Association of multiple copies of the N-myc oncogene with rapid progression of neuroblastomas

Eighty-nine patients with untreated primary neuroblastomas were studied to determine the relation between the number of copies of the N-myc oncogene and survival without disease progression. Genomic amplification (3 to 300 copies) of N-myc was detected in 2 of 16 tumors in Stage II, 13 of 20 in Stage III, and 19 of 40 in Stage IV; in contrast, 8 Stage I and 5 Stage IV-S tumors all had 1 copy of the gene (P less than 0.01). Analysis of progression-free survival in all patients revealed that amplification of N-myc was associated with the worst prognosis (P less than 0.0001); the estimated progression-free survival at 18 months was 70 per cent, 30 per cent, and 5 per cent for patients whose tumors had 1, 3 to 10, or more than 10 N-myc copies, respectively. Of 16 Stage II tumors, 2 with amplification metastasized, whereas only 1 of 14 without amplification did so (P = 0.03). Stage IV tumors with amplification progressed most rapidly: nine months after diagnosis the estimated progression-free survival was 61 per cent, 47 per cent, and 0 per cent in patients whose tumors had 1, 3 to 10, or more than 10 copies, respectively (P less than 0.0001). These results suggest that genomic amplification of N-myc may have a key role in determining the aggressiveness of neuroblastomas.

Molecular mechanisms underlying bile acid-stimulated glucagon-like peptide-1 secretion

BACKGROUND AND PURPOSE

The glucagon-like peptides GLP-1 and GLP-2 are secreted from enteroendocrine L-cells following nutrient ingestion. Drugs that increase activity of the GLP-1 axis are highly successful therapies for type 2 diabetes, and boosting L-cell secretion is a potential strategy for future diabetes treatment. The aim of the present study was to further our understanding of the bile acid receptor GPBA (TGR5), an L-cell target currently under therapeutic exploration.

EXPERIMENTAL APPROACH

GLUTag cells and mixed primary murine intestinal cultures were exposed to bile acids and a specific agonist, GPBAR-A. Secretion was measured using hormone assays and intracellular calcium and cAMP responses were monitored using real-time imaging techniques.

KEY RESULTS

Bile acid-triggered GLP-1 secretion from GLUTag cells was GPBA-dependent, as demonstrated by its abolition following tgr5 siRNA transfection. Bile acids and GPBAR-A increased GLP-1 secretion from intestinal cultures, with evidence for synergy between the effects of glucose and GPBA activation. Elevation of cAMP was observed following GPBA activation in individual GLUTag cells. Direct calcium responses to GPBAR-A were small, but in the presence of the agonist, a subpopulation of cells that was previously poorly glucose-responsive exhibited robust glucose responses. In vivo, increased delivery of bile to more distal regions of the ileum augmented L-cell stimulation.

CONCLUSIONS AND IMPLICATIONS

GPBA signalling in L-cells involves rapid elevation of cAMP, and enhanced calcium and secretory responses to glucose. Modulation of this receptor therapeutically may be an attractive strategy to enhance GLP-1 secretion and achieve better glycaemic control in diabetic patients.

Electrostatic enhancement of diffusion-controlled protein-protein association: comparison of theory and experiment on barnase and barstar

The electrostatic enhancement of the association rate of barnase and barstar is calculated using a transition-state theory like expression and atomic-detail modeling of the protein molecules. This expression predicts that the rate enhancement is simply the average Boltzmann factor in the region of configurational space where association occurs instantaneously in the diffusion-controlled limit. Based on experimental evidence, this "transition state" is defined by configurations in which, relative to the stereospecifically bound complex, the two proteins are shifted apart by approximately 8 A (so a layer of water can be accommodated in the interface) and the two binding surfaces are rotated away by 0 degrees to 3 degrees. The values of the average Boltzmann factor, calculated by solving the Poisson-Boltzmann equation, for the wild-type complex and 16 complexes with single mutations are found to correlate well with experimental results for the electrostatic rate enhancement. The predicted rate enhancement is found to be somewhat insensitive to the precise definition of the transition state, due to the long-range nature of electrostatic interactions. The experimental ionic strength dependence of the rate enhancement is also reasonably reproduced.

Surface markers and prognostic factors in acute lymphoblastic leukemia

We investigated the surface markers on lymphoblasts from 37 patients with acute lymphoblastic leukemia. Spontaneous rosette formation with sheep erythrocytes (E rosettes) identified T cells and the presence of surface immunoglobulin identified B cells. Eight patients had T-marker lymphoblasts; 28 had no markers (null lymphoblasts), and one patient had B-marker lymphoblasts. The eight patients with T-marker acute lymphoblastic leukemia had massive leukemic infiltration, frequently a mediastinal mass, and a poor prognosis. The T-marker lymphoblasts had a weak or negative periodic acid-Schiff reaction and a very low antigenic stimulation to allogeneic lymphocytes. The association of T-marker lymphoblasts and some of the conventional poor-risk factors appears to be reliable in predicting a poor prognosis.

Epigenetic inactivation of the miR-34a in hematological malignancies

miR-34a is a transcriptional target of p53 and implicated in carcinogenesis. We studied the role of miR-34a methylation in a panel of hematological malignancies including acute leukemia [acute myeloid leukemia (AML) and acute lymphoblastic leukemia (ALL)], chronic leukemia [chronic lymphocytic leukemia (CLL) and chronic myeloid leukemia (CML)], multiple myeloma (MM) and non-Hodgkin's lymphoma (NHL). The methylation status of miR-34a promoter was studied in 12 cell lines and 188 diagnostic samples by methylation-specific polymerase chain reaction. miR-34a promoter was unmethylated in normal controls but methylated in 75% lymphoma and 37% myeloma cell lines. Hypomethylating treatment led to re-expression of pri-miR-34a transcript in lymphoma cells with homozygous miR-34a methylation. In primary samples at diagnosis, miR-34a methylation was detected in 4% CLL, 5.5% MM samples and 18.8% of NHL at diagnosis but none of ALL, AML and CML (P = 0.011). In MM patients with paired samples, miR-34a methylation status remained unchanged at progression. Amongst lymphoid malignancies, miR-34a was preferentially methylated in NHL (P = 0.018), in particular natural killer (NK)/T-cell lymphoma. In conclusion, amongst hematological malignancies, miR-34a methylation is preferentially hypermethylated in NHL, in particular NK/T-cell lymphoma, in a tumor-specific manner, therefore the role of miR-34a in lymphomagenesis warrants further study.

Relation of arterial stiffness with gestational age and birth weight

BACKGROUND

The cardiovascular risk of individuals who are born small as a result of prematurity remains controversial. Given the previous findings of stiffer peripheral conduit arteries in growth restricted donor twins in twin-twin transfusion syndrome regardless of gestational age, we hypothesised that among children born preterm, only those with intrauterine growth retardation are predisposed to an increase in cardiovascular risks.

AIM

To compare brachioradial arterial stiffness and systemic blood pressure (BP) among children born preterm and small for gestational age (group 1, n = 15), those born preterm but having birth weight appropriate for gestational age (group 2, n = 36), and those born at term with birth weight appropriate for gestational age (group 3, n = 35).

METHODS

Systemic BP was measured by an automated device (Dinamap), while stiffness of the brachioradial arterial segment was assessed by measuring pulse wave velocity (PWV). The birth weight was adjusted for gestational age and expressed as a z score for analysis.

RESULTS

The 86 children were studied at a mean (SD) age of 8.2 (1.7) years. Subjects from group 1, who were born at 32.3 (2.0) weeks' gestation had a significantly lower z score of birth weight (-2.29 (0.63), p<0.001), compared with those from groups 2 and 3. They had a significantly higher mean blood pressure (p<0.001) and their diastolic blood pressure also tended to be higher (p = 0.07). Likewise, their brachioradial PWV, and hence arterial stiffness, was the highest of the three groups (p<0.001). While subjects from group 2 were similarly born preterm, their PWV was not significantly different from that of group 3 subjects (p = 1.00) and likewise their z score of birth weight did not differ (-0.01 (0.71) v -0.04 (1.1), p = 1.00). Brachioradial PWV correlated significantly with systolic (r = 0.31, p = 0.004), diastolic (r = 0.38, p<0.001), and mean (0.47, p<0.001) BP, and with z score of birth weight (r = -0.43, p<0.001). Multiple linear regression identified mean BP and z score of birth weight as significant determinants of PWV.

CONCLUSION

The findings of the present study support the hypothesis that among children born preterm, only those with intrauterine growth retardation are disadvantaged as a result of increase in systemic arterial stiffness and mean blood pressure.

Cellular uptake and nuclear binding of insulin in human cultured lymphocytes: evidence for potential intracellular sites of insulin action

Human cultured lymphocytes (IM-9) were used to demonstrate that insulin can enter the intact cell and bind to the nucleus. When these lymphocytes were incubated with 125I-labeled insulin, specific cellular uptake reached a maximum within 2 min and remained at a plateau for 90 min or longer. Partially purified nuclei from such cells contained approximately 15-20% of the total cellular radioactivity. Nuclei freed of all other cellular fractions (by washing the partially purified nucleic with Triton X-100) bound approximately 7% of the total cellular radioactivity. In contrast to the rapid uptake of labeled insulin into the intact cell, specific binding to the nucleus was half-maximal after 5 min of incubation and maximal after 90 min. Both the cellular uptake and subsequent nuclear binding of labeled insulin were progressively inhibited by increasing concentrations of unlabeled hormone. Independent evidence for the nuclear binding of insulin was obtained by preparing autoradiographs of lymphocytes incubated for various times with labeled insulin. Such preparations strongly suggest that insulin binds to the plasma membrane, enters the cytosol, and then binds to the nucleus.

Efficacy and tolerability of a Chinese herbal medicine concoction for treatment of atopic dermatitis: a randomized, double-blind, placebo-controlled study

BACKGROUND

There has been considerable interest in traditional Chinese herbal medicine (TCHM) as a treatment for atopic dermatitis (AD). A twice-daily concoction of an ancestral formula containing five herbs has been found to be beneficial in an open study.

OBJECTIVES

To assess the efficacy and tolerability of the concoction in children with AD.

METHODS

Following a 2-week run-in period, children with long-standing moderate-to-severe AD were randomized to receive a 12-week treatment with twice-daily dosing of three capsules of either TCHM or placebo. The SCORing of Atopic Dermatitis (SCORAD) score, Children's Dermatology Life Quality Index (CDLQI), allergic rhinitis score, and requirement for topical corticosteroid and oral antihistamine were assessed before and at weeks 4, 8, 12 and 16 after treatment. Adverse events, tolerability, haematological and biochemical parameters were monitored during the study.

RESULTS

Eighty-five children with AD were recruited. Over 12 weeks, the mean SCORAD score fell from 58.3 to 49.7 in the TCHM group (n = 42; P = 0.003) and from 56.9 to 46.9 in the placebo group (n = 43; P = 0.001). However, there was no significant difference in the scores at the corresponding time points between the two groups. The CDLQI in TCHM-treated patients was significantly improved compared with patients receiving placebo at the end of the 3-month treatment and 4 weeks after stopping therapy (P = 0.008 and 0.059, respectively). The total amount of topical corticosteroid used was also significantly reduced by one-third in the TCHM group (P = 0.024). No serious adverse effects were observed between the groups.

CONCLUSIONS

The TCHM concoction is efficacious in improving quality of life and reducing topical corticosteroid use in children with moderate-to-severe AD. The formulation was palatable and well tolerated.

Entry of insulin into human cultured lymphocytes: electron microscope autoradiographic analysis

Electron microscope autoradiographs were prepared of IM-9 human cultured lymphocytes incubated with iodine-125-labeled insulin. With the use of [125I]insulin and Ilford L-4 emulsion, the technique had a resolution half-distance of approximately 0.085 micrometer. Autoradiographs revealed a time-dependent entry of insulin into the cell interior that was maximal after 30 minutes of incubation. At this time point nearly 40 percent of the [125I]insulin was in the interior of the cell at a distance 1 micrometer or greater from the plasma membrane. Grain distribution and volume density analyses revealed that the intracellular insulin was concentrated in the endoplasmic reticulum and nuclear membrane.

Statistical mechanics of image restoration and error-correcting codes

We develop a statistical-mechanical formulation for image restoration and error-correcting codes. These problems are shown to be equivalent to the Ising spin glass with ferromagnetic bias under random external fields. We prove that the quality of restoration/decoding is maximized at a specific set of parameter values determined by the source and channel properties. For image restoration in a mean-field system a line of optimal performance is shown to exist in the parameter space. These results are illustrated by solving exactly the infinite-range model. The solutions enable us to determine how precisely one should estimate unknown parameters. Monte Carlo simulations are carried out to see how far the conclusions from the infinite-range model are applicable to the more realistic two-dimensional case in image restoration.

Monoclonal antibodies to the human insulin receptor block insulin binding and inhibit insulin action

Antibodies to the insulin receptor were prepared in BALB/c mice by immunization with IM-9 human lymphocytes, a cell type that has a large number of plasma membrane insulin receptors. The spleens of these mice were then removed, and their lymphocytes were fused to a mouse myeloma cell line, FO cells. After screening over 1,200 resulting hybrids, one stable hybrid was obtained that produced IgG1 antibodies directed towards the insulin receptor. This antibody blocked 125I-labeled insulin binding to its receptor by more than 90% in three human tissues: IM-9 cultured lymphocytes, freshly isolated adipocytes, and placenta membranes. In contrast, the antibody did not inhibit insulin binding to rat adipocytes and rat liver plasma membranes, suggesting that the antibody was species specific. In IM-9 cells, which had their proteins prelabeled with [35S]methionine, the antibody precipitated two polypeptides with molecular weights of 135,000 and 95,000; these molecular weights are identical to those previously identified as the alpha and beta subunits of the insulin receptor. The monoclonal antibody inhibited the actions of insulin on both human adipocytes and fibroblasts, suggesting that the antibody was an antagonist of insulin action. The present studies suggest, therefore, that monoclonal antibodies to the insulin receptor may provide new insights into the structure of the insulin receptor and its interaction with insulin.

Highly efficient asymmetric epoxidation of alkenes with a D(4)-symmetric chiral dichlororuthenium(IV) porphyrin catalyst

A dichlororuthenium(IV) complex of 5,10,15,20-tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-octahydro-1,2:5,8-dimethanoanthrance-9-yl]porphyrin, [Ru(IV)(D(4)-Por)Cl(2)] (1), was prepared by heating [Ru(II)(D(4)-Por)(CO)(MeOH)] (2) in refluxing CCl(4). Complex 1 is characterized by (1)H NMR (paramagnetically shifted pyrrolic protons at delta(H) = -52.3 ppm), FAB-mass spectroscopies, and magnetic susceptibility measurement (mu(eff) = 3.1 mu(B)). The ruthenium complex exhibits remarkable catalytic activity toward enantioselective alkene epoxidation using 2,6-dichloropyridine N-oxide (Cl(2)pyNO) as terminal oxidant. The Ru(IV)-catalyzed styrene epoxidation is achieved within 2 h (versus 48 h for the 2-catalyzed reaction), and optically active styrene oxide was obtained in 69% ee and 84% yield (875 turnovers). Likewise, substituted styrenes and some conjugated cis-disubstituted alkenes (e.g., cis-beta-methylstyrene, cis-1-phenyl-3-penten-1-yne, 1,2-dihydronaphthalene, and 2,2-dimethylchromenes) are converted effectively to their organic epoxides in 50-80% ee under the Ru(IV)-catalyzed conditions, and more than 850 turnovers of epoxides have been attained. When subjecting 1 to four repetitive uses by recharging the reaction mixture with Cl(2)pyNO and styrene, styrene oxide was obtained in a total of 2190 turnovers and 69% ee. UV-vis and ESI-mass spectral analysis of the final reaction mixture revealed that a ruthenium-carbonyl species could have been formed during the catalytic reaction, leading to the apparent catalyst deactivation. We prepared a heterogeneous chiral ruthenium porphyrin catalyst by immobilizing 1 into sol-gel matrix. The heterogeneous catalyst is highly active toward asymmetric styrene epoxidation producing styrene oxide in 69% ee with up to 10,800 turnovers being achieved. The loss of activity of the Ru/sol-gel catalyst is ascribed to catalyst leaching and/or deactivation. On the basis of Hammett correlation (rho(+) = -1.62, R = 0.99) and product analysis, a dioxoruthenium(VI) porphyrin intermediate is not favored.

Does age or gender influence quality of life in children with atopic dermatitis?

BACKGROUND

Quality of life (QoL) is impaired in children with atopic dermatitis (AD) but the various aspects of QoL may not be equally affected. Aim. To evaluate if age and gender affect some aspects of QoL in children with AD.

METHOD

The Children's Dermatology Life Quality Index (CDLQI) was used for all children with AD seen at a paediatric dermatology clinic over a 3-year period. Disease severity was assessed using the SCORing Atopic Dermatitis (SCORAD) and Nottingham Eczema Severity Score (NESS) tools.

RESULTS

We reviewed CDLQI in 133 children (70 male and 63 female; age range 5-16 years) with AD. Itch, sleep disturbance, treatment and swimming/sports were the four aspects of QoL issues that were most commonly affected, in 50%, 47%, 38% and 29% of patients, respectively. Problems with interpersonal issues (friendship, school/holidays, and teasing/bullying) occurred in only a minority of children (<or= 10%). Girls had more problems with issues of clothes and shoes than did boys (OR = 2.86, 95% CI 1.05-8.00; P = 0.038). Significant itch and sleep disturbance affected both genders similarly but were generally more common in children <or= 10 years (itch: OR = 2.31, 95% CI 1.04-5.14; P = 0.039; and sleep: OR = 2.31, 95% CI 1.05-5.13; P = 0.037).

CONCLUSIONS

Not all aspects of QoL are affected equally in children with AD. The disease seems to affect personal domains of itch and sleep more than the interpersonal issues. Age and gender are relevant factors in QoL, with the issue of clothes/shoes being more troublesome for girls. itch and sleep disturbance seem to be a problem mainly in younger children.

Comparative analysis of Epstein-Barr virus gene polymorphisms in nasal T/NK-cell lymphomas and normal nasal tissues: implications on virus strain selection in malignancy

Whether particular Epstein-Barr virus (EBV) strains are preferentially selected in malignant diseases remains controversial. Assessment of the importance of strain variation in the pathogenicity of EBV has been hampered principally by the lack of accurate data on the prevalence of virus variants in the normal population. To clarify this issue, a detailed comparative analysis of the EBV genomes contained in normal nasal and nasopharyngeal mucosal tissues and in nasal T/NK-cell lymphoma, which originates at these anatomic sites, was carried out by PCR amplification across the 30-bp deletion and the 33-bp repeat loci in the LMP1 gene and the type-specific polymorphic loci in the EBNA2 and EBNA3C genes and by sequence analysis of the 3' C-terminal region of the LMP1 gene. Whilst the majority of EBV strains in either normal or tumour tissues were type 1 viruses with similar numbers of LMP1 repeats, a marked predominance of LMP1 deletion (del-LMP1) over non-deleted/wild-type LMP1 (wt-LMP1) variants was observed in nasal T/NK-cell lymphoma. Although del-LMP1 variants were also prevalent in the normal carriers of our population, wt-LMP1 was detected at a significantly higher frequency in normal vs. tumour tissues (p = 0.036). More critically, wt-LMP1 variants were found frequently in mixed infection with del-LMP1 variants in the normal carriers. Sequence analysis identified 2 major del-LMP1 (and several wt-LMP1) variants containing signatory nucleotide changes in relation to the prototype B95-8 sequence in both normal and neoplastic nasal tissues. Together, our data provide strong evidence for a selection mechanism for del-LMP1 over the wt-LMP1 variants in tumours.

Clinical implications of oncogene activation in human neuroblastomas

Amplification of the oncogene N-myc has been identified in almost all human neuroblastoma cell lines tested. Eighty-nine primary neuroblastomas from untreated patients were studied to determine the frequency and clinical significance of N-myc amplification. Tumor DNA was analyzed by hybridization with the radiolabeled probe pNB-1 for N-myc. Amplification (3-300 copies) of the N-myc gene was found in 34 of the 89 tumors (38%). Amplification was not found in 8 Stage I or 5 Stage IV-S tumors, but it was found in 2 of 16 with Stage II, 13 of 20 with Stage III, and 19 of 40 with Stage IV tumors (P less than 0.01). Correlation of N-myc amplification with progression-free survival (PFS) indicated that N-myc amplification was associated with a worse prognosis (P less than 0.0001). The PFS at 18 months was 70%, 30%, and 5% for patients whose tumors had 1, 3-10, and more than 10 copies, respectively. Even within individual stages, the presence of N-myc amplification correlated with rapid progression. For instance, of 16 patients with Stage II disease, the 2 with N-myc amplification developed progressive disease rapidly, whereas only 1 of 14 without amplification progressed (P = 0.03). Similarly, those with Stage III and IV disease whose tumors have multiple copies of N-myc had a substantially worse prognosis. The correlation between N-myc amplification and age at diagnosis was also analyzed. Although N-myc amplification was detected in only 4 of 28 infants less than 1 year of age, compared to 30 of 61 older patients (P less than 0.005), this difference disappeared when corrected for disease stage. The results suggest that N-myc amplification is a powerful prognostic indicator, and that this gene may play an important role in the progression of certain neuroblastomas.

Improvement in survival after excision of primary tumor in stage III neuroblastoma

Fifty-eight patients with stage III neuroblastoma (according to the Childrens Cancer Study Group) underwent 86 operative procedures. Initial diagnostic or therapeutic operations were followed by chemotherapy and radiation therapy, and second- or third-look procedures were performed on patients whose tumors showed evidence of clinical response. Complete resection was obtained during the initial procedure in 12 patients, during the second operation in 12 others, and at the time of the third procedure in two additional children. Twenty of these 26 patients have survived with no evidence of disease for a median duration of greater than 3 years since initiation of therapy. Only nine of the 32 patients in whom complete tumor excision could not be accomplished are still alive. The chemotherapy and radiation therapy employed in this protocol may have enhanced resectability in many patients. The site of the primary tumor does not seem to influence ease of resectability or outcome in this group. The "favorable" prognostic factors of patient age and histopathology of the tumor do not necessarily predict that the tumor will be resectable. While patients with complete resection at the time of the second operation had an outcome superior to those with incomplete resections, the influence of the inherent tumor biology or other selection factors on the eventual tumor resectability in these patients is not known. Extensive operative procedures were required to completely resect stage III tumors, and a moderate complication rate may be anticipated. However, this may be justifiable if complete tumor resection can be achieved and ultimate patient survival possibly enhanced.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the in vitro effect of biguanides and sulfonylureas on insulin binding of its receptors in target cells

The in vitro effects of two biguanides (phenformin and metformin) and four sulfonylureas (tolbutamide, glyburide, gliclazide, and glisolamide) on insulin binding to its receptors were studied in four cultured cell lines: human skin fibroblasts, IM-9 lymphoblasts, MCF-7 human mammary carcinoma, and H35 rat hepatoma. After a 24-h preincubation with maximal stimulatory concentrations of phenformin, specific [125I] insulin binding to its receptors in the four different cell lines were increased over control by 67.2 +/ 17.0%, 101.3 +/- 11.5%, 65.1 +/- 8.0%, and 44.0 +/- 12.1%, respectively (mean +/- SE). Phenformin was effective in IM-9 cells that were down-regulated by unlabeled insulin, and the effect of phenformin on insulin binding was not affected by inhibition of protein synthesis with cycloheximide. In concert with this observation. Scatchard plots indicated that phenformin increased the insulin receptor's affinity rather than the number of insulin-binding sites on IM-9 cells. Metformin was also effective in significantly enhancing insulin binding in both IM-9 and MCF-7 cells. In contrast to the effects of biguanides, none of the four sulfonylureas tested had any significant influence on insulin binding to any of the four cell lines. These agents were also ineffective in IM-9 cells that were down-regulated by insulin. Therefore, these studies suggest that: 1) in vitro, biguanides enhance insulin binding to its receptors in a variety of cell types; 2) this effect of biguanides doesn't depend on new receptor synthesis; it is a result of changes in the affinity of the insulin receptor; and 3) in contrast to the biguanides, the sulfonylureas do not have a major direct effect on insulin binding to its receptors in most cell types.

MUC13 protects colorectal cancer cells from death by activating the NF-κB pathway and is a potential therapeutic target

MUC13 is a transmembrane mucin glycoprotein that is over produced by many cancers, although its functions are not fully understood. Nuclear factor-κB (NF-κB) is a key transcription factor promoting cancer cell survival, but therapeutically targeting this pathway has proved difficult because NF-κB has pleiotropic functions. Here, we report that MUC13 prevents colorectal cancer cell death by promoting two distinct pathways of NF-kB activation, consequently upregulating BCL-X_L. MUC13 promoted tumor necrosis factor (TNF)-induced NF-κB activation by interacting with TNFR1 and the E3 ligase, cIAP1, to increase ubiquitination of RIPK1. MUC13 also promoted genotoxin-induced NF-κB activation by increasing phosphorylation of ATM and SUMOylation of NF-κB essential modulator. Moreover, elevated expression of cytoplasmic MUC13 and NF-κB correlated with colorectal cancer progression and metastases. Our demonstration that MUC13 enhances NF-κB signaling in response to both TNF and DNA-damaging agents provides a new molecular target for specific inhibition of NF-κB activation. As proof of principle, silencing MUC13 sensitized colorectal cancer cells to killing by cytotoxic drugs and inflammatory signals and abolished chemotherapy-induced enrichment of CD133⁺ CD44⁺ cancer stem cells, slowed xenograft growth in mice, and synergized with 5-fluourouracil to induce tumor regression. Therefore, these data indicate that combining chemotherapy and MUC13 antagonism could improve the treatment of metastatic cancers.

A potential mechanism of local anti-inflammatory action of alpha-melanocyte-stimulating hormone within the brain: modulation of tumor necrosis factor-alpha production by human astrocytic cells

The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) occurs in CNS tissue in neurological disorders, infection, and injury. Its excessive production is believed to contribute to local pathology, in which case modulation of TNF-alpha production should promote survival of neural tissue. The neuropeptide alpha-melanocyte stimulating hormone [alpha-MSH (1-13)] inhibits TNF-alpha production in vivo and in vitro, and in this research we tested the capacity of the peptide, and of an anti-inflammatory COOH-terminal tripeptide fragment of it, to inhibit TNF-alpha production induced by bacterial endotoxin in cells of a human glioma line (A-172, anaplastic astrocytoma cells). Both peptides were effective, although the alpha-MSH (1-13) sequence was more potent. Preincubation of the cells with alpha-MSH (1-13) markedly increased its effectiveness. The anticytokine effect of alpha-MSH in glioma cells may be mediated by human melanocortin-1 receptors; mRNA for this receptor subtype was isolated from resting A-172 cells. These results, combined with prior evidence of effectiveness of alpha-MSH molecules in modulating inflammatory processes and of their low toxicity, suggest that the molecules may be useful in the treatment of CNS disorders that have an inflammatory component.

Prognostic value of histopathology in advanced neuroblastoma: a report from the Childrens Cancer Study Group

We report the histopathologic findings in 420 patients with stage III and IV neuroblastoma enrolled in Childrens Cancer Study Group trials conducted from 1980 to 1983. A prospective study of individual cytohistologic features showed that outcome was related in a statistically significant manner to mitotic rate, multi-nuclearity, foam cells, ganglion cells, necrosis, and calcification, but only the latter was consistent for both stages. A similar test of four selected published classifications indicated the greatest prognostic value for the system developed by Shimada et al to distinguish favorable from unfavorable tumors. This classification proved significant in both stages and on examination of both primary and metastatic sites. Concordance in histologic assignment of prognosis by two observers was 83%. We conclude that the Shimada classification is valid and reproducible, and that it may be useful in planning therapy in advanced neuroblastoma. Selected cytohistologic parameters and the other classifications were less strongly predictive of outcome, but are worthy of continued study.

Ammonia clearance by peritoneal dialysis and continuous arteriovenous hemodiafiltration

We report the use of continuous arteriovenous hemodiafiltration (CAVHD) in a neonate with severe hyperammonemia due to a urea cycle disorder. We compared the ammonia clearance (C(NH3)) for peritoneal dialysis (PD) and CAVHD. C(NH3) for CAVHD was 7.45 ml/min per m2 at a dialysate flow of 300 ml/h and was 10.55 ml/min per m2 at a dialysate flow rate of 600 ml/h. The mean PD clearance was 2.15 ml/min per m2. Our data suggest that CAVHD is superior to PD for the removal of plasma ammonia. We conclude that CAVHD should be considered a reasonable alternative in the treatment of neonatal hyperammonemia in urea cycle disorders when medical treatment fails.

The significance of LMO2 expression in the progression of prostate cancer

LIM domain only 2 (LMO2) proteins are important regulators in determining cell fate and controlling cell growth and differentiation. This study has investigated LMO2 expression in human prostatic tissue specimens, prostate cancer cell lines, and xenografts; and has assessed the possible role and mechanism of LMO2 in prostate carcinogenesis. Immunohistochemical analysis on a tissue microarray consisting of 91 human prostate specimens, including normal, prostatic hyperplasia, high-grade prostatic intraepithelial neoplasia, and invasive carcinoma, revealed that overexpression of LMO2 was significantly associated with advanced tumour stage, as measured by Gleason score (p = 0.012), as well as with the development of distant metastasis (p = 0.018). These data were supported by quantitative real-time PCR experiments, where LMO2 mRNA levels were found to be significantly higher in prostate tumour specimen than in normal epithelium (p = 0.037). The expression of LMO2 in cell lines and xenografts representing androgen-dependent (AD) and androgen-independent (AI) prostate cancer stages was further studied. Consistent with the in vivo data, LMO2 mRNA and protein were found to be overexpressed in the more aggressive AI cells (PC3, DU145, and AI CWR22 xenografts) compared with less aggressive AD cells (LNCaP and AD CWR22 xenografts). Furthermore, stable introduction of LMO2 into LNCaP cells conferred enhanced cell motility and invasiveness in vitro, accompanied by down-regulation of E-cadherin expression. Taken together, these findings provide the first evidence to support the hypothesis that LMO2 may play an important role in prostate cancer progression, possibly via repression of E-cadherin expression.