Macrophage-secreted granulin supports pancreatic cancer metastasis by inducing liver fibrosis

Pancreatic ductal adenocarcinoma (PDAC) is a devastating metastatic disease for which better therapies are urgently needed. Macrophages enhance metastasis in many cancer types; however, the role of macrophages in PDAC liver metastasis remains poorly understood. Here we found that PDAC liver metastasis critically depends on the early recruitment of granulin-secreting inflammatory monocytes to the liver. Mechanistically, we demonstrate that granulin secretion by metastasis-associated macrophages (MAMs) activates resident hepatic stellate cells (hStCs) into myofibroblasts that secrete periostin, resulting in a fibrotic microenvironment that sustains metastatic tumour growth. Disruption of MAM recruitment or genetic depletion of granulin reduced hStC activation and liver metastasis. Interestingly, we found that circulating monocytes and hepatic MAMs in PDAC patients express high levels of granulin. These findings suggest that recruitment of granulin-expressing inflammatory monocytes plays a key role in PDAC metastasis and may serve as a potential therapeutic target for PDAC liver metastasis.

Differential proteomic approach for identification and verification of aberrantly glycosylated proteins in adenocarcinoma lung cancer (ADLC) plasmas by lectin-capturing and targeted mass spectrometry

To investigate quantitative differences in aberrant glycosylation of target glycoproteins between noncancerous group and patient group with adenocarcinoma lung cancer (ADLC), differential proteomic approach was developed by cooperatively using comparative lectin-capturing, targeted mass spectrometry (MRM MS), and antibody/lectin sandwich ELISA. Plasma samples comparatively prepared from 3 ADLC patients and 3 controls, with and without lectin-fractionation using fucose-specific Aleuria aurantia lectin (AAL), were trypsin-digested and analyzed for target glycoproteins, alpha-1-acid glycoprotein (AGP) and ceruloplasmin (CP), by MRM MS. From the MRM MS data the abundance levels of AAL-captured glycoforms of both targets were significantly higher in ADLC cases compared to controls, although the levels in total protein abundance were comparable between ADLC and control groups. This difference between ADLC and control groups in the fucosylated glycoform levels was originated mainly from aberrant fucosylation on the targets in ADLC plasmas rather than change in total protein abundance of the targets, and also confirmed by sandwich ELISA. AGP and CP were further verified to be biomarker candidates by MRM-based analysis of AAL-captured plasmas (30 ADLC cases, 30 controls), with AUROC 0.758 and 0.847 respectively. This differential proteomic approach can be useful for identifying and verifying biomarker candidate involved in aberrant protein glycosylation.

BIOLOGICAL SIGNIFICANCE

The present paper introduces an efficient differential proteomic method to investigate quantitative differences in aberrant protein glycosylation of serological glycoproteins between noncancerous group and lung cancer patient group. This differential proteomic approach consisting of the targeted MRM MS of comparatively lectin-captured plasma fractions and the antibody/lectin sandwich ELISA-based assay was evaluated to be useful for identification of aberrantly fucosylated glycoproteins AGP and CP in lung cancer plasmas. In addition, we have demonstrated that the MRM MS-based differential proteomic approach is also useful for high-throughput verification of the aberrantly fucosylated glycoproteins AGP and CP using the large number of individual plasmas. Therefore, the present MRM MS-based differential proteomic strategy with lectin-capturing can be a powerful tool for high-throughput verification of aberrantly glycosylated biomarker candidates, identified preliminary by mass profiling experiments in proteomic fields but requiring further validation using a large number of cohorts.

Decreased prevalence of high-risk human papillomavirus infection is associated with obesity

PURPOSE OF INVESTIGATION

Obesity is correlated with low education, low economic status, and lower rates of Pap smears, which are known as socio-demographic risk factors for cervical cancer. However, the association between obesity and high-risk human papillomavirus (HR-HPV) infection, the necessary cause of cervical cancer, and its related precursors, is not established.

MATERIALS AND METHODS

The authors examined the association between obesity and HR-HPV infection in 6,868 patients, who participated in annual health examinations at the Kangbuk Samsung Hospital in Seoul, Korea, from January through December 2007.

RESULTS

The prevalence of HR-HPV infection was 14.8%. Women infected with HR-HPV had a lower body mass index (BMI), when compared with non-infected women. After adjustment for alcohol intake, cigarette smoking, and marital status, HR-HPV infection was found to be negatively associated with BMI. When the analysis was stratified according to BMI, the risk of HR-HPV infection was significantly lower among those who were overweight (OR = 0.817, 95% CI = 0.680-0.982), or obese (OR = 0.688, 95% CI = 0.556-0.851), when compared with women with normal weight.

CONCLUSION

HR-HPV infection was associated with obesity defined by BMI, with a lower prevalence of infection observed in obese women.

Identification of a mimotope for circulating anti-cytokeratin 8/18 antibody and its usage for the diagnosis of breast cancer

A novel circulating tumor-associated autoantibody, K94, obtained from a hepatocellular carcinoma (HCC) mouse model was characterized. The target antigen of K94 autoanti-body was expressed in various tumor cell lines including liver cancer, and its secretion was detectable using MCF-7 breast carcinoma cells. Proteomic analysis revealed that the protein bands reactive to K94 included cytokeratin (CK) 8 and 18, which are known to be related to tumorigenesis and form a heterotypic complex with each other. However, K94 showed no activity toward CK8 or CK18 separately. The epitope of the K94 antibody was only presented by a complex between CK8 and CK18, which was confirmed by analysis using recombinant CK8 and CK18 proteins. To formulate an assay for anti-CK8/18 complex autoantibody, a mimotope peptide reactive to K94 was selected from loop-constrained heptapeptide (-CX₇C-) display phage library, of which sequence was CISPDAHSC (K94p1). A mimotope enzyme-linked immunosorbent assay (ELISA) using phage-displayed K94p1 peptide as a coating antigen was able to discriminate breast cancer (n=30) patients from normal subjects (n=30) with a sensitivity of 50% and a specificity of 82.61%. CA15.3 was detected at very low levels in the same breast cancer subjects and did not discriminate breast cancer patients from normal subjects, although it is a conventional biomarker of breast cancer. These results suggest that a mimotope ELISA composed of K94p1 peptide may be useful for the diagnosis of breast cancer.

Utility of Basal luteinizing hormone levels for detecting central precocious puberty in girls

The hallmark of puberty is the progressive increase in gonadotropin-releasing hormone (GnRH) activity, reflected by an increase in the circulating concentration of luteinizing hormone (LH). The GnRH stimulation test is widely used in the evaluation of precocious puberty. The aim of our study was to assess the diagnostic utility of basal LH for the diagnosis of central precocious puberty (CPP) in girls. A total of 803 girls were referred to Ajou University Hospital for evaluation of precocious puberty between 2008 and 2011. All subjects underwent GnRH-stimulation tests as part of their evaluation. Serum LH and follicle stimulating hormone (FSH) were measured by immunoradiometric assay before and after the GnRH injection. Of the 803 subjects, 505 (62.9%) were included in the pubertal response group and 298 (37.1%) were in the prepubertal response group. Basal LH level was identified as a significant predictor for CPP. Based on the ROC curve, the optimal cut off point of basal LH related to 'pubertal response' was 1.1 IU/l, which was associated with 69.1% sensitivity and 50.5% specificity, with an area under the ROC curve of 0.620 (95% CI, 0.581-0.660). It is concluded that a single basal LH measurement can be used as a screening test to identify girls with CPP and to determine who should undergo GnRH stimulation test.

Oculomotor nerve palsy caused by posterior communicating artery aneurysm: evaluation of symptoms after endovascular treatment

We report the outcome of endovascular treatment in a series of patients presenting with posterior communicating artery aneurysm causing ocular motor nerve palsy. A retrospective study was made of ten patients who were treated by coil embolization of posterior communicating artery aneurysm caused by oculomotor nerve palsy. The assessed parameters were as follows: patient's age, presence of subarachnoid hemorrhage, aneurysm size, preoperative severity of symptoms, and timing of treatment after onset of symptoms. Improvement of oculomotor nerve palsy after treatment was noted in eight patients (80.0%). Complete recovery was noted in seven patients (70.0%), partial recovery in one patient (10.0%), and no recovery in two patients (20%). Clinical presentations with early management (≤2 days) were significant in influencing recovery. Complete recovery from ocular motor nerve palsy was significantly higher in patients with initial incomplete palsy compared with initial complete palsy patients (6/6 versus 1/4). Early treatment and initial partial palsy are relevant to improving prognoses. Endovascular treatment is favored method for treating oculomotor palsy.

A multiplex lectin-channel monitoring method for human serum glycoproteins by quantitative mass spectrometry

A mass profiling method and multiple reaction monitoring (MRM)-based quantitative approach were used to analyze multiple lectin-captured fractions of human serum using different lectins such as aleuria aurantia lectin (AAL), phytohemagglutinin-L(4) (L-PHA), concanavalin A (Con A), and Datura stramonium agglutinin (DSA) to quantitatively monitor protein glycosylation diversity. Each fraction, prepared by multiple lectin-fractionation and tryptic digestion, was analyzed by 1-D LC-MS/MS. Semi-quantitative profiling showed that the list of glycoproteins identified from each lectin-captured fraction is significantly different according to the used lectin. Thus, it was confirmed that the multiplex lectin-channel monitoring (LCM) using multiple lectins is useful for investigating protein glycosylation diversity in a proteome sample. Based on the semi-quantitative mass profiling, target proteins showing lectin-specificity among each lectin-captured fraction were selected and analyzed by the MRM-based method in triplicate using each lectin-captured fraction (average CV 7.9%). The MRM-based analysis for each lectin-captured fraction was similar to those obtained by the profiling experiments. The abundance of each target protein measured varied dramatically, based on the lectin-specificity. The multiplex LCM approach using MRM-based analyses is useful for quantitatively monitoring target protein glycoforms selectively fractionated by multiple lectins. Thus through multiplex LCM rather than single, we could inquire minutely into protein glycosylation states.

Identification of various types of α2-HS glycoprotein in sera of patients with pancreatic cancer: Possible implication in resistance to protease treatment

α2-Heremans-Schmid glycoprotein (human fetuin) is one of numerous serum proteins produced in the liver. Recently, the biological functions of fetuin, such as calcification and insulin resistance, have been clarified. However, these effects appear to be indirect, occurring through binding to other molecules. When equal amounts of fetuin in sera were treated with chymotrypsin, resistance to the protease treatment was observed in patients with pancreatic cancer, but not in normal volunteers. To investigate the molecular mechanism behind this resistance, gel-filtration chromatography was performed. The results revealed that high molecular types of fetuin showed a resistance to protease treatment. When fetuin was purified from sera of patients with pancreatic cancer and normal volunteers, certain types of proteins, including haptoglobin (which binds to fetuin derived from pancreatic cancer patients), were identified using mass spectrometry. Furthermore, the oligosaccharide structures of fetuin analyzed with lectin microarray differed between pancreatic cancer patients and normal volunteers. This macro/micro heterogeneity of fetuin might contribute to pancreatic cancer resistance to chymotrypsin treatment.

Comparative quantitation of aberrant glycoforms by lectin-based glycoprotein enrichment coupled with multiple-reaction monitoring mass spectrometry

Lectin enrichment-coupled multiple-reaction monitoring (MRM) mass spectrometry was employed to quantitatively monitor the variation of aberrant glycoforms produced under pathological states. For this, aberrant glycoforms of the tissue inhibitor of metalloproteinase 1 (TIMP1) and protein tyrosine phosphatase kappa (PTPkappa), previously known target proteins for N-acetylglucosaminyltransferase-V (GnT-V), were enriched by phytohemagglutinin-L(4) (L-PHA) lectin and comparatively analyzed in the conditioned medium of the WiDr colon cancer cell line and its GnT-V-overexpressing transfectant cells. Enriched glycoforms were digested, and the resultant peptides were comparatively quantified by MRM analysis. MRM quantitation data for the L-PHA-enriched samples revealed that the abundance of aberrant glycoforms of TIMP1 and PTPkappa was greatly increased (11.7- and 16.5-fold, respectively) in GnT-V-treated cells compared to the control cells, although the abundance of total TIMP1 and PTPkappa in GnT-V-treated cells was slightly different (1.1- and 0.5-fold, respectively) for unenriched samples compared to that in control cells. The dramatic variation in abundance of the aberrant glycoforms due to overexpressed GnT-V was confirmed quantitatively by comparative MRM analysis of lectin-enriched samples. This method is capable of comparatively quantitating the abundance of a protein of interest and its aberrant glycoform and will be useful for studying pathological mechanisms of cancer or verifying biomarker candidates.

Identification of autoantibody against fatty acid synthase in hepatocellular carcinoma mouse model and its application to diagnosis of HCC

Autoantibodies, which are generated by immune system recognizing the presence of the abnormal tumor-associated antigens, are promising biomarkers for early detection of tumors. Recently, we established a B cell hybridoma pool derived from H-ras12V transgenic mouse, a typical hepatocellular carcinoma model, as a source of tumor-associated autoantibodies without using any extracellular antigens and have characterized the specific target antigens against them. K1 autoantibody, one of them, was investigated in this study and its target antigen was identified by mass spectrometric analysis as fatty acid synthase (FASN), an important oncogenic protein. Moreover, a specific mimotope against K1 autoantibody was screened from the cyclic random hepta-peptide phage library and, using it as a coating antigen for ELISA, we could distinguish patients with hepatocellular carcinoma (HCC) vs. normal subjects with 96.55% sensitivity and 100% specificity. These results imply that anti-FASN autoantibody is induced in patients with HCC and detection of anti-FASN autoantibody can be used for the diagnosis of HCC.

Implication of aberrant glycosylation in cancer and use of lectin for cancer biomarker discovery

Aberrant glycosylation is frequently found in cancer, and efforts for biomarker discovery include the preparation of aberrant glycoproteins as promising analytes. Several lectins that bind to aberrant glycans and can be thus used to capture and enrich aberrant glycoproteins in the frontal stage during biomarker discovery are to be introduced.

Comprehensive clinical follow-up of late effects in childhood cancer survivors shows the need for early and well-timed intervention

BACKGROUND

Due to recent advances in treatment, nearly 80% of childhood cancer patients become long-term survivors. Studies on the late effects of survivors are under way worldwide. However, data on Asian survivors remain limited.

METHODS

Data on 241 survivors at the Long-term Follow-up Clinic in Severance Hospital, South Korea, were collected and late effects were confirmed by oncologists.

RESULTS

The median follow-up from diagnosis was 7.8 years. Late effects were identified in 59.8% of survivors and 23.2% had two or more late effects. Grade 3 or higher late effects were present in 10.8%. The most common late effects involved endocrine system (29.0%). Late effects were present in 95.7% of brain tumor survivors and 36.0% of Wilms' tumor survivors. Chemotherapy, hematopoietic stem-cell transplantation and radiotherapy were significant factors associated with the number and severity of late effects (P < 0.05). Brain tumor survivors had more severe late effects (P < 0.001), whereas Wilms' tumor survivors had fewer and milder late effects (P < 0.05).

CONCLUSION

The observation that over 50% of cancer survivors suffered from late effects during the short follow-up period and that a high frequency of endocrine late effects was present indicates the need for early and well-timed intervention of the survivors.

Susceptibility of porcine keratocytes to immune-mediated damage in xeno-related rejection

We admixed cultured porcine keratocytes or corneal endothelial cells in the presence of human sera or peripheral blood mononuclear cells (PBMCs) for 4 to 72 hours to investigate their immune-related susceptibilities to xeno-related rejection. We evaluated complement deposition at 48 hours by flow cytometry after staining with the C3 anti-goat cy3 antibody. The inhibition of proliferation of porcine corneal cells by human sera was examined using the 3-[4,5-dimethy/thiazol-2,5-dephenyl tetrazolium bromide (MTT) assay over 24 to 72 hours. The amount of 51chromium (Cr)-release was estimated after a reaction between the porcine cells and human PBMCs for 4 hours. There was greater C3 deposition in keratocytes (60.2%) than in endothelial cells (26.9%; P = .05, Mann-Whitney U test). Both keratocytes and endothelial cells showed significant levels of proliferative inhibition over a period of 72 hours. The number of 51Cr-release cells on interleukin-2 addition was significantly higher among keratocytes (88.0%) than endothelial cells (51.4%) at a 1:100 target:effector ratio (P = .04, Mann-Whitney U test). Our present data suggested that porcine keratocytes might be key target cells in xeno-related rejections when the porcine cornea is transplanted to primates.

Biochemical characterization of a glycosyltransferase homolog from an oral pathogen Fusobacterium nucleatum as a human glycan-modifying enzyme

Bacterial glycosyltransferases have drawn growing attention as economical enzymes for oligosaccharide synthesis, with their easy expression and relatively broad substrate specificity. Here, we characterized a glycosyltransferase homolog (Fnu_GT) from a human oral pathogen, Fusobacterium nucleatum. Bioinformatic analysis showed that Fnu_GT belongs to the glycosyltransferases family II. The recombinant Fnu_GT (rFnu_GT) expressed in Escherichia coli displayed the highest glycosylation activity when UDP-galactose (Gal) was used as a donor nucleotide-sugar with heptose or Nacetylglucosamine (GlcNAc) as an acceptor sugar. Interestingly, rFnu_GT transferred the galactose moiety of UDP-Gal to a nonreducing terminal GlcNAc attached to the trimannosyl core glycan, indicating its potential as an enzyme for humantype N-glycan synthesis.

Novel black soy peptides with antiobesity effects: activation of leptin-like signaling and AMP-activated protein kinase

OBJECTIVE

To investigate the mechanisms underlying the antiobesity effects of a novel isoflavone-free peptide mixture (BSP) derived from black soybean.

DESIGN

Long-term effects of BSP were evaluated in diet-induced obese (DIO) mice fed a high-fat (HF) diet without or with BSP (2, 5 or 10% of energy) for 13 weeks, or for 8 weeks in combination with exercise. Acute effects of BSP on food intake and body weight in rats and leptin-deficient ob/ob mice were evaluated. Cell culture models or tissue extracts were used to investigate the mechanisms underlying the antiobesity effect.

MEASUREMENT

Total food intake, body weight gain, white adipose tissue (WAT) mass, plasma concentrations of leptin, adiponectin, cholesterol and triglyceride were measured. Janus kinase 2 (JAK2)-dependent signal transducers and activators of the transcription 3 (STAT3) phosphorylation and AMP-activated protein kinase (AMPK) activity were determined using Western-blot in cultured cells or tissue extracts.

RESULTS

DIO mice fed an HF diet with BSP (2, 5 or 10%) for 13 weeks gained less body weight (21.4, 19.8 or 17.1 g, respectively) than the mice fed an HF diet without BSP (22.6 g) concurrent with inhibition of total food intake in a dose-dependent manner. BSP also significantly decreased food intake in rats and leptin-deficient ob/ob mice. The highest dose of BSP (10%) significantly elevated the plasma adiponectin and decreased plasma triglyceride. BSP activated JAK2-dependent STAT3 in a cell model, and elevated the level of hypothalamic phospho-STAT3 in ob/ob mice. BSP also phosphorylated AMPK and acetyl-CoA carboxylase of C2C12 myocytes in a dose-dependent manner. The antiobesity effect was augmented by low-intensity wheel-based exercise. In exercised mice, BSP significantly decreased periepididymal WAT mass and body weight gain.

CONCLUSION

These results provided evidences that BSP decreased appetite and HF diet-induced body weight gain particularly in combination with exercise, through leptin-like STAT3 phosphorylation and AMPK activation.

Acute prefrontal cortex TMS in healthy volunteers: Effects on brain 11C-αMtrp trapping

High-frequency repetitive transcranial magnetic stimulation (rTMS) of the left dorsolateral prefrontal cortex (LDLPFC) is a technique with purported efficacy as a treatment for major depression. Here, we assessed in vivo, in healthy volunteers, the effect of acute rTMS of the LDLPFC, relative to the stimulation of the left occipital cortex (LOC), on brain regional serotonin synthesis capacity, using the [(11)C]-alpha-methyl-tryptophan ((11)C-alphaMtrp)/PET method. Ten subjects were studied twice, once following rTMS of the LDLPFC and once following rTMS of the LOC in a randomized counterbalanced order. Three blocks of 15 trains of 10 Hz rTMS were delivered 10 min apart. Behavioural and autonomic measures were recorded before and after each rTMS session. Comparisons of TMS-related changes in regional normalized brain uptake and trapping of (11)C-alphaMtrp (K*) values were carried out using SPM99. Statistically significant regional differences were identified on the basis of an extent threshold of 50 voxels, with a peak threshold of p=0.005 uncorrected. Behavioural and autonomic measures were unaffected by rTMS. Relative to LOC stimulation, LDLPFC rTMS was associated with marked changes in normalized K* in limbic areas, with significantly lower values in the left parahippocampal gyrus (BA 28) and the right insula (BA 13), and higher values in the right cingulate gyrus (BA 31) and cuneus (BA 18). These findings indicate that acute rTMS of the LDLPFC in healthy volunteers modulates aspects of tryptophan/5-HT metabolism in limbic areas. Such adaptive changes may contribute to the mechanism of action of prefrontal rTMS in major depression.

Alteration of the substrate specificity of Thermus caldophilus ADP-glucose pyrophosphorylase by random mutagenesis through error-prone polymerase chain reaction

Expanding the scope of stereoselectivity is of current interest in enzyme catalysis. In this study, using error-prone polymerase chain reaction (PCR), a thermostable adenosine diphosphate (ADP)-glucose pyrophosphorylase (AGPase) from Thermus caldophilus GK-24 has been altered to improve its catalytic activity toward enatiomeric substrates including [glucose-1-phosphate (G-1-P) + uridine triphosphate (UTP)] and [N-acetylglucosamine-1-phosphate (GlcNAc) + UTP] to produce uridine diphosphate (UDP)-glucose and UDP-N-acetylglucosamine, respectively. To elucidate the amino acids responsible for catalytic activity, screening for UDP-glucose pyrophosphorylase (UGPase) and UDP-N-acetylglucosamine pyrophosphorylase (UNGPase) activities was carried out. Among 656 colonies, two colonies showed UGPase activities and three colonies for UNGPase activities. DNA sequence analyses and enzyme assays showed that two mutant clones (H145G) specifically have an UGPase activity, indicating that the changed glycine residue from histidine has the base specificity for UTP. Also, three double mutants (H145G/A325V) showed a UNGPase, and A325 was associated with sugar binding, conferring the specificity for the sugar substrates and V325 of the mutant appears to be indirectly involved in the binding of the N-acetylamine group of N-acetylglucosmine-1-phosphate.

Population Research of Genetic Polymorphism at Amino Acid Position 631 in Chicken Mx Protein with Differential Antiviral Activity

A single amino acid substitution between Asn and Ser at position 631 in the chicken Mx protein has been reported to determine resistant and sensitive antiviral activity. In this study, we investigate whether various kinds of chicken breeds and jungle fowls carry the resistant or sensitive Mx allelic gene by using the mismatched PCR-restriction fragment length polymorphism (RFLP) technique. In total, 271 samples from 36 strains of 17 chicken breeds and from 3 kinds of jungle fowls were examined. The rates of the resistant Mx gene and sensitive gene were 59.2% and 40.8%, respectively. Only a Red jungle fowl captured in Laos carried the resistant Mx gene, and the other three Red jungle fowls from Indonesia and Gray and Green jungle fowls all had the sensitive Mx gene. These results were confirmed by the determination of amino acid sequences in the GTPase effector domain of jungle fowls.

Ganglioside GM3 is involved in neuronal cell death

Gangliosides abundant in the nervous system have been implicated in a broad range of biological functions, including the regulation of cell proliferation and death. Glutamate-induced cell death, which is accompanied by an accumulation of reactive oxygen species (ROS), is a major contributor to pathological cell death within the nervous system. However, the mechanism underlying this neuronal cell death has not been fully elucidated. In this study, we report that ganglioside GM3 is involved in neuronal cell death. GM3 was up-regulated in the mouse hippocampal cell line HT22 death caused by glutamate. Increment in GM3 levels by both the exogenous addition of GM3 and the overexpression of the GM3 synthase gene induced neuronal cell death. Overexpression of GM3 synthase by microinjecting mRNA into zebrafish embryos resulted in neuronal cell death in the central nervous system (CNS). Conversely, RNA interference-mediated silencing of GM3 synthase rescued glutamate-induced neuronal death, as evidenced by the inhibition of massive ROS production and intracellular calcium ion influx. 12-lipoxygenase (12-lipoxygenase) (12-LOX) was recruited to glycosphingolipid-enriched microdomains (GEM) in a GM3-dependent manner during oxidative glutamate toxicity. Our findings suggest that GM3 acts as not only a mediator of oxidative HT22 death by glutamate but also a modulator of in vivo neuronal cell death.

Identification of target proteins of N-acetylglucosaminyl transferase V in human colon cancer and implications of protein tyrosine phosphatase kappa in enhanced cancer cell migration

To gain a better understanding of the mechanism underlying colon cancer and to search for potential markers of colon cancer prognosis, a comparative proteomic analysis of colon cancer WiDr cells was conducted using 2-DE and lectin blot, followed by identification based on ESI-MS. Through these approaches 14 proteins were identified as candidate target proteins for N-acetylglucosaminyl transferase V (GnT-V) that would be expected to be implicated in the progression of colon cancer. We selected protein tyrosine phosphatase kappa (PTPkappa) as a model protein to validate this approach to the discovery of novel biomarkers in colon cancer. PTPkappa underwent an aberrant glycosylation in GnT-V-overexpressing WiDr cells, and the aberrantly glycosylated PTPkappa was vulnerable to proteolytic cleavage. The enhanced cleavage of PTPkappa in GnT-V-overexpressing cells was responsible for the mitigation of the homophilic binding capacity, resulting in an increase in cancer cell migration.

Monitoring of pH inhibition on microbial activity in a continuous flow reactor by pseudo toxic concentration (C(PT)) concept and time delay model

The pseudo toxic concentration (C(PT)) concept was introduced as a quantification method to describe pH as an inhibitor concentration. In this research, the applicability of the C(PT) concept model for the detection of pH inhibitions was expanded for a continuous flow activated sludge reactor. A pilot equipped with an inhibition detection system was installed. Inhibitory wastewater was injected for 1 h and the relative activity was calculated by the maximum respiration rate. At the same time, the coefficients for the C(PT) concept model were estimated. At the dynamic conditions, the estimated relative activity by the C(PT) concept model showed time lag compared to the measured one. However, the time lag problem was successfully resolved by introducing a transfer function into the C(PT) concept model. The C(PT) concept model combined with a transfer function (C(PT) + TF model) successfully tracked the variation of the relative activity under dynamic conditions. The C(PT) + TF model could detect 50% inhibition faster than the respirometry based method by approximately 10 min. Moreover, it had additional advantages such as being inexpensive, easy to install and simple to operate. In conclusion, the C(PT) + TF model was an effective and convenient detection method of pH inhibition.

Practical approach to parameter estimation for ASM3+ bio-P module applied to five-stage step-feed EBPR process

Various parameter optimization approaches to a five-stage step-feed EBPR process modeled using the ASM3+bio-P module were examined. Five stoichiometric (Y(STO,NO), Y(H,O2, Y(H,NO,) Y(PAO,O2), Y(PO4)) and seven kinetic parameters (k(STO), eta(NO), b(H), mu(max),PAO, q(PHA), q(PP), mu(max),A) were estimated. The optimization approaches could be classified based on the data sources (batch experiments or CSTR operation data) and the number of target variables used in calculating the objective function. Optimized parameter values obtained by each approach were validated with CSTR operation data that were not used for parameter optimization. The results showed that the parameter optimization only with batch experimental results could not be directly applied to CSTR operation data. ASM3 + bio-P module parameters could be finely optimized only with CSTR operation data when sufficient target variables for objective function calculation were applied. When the number of target variables was increased, prediction performance was significantly improved. Once optimized, the model was able to predict the characteristic features of the five-stage step-feed process; namely, a high PAO yield, fast PAO growth, fast X(pp) storage, slow X(STO) and X(PHA) storage.

Rule-based fuzzy inference system for estimating the influent COD/N ratio and ammonia load to a sequencing batch reactor

A fuzzy inference system using sensor measurements was developed to estimate the influent COD/N ratio and ammonia load. The sensors measured ORP, DO and pH. The sensor profiles had a close relationship with the influent COD/N ratio and ammonia load. To confirm this operational knowledge for constructing a rule set, a correlation analysis was conducted. The results showed that a rule generation method based only on operational knowledge did not generate a sufficiently accurate relationship between sensor measurements and target variables. To compensate for this defect, a decision tree algorithm was used as a standardized method for rule generation. Given a set of inputs, this algorithm was used to determine the output variables. However, the generated rules could not estimate the continuous influent COD/N ratio and ammonia load. Fuzzified rules and the fuzzy inference system were developed to overcome this problem. The fuzzy inference system estimated the influent COD/N ratio and ammonia load quite well. When these results were compared to the results from a predictive polynomial neural network model, the fuzzy inference system was more stable.

Identification of the adverse effect of nitrate on the phosphate release rate and improvement of EBPR process models

The adverse effect of nitrate on the phosphate release rate in the anaerobic phase was observed and was hardly explainable with conventional EBPR process models. Four possible mechanisms were proposed including substrate competition, reduced fermentation, parallel reaction and sequential reaction. Batch experiments were designed and conducted to identify the dominant mechanism. Results showed that the sequential reaction was the only possible mechanism where only denitrification occurred if any nitrate existed in the anaerobic phase. Then the phosphate release following after the nitrate was completely removed. Nitrate inhibition effect was added into the PHA storage rate to incorporate the sequential reaction in the conventional ASM3 plus EAWAG bio-P module (ASM3 + P). Nitrate inhibition coefficient, K(I,NO,PAO) was found to be as low as 0.05 mg/L. This correlated well with experimental observation where no also meant that the anaerobic compartment of a continuous flow reactor could be seriously affected by the residual nitrate contained in the sludge recycle flow. This phenomenon caused overestimation of the phosphate uptake rate and consequently underestimation of PO4(3-) -P concentration. This problem was resolved by incorporation of a nitrate inhibition term in the ASM3 + P for more accurate simulation of the EBPR process.

Equipment fault diagnosis system of sequencing batch reactors using rule-based fuzzy inference and on-line sensing data

The importance of a detection technique to prevent process deterioration is increasing. For the fast detection of this disturbance, a diagnostic algorithm was developed to determine types of equipment faults by using on-line ORP and DO profile in sequencing batch reactors (SBRs). To develop the rule base for fault diagnosis, the sensor profiles were obtained from a pilot-scale SBR when blower, influent pump and mixer were broken. The rules were generated based on the calculated error between an abnormal profile and a normal profile, e(ORP)(t) and e(DO)(t). To provide intermediate diagnostic results between "normal" and "fault", a fuzzy inference algorithm was incorporated to the rules. Fuzzified rules could present the diagnosis result "need to be checked". The diagnosis showed good performance in detecting and diagnosing various faults. The developed algorithm showed its applicability to detect faults and make possible fast action to correct them.

Parameter sensitivity analysis for activated sludge models No. 1 and 3 combined with one-dimensional settling model

The aim of this study was to suggest a sensitivity analysis technique that can reliably predict effluent quality and minimize calibration efforts without being seriously affected by influent composition and parameter uncertainty in the activated sludge models No. 1 (ASM1) and No. 3 (ASM3) with a settling model. The parameter sensitivities for ASM1 and ASM3 were analyzed by three techniques such as SVM-Slope, RVM-SlopeMA, and RVM-AreaCRF. The settling model parameters were also considered. The selected highly sensitive parameters were estimated with a genetic algorithm, and the simulation results were compared as deltaEQ. For ASM1, the SVM-Slope technique proved to be an acceptable approach because it identified consistent sensitive parameter sets and presented smaller deltaEQ under every tested condition. For ASM3, no technique identified consistently sensitive parameters under different conditions. This phenomenon was regarded as the reflection of the high sensitivity of the ASM3 parameters. But it should be noted that the SVM-Slope technique presented reliable deltaEQ under every influent condition. Moreover, it was the simplest and easiest methodology for coding and quantification among those tested. Therefore, it was concluded that the SVM-Slope technique could be a reasonable approach for both ASM1 and ASM3.

Forecasting influent flow rate and composition with occasional data for supervisory management system by time series model

The information on the incoming load to wastewater treatment plants is not often available to apply modelling for evaluating the effect of control actions on a full-scale plant. In this paper, a time series model was developed to forecast flow rate, COD, NH4(+)-N and PO4(3-)-P in influent by using 250 days data of field plant operation data. The data for 150 days and 100 days were used for model development and model validation, respectively. The missing data were interpolated by the spline method and the time series model. Three different methods were proposed for model development: one model and one-step to seven-step ahead forecasting (Method 1); seven models and one-step-ahead forecasting (Method 2); and one model and one-step-ahead forecasting (Method 3). Method 3 featured only one-step-ahead forecasting that could avoid the accumulated error and give simple estimation of coefficients. Therefore, Method 3 was the reliable approach to developing the time series model for the purpose of this research.

Bis induces growth inhibition and differentiation of HL-60 cells via up-regulation of p27

Bis (Bag-3, CAIR), a Bcl-2-interacting protein, promotes the anti-apoptotic activity of Bcl-2 and increased levels of Bis have been observed in several disease models. The involvement of Bcl-2 and some Bcl-2-binding proteins in differentiation has recently been reported. However, the relevance of Bis to cellular differentiation remains unknown. The findings herein show that Bis expression is up-regulated during the differentiation of HL-60 cells. To investigate the effect of Bis expression on differentiation, we established Bis-overexpressing HL-60 cells (HL-60-bis). HL-60-bis cells have a low nuclear: cytoplasmic ratio and indented nucleus in Wright- Giemsa staining, and an increased expression of CD11b in immunofluorescence study, indicating the promotion of differentiation. The overexpression of Bis also resulted in a retarded cell growth rate, accompanied by the accumulation of HL-60 cells at the G0/G1 phase of the cell cycle, which was sustained during the differentiation process. Western blot analysis revealed that the expression of p27, a representative inducer of cell cycle arrest at the G1 phase, was increased 2.5-fold in HL-60-bis cells compared to HL-60-neo cells. These results suggest that the Bis induced growth inhibition of HL-60 cells promotes G0/G1 phase arrest via up-regulation of p27, which seems to be a prerequisite for differentiation. Further studies will be required to define the exact roles of Bis on cellular differentiation more precisely.

Identification of target proteins of N-acetylglucosaminyl-transferase V and fucosyltransferase 8 in human gastric tissues by glycomic approach

To understand better the mechanism underlying gastric cancer and search for potential markers for gastric cancer prognosis, the proteomic analysis of gastric cancer tissues was conducted using two-dimensional gel electrophoresis and lectin blot, followed by electrospray ionization-mass spectrometry. These approaches permitted identification of glyco- or putative glycosylated proteins which may be associated with tumorigenesis. The proteins identified include molecules involved in sugar metabolism, signal transduction, proteolysis, and stress, as well as several unknown proteins, which were aberrantly glycosylated as evidenced by the L-phytohemagglutinin blot.

Glycoprotein isolated from Solanum nigrum L. inhibits the DNA-binding activities of NF-κB and AP-1, and increases the production of nitric oxide in TPA-stimulated MCF-7 cells

Solanum nigrum L. (SNL) has been used in traditional folk medicine to treat numerous cancers. We isolated a glycoprotein (150 kDa) from SNL and tested its effect on the modulation of transcriptional factors (NF-kappa B and AP-1) and iNO production in TPA induced-MCF-7 cells, which are part of the human breast cancer cell line, without estrogen receptors. However, the mechanism of SNL glycoprotein in pharmacological and biochemical actions in cancer cells has not been studied. To test the effect of SNL glycoprotein on the DNA-binding activities of nuclear factor-kappa B (NF-kappaB) and activator protein-1 (AP-1), and nitric oxide (NO) production, these experiments were carried out using electrophoretic mobility shift assays (EMSA), western blot analysis, and the Griess method. Results in this experiment showed that SNL glycoprotein inhibits 12-O-Tetra decanoylphorbol-13-acetate (TPA; 100 nM)-induced DNA-binding activities of NF-kappaB and AP-1, and enhances NO production in MCF-7 cells. That is, our results indicated that SNL glycoprotein has the capacity to modulate the TPA-induced DNA-binding activities of transcription factors and NO production, which play a critical role with respect to cytotoxicity in MCF-7 cells. Therefore, SNL glycoprotein might be one of the agents that blocks TPA-mediated signal responses in tumor cells.

CA repeats in the 3'-untranslated region of bcl-2 mRNA mediate constitutive decay of bcl-2 mRNA

An AU-rich element (ARE) in the 3'-untranslated region (UTR) of bcl-2 mRNA has previously been shown to be responsible for destabilizing bcl-2 mRNA during apoptosis through increasing AUF1 binding. In the present study, we investigated the effect of the region upstream of the ARE on bcl-2 mRNA stability using serial deletion constructs of the 3'-UTR of bcl-2. Deletion of 30 nucleotides mostly consisting of the CA repeats, located upstream of the ARE, resulted in the stabilization of bcl-2 mRNA abundance, in the absence or presence of the ARE. The specificity of the CA repeats in terms of destabilizing bcl-2 mRNA was proven by the substituting the CA repeats with other alternative repeats of purine/pyrimidine, but this had no effect on the stability of bcl-2 mRNA. CA repeats alone, however, failed to confer instability to bcl-2 or gfp reporter mRNAs, indicating a requirement for additional sequences in the upstream region of the 3'-UTR. Serial deletion and replacement of a part of the region upstream of the CA repeats revealed that the entire 131-nucleotide upstream region is an essential prerequisite for the CA repeat-dependent destabilization of bcl-2 mRNA. Unlike the ARE, CA repeat-mediated degradation of bcl-2 mRNA was not accelerated upon apoptotic stimulus. Moreover, the upstream sequences and CA repeats are conserved among mammals. Collectively, CA repeats contribute to the constitutive decay of bcl-2 mRNA in the steady states, thereby maintaining appropriate bcl-2 levels in mammalian cells.

Native antiviral specificity of chicken Mx protein depends on amino acid variation at position 631

An attempt was made to determine whether amino acid variation at position 631 in the chicken Mx protein definitely influences antiviral specificity, using an artificial mutation technique by which a single amino acid was reciprocally substituted between Ser (AGT) and Asn (AAT) at position 631 of the negative and positive chicken Mx, respectively. Using permanently transfected 3T3 cell lines, the antiviral potential of chicken Mx against vesicular stomatitis virus infection was analysed. The results indicated that the phenotype of antiviral activity depends on the amino acid difference at position 631; that is, the genotype coding Asn at position 631 corresponds to the positive antiviral phenotype, and the genotype coding Ser corresponds to the negative phenotype. The present study has confirmed that the antiviral specificity of chicken Mx protein is determined by an amino acid substitution at the carboxy terminus.

Analysis of plausible downstream target genes of Hoxc8 in F9 teratocarcinoma cells. Putative downstream target genes of Hoxc8

Although Hox genes are known to mediate developmental decisions involved in pattern formation during embryogenesis, it is still not well understood what Hox regulates. In order to analyze Hoxc8 downstream target genes, a stable cell line overexpressing Hoxc8 was established using F9 murine teratocarcinoma cells, proteom samples were analyzed by 2-DE, and compared with controls. The protein spots having differences more than 4 fold in intensity were selected, analyzed by MALDI-TOF, and grouped in terms of putative function; cytoskeleton and motility (vimentin, gamma-actin, tropomyosin, and tubulin beta-5 chain); folding, modification and degradation of protein (GRP78, proteasome subunit alpha type 5, 26S proteasome regulatory subunit p27 protein, and PDIR); metabolism (ATP synthase beta subunit, Pgam1, and CAII); transcription/translation factors and general nucleic acid binding proteins (RbAp46, PCNA, eEF-1-beta, and nucleophosmin). Although it may not be significant, 50% of the genes were located on chromosomes 2 and 3, suggesting the possibility of a non-random distribution of Hox downstream genes. Almost 50% of the genes analyzed showed some relation with Hox protein directly or indirectly; i.e., tubulin beta 5, EF-1 beta and PCNA have been reported to contain putative Hox binding regulatory sites and genes like vimentin, pgam1 and nucleophosmin to be regulated by RA, a potent modulator of Hox expression. These results altogether imply that proteom analysis could be a possible tool for the analysis of the potent Hox realizator genes, which provides a new insight into the function of Hox on pattern formation during embryogenesis.

A glycomic approach to hepatic tumors in N-acetylglucosaminyltransferase III (GnT-III) transgenic mice induced by diethylnitrosamine (DEN): identification of haptoglobin as a target molecule of GnT-III

A glycomic approach to the identification of target molecules in glycosyltransferase gene targeting mice is a promising strategy to understand the biological significance of glycosyltransferase genes in vivo. In order to understand the biological effects of N-acetylglucosaminyltransferase III (GnT-III) on tumor formation in the liver, diethylnitrosamine (DEN) induced tumor formation in the GnT-III transgenic mice was examined. Our findings show that the incidence of hepatic tumor could be dramatically suppressed. A glycomic approach using two-dimensional gel electrophoresis followed by lectin blot analysis and sequence analysis revealed that haptoglobin, a radical scavenger molecule in serum was heavily glycosylated in hepatic tumor-bearing GnT-III transgenic mice that had been treated with DEN. Immunoprecipitation followed by E4-PHA lectin blot analysis also confirmed that the bisecting GlcNAc, a product of GnT-III was added to haptoglobin molecules. Since the use of DEN is known to lead to the production of lipid peroxidation products which facilitate this reaction and haptoglobin is an acute phase reactant, acting as a radical scavenger against hemoglobin or iron stimulated lipid peroxidation, a relationship between the glycosylation of haptoglobin and the suppression of hepatoma development can not be ruled out. This paper is the first report that shows a relationship between the sugar chains of glycoproteins with radical scavenger activity and hepatocarcinogenesis.

Prometastatic effect of N-acetylglucosaminyltransferase V is due to modification and stabilization of active matriptase by adding beta 1-6 GlcNAc branching

Oligosaccharide moieties of glycoproteins are structurally altered during development, carcinogenesis, and malignant transformations. It is well known that beta1-6 GlcNAc branching, a product of UDP-GlcNAc alpha-mannoside beta1-6-N-acetylglucosaminyltransferase (GnT-V), is associated with malignant transformation as the results of such alterations. However, the mechanism by which beta1-6 GlcNAc branching is linked to metastasis remains unclear, because the identification of specific glycoprotein(s) that are glycosylated by GnT-V and its biological function have not been examined. We herein report that matriptase, which activates both urokinase-type plasminogen activator and hepatocyte growth factor, is a target protein for GnT-V. The overexpression of GnT-V in gastric cancer cells leads to severe peritoneal dissemination in athymic mice, which can be attributed to the increased expression of matriptase. This increase was due to the acquired resistance of matriptase to degradation, since it is glycosylated by GnT-V and a corresponding increase in the active form. These results indicate that this process is a key element in malignant transformation, as the direct result of oligosaccharide modification.