a challenge for immune monitoring of patients. We have established a reproducible method using peptide-pulsed K562-A*0201 cells as APC to expand Ag-specific T cells in vitro. This method may be applied for monitoring T-cell responses in cancer immunotherapy clinical trials.

METHODS

Autologous PBMC from HLA-A*0201+ healthy donors and patients with melanoma were stimulated with peptide-pulsed K562-A*0201 cells under varying conditions. We investigated (1) different culture conditions, including the requirements for serum and cytokines for expansion of CD8+ T lymphocytes; (2) a range of peptide concentrations for Ag loading; (3) phenotypic characterization of responding T cells; and (4) APC:responder ratios and their effects on T-cell expansion. We validated these conditions by ELISPOT and intracellular cytokine staining (ICS) assays using peptides from influenza, Epslein-Barr Virus (EBV) and tyrosinase.

RESULTS

Conditions for optimal T-cell expansion using K562-A*0201 APC included input of 2 x 10(6) PBMC, a 10 microg/mL peptide concentration to pulse K562-A*0201 cells, a 1:30 APC:responder T-cell ratio and culture in 10% autologous plasma supplemented with IL-2 and IL-15. In these conditions, Ag-specific T cells expanded >100-fold over a 10-day culture period (peak at day 12).

DISCUSSION

This bulk culture method is simple and reliable for expanding human Ag-specific T cells using peptide-pulsed K562-A*0201 cells. This HLA-matched APC line can be adapted to other HLA haplotypes, and has advantages for monitoring clinical trials of immunotherapy with limited availability of autologous APC and PBMC from patients.

Relationships between sediment microbial communities and pollutants in two California salt marshes

Salt marshes are important ecosystems whose plant and microbial communities can alter terrestrially derived pollutants prior to coastal water discharge. However, knowledge regarding relationships between anthropogenic pollutant levels and salt marsh microbial communities is limited, and salt marshes on the West Coast of the United States are rarely examined. In this study, we investigated the relationships between microbial community composition and 24 pollutants (20 metals and 4 organics) in two California salt marshes. Multivariate ordination techniques were used to assess how bacterial community composition, as determined by terminal restriction fragment length polymorphism and phospholipid fatty acid analyses, was related to pollution. Sea urchin embryo toxicity measurements and plant tissue metabolite profiles were considered two other biometrics of pollution. Spatial effects were strongly manifested across marshes and across channel elevations within marshes. Utilizing partial canonical correspondence analysis, an ordination technique new to microbial ecology, we found that several metals were strongly associated with microbial community composition after accounting for spatial effects. The major patterns in plant metabolite profiles were consistent with patterns across microbial community profiles, but sea urchin embryo assays, which are commonly used to evaluate ecological toxicity, had no identifiable relationships with pollution. Whereas salt marshes are generally dynamic and complex habitats, microbial communities in these marshes appear to be relatively sensitive indicators of toxic pollutants.

Antepartum immunoprophylaxis of three doses of hepatitis B immunoglobulin is not effective: a single-centre randomized study

To investigate the efficacy of antepartum administration of three doses of hepatitis B immunoglobulin (HBIg), currently being used in China, 250 pregnant women who were seropositive for hepatitis B e antigen (HBeAg) were randomly divided into study (117 cases) and control groups (133 cases). Subjects in the study group received HBIg 400 IU intramuscularly once a month at the third, second and first month before delivery; subjects in the control group received no antepartum treatment. All neonates received passive-active immunization after birth. The maternal hepatitis B virus (HBV) markers, hepatitis B surface antigen (HBsAg) titres and HBV deoxyribonucleic acid (DNA) levels were measured at week 28 of gestation (before the antepartum treatment) and at labour; the neonatal serum HBV markers were detected at birth and at 12 months after birth. No side-effects were found in any of the women or their neonates. No statistical differences were seen between the maternal HBsAg and HBV DNA levels of the study and control groups at labour nor the protective efficacy rates of postnatal immunoprophylaxis at 12 months after birth (P > 0.05, respectively). To conclude, antepartum administration of three doses of HBIg for the HBeAg-positive women is inefficacious.

Histopathological characteristics of a novel knock-in mouse prostate cancer model

Prostate cancer is relatively unique to man. There is no naturally occurring prostate cancer in the mouse. Pre-clinical studies involve the establishment of a genetically engineered mouse prostate cancer model with features close to those of the human situation. A new knock-in mouse adenocarcinoma prostate (KIMAP) model was established, which showed close-to-human kinetics of tumor development. In order to determine if the similar kinetics is associated with heterogeneous tumor architecture similar to the human situation, we utilized a new mouse histological grading system (Gleason analogous grading system) similar to the Gleason human grading system and flow cytometry DNA analysis to measure and compare the adenocarcinoma of the KIMAP model with human prostate cancer. Sixty KIMAP prostate cancer samples from 60 mice were measured and compared with human prostate cancer. Flow cytometry DNA analysis was performed on malignant prostate tissues obtained from KIMAP models. Mice with prostate cancer from KIMAP models showed a 53.3% compound histological score rate, which was close to the human clinical average (50%) and showed a significant correlation with age (P = 0.001). Flow cytometry analyses demonstrated that most KIMAP tumor tissues were diploid, analogous to the human situation. The similarities of the KIMAP mouse model with tumors of the human prostate suggest the use of this experimental model to complement studies of human prostate cancer.

Stable gene silencing of cyclin B1 in tumor cells increases susceptibility to taxol and leads to growth arrest in vivo

Cyclin B1 is the regulatory subunit of cyclin-dependent kinase 1 (Cdk1) and is critical for the initiation of mitosis. Accumulating data indicate that the deregulation of cyclin B1 is tightly linked to neoplastic transformation. To study the phenotype and the potential preclinical relevance, we generated HeLa cell lines stably transfected with the plasmids encompassing short hairpin RNA (shRNA) targeting cyclin B1. We demonstrate that the reduction of cyclin B1 caused inhibition of proliferation by arresting cells in G2 phase and by inducing apoptosis. Cells, entering mitosis, were impaired in chromosome condensation and alignment. Importantly, HeLa cells with reduced cyclin B1 were more susceptible to the treatment of small interfering RNA targeting Polo-like kinase 1 (Plk1) and to the administration of the chemotherapeutic agent taxol. Finally, HeLa cells with reduced cyclin B1 showed inhibited tumor growth in nude mice compared to that of control cells. In summary, our data indicate that cyclin B1 is an essential molecule for tumor cell survival and aggressive proliferation, suggesting that the downregulation of cyclin B1, especially in combination with other molecular targets, might become an interesting strategy for antitumor intervention.

Cellular response to endoplasmic reticulum stress: a matter of life or death

The proper functioning of the endoplasmic reticulum (ER) is critical for numerous aspects of cell physiology. Accordingly, all eukaryotes react rapidly to ER dysfunction through a set of adaptive pathways known collectively as the ER stress response (ESR). Normally, this suite of responses succeeds in restoring ER homeostasis. However, in metazoans, persistent or intense ER stress can also trigger programmed cell death, or apoptosis. ER stress and the apoptotic program coupled to it have been implicated in many important pathologies but the regulation and execution of ER stress-induced apoptosis in mammals remain incompletely understood. Here, we review what is known about the ESR in both yeast and mammals, and highlight recent findings on the mechanism and pathophysiological importance of ER stress-induced apoptosis.

Efficient production of laccases by Trametes sp. AH28-2 in cocultivation with a Trichoderma strain

A biocontrol fungus isolated from rotting wood was identified as a Trichoderma strain (named as Trichoderma sp. ZH1) by internal transcribed spacer (ITS) sequences of rRNA genes. The laccase yield of Trametes sp. AH28-2 in cocultivation with Trichoderma sp. ZH1 reached 6,210 U l(-1), approximately identical to those induced by toxic aromatic inducers. Cocultures maintained 60-70 % of their highest laccase activity obtained at 5 days after inoculation of the biocontrol fungus, at least for 20 days. Furthermore, a novel laccase isozyme (LacC) was obtained through the fungal interactions. The molecular weight of LacC is about 64 kDa, and its isoelectric point is 6.6. The temperature and pH optimum for LacC to oxidize guaiacol are 55 degrees C and 5.0, respectively. LacC is stable both at 60 degrees C and pH 4.0-8.0. Furthermore, the K (m) values of LacC for various substrates were also determined. Our work demonstrates a safe strategy for the production of industrial laccases, instead of the traditional method of chemical induction.

Cytogenetic mapping of 11 functional genes to chicken chromosomes by fluorescence in situ hybridization

With chicken bacterial artificial chromosome (BAC) DNA as probes, 11 non-assigned functional genes were localized to chicken chromosomes 1 or 2 by fluorescence in situ hybridization (FISH). The 11 genes and their chromosomal positions are as follows: ALVEB5, 1p26-24; ACO2, 1p16-14; HSP108, 1p14-13; CD4, 1q11; HSD3B; 1q11; SOD1, 1q14-21; LAMP1, 1q24-31; P2Y5, 1q35-36; EN2, 2p31-24; NPY, 2p14-13 and CA2, 2q31-32. Metaphase chromosome spreads used for hybridization were prepared from embryonic chicken fibroblast cultures. The gene position was identified according to the international standardized G-banded karyotype of chicken by measuring the relative fractional length from the telomere of the p-arm to the hybridization signal (FLpter). The 11 genes mapped newly will enrich the cytogenetic map and serve as additional anchor markers for integrating the cytogenetic map with the genetic map of chicken.

Gain of 1q25–32, 12q23–24.3, and 17q12–22 facilitates tumorigenesis and progression of human squamous cell lung cancer

To explore the genetic changes involved in the stepwise development of lung cancer, we have determined the genetic events associated with the histological progression from normal bronchial epithelium to squamous cell carcinoma. Comparative genomic hybridization was used to identify chromosomal imbalances in 54 microdissected samples, including squamous metaplasia, dysplasia, carcinoma in situ, and invasive tumour derived from 23 patients with squamous cell carcinoma of the lung. Histopathological progression was accompanied by an increased number of chromosomal abnormalities. Gains of 1q25-32, 12q23-24.3, and 17q12-22, in particular, were detected at high frequencies in both carcinoma in situ and invasive tumours and were found more often in the cases with lymph node metastases than in those without. Our previous expression profiling of squamous cell carcinomas had identified overexpression of laminin5 gamma2, a gene located at 1q25-31. Therefore, this was investigated at the protein level by immunohistochemical analysis in 336 samples of squamous cell carcinoma of the lung. Consistent with the genomic data for this region, the expression level of laminin5 gamma2 was higher in the primary tumours with lymph node metastases than in tumours without metastases (p = 0.012). These data suggest that gains of genes from 1q25-32, 12q23-24.3, and 17q12-22 facilitate tumorigenesis and progression of squamous cell carcinoma of the lung, and may serve as potential predictors for this disease.

Inhibition of glycogen synthase kinase 3beta suppresses coxsackievirus-induced cytopathic effect and apoptosis via stabilization of beta-catenin

Coxsackievirus B3 (CVB3), a common human pathogen for viral myocarditis, induces a direct cytopathic effect (CPE) and apoptosis on infected cells. To elucidate the mechanisms that contribute to these processes, we studied the role of glycogen synthase kinase 3beta (GSK3beta). GSK3beta activity was significantly increased after CVB3 infection and addition of tyrosine kinase inhibitors blocked CVB3-triggered GSK3beta activation. Inhibition of caspase activity had no inhibitory effect on CVB3-induced CPE; however, blockage of GSK3beta activation attenuated both CVB3-induced CPE and apoptosis. We further showed that CVB3 infection resulted in reduced beta-catenin protein expression, and GSK3beta inhibition led to the accumulation and nuclear translocation of beta-catenin. Finally, we found that CVB3-induced CPE and apoptosis were significantly reduced in cells stably overexpressing beta-catenin. Taken together, our results demonstrate that CVB3 infection stimulates GSK3beta activity via a tyrosine kinase-dependent mechanism, which contributes to CVB3-induced CPE and apoptosis through dysregulation of beta-catenin.

cDNA cloning, genomic structure, chromosomal mapping and expression analysis of ADIPOQ (adiponectin) in chicken

We report sequence, tissue expression and map position data for the adiponectin gene (ADIPOQ) in chicken. This gene is involved in adipocyte differentiation in mammals and may play similar roles in chicken. The complete coding sequence of chicken ADIPOQ encodes a 244 amino acid protein. The coding region of the chicken ADIPOQ is organized in two exons and spans an approximately 2.1 kb genomic region. Domain/motif structures of the adiponectin protein among chicken and mammalian homologs are highly conserved. Reverse transcription-PCR revealed chicken ADIPOQ mRNA displayed high expression levels in fat tissue, heart, stomach and skin and weak expression in muscle. Analysis of a radiation hybrid panel indicated that ADIPOQ showed the most significant linkage to FOXL2 (LOD = 12.63, 12 cR) and ATSV (LOD = 7.53, 3 cR) both of which are located on chicken chromosome 9. Information provided in this study will be useful in further studies to determine the role the adiponectin gene plays in the regulation of glucose and lipid metabolism and body weight in chicken.

Monte Carlo charged-particle tracking and energy deposition on a Lagrangian mesh

A Monte Carlo algorithm for alpha particle tracking and energy deposition on a cylindrical computational mesh in a Lagrangian hydrodynamics code used for inertial confinement fusion (ICF) simulations is presented. The straight line approximation is used to follow propagation of "Monte Carlo particles" which represent collections of alpha particles generated from thermonuclear deuterium-tritium (DT) reactions. Energy deposition in the plasma is modeled by the continuous slowing down approximation. The scheme addresses various aspects arising in the coupling of Monte Carlo tracking with Lagrangian hydrodynamics; such as non-orthogonal severely distorted mesh cells, particle relocation on the moving mesh and particle relocation after rezoning. A comparison with the flux-limited multi-group diffusion transport method is presented for a polar direct drive target design for the National Ignition Facility. Simulations show the Monte Carlo transport method predicts about earlier ignition than predicted by the diffusion method, and generates higher hot spot temperature. Nearly linear speed-up is achieved for multi-processor parallel simulations.

Magnesium supplementation prevents chronic cyclosporine nephrotoxicity via adjusting nitric oxide synthase activity

INTRODUCTION

Nitric oxide synthase (NOS) is a protective factor for chronic cyclosporine nephrotoxicity by virtue of adjusting the production of nitric oxide (NO). The aim of this study was to explore the role of NOS in the effect of magnesium supplementation to prevent chronic cyclosporine nephrotoxicity.

METHODS

Rats maintained on a low-salt diet were divided into three groups: normal controls, cyclosporine group (CsA 15 mg x kg(-1) x d(-1) subcutaneously) and CsA + Mg2+ group (CsA subcutaneously and dietary supplementation with 0.6% Mg enriched by MgCl2). On day 28, plasma Mg2+, plasma creatinine, NOS activity, and NO content in renal tissue were examined. The renal expression of endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) in kidneys was determined by an immunohistochemistry technique. The lesions of chronic cyclosporine nephrotoxicity were identified by HE and PAS stains as well as electron microscope.

RESULTS

After 28 days of CsA administration, characteristic histological lesions of chronic cyclosporine nephotoxicity were observed, including arteriolopathy, tubular atrophy and interstitial fibrosis. Giant mitochondria and microcalcifications were observed by electron microscopy. Simultaneously, constitutive nitric oxide synthase (cNOS) activity in kidneys was increased, but NO content did not increase correspondingly (P < .05) compared with normal controls. Dietary supplementation with Mg2+ ameliorated the CsA-induced histological lesions. cNOS activity was decreased to normal levels and NOS was increased (P < .05) compared with animals that only received CsA. CsA and magnesium supplementation did not change iNOS activity.

CONCLUSIONS

Dietary supplementation with Mg2+ seems to improve renal function and almost abolish CsA-induced histological lesions via altering the abnormal activation of cNOS in this model.