Social insect cuticular hydrocarbon (CHC) mixtures are among the most complex chemical cues known and are important in nest-mate, caste and species recognition. Despite our growing knowledge of the nature of these cues, we have very little insight into how social insects actually perceive and discriminate among these chemicals. In this study, we use the newly developed technique of differential olfactory conditioning to pure, custom-designed synthetic colony odours to analyse signal discrimination in Argentine ants, Linepithema humile. Our results show that tri-methyl alkanes are more easily learned than single-methyl or straight-chain alkanes. In addition, we reveal that Argentine ants can discriminate between hydrocarbons with different branching patterns and the same chain length, but not always between hydrocarbons with the same branching patterns but different chain length. Our data thus show that biochemical characteristics influence those compounds that ants can discriminate between, and which thus potentially play a role in chemical signalling and nest-mate recognition.

Background

Previous investigation has demonstrated that CD4+ T cells play a crucial role in effective immunity against Helicobacter pylori (H.pylori) infection. It has been well proved that Lpp20 is one of major protective antigens that induce immune responses after H.pylori invades host. Therefore it is valuable to identify CD4+ T cell epitopes on Lpp20, which is uncharacterized.

Methods

Putative epitopes of H-2d restricted CD4+ T cell on Lpp20 of H.pylori were predicted by the SYFPEITHI algorithm and then eight hypothetical epitope peptides were synthesized. After BALB/c mice were primed with recombinant Lpp20, splenic CD4+ T cells were isolated and stimulated with synthesized peptides to measure T cell proliferation and MHC restriction. Cytokine profile was determined by ELISA and real-time PCR. Two identified epitopes were used to immunize mice to investigate CD4+ T cell response by flow cytometry.

Results

Two of eight peptides were able to stimulate CD4+ T cell proliferation and were mapped to residues 83-97aa and 58-72aa on Lpp20 respectively. These two peptides additively stimulated Th1 cells to secrete IFN-γ. The percentage of CD4+ T cell from mice immunized with two identified epitopes respectively was higher than the control group.

Conclusion

The identification and characterization of two CD4+ T cell epitopes of Lpp20 helps understand the protective immunity of Lpp20 in H.pylori infection and design effective epitope vaccines against H.pylori.

Background

MicroRNAs (miRNAs) are small, non-coding RNAs capable of postranscriptionally regulating gene expression. Accurate expression profiling is crucial for understanding the biological roles of miRNAs, and exploring them as biomarkers of diseases.

Methodology/Principal Findings

A novel, highly sensitive, and reliable miRNA quantification approach,termed S-Poly(T) miRNA assay, is designed. In this assay, miRNAs are subjected to polyadenylation and reverse transcription with a S-Poly(T) primer that contains a universal reverse primer, a universal Taqman probe, an oligo(dT)11 sequence and six miRNA-specific bases. Individual miRNAs are then amplified by a specific forward primer and a universal reverse primer, and the PCR products are detected by a universal Taqman probe. The S-Poly(T) assay showed a minimum of 4-fold increase in sensitivity as compared with the stem-loop or poly(A)-based methods. A remarkable specificity in discriminating among miRNAs with high sequence similarity was also obtained with this approach. Using this method, we profiled miRNAs in human pulmonary arterial smooth muscle cells (HPASMC) and identified 9 differentially expressed miRNAs associated with hypoxia treatment. Due to its outstanding sensitivity, the number of circulating miRNAs from normal human serum was significantly expanded from 368 to 518.

Conclusions/Significance

With excellent sensitivity, specificity, and high-throughput, the S-Poly(T) method provides a powerful tool for miRNAs quantification and identification of tissue- or disease-specific miRNA biomarkers.

The contemporary problem of prostate cancer overtreatment can be partially attributed to the diagnosis of potentially indolent prostate cancers that pose low risk to aged men, and lack of sufficiently accurate risk stratification methods to reliably seek out men with indolent diseases. Since progressive acquisition and accumulation of genomic alterations, both genetic and epigenetic, is a defining feature of all human cancers at different stages of disease progression, it is hypothesized that RNA and DNA alterations characteristic of indolent prostate tumors may be different from those previously characterized in the setting of clinically significant prostate cancer. Approaches capable of detecting such alterations on a genome-wide level are the most promising. Such analysis may uncover molecular events defining early initiating stages along the natural history of prostate cancer progression, and ultimately lead to rational development of risk stratification methods for identification of men who can safely forego treatment. However, defining and characterizing indolent prostate cancer in a clinically relevant context remains a challenge, particularly when genome-wide approaches are employed to profile formalin-fixed paraffin-embedded (FFPE) tissue specimens. Here, we provide the conceptual basis underlying the importance of understanding indolent prostate cancer from molecular profiling studies, identify the key hurdles in sample acquisition and variables that affect molecular data derived from FFPE tissues, and highlight recent progresses in efforts to address these technical challenges.

We report on a novel binding gel for phosphate, based on ferrihydrite, and its use in diffusive gradients in thin films (DGT) for measuring labile phosphate species in waters, sediments, and soils. An existing method of binding layer preparation was modified to overcome potential problems with deterioration of ferrihydrite due to conversion to goethite. The gel was characterized regarding its suitability for conventional DGT measurements as well as for measuring two-dimensional distributions of P with high spatial resolution using laser ablation-inductively coupled plasma mass spectrometry (LA-ICPMS). The effects of pH, ionic strength and storage time of gels on phosphate binding were investigated and the kinetics of binding and the maximum binding capacity were determined. The gel is shown to have a considerably higher P capacity than the conventional ferrihydrite DGT binding layers. LA-ICPMS analysis of DGT standards with P concentrations ranging from 0.088 ± 0.005 to 4.47 ± 0.16 μg cm−2 resulted in reproducible calibration curves which could be described using a simple power function. We demonstrate that the new gel is well suited for analyzing small-scale changes of P concentrations in soils. Moreover, the gel can be used as an alternative to conventional DGT gels that incorporate powdered ferrihydrite, with improved characteristics for the determination of labile phosphate.

Comment on: Rokavec M, et al. Mol Cell 2012; 45:777-89.

Erianthus arundinaceum is a wild relative species of sugarcane. The aim of this research was to demonstrate the feasibility of cDNA-SRAP for differential gene expression and to explore the molecular mechanism of drought resistance in E. arundinaceum. cDNA-SRAP technique, for the first time, was applied in the analysis of differential gene expression in E. arundinaceum under drought stress. In total, eight differentially expressed genes with length of 185–427 bp were successfully isolated (GenBank Accession numbers: EU071770, EU071772, EU071774, EU071776, EU071777, EU071779, EU071780, and EU071781). Based on their homologies with genes in GenBank, these genes were assumed to encode ribonuclease III, vacuolar protein, ethylene insensitive protein, aerobactin biosynthesis protein, photosystem II protein, glucose transporter, leucine-rich repeat protein, and ammonia monooxygenase. Real-time PCR analysis on the expression profiling of gene (EU071774) encoding ethylene-insensitive protein and gene (EU071781) encoding ammonia monooxygenase revealed that the expression of these two genes was upregulated both by PEG and ABA treatments, suggesting that they may involve in the drought resistance of E. arundinaceum. This study constitutes the first report of genes activated in E. arundinaceum by drought stress and opens up the application of cDNA-SRAP in differential gene expression analysis in E. arundinaceum under certain stress conditions.

Autologous adult cardiomyocytes are not utilized for heart repair strategies because of their rapid apoptosis after implantation. We examined whether induction of heme oxygenase-1 (HO-1), a mediator of preconditioning, could enhance early postimplant myocyte survival. Three-dimensional 5×5 mm patches of full-thickness adult murine atrial wall, including cardiomyocytes, capillary networks, and extracellular matrix, were cultured with or without HO-1 inducer cobalt protoporphyrin (CoPP), or the HO-1 inhibitor, tin protoporphyrin (SnPP), or both. Patches were then implanted subcutaneously. Freshly procured atrial wall patches implanted without preculturing served as additional controls. By 14 days postimplant, graft cardiomyocyte content was significantly greater in CoPP-treated patches than in either control group (p<0.02). Adult cardiomyocytes did not contract in culture or immediately after implantation. However, by 14 days postimplant, spontaneous contraction had recovered in 47% of CoPP-treated patches, but in only 6% of precultured patches without CoPP, 0% of SnPP-treated patches, and 0% of uncultured patches (p<0.03). CoPP-treated adult cardiomyocyte patches were also observed to remodel spontaneously into endothelial-lined chambers that pumped nonclotting blood. These findings demonstrate that adult cardiomyocytes have more plasticity and capacity for functional recovery than previously recognized and could have application as an autologous cardiomyocyte source for tissue engineering.

BACKGROUND

The diversity and complexity of the human androgen receptor (AR) splicing variants are well appreciated but not fully understood. The goal of this study is to generate a comprehensive expression signature of AR variants in castration-resistant prostate cancer (CRPC), and to address the relative importance of the individual variants in conferring the castration-resistant phenotype.

METHODS

A modified RNA amplification method, termed selective linear amplification of sense RNA, was developed to amplify all AR transcripts containing AR exon 3 in CRPC specimens, which were profiled using tiling expression microarrays. Coding sequences for the AR variants were cloned into expression vectors and assessed for their transcriptional activities. Quantitative RT-PCR was used to determine their in vivo expression patterns in an expanded set of clinical specimens.

RESULTS

In addition to expression peaks in AR intron 3, a novel AR exon, termed exon 9, was discovered. Exon 9 was spliced into multiple novel AR variants. Different AR splicing variants were functionally distinctive, with some demonstrating constitutive activity while others were conditionally active. Conditionally active AR-Vs may activate AR signaling depending on the cellular context. Importantly, AR variant functions did not appear to depend on the full-length AR.

CONCLUSIONS

This study provided the first unbiased snapshot of the AR variant signature consisting of multiple AR variants with distinctive functional properties, directly in CRPC specimens. Study findings suggest that the aggregate function of multiple AR variants may confer a castration-resistant phenotype independent of the full-length AR.

In the last two decades, the accumulation of heavy metal in crop grains has become the study hotspot. In this study, 19 representative elite maize inbred lines and 3 hybrid varieties were investigated at the seedling stage, which can accumulate Pb and Cd in the stems and leaves, respectively. The results demonstrated that significant differences are among inbred lines for accumulation of heavy metals, implying that the Cd accumulation is significant correlation between the male parents and their hybrids and some inbred lines have been selected for cross-breeding with low Pb or Cd accumulation, such as S37, 9782, and ES40; Moreover, some inbred lines could be suitable for phytoremediation species for soil bioremediation with high levels of Pb and Cd accumulation, including 178, R08, 48-2, and Mo17ht.

Purpose

Prostate cancer (PCa) is characterized by deregulated expression of several tumor suppressor or oncogenic miRNAs. The objective of this study was the identification and characterization of miR-let-7c as a potential tumor suppressor in PCa.

Experimental Design

Levels of expression of miR-let-7c were examined in human PCa cell lines and tissues using qRT-PCR and in situ hybridization. Let-7c was overexpressed or suppressed to assess the effects on the growth of human PCa cell lines. Lentiviral-mediated re-expression of let-7c was utilized to assess the effects on human PCa xenografts.

Results

We identified miR-let-7c as a potential tumor suppressor in PCa. Expression of let-7c is downregulated in castration-resistant prostate cancer (CRPC) cells. Overexpression of let-7c decreased while downregulation of let-7c increased cell proliferation, clonogenicity and anchorage-independent growth of PCa cells in vitro. Suppression of let-7c expression enhanced the ability of androgen-sensitive PCa cells to grow in androgen-deprived conditions in vitro. Reconstitution of Let-7c by lentiviral-mediated intratumoral delivery significantly reduced tumor burden in xenografts of human PCa cells. Furthermore, let-7c expression is downregulated in clinical PCa specimens compared to their matched benign tissues, while the expression of Lin28, a master regulator of let-7 miRNA processing, is upregulated in clinical PCa specimens.

Conclusions

These results demonstrate that microRNA let-7c is downregulated in PCa and functions as a tumor suppressor, and is a potential therapeutic target for PCa.

Pb(In0.5Nb0.5)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) ferroelectric crystals attracted extensive attentions in last couple years, due to their higher usage temperatures range (> 30°C) and coercive fields (~5kV/cm), meanwhile maintaining similar electromechanical couplings (k33> 90%) and piezoelectric coefficients (d33~1500pC/N), when compared to their binary counterpart Pb(Mg1/3Nb2/3)O3-PbTiO3. In this article, we reviewed recent developments on the PIN-PMN-PT single crystals, including the Bridgman crystal growth, dielectric, electromechanical, piezoelectric and ferroelectric behaviors as function of temperature and dc bias. Mechanical quality factor Q was studied as function of orientation and phase. Of particular interest is the dynamic strain, which related to the Q and d33, was found to be improved when compared to binary system, exhibiting the potential usage of PIN-PMN-PT in high power application. Furthermore, PIN-PMN-PT crystals exhibit improved thickness dependent properties, due to their small domain size, being on the order of 1μm. Finally, the manganese acceptor dopant in the ternary crystals was investigated and discussed briefly in this paper.

MicroRNAs (miRNAs) are small noncoding RNAs (18-25 nucleotides) that regulate gene expression at the post-transcriptional level. Recent studies have demonstrated the presence of miRNAs in the blood circulation. Deregulation of miRNAs in serum or plasma has been associated with many diseases including cancers and cardiovascular diseases, suggesting the possible use of miRNAs as diagnostic biomarkers. However, the detection of the small amount of miRNAs found in serum or plasma requires a method with high sensitivity and accuracy. Therefore, the current study describes polymerase chain reaction (PCR)-based methods for measuring circulating miRNAs. Briefly, the procedure involves four major steps: (1) sample collection and preparation; (2) global miRNAs profiling using quantitative real-time PCR (qRT-PCR); (3) data normalization and analysis; and (4) selection and validation of miRNA biomarkers. In conclusion, qRT-PCR is a promising method for profiling of circulating miRNAs as biomarkers.

Background

High-intensity focused ultrasound (HIFU) is considered to be an alternative to surgery. Extracorporeal ultrasound-guided HIFU (USgFU) has been clinically used to treat solid tumors. Preliminary trials in a small sample of a Western population suggested that this modality was safe. Most trials are performed in China thereby providing comprehensive data for understanding the safety profile. The aim of this study was to evaluate adverse events of USgFU therapy.

Methods and Findings

Clinical data were searched in 2 Chinese databases. Adverse events of USgFU were summarized and compared with those of magnetic resonance-guided HIFU (MRgFU; for uterine, bone or breast tumor) and transrectal ultrasound-guided HIFU (for prostate cancer or benign prostate hyperplasia). USgFU treatment was performed using 7 types of device. Side effects were evaluated in 13262 cases. There were fewer adverse events in benign lesions than in malignant lesions (11.81% vs. 21.65%, p<0.0001). Rates of adverse events greatly varied between the disease types (0–280%, p<0.0001) and between the applied HIFU devices in both malignant (10.58–44.38%, p<0.0001) and benign lesions (1.67–17.57%, p<0.0001). Chronological analysis did not demonstrate a decrease in the rate of adverse events. Based upon evaluable adverse events, incidences in USgFU were consistent with those in MRgFU or transrectal HIFU. Some side effects frequently occurred following transrectal HIFU were not reported in USgFU. Several events including intrahepatic metastasis, intraoperative high fever, and occlusions of the superior mesenteric artery should be of particular concern because they have not been previously noted. The types of adverse events suggested that they were ultrasonic lesions.

Conclusion

The frequency of adverse events depended on the location of the lesion and the type of HIFU device; however, side effects of USgFU were not yet understood. USgFU did not decrease the incidence of adverse events compared with MRgFU.

Oxidative stress is considered to be involved in the pathophysiology of all cancers. In order to evaluate the total oxidant/antioxidant status in patients with thyroid cancer and to investigate the relationship between oxidative stress parameters and serum thyroid profiles among thyroid cancer patients and various controls, we determined oxidative status including total antioxidant status (TAS) and total oxidant status (TOS) and calculation of oxidative stress index (OSI) in sera in 82 thyroid cancer patients, 56 benign thyroid disease patients, and 50 healthy controls. It was found that serum TAS levels were significantly lower in patients with thyroid cancer than in controls (P<0.001), while serum TOS levels and OSI values were significantly higher (both P<0.001) in the cancer patients. No significant correlations were observed between various oxidative stress markers and thyroid profiles in either the thyroid cancer patients or the controls. Receiver operating characteristic curve analysis demonstrated that OSI was the best indicator for distinguishing cancer patients from benign thyroid diseased or healthy controls, followed by TOS and TAS. Risk estimate statistics also indicated that TOS and/or OSI were good risk factors to discriminate patients with thyroid cancer from two controls. These findings suggested that oxidants are increased and antioxidants are decreased in patients with thyroid cancer. OSI may be a more useful oxidative stress biomarker than TAS and TOS for monitoring the clinical status of thyroid cancer patients.

Recent outbreaks of human enterovirus 71 (EV71) infection and EV71-associated hand, foot, and mouth disease (HFMD) in China have affected millions and potentially lead to life-threatening complications in newborns. Furthermore, these outbreaks represent a significant global public health issue in the world. Understanding the epidemiology of HFMD and EV71 infection and their transmission patterns in China is essential for controlling outbreaks. However, no studies on the outbreaks of HFMD and EV71 infection in China during 2010 have been reported. In this report, we carried out an epidemiological analysis to study an outbreak of HFMD and EV71 infection in 2010 in the city of Nanchang in the Jiangxi province of People's Republic of China. From April 7 to May 11, 2010, a total of 109 HFMD cases were reported, and in this report the HFMD cases were studied by both epidemiological and laboratory analyses. The epidemiological study indicates that children aged younger than 8 years old represented more than 90% of the reported cases, with the age group of 1–3 years containing the highest number of cases. Laboratory studies detected a high prevalence of EV71 amongst the cases in our study, suggesting EV71 as a common enterovirus found in HFMD cases in Nanchang. Phylogenetic analysis of the sequence of the VP1 region of four EV71 isolates indicated that the Nanchang strains belong to the C4 subgenotype commonly found in China during outbreaks in 2008 but contain distinct variations from these strains. Our study for the first time characterizes the epidemiology of HFMD and EV71 infection in China in 2010 and furthermore, provides the first direct evidence of the genotype of EV71 circulating in Nanchang, China. Our study should facilitate the development of public health measures for the control and prevention of HFMD and EV71 infection in at-risk individuals in China.

Genomic biomarkers for the detection of drug-induced liver injury (DILI) from blood are urgently needed for monitoring drug safety. We used a unique data set as part of the Food and Drug Administration led MicroArray Quality Control Phase-II (MAQC-II) project consisting of gene expression data from the two tissues (blood and liver) to test cross-tissue predictability of genomic indicators to a form of chemically-induced liver injury. We then use the genomic indicators from the blood as biomarkers for prediction of acetaminophen-induced liver injury and show that the cross tissue predictability of a response to the pharmaceutical agent (accuracy as high as 92.1%) is better than, or at least comparable to, that of non-therapeutic compounds. We provide a database of gene expression for the highly informative predictors which brings biological context to the possible mechanisms involved in DILI. Pathway-based predictors were associated with inflammation, angiogenesis, Toll-like receptor signaling, apoptosis and mitochondrial damage. The results demonstrate for the first time and support the hypothesis that genomic indicators in the blood can serve as potential diagnostic biomarkers predictive of DILI.

The electrical properties of Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) based polycrystalline ceramics and single crystals were investigated as a function of scale ranging from 500 microns to 30 microns. Fine-grained PMN-PT ceramics exhibited comparable dielectric and piezoelectric properties to their coarse-grained counterpart in the low frequency range (<10 MHz), but offered greater mechanical strength and improved property stability with decreasing thickness, corresponding to higher operating frequencies (>40 MHz). For PMN-PT single crystals, however, the dielectric and electromechanical properties degraded with decreasing thickness, while ternary Pb(In1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) exhibited minimal size dependent behavior. The origin of property degradation of PMN-PT crystals was further studied by investigating the dielectric permittivity at high temperatures, and domain observations using optical polarized light microscopy. The results demonstrated that the thickness dependent properties of relaxor-PT ferroelectrics are closely related to the domain size with respect to the associated macroscopic scale of the samples.

Background

The Cancer/Testis Antigens (CTAs) are an important group of proteins that are typically restricted to the testis in the normal adult but are aberrantly expressed in several types of cancers. As a result of their restricted expression patterns, the CTAs could serve as unique biomarkers for cancer diagnosis/prognosis. The aim of this study was to identify promising CTAs that are associated with prostate cancer (PCa) recurrence following radical prostatectomy (RP).

Methods

The expression of 5 CTAs was measured by quantitative multiplex real-time PCR using prostate tissue samples obtained from 72 patients with apparently clinically localized PCa with a median of two years follow-up (range, 1 to 14 years).

Results

The expression of CTAs namely, CEP55, NUF2, PBK and TTK were significantly higher while PAGE4 was significantly lower in patients with recurrent disease. All CTAs with the exception of TTK were significantly correlated with the prostatectomy Gleason score, but none were correlated with age, stage, or preoperative PSA levels. In univariate proportional hazards models, CEP55 (HR = 3.59, 95% CI: 1.50-8.60), p = 0.004; NUF2 (HR = 2.28, 95% CI: 1.11-4.67), p = 0.024; and PAGE4 (HR = 0.44, 95% CI: 0.21-0.93), p = 0.031 were significantly associated with the risk of PCa recurrence. However, the results were no longer significant after adjustment for prostatectomy Gleason score.

Conclusions

To our knowledge, this is the first study to identify CTAs as biomarkers that can differentiate patients with recurrent and non-recurrent disease following RP and underscores its potential impact on PCa prognosis and treatment.

The MYC onco-protein is a transcription factor that regulates cell proliferation, metabolism, protein synthesis, mitochondrial function and stem cell renewal. A region on chromosome 8q24 encompassing the MYC locus is amplified in prostate cancer, but this occurs mostly in advanced disease suggesting that MYC alterations occur late in prostate cancer. By contrast, MYC mRNA is elevated in most prostate cancers, even those of relatively low stage and grade (e.g. Gleason score 6) suggesting that MYC plays a role in initiation. However, since MYC protein levels are tightly regulated, elevated MYC mRNA does not necessarily imply elevated MYC protein. Thus, it is critical to determine whether MYC protein is elevated in human prostate cancer, and if so, at what stage of the disease this elevation occurs. Prior studies of MYC protein localization have been hampered by lack of suitable antibodies and controls. We utilized a new anti-MYC antibody coupled with genetically-defined control experiments to localize MYC protein within human tissue microarrays consisting of normal, atrophy, PIN, primary adenocarcinoma, and metastatic adenocarcinoma. Nuclear overexpression of MYC protein occurred frequently in luminal cells of PIN, as well as in most primary carcinomas and metastatic disease. MYC protein did not correlate with gain of 8q24, suggesting alternative mechanisms for MYC overexpression. These results provide evidence that upregulation of nuclear MYC protein expression is a highly prevalent and early change in prostate cancer and suggest that increased nuclear MYC may be a critical oncogenic event driving human prostate cancer initiation and progression.

Background

Small cell carcinoma of the prostate is an uncommon neoplasm, the origin of which has been controversial. To address this, we performed transcriptome profiling and TP53 sequencing of concurrent small cell and prostatic adenocarcinoma to determine the relationship between these entities.

Methods

We identified an unusual case of primary prostate cancer that contained adjacent acinar adenocarcinoma (Gleason score 4+3=7) and small cell carcinoma. We performed laser capture microdissection to isolate tumor components and performed gene expression and TP53 gene sequence analysis on each component, with results validated by immunohistochemistry for PSA, PSAP, PSMA, androgen receptor, NKX 3.1 and neuroendocrine markers.

Results

Transcriptome profiling of the carcinoma components identified 99 genes with a greater than 10-fold differential expression between prostatic adenocarcinoma and small cell carcinoma, many of which have not been previously reported in prostate cancer. The small cell carcinoma component demonstrated upregulation of proliferative and neuroendocrine markers and tyrosine kinase receptors, and downregulation of cell adhesion molecules, supporting the aggressive nature of this form of carcinoma. Sequencing of the TP53 gene suggested a common clonal origin for both components.

Conclusions

This is the first report of a primary small cell carcinoma of the prostate subjected to extensive molecular analysis and the first to show a clonal relation between two morphologically distinct prostate cancer types. The evidence of progression to small cell carcinoma may yield important insights into the pathogenesis of this entity and provide a novel spectrum of molecular markers to further dissect cellular pathways important in tumor progression.

Hormone therapies targeting androgen receptor signaling are the mainstay of treatment for patients with advanced prostate cancer. The length of clinical remission induced by hormone therapies varies substantially among treated patients. Why some patients progress rapidly after treatment while others benefit with prolonged remission is a question that remains unsolved. The androgen receptor signaling pathway is the key molecular determinant of castration resistance, and a key target for prostate cancer drug design. Recent advances in characterizing molecular processes leading to the development of castration-resistant prostate cancer, including the discovery of multiple androgen receptor splicing variants, offer opportunities for rational development of new clinical tools or approaches to predict, monitor or control/prevent prostate cancer progression in the castrate setting.

Electric fatigue tests have been conducted on pure and manganese modified Pb(In0.5Nb0.5)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystals along different crystallographic directions. Polarization degradation was observed to suddenly occur above 50–100 bipolar cycles in <110> oriented samples, while <001> oriented samples exhibited almost fatigue free characteristics. The fatigue behavior was investigated as a function of orientation, magnitude of the electric field and manganese dopant. It was found that <001> oriented PIN-PMN-PT crystals were fatigue free, due to its small domain size, being on the order of 1µm. The <110> direction exhibited a strong electrical fatigue behavior due to mechanical degradation. Micro/macro cracks were developed in fatigued <110> oriented single crystals. Fatigue and cracks were the results of strong anisotropic piezoelectric stress and non-180° domain switching, which completely locked the non-180° domains. Furthermore, manganese modified PIN-PMN-PT crystals were found to show improved fatigue behavior due to its enhanced coercive field.

Prostate cancer (CaP) progresses from prostatic intraepithelial neoplasia through locally invasive adenocarcinoma to castration resistant (CR) metastatic carcinoma1. Although radical prostatectomy, radiation and androgen ablation are effective therapies for androgen-dependent (AD) CaP, metastatic CR-CaP is a major complication with high mortality2. Androgens stimulate growth and survival of prostate epithelium and early CaP. Although most patients initially respond to androgen ablation, many develop CR-CaP within 12-18 months2. Despite extensive studies, the mechanisms underlying CR-CaP emergence remain poorly understood and their elucidation is critical for development of improved therapies. Curiously, CR-CaP remains androgen receptor (AR) dependent and potent AR antagonists induce tumor regression in castrated mice3. The role of inflammation in CR-CaP has not been addressed, although it was reported that intrinsic NF-κB activation supports its growth4. Inflammation is a localized protective reaction to injury or infection, but it also has a pathogenic role in many diseases, including cancer5. Whereas acute inflammation is critical for host defense, chronic inflammation contributes to tumorigenesis and metastatic progression. The inflammation-responsive IκB kinase (IKK) β and its target NF-κB have important tumor promoting functions within malignant cells and inflammatory cells6. The latter, including macrophages and lymphocytes, are important elements of the tumor microenvironment7-9, but the mechanisms underlying their recruitment remain obscure, although thought to depend on chemokine and cytokine production10. We found that CaP progression is associated with inflammatory infiltration and activation of IKKα, which stimulates metastasis by an NF-κB-independent, cell autonomous, mechanism11. We now show that androgen ablation causes infiltration of regressing AD tumors with leukocytes, including B cells, in which IKKβ activation results in production of cytokines that activate IKKα and STAT3 in CaP cells to enhance hormone-free survival.

Background

Urease B is an important virulence factor that is required for Helicobacter pylori to colonise the gastric mucosa. Mouse monoclonal antibodies (mAbs) that inhibit urease B enzymatic activity will be useful as vaccines for the prevention and treatment of H. pylori infection. Here, we produced murine mAbs against urease B that neutralize the enzyme's activity. We mapped their epitopes by phage display libraries and investigated the immunogenicity of the selected mimotopes in vivo.

Results

The urease B gene was obtained (GenBank accession No. DQ141576) and the recombinant pGEX-4T-1/UreaseB protein was expressed in Escherichia coli as a 92-kDa recombinant fusion protein with glutathione-S-transferase (GST). Five mAbs U001-U005 were produced by a hybridoma-based technique with urease B-GST as an immunogen. Only U001 could inhibit urease B enzymatic activity. Immunoscreening via phage display libraries revealed two different mimotopes of urease B protein; EXXXHDM from ph.D.12-library and EXXXHSM from ph.D.C7C that matched the urease B proteins at 347-353 aa. The antiserum induced by selected phage clones clearly recognised the urease B protein and inhibited its enzymatic activity, which indicated that the phagotope-induced immune responses were antigen specific.

Conclusions

The present work demonstrated that phage-displayed mimotopes were accessible to the mouse immune system and triggered a humoral response. The urease B mimotope could provide a novel and promising approach for the development of a vaccine for the diagnosis and treatment of H. pylori infection.