Clinical features of 53 cases with pustulotic arthro-osteitis

We have described clinical features of 53 cases with pustulotic arthro-osteitis. Anterior chest wall symptoms such as intersterno-costoclavicular or manubriosternal lesions were observed in all of 53 cases. Spondylitis or spondylodiscitis was found in 18 cases. Sacroiliitis resembling ankylosing spondylitis was seen in 7 cases. Peripheral inflammatory arthritis was seen in 14 cases, which were of nonerosive, of oligoarthritis type, and cured within 1 to 2 months, leaving no residue. HLA B27 was never found, and RAW factor was negative. Histological examinations revealed nonspecific chronic inflammation of bone and soft tissue. Pustulotic arthro-osteitis is apparently distinct from known rheumatic diseases such as rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, and Reiter's disease. We have proposed that this condition should be classified as a member of the "seronegative spondylo-arthritis' group as designated by Wright and Moll.

Spontaneous regression of localized neuroblastoma detected by mass screening

PURPOSE

To clarify whether and when neuroblastomas identified through screening do regress, and to ascertain how to treat them appropriately, we observed screened patients who had localized tumors, without any therapeutic intervention.

PATIENTS AND METHODS

The criteria for the observation program were as follows: disease stage I or II; tumor less than 5 cm in diameter; no invasion to the intraspinal canal or growth to the great vessels; urinary vanillylmandelic acid (VMA) and homovanillic acid (HVA) less than 50 microg/mg creatinine; and informed consent. Of 25 patients identified through screening for 6-month-old infants in Saitama Prefecture, Japan between April 1994 and March 1996, 11 patients who met the criteria and one other patient with stage III tumor were enrolled onto the program. They were examined by abdominal ultrasonography (US) and their urinary VMA and HVA levels were assessed approximately once per month. The observation periods ranged from 4 to 27 months.

RESULTS

The 11 tumors decreased in size, although one of these 11 tumors initially enlarged until the patient was 12 months of age and decreased in size thereafter. One other tumor slightly increased in size. Urinary VMA levels decreased in all patients. None of the tumors had completely disappeared by the last observation day.

CONCLUSION

Our results suggest that regression of screened neuroblastoma is not a rare phenomenon. At present, it seems reasonable to adopt a wait-and-see strategy, with careful observation, for selected stage I or II tumors identified in infants screened at 6 months of age.

Expression of NADH/NADPH oxidase p22phox in human coronary arteries

BACKGROUND

NADH/NADPH oxidase is an important source of superoxide in the vasculature. Recently, we found that polymorphism of the gene p22phox, a critical component of this oxidase, is associated with a risk of coronary artery disease. The aim of this study was to investigate the localization of p22phox in human coronary arteries and to examine its difference in expression between nonatherosclerotic and atherosclerotic coronary arteries.

METHODS AND RESULTS

Using coronary artery sections from autopsied cases (n=11), the expression of p22phox was examined by immunohistochemistry and Western blotting. In nonatherosclerotic coronary arteries, p22phox was weakly expressed, mainly in the adventitia. In atherosclerotic coronary arteries, intensive immunoreactivity was detected in neointimal and medial smooth muscle cells and infiltrating macrophages in hypercellular regions and at the shoulder region. Semiquantitative analysis and Western blotting showed that the expression of p22phox in atherosclerotic coronary arteries was more pronounced than that in nonatherosclerotic arteries. Double staining revealed p22phox expression in adventitial fibroblasts, smooth muscle cells, macrophages in the neointima and media, and endothelial cells.

CONCLUSIONS

As atherosclerosis progressed, the expression of p22phox increased through the vessel wall. p22phox might participate in the pathogenesis and pathophysiology of atherosclerotic coronary disease.

Identification of two Sox17 messenger RNA isoforms, with and without the high mobility group box region, and their differential expression in mouse spermatogenesis

The different mRNA isoforms of the mouse Sox17 gene were isolated from adult mouse testis cDNAs. One form (referred to as form Sox17) encodes an Sry-related protein of 419 amino acids containing a single high mobility group box near the NH2-terminus, while the other form (referred to as form t-Sox17) shows a unique mRNA isoform of the Sox17 gene with a partial deletion of the HMG box region. Analysis of genomic DNA revealed that these two isoforms were produced at least by alternative splicing of the exon corresponding to the 5' untranslated region and NH2-terminal 102 amino acids. RNA analyses in the testis revealed that form Sox17 began at the pachytene spermatocyte stage and was highly accumulated in round spermatids. Protein analyses revealed that t-Sox17 isoforms, as well as Sox17 isoforms, were translated into the protein products in the testis, although the amount of t-Sox17 products is lower in comparison to the high accumulation of t-Sox17 mRNA. By the electrophoretic mobility-shift assay and the random selection assay using recombinant Sox17 and t-Sox17 proteins, Sox17 protein is a DNA-binding protein with a similar sequence specificity to Sry and the other members of Sox family proteins, while t-Sox17 shows no apparent DNA-binding activity. Moreover, by a cotransfection experiment using a luciferase reporter gene, Sox17 could stimulate transcription through its binding site, but t-Sox17 had little effect on reporter gene expression. Thus, these findings suggest that Sox17 may function as a transcriptional activator in the premeiotic germ cells, and that a splicing switch into t-Sox17 may lead to the loss of its function in the postmeiotic germ cells.

Effects of 1 alpha-hydroxyvitamin D3 on lumbar bone mineral density and vertebral fractures in patients with postmenopausal osteoporosis

The effects of 1 alpha-hydroxyvitamin D3 [1 alpha(OH)D3] on bone mineral density, fracture incidence, and bone metabolism were evaluated by a double-blind, placebo-controlled study. Eighty postmenopausal osteoporotic Japanese women (71.9 +/- 7.3 years, mean +/- SD) were randomly assigned to 1 microgram of 1 alpha(OH)D3 daily or inactive placebo for 1 year. All patients were given supplemental calcium (300 mg of elemental calcium daily). Lumbar (L2-L4) bone mineral density (BMD) determined by dual energy X-ray absorptiometry increased 0.65% with 1 alpha(OH)D3 treatment and decreased 1.14% with placebo (P = 0.037). BMD in both the femoral neck and Ward's triangle did not yield any significant differences between the two groups, whereas trochanter BMD in the 1 alpha(OH)D3-treated group increased 4.20% and decreased 2.37% with placebo (P = 0.055). X-ray analysis demonstrated that new vertebral fractures occurred in two patients with 1 alpha(OH)D3 and in seven patients with placebo. The vertebral fracture rate in the treated group was significantly less (75/1000 patient years) than in the control group (277/1000 patient years; P = 0.029). Hypercalcemia (12.1 mg/100 ml) occurred in one patient receiving 1 alpha(OH)D3; however, the serum calcium level in this patient promptly decreased to the reference range after cessation of the treatment. There were no significant changes in serum creatinine level in either group. A significant increase in urinary excretion of calcium was found but there was no significant change in urinary excretion of hydroxyproline in the treated group. The serum level of bone-derived alkaline phosphatase activity significantly decreased by -26 +/- 26 (mU/ml) after the treatment (P = 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)

Genetic control of the immune response in mice to a Plasmodium falciparum sporozoite vaccine. Widespread nonresponsiveness to single malaria T epitope in highly repetitive vaccine

Different H-2 congenic strains of mice were immunized with a P. falciparum sporozoite vaccine currently being tested in humans, or with different segments of the vaccine molecule. Specific IgG production or lymph node cell proliferation in response to different antigens was then determined. Only four of seven strains (representing three of eight possible different class II restriction molecules) responded to the vaccine. Of those restriction molecules, only one, I-Ab, was associated with a response to a malaria-encoded T epitope [contained within NP(NANP)3NA], while the other two molecules (E alpha dE beta d and E alpha kE beta s) were associated with a T cell response to a nonmalarial epitope(s) carboxyterminal to the malaria sequence and encoded by a tetracycline resistance gene, read out of frame. If an analogous situation applies in humans, natural boosting by sporozoites will be very restricted. This has serious implications for the effectiveness of the vaccine, since constant high levels of antisporozoite antibodies and possibly antibody-independent T cell effector functions are required for immunity.

Agonist analysis of 2-(carboxycyclopropyl)glycine isomers for cloned metabotropic glutamate receptor subtypes expressed in Chinese hamster ovary cells

1. 2-(Carboxycyclopropyl)glycines (CCGs) are conformationally restricted glutamate analogues and consist of eight isomers including L- and D-forms. The agonist potencies and selectivities of these compounds for metabotropic glutamate receptors (mGluRs) were studied by examining their effects on the signal transduction of representative mGluR1, mGluR2 and mGluR4 subtypes in Chinese hamster ovary cells expressing the individual cloned receptors. 2. Two extended isomers of L-CCG, L-CCG-I and L-CCG-II, effectively stimulated phosphatidylinositol hydrolysis in mGluR1-expressing cells. The rank order of potencies of these compounds was L-glutamate > L-CCG-I > L-CCG-II. 3. L-CCG-I and L-CCG-II were effective in inhibiting the forskolin-stimulated adenosine 3':5'-cyclic monophosphate (cyclic AMP) accumulation in mGluR2-expressing cells. Particularly, L-CCG-I was a potent agonist for mGluR2 with an EC50 value of 3 x 10(-7) M, which was more than an order of potency greater than that of L-glutamate. 4. L-CCG-I evoked an inhibition of the forskolin-stimulated cyclic AMP production characteristic of mGluR4 with a potency comparable to L-glutamate. 5. In contrast to the above compounds, the other CCG isomers showed no appreciable effects on the signal transduction involved in the three mGluR subtypes. 6. This investigation demonstrates not only the importance of a particular isomeric structure of CCGs in the interaction with the mGluRs but also a clear receptor subtype specificity for the CCG-receptor interaction, and indicates that the CCG isomers would serve as useful agonists for investigation of functions of the mGluR family.

An EMG-Based Control for an Upper-Limb Power-Assist Exoskeleton Robot

Many kinds of power-assist robots have been developed in order to assist self-rehabilitation and/or daily life motions of physically weak persons. Several kinds of control methods have been proposed to control the power-assist robots according to user's motion intention. In this paper, an electromyogram (EMG)-based impedance control method for an upper-limb power-assist exoskeleton robot is proposed to control the robot in accordance with the user's motion intention. The proposed method is simple, easy to design, humanlike, and adaptable to any user. A neurofuzzy matrix modifier is applied to make the controller adaptable to any users. Not only the characteristics of EMG signals but also the characteristics of human body are taken into account in the proposed method. The effectiveness of the proposed method was evaluated by the experiments.

Integrins (alpha7beta1) in muscle function and survival. Disrupted expression in merosin-deficient congenital muscular dystrophy

Mutations in genes coding for dystrophin, for alpha, beta, gamma, and delta-sarcoglycans, or for the alpha2 chain of the basement membrane component merosin (laminin-2/4) cause various forms of muscular dystrophy. Analyses of integrins showed an abnormal expression and localization of alpha7beta1 isoforms in myofibers of merosin-deficient human patients and mice, but not in dystrophin-deficient or sarcoglycan-deficient humans and animals. It was shown previously that skeletal muscle fibers require merosin for survival and function (Vachon, P.H., F. Loechel, H. Xu, U.M. Wewer, and E. Engvall. 1996. J. Cell Biol. 134:1483-1497). Correction of merosin deficiency in vitro through cell transfection with the merosin alpha2 chain restored the normal localization of alpha7beta1D integrins as well as myotube survival. Overexpression of the apoptosis-suppressing molecule Bcl-2 also promoted the survival of merosin-deficient myotubes, but did not restore a normal expression of alpha7beta1D integrins. Blocking of beta1 integrins in normal myotubes induced apoptosis and severely reduced their survival. These findings (a) identify alpha7beta1D integrins as the de facto receptors for merosin in skeletal muscle; (b) indicate a merosin dependence for the accurate expression and membrane localization of alpha7beta1D integrins in myofibers; (c) provide a molecular basis for the critical role of merosin in myofiber survival; and (d) add new insights to the pathogenesis of neuromuscular disorders.

Degeneration in vitro of post-mitotic neurons overexpressing the Alzheimer amyloid protein precursor

A pathological hallmark of Alzheimer's disease is the deposition of amyloid fibrils in the brain. The principal component of amyloid fibrils is beta/A4 amyloid protein, which can be generated by the aberrant processing of a large membrane-bound glycoprotein, the beta/A4 amyloid protein precursor (APP)3. To test whether overexpression of APP generates abnormally processed derivatives that affect the viability of neurons, we stably transfected full-length human APP complementary DNA into murine embryonal carcinoma P19 cells. These cells differentiate into post-mitotic neurons and astrocytes after exposure to retinoic acid. When differentiation of the APP cDNA-transfected P19 cells was induced, all neurons showed severe degenerative changes and disappeared within a few days. The degenerating neurons contained large amounts of APP derivatives that were truncated at the amino terminus and encompassed the entire beta/A4 domain. These results suggest that post-mitotic neurons are vulnerable to overexpressed APP, which undergoes aberrant processing to generate potentially amyloidogenic fragments.

C-type natriuretic peptide is a growth inhibitor of rat vascular smooth muscle cells

C-type natriuretic peptide (CNP) which potently stimulates particulate guanylate cyclase activity in cultured rat vascular smooth muscle cells (VSMC) inhibited serum-induced DNA synthesis of the cells 10-fold more effectively than alpha-human atrial natriuretic peptide (alpha-hANP). The inhibitory effect of CNP was mimicked by 8-bromo-cGMP. The proliferation of VSMC was also suppressed by CNP more potently than alpha-hANP, while the peptide was less active for cGMP augmentation and for vasorelaxation than alpha-hANP in isolated rat aorta. These results suggest that CNP may be a growth regulating factor of VSMC rather than a vasodilator.

Highly Diastereo- and Enantioselective Direct Aldol Reactions of Aldehydes and Ketones Catalyzed by Siloxyproline in the Presence of Water

Proline-based organocatalysts have been developed for a highly enantioselective, direct aldol reaction of aldehydes and ketones in the presence of water. While several surfactant-proline combined catalysts have proved effective, proline derivatives with a hydrophobic moiety such as trans-siloxy-L-proline and cis-siloxy-D-proline, both of which are easily prepared from the same commercially available 4-hydroxy-L-proline, have been found to be the most effective organocatalysts examined in this study, affording the aldol product with excellent diastereo- and enantioselectivities, these two catalysts generating opposite enantiomers. Water affects the selectivity, and poor results are obtained under neat reaction conditions or in dry organic solvents. More than three equivalents of water are required for the best diastereo- and enantioselectivities, while three equivalents is the recommended amount from a synthetic point of view. The reaction proceeds in the organic phase, and also proceeds in the presence of a large amount of water. The large-scale preparation of aldols with the minimal use of an organic solvent, including in the purification step, is described.

Regulation of neuronal nitric-oxide synthase by calmodulin kinases

Phosphorylation of neuronal nitric-oxide synthase (nNOS) by Ca2+/calmodulin (CaM)-dependent protein kinases (CaM kinases) including CaM kinase Ialpha (CaM-K Ialpha), CaM kinase IIalpha (CaM-K IIalpha), and CaM kinase IV (CaM-K IV), was studied. It was found that purified recombinant nNOS was phosphorylated by CaM-K Ialpha, CaM-K IIalpha, and CaM-K IV at Ser847 in vitro. Replacement of Ser847 with Ala (S847A) prevented phosphorylation by CaM kinases. Phosphorylated recombinant wild-type nNOS at Ser847 (approximately 0.5 mol of phosphate incorporation into nNOS) exhibited a 30% decrease of Vmax with little change of both the Km for L-arginine and Kact for CaM relative to unphosphorylated enzyme. The activity of mutant S847D was decreased to a level 50-60% as much as the wild-type enzyme. The decreased NOS enzyme activity of phosphorylated nNOS at Ser847 and mutant S847D was partially due to suppression of CaM binding, but not to impairment of dimer formation which is thought to be essential for enzyme activation. Inactive nNOS lacking CaM-binding ability was generated by mutation of Lys732-Lys-Leu to Asp732-Asp-Glu (Watanabe, Y., Hu, Y., and Hidaka, H. (1997) FEBS Lett. 403, 75-78). It was phosphorylated by CaM kinases, as was the wild-type enzyme, indicating that CaM-nNOS binding was not required for the phosphorylation reaction. We developed antibody NP847, which specifically recognize nNOS in its phosphorylated state at Ser847. Using the antibody NP847, we obtained evidence that nNOS is phosphorylated at Ser847 in rat brain. Thus, our results suggest that CaM kinase-induced phosphorylation of nNOS at Ser847 alters the activity control of this enzyme.

Inhibition of neuronal nitric-oxide synthase by calcium/ calmodulin-dependent protein kinase IIalpha through Ser847 phosphorylation in NG108-15 neuronal cells

We have previously demonstrated that phosphorylation of neuronal nitric-oxide synthase (nNOS) at Ser(847) by Ca(2+)/calmodulin-dependent protein kinases (CaM kinases) attenuates the catalytic activity of the enzyme in vitro (Hayashi Y., Nishio M., Naito Y., Yokokura H., Nimura Y., Hidaka H., and Watanabe Y. (1999) J. Biol. Chem. 274, 20597-20602). In the present study we determined that CaM kinase IIalpha (CaM-K IIalpha) can directly phosphorylate nNOS on Ser(847), leading to a reduction of nNOS activity in cells. The phosphorylation abilities of purified CaM kinase Ialpha (CaM-K Ialpha), CaM-K IIalpha, and CaM-kinase IV (CaM-K IV) on Ser(847) were analyzed using the synthetic peptide nNOS-(836-859) (Glu-Glu-Arg-Lys-Ser-Tyr-Lys-Val-Arg-Phe-Asn-Ser-Val-Ser-Ser-Tyr-Ser- Asp-Ser-Arg-Lys-Ser-Ser-Gly) from nNOS as substrate. The relative V(max)/K(m) ratios of CaM kinases for nNOS-(836-859) were found to be as follows: CaM-K IIalpha, 100; CaM-K Ialpha, 54.5; CaM-K IV, 9.1. Co-transfection of constitutively active CaM-K IIalpha1-274 but not inactive CaM-K IIalpha1-274, generated by mutation of Lys(42) to Ala, with nNOS into NG108-15 cells, resulted in increased Ser(847) phosphorylation in the presence of okadaic acid, an inhibitor of protein phosphatase (PP)1 and PP2A, with a concomitant inhibition of NOS enzyme activity. In addition, this latter decrease could be reversed by treatment with exogenous PP2A. Cells expressing mutant nNOS (S847A) proved resistant to phosphorylation and a decrease of NOS activity. Thus, our results indicate that Ca(2+) triggers cross-talk signal transduction between CaM kinase and NO and CaM-K IIalpha phosphorylating nNOS on Ser(847), which in turn decreases the gaseous second messenger NO in neuronal cells.

A novel role of follistatin, an activin-binding protein, in the inhibition of activin action in rat pituitary cells. Endocytotic degradation of activin and its acceleration by follistatin associated with cell-surface heparan sulfate

There are two types of the activin-binding protein follistatin (FS), FS-288 and FS-315. These result from alternative splicing of mRNA. FS-288 exhibits high affinity for cell-surface heparan sulfate proteoglycans, whereas FS-315 shows low affinity. To understand the physiological role of cell-associated FS, we investigated the binding of activin to cell-associated FS and its behavior on the cell surface using primary cultured rat pituitary cells. Affinity cross-linking experiments using 125I-activin A demonstrated that activin bound to rat pituitary cells via FS as well as to their receptors on the cell surface. FS-288 promoted the binding of activin A to the cell surface more markedly than FS-315. When the cells were incubated with 125I-activin A in the presence of FS-288, significant degradation of activin A was observed, and this was dependent on the FS-288 concentration. This activin degradation was abolished by heparan sulfate, chloroquine, and several lysosomal enzyme inhibitors. Moreover, FS-288 stimulated cellular uptake of activin A, whereas chloroquine suppressed lysosomal degradation following internalization, as demonstrated by microscopic autoradiography. These results suggest that cell-associated FS-288 accelerates the uptake of activin A into pituitary cells, leading to increased degradation by lysosomal enzymes, and thus plays a role in the activin clearance system.

Direct proline-catalyzed asymmetric alpha-aminoxylation of aldehydes and ketones

The direct proline-catalyzed asymmetric alpha-aminoxylation of aldehydes and ketones has been developed using nitrosobenzene as an oxygen source, affording alpha-anilinoxy-aldehydes and -ketones with excellent enantioselectivity. Reaction conditions have been optimized, and low temperature (-20 degrees C) was found to be a key for the successful alpha-aminoxylation of aldehydes, while slow addition of nitrosobenzene is essential for that of ketones. The scope of the reaction is presented.

Changes in expressions of proinflammatory cytokines IL-1beta, TNF-alpha and IL-6 in the brain of senescence accelerated mouse (SAM) P8

The senescence-accelerated mouse (SAM) is known to be a murine model for accelerated aging. The SAMP8 strain shows age-related deterioration of learning and memory at an earlier age than control mice (SAMR1). In the present study, we investigated the changes in expressions of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in the brain of SAMP8. In the hippocampus of 10 months old SAMP8, the expression of IL-1 mRNA was significantly elevated in comparison with that of SAMR1. In both strains of SAMs, increases in IL-1beta protein in the brain were observed at 10 months of age compared with 2 and 5 months. The only differences found between the strain in protein levels were at 10 months and were elevations in IL-1beta in the hippocampus and hypothalamus, and in TNF-alpha and IL-6 in the cerebral cortex and the hippocampus in SAMP8 as compared with SAMR1. However, lipopolysaccharide-induced increases in the expression of these cytokines in brain did not differ between SAMP8 and SAMR1. Increases in expression of proinflammatory cytokines in the brain may be involved in the age-related neural dysfunction and/or learning deficiency in SAMP8.

Three histidine residues of amyloid-beta peptide control the redox activity of copper and iron

Zinc, iron and copper are concentrated in senile plaques of Alzheimer disease. Copper and iron catalyze the Fenton-Haber-Weiss reaction, which likely contributes to oxidative stress in neuronal cells. In this study, we found that ascorbate oxidase activity and the intensity of ascorbate radicals measured using ESR spectroscopy, generated by free Cu(II), was decreased in the presence of amyloid-beta (Abeta), the major component of senile plaques. Specifically, the ascorbate oxidase activity was strongly inhibited (85% decrease) in the presence of Abeta1-16 or Abeta1-42, whereas it was only slightly inhibited in the presence of Abeta1-12 or Abeta25-35 (<20% inhibition). Ascorbate-dependent hydroxyl radical generation by free Cu(II) decreased in the presence of Abeta in the identical order of Abeta1-42, Abeta1-16 > Abeta1-12 and was abolished in the presence of 2-fold molar excess glycylhystidyllysine (GHK). Ascorbate oxidase activity and ascorbate-dependent hydroxyl radical generation by free Fe(III) were inhibited by Abeta1-42, Abeta1-16, and Abeta1-12. Although Cu(II)-Abeta shows a significant SOD-like activity, the rate constant for the reaction of superoxide with Cu(II)-Abeta was much slower than that with SOD. Overall, our results suggest that His6, His13, and His14 residues of Abeta1-42 control the redox activity of transition metals present in senile plaques.

Protein and RNA synthesis in the skeletal muscle of hereditary dystrophic mouse

Protein and RNA contents in muscle of normal and hereditary dystrophic mice C57BL/6J-dy/dy were reexamined on the basis of DNA. It was observed that protein and RNA contents in dystrophic muscle decreased at the early stage of the disease, in disagreement with the reported results on a wet weight basis, in which RNA content in dystrophic muscle had been found to increase. Rates of protein and RNA systhesis in the early stage of the disease were also determined with a concomitant check of the specific activities of free amino acids and free nucleotides. The rates of both protein and RNA synthesis (i.e., specific activities of protein and RNA) were higher in the dystrophic muscle, but when they were expressed on a DNA basis, the total protein synthesis per cell was the same as that of normal muscle and the total RNA synthesis per cell showed a smaller increase in dystrophic muscle. These apparent increases of protein and RNA synthesis were discussed in connection with the decreased protein and RNA contents in the cells of dystrophic muscle. The synthesized RNAs seemed to contain mRNA on the basis of sedimentation character and Millipore filter binding ability. However, no particular RNA was mainly synthesized in dystrophic muscle.

Cytogenetic findings and prognosis in neuroblastoma with emphasis on marker chromosome 1

The relationship between cytogenetic findings and prognosis in 51 pediatric patients with neuroblastoma is described. Patients were classified into the following four groups based on karyotypic findings: (1) near diploidy, 42 to 47 chromosomes (n = 11); (2) hyperdiploidy, 50 to 56 chromosomes (n = 4); (3) near triploidy, 60 to 77 chromosomes (n = 33); and (4) hypotetraploidy, 80 to 83 chromosomes (n = 3). Patients with near diploid or hypotetraploid karyotypes also had several structural abnormalities including marker chromosome 1, with or without double minutes (DM) or homogeneously staining regions (HSR). Most of these patients were 1 year of age or older and had advanced tumors. The patients who were in the hyperdiploid or near triploid category had few structural abnormalities; all of them, except one, were younger than 1 year of age, had localized tumors, and are long-term, disease-free survivors. Kaplan-Meier analysis of survival rates disclosed a significant difference favoring the latter group (P less than 0.001). N-myc gene amplification was found in five patients of the former group but in no patients of the latter group. The presence or absence of DM or HSR in the former group had no statistically demonstrable effect on survival. However, the presence of marker chromosome 1 appears to indicate a poor prognosis. Five patients with Stage IV-S disease had near triploid abnormalities similar to findings in patients with localized tumors. We propose that localized and Stage IV-S neuroblastomas can be classified as one disease category, and that patients with near diploid or hypotetraploid karyotypes are clinically distinct from those having hyperdiploid or near triploid karyotypes. We consider that chromosomal pattern is a more influential prognostic factor than age, disease stage, or N-myc gene amplification.

PTEN, NHERF1 and PHLPP form a tumor suppressor network that is disabled in glioblastoma

The PI3K-Akt pathway is activated in cancer by genetic or epigenetic events and efforts are under way to develop targeted therapies. PTEN tumor suppressor is the major brake of the pathway and a common target for inactivation in glioblastoma, one of the most aggressive and therapy-resistant cancers. To achieve potent inhibition of the PI3K-Akt pathway in glioblastoma, we need to understand its mechanism of activation by investigating the interplay between its regulators. We show here that PTEN modulates the PI3K-Akt pathway in glioblastoma within a tumor suppressor network that includes NHERF1 and PHLPP1. The NHERF1 adaptor, previously characterized by our group as a PTEN ligand and regulator, shows also PTEN-independent Akt-modulating effects that led us to identify the PHLPP1/PHLPP2 Akt phosphatases as NHERF1 ligands. NHERF1 interacts via its PDZ domains with PHLPP1/PHLPP2 and scaffolds heterotrimeric complexes with PTEN. Functionally, PHLPP1 requires NHERF1 for membrane localization and growth suppressive effects. PHLPP1 loss boosts Akt phosphorylation only in PTEN-negative cells and cooperates with PTEN loss for tumor growth. In a panel of low-grade and high-grade glioma patient samples, we show for the first time a significant disruption of all three members of the PTEN-NHERF1-PHLPP1 tumor suppressor network in high-grade tumors, correlating with Akt activation and patients’ abysmal survival. We thus propose a PTEN-NHERF1-PHLPP PI3K-Akt pathway inhibitory network that relies on molecular interactions and can undergo parallel synergistic hits in glioblastoma.