Apolipoprotein E2 inhibits mitochondrial apoptosis in pancreatic cancer cells through ERK1/2/CREB/BCL-2 signaling.

BACKGROUND: Apolipoprotein E2 (ApoE2) is a pleiotropic protein that influences several aspects of cancer metabolism and development. Evading apoptosis is a vital factor for facilitating cancer cell growth. However, the role and mechanism of ApoE2 in regulating cell apoptosis of pancreatic cancer remain unclear. METHODS: In this study, we firstly detected the mRNA and protein expressions of ApoE2 in PANC-1 and Capan-2 cells by real-time polymerase chain reaction and Western blotting. We then performed TUNEL and flow cytometric analyses to explore the role of recombinant human ApoE2, pCMV6-ApoE2 and siApoE2 in the apoptosis of PANC-1 and Capan-2 cells. Furthermore, we investigated the molecular mechanism through which ApoE2 affected apoptosis in PANC-1 cells using immunofluorescence, immunoprecipitation, Western blotting and co-immunoprecipitation analysis. RESULTS: ApoE2 phosphorylated ERK1/2 and inhibited pancreatic cancer cell apoptosis. In addition, our data showed that ApoE2/ERK1/2 altered the expression and mitochondrial localization of BCL-2 via activating CREB. ApoE2/ERK1/2/CREB also increased the total BCL-2/BAX ratio, inhibited the opening of the mitochondrial permeability transition pore and the depolarization of mitochondrial transmembrane potential, blocked the leakage of cytochrome-c and the formation of the apoptosome, and consequently, suppressed mitochondrial apoptosis. CONCLUSIONS: ApoE2 regulates the mitochondrial localization and expression of BCL-2 through the activation of the ERK1/2/CREB signaling cascade to evade the mitochondrial apoptosis of pancreatic cancer cells. ApoE2 may be a distinct prognostic marker and a potential therapeutic target for pancreatic cancer.

Segmentation Method for Ship-Radiated Noise Using the Generalized Likelihood Ratio Test on an Ordinal Pattern Distribution.

Due to the diversity of ship-radiated noise (SRN), audio segmentation is an essential procedure in the ship statuses/categories identification. However, the existing segmentation methods are not suitable for the SRN because of the lack of prior knowledge. In this paper, by a generalized likelihood ratio (GLR) test on the ordinal pattern distribution (OPD), we proposed a segmentation criterion and introduce it into single change-point detection (SCPD) and multiple change-points detection (MCPD) for SRN. The proposed method is free from the acoustic feature extraction and the corresponding probability distribution estimation. In addition, according to the sequential structure of ordinal patterns, the OPD is efficiently estimated on a series of analysis windows. By comparison with the Bayesian Information Criterion (BIC) based segmentation method, we evaluate the performance of the proposed method on both synthetic signals and real-world SRN. The segmentation results on synthetic signals show that the proposed method estimates the number and location of the change-points more accurately. The classification results on real-world SRN show that our method obtains more distinguishable segments, which verifies its effectiveness in SRN segmentation.

Low Complexity Equalization of Orthogonal Chirp Division Multiplexing in Doubly-Selective Channels.

Orthogonal Chirp Division Multiplexing (OCDM) is a modulation scheme which outperforms the conventional Orthogonal Frequency Division Multiplexing (OFDM) under frequency selective channels by using chirp subcarriers. However, low complexity equalization algorithms for OCDM based systems under doubly selective channels have not been investigated yet. Moreover, in OCDM, the usage of different phase matrices in modulation will lead to extra storage overhead. In this paper, we investigate an OCDM based modulation scheme termed uniform phase-Orthogonal Chirp Division Multiplexing (UP-OCDM) for high-speed communication over doubly selective channels. With uniform phase matrices equipped, UP-OCDM can reduce the storage requirement of modulation. We also prove that like OCDM, the transform matrix of UP-OCDM is circulant. Based on the circulant transform matrix, we show that the channel matrices in UP-OCDM system over doubly selective channels have special structures that (1) the equivalent frequency-domain channel matrix can be approximated as a band matrix, and (2) the transform domain channel matrix in the framework of the basis expansion model (BEM) is a sum of the product of diagonal and circulant matrices. Based on these special channel structures, two low-complexity equalization algorithms are proposed for UP-OCDM in this paper. The equalization algorithms are based on block LDL H factorization and iterative matrix inversion, respectively. Numerical simulations are finally proposed to show the performance of UP-OCDM and the validity of the proposed low complexity equalization algorithms. It is shown that when the channel is doubly selective, UP-OCDM and OCDM have similar BER performance, and both of them outperform OFDM. Moreover, the proposed low complexity equalizers for UP-OCDM both show better BER performance than their OFDM counterparts.

Application of Differential Entropy in Characterizing the Deformation Inhomogeneity and Life Prediction of Low-Cycle Fatigue of Metals.

The relation between deformation inhomogeneity and low-cycle-fatigue failure of T2 pure copper and the nickel-based superalloy GH4169 under symmetric tension-compression cyclic strain loading is investigated by using a polycrystal representative volume element (RVE) as the material model. The anisotropic behavior of grains and the strain fields are calculated by crystal plasticity, taking the Bauschinger effect into account to track the process of strain cycles of metals, and the Shannon's differential entropies of both distributions of the strain in the loading direction and the first principal strain are employed at the tension peak of the cycles as measuring parameters of strain inhomogeneity. Both parameters are found to increase in value with increments in the number of cycles and they have critical values for predicting the material's fatigue failure. Compared to the fatigue test data, it is verified that both parameters measured by Shannon's differential entropies can be used as fatigue indicating parameters (FIPs) to predict the low cycle fatigue life of metal.

WNT5A modulates cell cycle progression and contributes to the chemoresistance in pancreatic cancer cells.

BACKGROUND: Although there are many studies on the mechanism of chemoresistance in cancers, studies on the relations between WNT5A and chemoresistance in pancreatic cancer are rare. The present study was to examine the role of WNT5A in the regulation of cell cycle progression and in chemo-resistance in pancreatic cancer tissues and cell lines. METHODS: Fresh pancreatic cancer and paracarcinoma tissues were obtained from 32 patients. The expressions of WNT5A, AKT/p-AKT and Cyclin D1 were detected by immunohistochemistry, and the correlation between WNT5A expression and clinicopathological characteristics was analyzed. The relationship between WNT5A expression and gemcitabine resistance was studied in PANC-1 and MIAPaCa2 cell lines. The effect of WNT5A on the regulation of cell cycle and gemcitabine cytotoxicity were investigated. The associations among the expressions of p-AKT, Cyclin D1 and WNT5A were also analyzed in cell lines and the effect of WNT5A on restriction-point (R-point) progression was evaluated. RESULTS: WNT5A, p-AKT and Cyclin D1 were highly expressed in pancreatic cancer tissues, and the WNT5A expression was correlated with the TNM stages. In vitro, WNT5A expression was associated with gemcitabine chemoresistance. The percentage of cells was increased in G0/G1 phase and decreased in S phase after knockdown of WNT5A in PANC-1. WNT5A promoted Cyclin D1 expression through phosphorylation of AKT which consequently enhanced G1-S transition and gemcitabine resistance. Furthermore, WNT5A enhanced the cell cycle progression toward R-point through regulation of retinoblastoma protein (pRb) and pRb-E2F complex formation. CONCLUSIONS: WNT5A induced chemoresistance by regulation of G1-S transition in pancreatic cancer cells. WNT5A might serve as a predictor of gemcitabine response and as a potential target for tumor chemotherapy.

Inhibiting effect of Astragalus polysaccharides on the functions of CD4+CD25 highTreg cells in the tumor microenvironment of human hepatocellular carcinoma.

BACKGROUND: Astragalus polysaccharides (APS), the main active extract from Astragalus membranaceus (a traditional Chinese medicinal herb), is associated with a variety of immunomodulatory activities. The purpose of the present study was to examine the effect of APS on the function of Treg cells in the tumor microenvironment of human hepatocellular carcinoma (HCC) and to identify the pharmacologic mechanism of APS responsible for the anti-chemotactic activity in CD4+CD25highTreg cells in tumor site of HCC. METHODS: The prevalence of Treg in fresh tissue samples from 31 patients with HCC after radicalhepatectomy was detected. CD4, CD25 and CD127 were selected as Treg cell makers to phenotype cell populations. The expression of FOXp3 mRNA was also analyzed. The migration and proliferation of Treg cells were observed. Interleukin (IL)-4, IL-10, IFN-γ and SDF-1 in cell supernatant were detected. For all tests, functions of Treg cells were evaluated after treatment with APS. RESULTS: APS can inhibit the growth and proliferation of CD4+CD25+Treg cells in vitro in a dose- and time-dependent manner. APS may inhibit CD4+CD25+Treg cells through restoring the cytokine imbalance and reducing the expression of FOXp3 in local HCC microenvironments. SDF-1 played an important role in there recruitment of Treg cells into the tumor microenvironment of HCC. APS might have inhibiting effects on Treg cell migration by blocking SDF-1 or its receptor through the CXCR4/CXCL12 pathway. CONCLUSIONS: The increase in numbers of tumor associated Treg cells might play a role in modulation of the immune response against HCC. APS can restore the cytokine balance in the tumor micro environment and suppress the expression of FOXp3 mRNA to inhibit the immune suppressive effects of Treg cells. The application of APS in the tumor microenvironment might act to enhance the anti-tumor effects of the immunotherapy-based methods, and consequently to increase the survival rate in HCC.

[The short term therapeutic effects of radioactive (125)I seeds implantation for treatment of non-small-cell lung cancer].

OBJECTIVE: To explore influential factors of local therapeutic effect in CT guided brachytherapy of (125)I seeds for non-small-cell lung carcinoma (NSCLC). METHODS: Totally 141 primary NSCLC patients diagnosed by bronchoscope or puncture biopsy were treated with CT guided (125)I seeds implantation treatment from 2003 January to 2005 January. Among them, 26 patients were treated with seeds implantation only and remaining 115 combined with chemical therapy. Preplans were performed by using treatment planning system before the implantation. We took the implantation with the prescription dose of 80 - 110 Gy, 1 seed per 1 cm(3), under the guide of computed tomography. Six months after implantation treatment, CT graphs were taken to evaluate the therapeutic effect. RESULTS: All the patients were survival until 6 months after implantation, and 37 were complete remission, 93 were partial remissions. The effective rate was 92.2%. Among all the observed factors, pathologic type(F = 5.162, P = 0.023), dose of cover 100% tumor (D(100)) (F = 100.713, P = 0.000) and treatment methods (F = 16.205, P = 0.000) were the independent influent factors (P < 0.05). Among these, D(100) was the most important factor (P = 0.000). Single factor analysis indicated that pathologic type (χ(2) = 7.313, P = 0.007), D(100) (χ(2) = 71.6, P = 0.000) and treatment methods (χ(2) = 20.5, P = 0.000) were significant influent factors. Of all 141 cases, 24 had complications during or after implantation treatment, while no severe complications were reported. There was no significant correlation between complication and local therapeutic effect (P > 0.05). CONCLUSION: CT guided implantation of (125)I seeds for lung cancer has good clinical effects and few complications. D(100) is the most important factor to influence the local therapeutic effect. Implantation treatment combined with chemotherapy is an ideal measure for NSCLC treatment.

Specific binding of activated Vip3Aa10 to Helicoverpa armigera brush border membrane vesicles results in pore formation.

Helicoverpa armigera is one of the most harmful pests in China. Although it had been successfully controlled by Cry1A toxins, some H. armigera populations are building up resistance to Cry1A toxins in the laboratory. Vip3A, secreted by Bacillus thuringiensis, is another potential toxin against H. armigera. Previous reports showed that activated Vip3A performs its function by inserting into the midgut brush border membrane vesicles (BBMV) of susceptible insects. To further investigate the binding of Vip3A to BBMV of H. armigera, the full-length Vip3Aa10 toxin expressed in Escherichia coli was digested by trypsin or midgut juice extract, respectively. Among the fragments of digested Vip3Aa10, only a 62kDa fragment (Vip3Aa10-T) exhibited binding to BBMV of H. armigera and has insecticidal activity. Moreover, this interaction was specific and was not affected by the presence of Cry1Ab toxin. Binding of Vip3Aa10-T to BBMV resulted in the formation of an ion channel. Unlike Cry1A toxins, Vip3Aa10-T was just slightly associated with lipid rafts of BBMV. These data suggest that although activated Vip3Aa10 specifically interacts with BBMV of H. armigera and forms an ion channel, the mode of action of it may be different from that of Cry1A toxins.

Effect of antiallergic herbal agents on chloride channel-3 and immune microenvironment in nasal mucosal epithelia of allergic rhinitis rabbits.

BACKGROUND: Allergic rhinitis (AR) is a Th2 dominant cytokine response. Chloride channel-3 (ClC-3) plays an important role in nasal mucosal edema and inflammatory pathologic changes in AR. Antiallergic herbal agents (AHA) are antiallergic herbal products. In the previous study, we have demonstrated that AHA clearly inhibited allergic medium and relieved allergic reaction of AR. The aim of this study was to evaluate the function of ClC-3 and discuss the possible therapeutic effects of AHA on immune microenvironment in AR. METHODS: AHA were produced and used to treat AR. An animal model of an AR rabbit was established by ovalbumin (OVA). The rhinitis rabbits were randomly divided into three groups: AHA treated group (AHATG), model group (MG) and healthy control group (HCG). The expressions of ClC-3 protein were examined by immunohistochemical method. The mucosal epithelial cells of all the rabbit groups were primarily cultured with tissue culture method in vitro with or without rhIL-4 or rhIL-2. Furthermore, the expressions of ClC-3 mRNA were detected by real-time PCR. The levels of monocyte chemotactic factor-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) protein in culture supernatants were measured by ELISA. RESULTS: The expressions of ClC-3 mRNA increased more in mucosal epithelial cells of MG than those in AHATG and HCG (P < 0.01). The levels of ClC-3 mRNA, MCP-1 and VCAM-1 protein in culture supernatants of MG were significantly higher than those in the other two groups (P < 0.01). Those were significantly increased in MG untreated 12 hours later than those in other two groups (P < 0.01). The expressions of ClC-3 mRNA, MCP-1 and VCAM-1 protein in culture supernatants of MG and HCG treated with rhIL-4 were significantly higher than those in the AHATG treated with rhIL-4 (P < 0.01). The levels of ClC-3 mRNA, MCP-1 and VCAM-1 protein in culture supernatants of all groups treated with rhIL-2 showed no significant changes (P > 0.05). CONCLUSIONS: AHA can inhibit the secretions of ClC-3, MCP-1 and VCAM-1 in mucosal epithelia and improve inflammatory reaction of AR. ClC-3 plays an important role in the secretion of cytokines and mucosal inflammatory response in AR. RhIL-4 can enhance the secretion of ClC-3, MCP-1 and VCAM-1 in mucosal epithelial cells, especially during the AR process. These enhanced effects of rhIL-4 were significantly suppressed by AHA. The secretions of ClC-3, MCP-1 and VCAM-1 can not be induced obviously by rhIL-2 in mucosal epithelial cells in AR.

Effects of antiallergic herbal agents on cystic fibrosis transmembrane conductance regulator in nasal mucosal epithelia of allergic rhinitis rabbits.

BACKGROUND: It has been found that the expression of cystic fibrosis transmembrane conductance regulator (CFTR) is closely related to allergic rhinitis (AR). In the previous study, we have demonstrated that antiallergic herbal agents (AHA) can obviously inhibit the allergic reaction of AR. The aim of this study was to explore the expression of CFTR and the effects of AHA on CFTR to improve the allergic reaction of AR. METHODS: An animal model of an AR rabbit was established using ovalbumin (OVA). The rhinitis rabbits were randomly assigned to three groups: AHA treating group (AHATG), modeling group (MG) and healthy controlling group (HCG). The expressions of CFTR protein were examined by immunohistochemical method. The mucosal epithelial cells of all the rabbits were primarily cultured with tissue culture method in vitro and treated with or without glibenclamide for 24 hours. The levels of monocyte chemotactic factor-1 (MCP-1) and RANTES protein in supernatants of culture were measured by ELISA, and the expressions of CFTR mRNA were detected by real-time PCR. RESULTS: The expressions of CFTR mRNA and protein greatly increased in mucosal epithelial cells of MG. The protein concentrations of MCP-1, RANTES in culture supernatants of MG were significantly higher than those in the other two groups (P < 0.01), and they reached much higher level than those at the start points in the MG (P < 0.05) and were significantly different compared with those in the AHATG after being cultured for 24 hours (P < 0.01). CFTR mRNA in MG + glibenclamide were much lower than those in MG (P < 0.05). RANTES and CFTR mRNA treated with glibenclamide in AHATG were significantly lower than those in the AHATG (P < 0.01). Minimal changes in the secretions of MCP-1 in the epithelial cells were detected between AHATG and AHATG + glibenclamide (P > 0.05). CONCLUSIONS: AHA can inhibit the secretions of CFTR, RANTES and MCP-1 in mucosal epithelia and improve inflammatory reaction of AR. CFTR may play an important role in the secretion of RANTES and mucosal inflammatory response in AR. Glibenclamide can inhibit the CFTR secretion in mucosal epithelial cells, in particular during AR process. These effects of glibenclamide on secretion of RANTES can be effectively strengthened by AHA.