Chronic electrical stimulation of the ventralis intermedius nucleus of the thalamus as a treatment of movement disorders

Tremor was suppressed by test stimulation of the thalamic ventralis intermedius (VIM) nucleus at high frequency (130 Hz) during stereotaxy in nonanesthetized patients suffering from Parkinson's disease or essential tremor. Ventralis intermedius stimulation has since been used by the authors over the last 8 years as a treatment in 117 patients with movement disorders (80 cases of Parkinson's disease, 20 cases of essential tremor, and 17 cases of various dyskinesias and dystonias including four multiple sclerosis). Chronic electrodes were stereotactically implanted in the VIM and connected to a programmable stimulator. Results depend on the indication. In Parkinson's disease patients, tremor, but not bradykinesia and rigidity, was selectively suppressed for as long as 8 years. Administration of L-Dopa was decreased by more than 30% in 40 Parkinson's disease patients. In essential tremor patients, results were satisfactory but deteriorated with time in 18.5% of cases, mainly for patients who presented an action component of their but deteriorated with time in 18.5% of cases, mainly for patients who presented an action component of their tremor. In other types of dyskinesias (except multiple sclerosis), results were much less favorable. Fifty-nine patients underwent bilateral implantation and 14 other patients received implantation contralateral to a previous thalamotomy. Thirty-seven patients (31.6%) experienced minor side effects, which were always well tolerated and immediately reversible. Three secondary scalp infections led to temporary removal of the implanted material. There was no permanent morbidity. This tremor suppression effect could be due to the inhibition or jamming of a retroactive loop. Chronic VIM stimulation, which is reversible, adaptable, and well tolerated even by patients undergoing bilateral surgery (74 of 117 patients) and by elderly patients, should replace thalamotomy in the regular surgical treatment of parkinsonian and essential tremors.

Association between CD8+ T-cell infiltration and breast cancer survival in 12,439 patients

BACKGROUND

T-cell infiltration in estrogen receptor (ER)-negative breast tumours has been associated with longer survival. To investigate this association and the potential of tumour T-cell infiltration as a prognostic and predictive marker, we have conducted the largest study of T cells in breast cancer to date.

PATIENTS AND METHODS

Four studies totalling 12 439 patients were used for this work. Cytotoxic (CD8+) and regulatory (forkhead box protein 3, FOXP3+) T cells were quantified using immunohistochemistry (IHC). IHC for CD8 was conducted using available material from all four studies (8978 samples) and for FOXP3 from three studies (5239 samples)-multiple imputation was used to resolve missing data from the remaining patients. Cox regression was used to test for associations with breast cancer-specific survival.

RESULTS

In ER-negative tumours [triple-negative breast cancer and human epidermal growth factor receptor 2 (human epidermal growth factor receptor 2 (HER2) positive)], presence of CD8+ T cells within the tumour was associated with a 28% [95% confidence interval (CI) 16% to 38%] reduction in the hazard of breast cancer-specific mortality, and CD8+ T cells within the stroma with a 21% (95% CI 7% to 33%) reduction in hazard. In ER-positive HER2-positive tumours, CD8+ T cells within the tumour were associated with a 27% (95% CI 4% to 44%) reduction in hazard. In ER-negative disease, there was evidence for greater benefit from anthracyclines in the National Epirubicin Adjuvant Trial in patients with CD8+ tumours [hazard ratio (HR) = 0.54; 95% CI 0.37-0.79] versus CD8-negative tumours (HR = 0.87; 95% CI 0.55-1.38). The difference in effect between these subgroups was significant when limited to cases with complete data (P heterogeneity = 0.04) and approached significance in imputed data (P heterogeneity = 0.1).

CONCLUSIONS

The presence of CD8+ T cells in breast cancer is associated with a significant reduction in the relative risk of death from disease in both the ER-negative [supplementary Figure S1, available at Annals of Oncology online] and the ER-positive HER2-positive subtypes. Tumour lymphocytic infiltration may improve risk stratification in breast cancer patients classified into these subtypes. NEAT ClinicalTrials.gov: NCT00003577.

Recovery from spinal cord injury mediated by antibodies to neurite growth inhibitors

There is little axonal growth after central nervous system (CNS) injury in adult mammals. The administration of antibodies (IN-1) to neutralize the myelin-associated neurite growth inhibitory proteins leads to long-distance regrowth of a proportion of CNS axons after injury. Our aim was: to determine if spinal cord lesion in adult rats, followed by treatment with antibodies to neurite growth inhibitors, can lead to regeneration and anatomical plasticity of other spinally projecting pathways; to determine if the anatomical projections persist at long survival intervals; and to determine whether this fibre growth is associated with recovery of function. We report here that brain stem-spinal as well as corticospinal axons undergo regeneration and anatomical plasticity after application of IN-1 antibodies. There is a recovery of specific reflex and locomotor functions after spinal cord injury in these adult rats. Removal of the sensorimotor cortex in IN-1-treated rats 2-3 months later abolished the recovered contact-placing responses, suggesting that the recovery was dependent upon the regrowth of these pathways.

ASCT2/SLC1A5 controls glutamine uptake and tumour growth in triple-negative basal-like breast cancer

Alanine, serine, cysteine-preferring transporter 2 (ASCT2; SLC1A5) mediates uptake of glutamine, a conditionally essential amino acid in rapidly proliferating tumour cells. Uptake of glutamine and subsequent glutaminolysis is critical for activation of the mTORC1 nutrient-sensing pathway, which regulates cell growth and protein translation in cancer cells. This is of particular interest in breast cancer, as glutamine dependence is increased in high-risk breast cancer subtypes. Pharmacological inhibitors of ASCT2-mediated transport significantly reduced glutamine uptake in human breast cancer cell lines, leading to the suppression of mTORC1 signalling, cell growth and cell cycle progression. Notably, these effects were subtype-dependent, with ASCT2 transport critical only for triple-negative (TN) basal-like breast cancer cell growth compared with minimal effects in luminal breast cancer cells. Both stable and inducible shRNA-mediated ASCT2 knockdown confirmed that inhibiting ASCT2 function was sufficient to prevent cellular proliferation and induce rapid cell death in TN basal-like breast cancer cells, but not in luminal cells. Using a bioluminescent orthotopic xenograft mouse model, ASCT2 expression was then shown to be necessary for both successful engraftment and growth of HCC1806 TN breast cancer cells in vivo. Lower tumoral expression of ASCT2 conferred a significant survival advantage in xenografted mice. These responses remained intact in primary breast cancers, where gene expression analysis showed high expression of ASCT2 and glutamine metabolism-related genes, including GLUL and GLS, in a cohort of 90 TN breast cancer patients, as well as correlations with the transcriptional regulators, MYC and ATF4. This study provides preclinical evidence for the feasibility of novel therapies exploiting ASCT2 transporter activity in breast cancer, particularly in the high-risk basal-like subgroup of TN breast cancer where there is not only high expression of ASCT2, but also a marked reliance on its activity for sustained cellular proliferation.

Mechanisms of cryoinjury in living cells

Biological metabolism in living cells dramatically diminishes at low temperatures, a fact that permits the long-term preservation of living cells and tissues for either scientific research or many medical and industrial applications (e.g., blood transfusion, bone marrow transplantation, artificial insemination, in vitro fertilization, food storage). However, there is an apparent contradiction between the concept of preservation and experimental findings that living cells can be damaged by the cryopreservation process itself. The challenge to cells during freezing is not their ability to endure storage at very low temperatures (less than -180 degrees C); rather, it is the lethality of an intermediate zone of temperature (-15 to -60 degrees C) that a cell must traverse twice--once during cooling and once during warming. Cryobiological research studies the underlying physical and biological factors affecting survival of cells at low temperatures (during the cooling and warming processes). These factors and mechanisms (or hypotheses) of cryoinjury and its prevention are reviewed and discussed, including the most famous two-factor hypothesis theory of Peter Mazur, concepts of cold shock, vitrification, cryoprotective agens (CPAs), lethal intracellular ice formation, osmotic injury during the addition/removal of CPAs and during the cooling/warming process, as well as modeling/methods in the cryobiological research.

lag-2 may encode a signaling ligand for the GLP-1 and LIN-12 receptors of C. elegans

The C. elegans lag-2 gene is required for several cell-cell interactions that rely on the receptors GLP-1 and LIN-12. In this paper, we report that lag-2 encodes a putative membrane protein with sequence similarity to Drosophila Delta, a proposed ligand for the Notch receptor. Furthermore, we show that the lag-2 promoter drives expression of a reporter protein in the signaling distal tip cell (DTC) of the DTC/germline interaction. By in situ hybridization, we have found that endogenous lag-2 mRNA is present in the DTC but not the germ line. One fusion protein, called LAG-2::beta-gal(intra), rescues a lag-2 null mutant and can be detected in both DTC and germ line. Taking these results together, we propose that lag-2 may encode a signaling ligand for GLP-1/LIN-12 and that the entire LAG-2 protein may be taken up into the receiving cell during induction by GLP-1 and lateral signaling by LIN-12.

Television viewing and change in body fat from preschool to early adolescence: The Framingham Children's Study

OBJECTIVE

To prospectively examine the relation between television watching and body fat change in children from preschool to early adolescence.

METHODS

In a longitudinal study, 106 children were enrolled during preschool years (mean age 4.0 y) and followed into early adolescence (mean age 11.1 y). Parents completed an annual questionnaire on the child's television and video habits. Body mass index (BMI), triceps skinfolds, and sum of five skinfolds were recorded yearly at annual clinic visits. Longitudinal statistical analyses were carried out using mixed modeling procedures to control for potential confounding by a number of factors.

RESULTS

Television watching was an independent predictor of the change in the child's BMI, triceps, and sum of five skinfolds throughout childhood. Its effect was only slightly attenuated by controlling for the baseline body fat, level of physical activity (as measured repeatedly by Caltrac accelerometer), percent of calories from fat, total calorie intake, or the parents' BMI or education. By age 11, children who watched 3.0 h or more of television per day had a mean sum of skinfolds of 106.2 mm, compared with a mean sum of skinfolds of 76.5 mm for those who watched less than 1.75 h per day (P=0.007). Furthermore, the adverse effect of television viewing was worse for those children who were also sedentary or had a higher-fat diet.

CONCLUSIONS

Children who watched the most television during childhood had the greatest increase in body fat over time. Healthy lifestyle education designed to prevent obesity and its consequences should target television-watching habits of children.

Recovery of function after spinal cord injury: mechanisms underlying transplant-mediated recovery of function differ after spinal cord injury in newborn and adult rats

Fetal spinal cord transplants placed into the site of spinal cord injury support axonal growth of host systems in both newborn and adult animals. The amount of axonal growth, however, is much more robust in the newborn animals. The current studies were designed to determine if the differences in the magnitude of the anatomical plasticity of host pathways in the presence of transplants is reflected in differences in recovery of function between the neonatal and adult operates. Newborn and adult rats received a midthoracic "overhemisection." Immediately following the hemisection embryonic (E14) spinal cord transplants were placed into the lesion site. All animals were trained and tested as adults, on a battery of qualitative and quantitative tests of motor function. Immunocytochemical methods were used to compare the extent of growth of descending (serotonergic and noradrenergic) and segmental (calcitonin gene-related peptide containing dorsal root axons) pathways in both groups. The growth of descending pathways into the transplants was substantially greater in density and spatial extent after lesions at birth than at maturity. The distribution of segmental dorsal root axons, in contrast, was similar in both groups. Fetal spinal cord transplants promoted recovery of motor function in both newborn and adult operates. The particular aspects of locomotor function which recover differ between the neonatal and adult operates, suggesting that the mechanisms underlying recovery of function must differ between the two groups.

Involvement of NADH/NADPH oxidase in human platelet ROS production

Platelets play an important role in atherosclerotic and thromboembolic vascular diseases. It has been reported that reactive oxygen species (ROS) could modify platelet function, and platelets themselves have the ability to produce ROS. However, the enzymatic sources of ROS in platelets have not been fully determined. The NADH/NADPH oxidase system was originally identified as the major source of ROS in phagocytes. Recently, it has become evident that this oxidase is functionally expressed not only in phagocytes but also in various cell types. The present study was undertaken to test the hypothesis that NADH/NADPH oxidase might be expressed in human platelets. Lucigenin-enhanced chemiluminescence (L-CL) and electron spin resonance (ESR) method demonstrated that human platelets obtained from healthy volunteers released ROS, and the released ROS were increased by stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA) or calcium ionophore. Homogenates of human platelets, as well as MEG01 cells, megakaryocytic cell line, had the enzymatic activity to produce superoxide in NADH/NADPH-dependent manners. This enzymatic activity was suppressed by diphenylene iodonium (DPI), an inhibitor of NADH/NADPH oxidase. Western blot analysis demonstrated that platelets and MEG01 cells expressed p22(phox) and p67(phox) proteins, components of NADH/NADPH oxidase. Thus, human platelets have the enzymatic activity of p22(phox)-based NADH/NADPH oxidase, and this oxidase is likely one of the important sources of ROS in platelets.

Multifunctional phototheranostic nanomedicine for cancer imaging and treatment

Cancer, as one of the most life-threatening diseases, shows a high fatality rate around the world. When improving the therapeutic efficacy of conventional cancer treatments, researchers also conduct extensive studies into alternative therapeutic approaches, which are safe, valid, and economical. Phototherapies, including photodynamic therapy (PDT) and photothermal therapy (PTT), are tumor-ablative and function-reserving oncologic interventions, showing strong potential in clinical cancer treatment. During phototherapies, the non-toxic phototherapeutic agents can be activated upon light irradiation to induce cell death without causing much damage to normal tissues. Besides, with the rapid development of nanotechnology in the past decades, phototheranostic nanomedicine also has attracted tremendous interests aiming to continuously refine their performance. Herein, we reviewed the recent progress of phototheranostic nanomedicine for improved cancer therapy. After a brief introduction of the therapeutic principles and related phototherapeutic agents for PDT and PTT, the existing works on developing of phototheranostic nanomedicine by mainly focusing on their categories and applications, particularly on phototherapy-synergized cancer immunotherapy, are comprehensively reviewed. More importantly, a brief conclusion and future challenges of phototheranostic nanomedicine from our point of view are delivered in the last part of this article.

Quantitative X-ray projection microscopy: phase-contrast and multi-spectral imaging

We outline a new approach to X-ray projection microscopy in a scanning electron microscope (SEM), which exploits phase contrast to boost the quality and information content of images. These developments have been made possible by the combination of a high-brightness field-emission gun (FEG)-based SEM, direct detection CCD technology and new phase retrieval algorithms. Using this approach we have been able to obtain spatial resolution of < 0.2 micro m and have demonstrated novel features such as: (i) phase-contrast enhanced visibility of high spatial frequency image features (e.g. edges and boundaries) over a wide energy range; (ii) energy-resolved imaging to simultaneously produce multiple quasi-monochromatic images using broad-band polychromatic illumination; (iii) easy implementation of microtomography; (iv) rapid and robust phase/amplitude-retrieval algorithms to enable new real-time and quantitative modes of microscopic imaging. These algorithms can also be applied successfully to recover object-plane information from intermediate-field images, unlocking the potentially greater contrast and resolution of the intermediate-field regime. Widespread applications are envisaged for fields such as materials science, biological and biomedical research and microelectronics device inspection. Some illustrative examples are presented. The quantitative methods described here are also very relevant to projection microscopy using other sources of radiation, such as visible light and electrons.

LAG-3+ tumor infiltrating lymphocytes in breast cancer: clinical correlates and association with PD-1/PD-L1+ tumors

Background

Novel immune checkpoint blockade strategies are being evaluated in clinical trials and include targeting the lymphocyte activation gene 3 (LAG-3) checkpoint, alone or in combination with PD-1/PD-L1 blockade. We investigated LAG-3 expression and its prognostic value in a large series of breast cancer patients, and correlated LAG-3 expression with key biomarkers including PD-1 and PD-L1.

Experimental design

LAG-3 expression was evaluated by immunohistochemistry on two tissue microarray series incorporating 4322 breast cancer primary excision specimens (N = 330 in the training and N= 3992 in the validation set) linked to detailed clinicopathologic, biomarker and long-term clinical outcome data. PD-1 and PD-L1 expressions were also evaluated by immunohistochemistry. Stromal or intra-epithelial tumor infiltrating lymphocytes (sTILs or iTILs) expressing LAG-3 or PD-1 were assessed by absolute count. PD-L1 expression was evaluated as the percentage of positive carcinoma cells per core. Kaplan-Meier curves and Cox proportional hazard models were used for survival analyses.

Results

After locking down interpretation cut-offs on the training set, LAG-3+ iTILs were found in 11% of cases in the validation set. In both sets, LAG-3+ iTILs were significantly associated with negative prognostic factors: young age, large tumor size, high proliferation, HER2E and basal-like breast cancer subtypes. In multivariate analyses, breast cancer patients with LAG-3+ iTILs had a significantly improved breast cancer-specific survival [hazard ratio (HR): 0.71, 95% CI 0.56-0.90], particularly among estrogen receptor-negative patients (HR: 0.50, 95% CI 0.36-0.69). Furthermore, we found that 53% of PD-L1+ and 61% of PD-1+ cases were also positive for LAG-3+ iTILs. Concurrent infiltration of LAG-3+ and CD8+ iTILs was significantly associated with increased breast cancer-specific survival (HR: 0.49, 95% CI 0.32-0.74).

Conclusion

LAG-3+ iTILs are enriched in estrogen receptor-negative breast cancers and represent an independent favorable prognostic factor. In addition, a high proportion of PD-1/PD-L1+ tumors are co-infiltrated with LAG-3+ TILs, supporting potential immune checkpoint blockade combination strategies as a treatment option for breast cancer patients.

Hematopoietic SCT with cryopreserved grafts: adverse reactions after transplantation and cryoprotectant removal before infusion

Transplantation of hematopoietic stem cells (HSCs) has been successfully developed as a part of treatment protocols for a large number of clinical indications, and cryopreservation of both autologous and allogeneic sources of HSC grafts is increasingly being used to facilitate logistical challenges in coordinating the collection, processing, preparation, quality control testing and release of the final HSC product with delivery to the patient. Direct infusion of cryopreserved cell products into patients has been associated with the development of adverse reactions, ranging from relatively mild symptoms to much more serious, life-threatening complications, including allergic/gastrointestinal/cardiovascular/neurological complications, renal/hepatic dysfunctions, and so on. In many cases, the cryoprotective agent (CPA) used-which is typically dimethyl sulfoxide (DMSO)-is believed to be the main causal agent of these adverse reactions and thus many studies recommend depletion of DMSO before cell infusion. In this paper, we will briefly review the history of HSC cryopreservation, the side effects reported after transplantation, along with advances in strategies for reducing the adverse reactions, including methods and devices for removal of DMSO. Strategies to minimize adverse effects include medication before and after transplantation, optimizing the infusion procedure, reducing the DMSO concentration or using alternative CPAs for cryopreservation and removing DMSO before infusion. For DMSO removal, besides the traditional and widely applied method of centrifugation, new approaches have been explored in the past decade, such as filtration by spinning membrane, stepwise dilution-centrifugation using rotating syringe, diffusion-based DMSO extraction in microfluidic channels, dialysis and dilution-filtration through hollow-fiber dialyzers and some instruments (CytoMate, Sepax S-100, Cobe 2991, microfluidic channels, dilution-filtration system, etc.) as well. However, challenges still remain: development of the optimal (fast, safe, simple, automated, controllable, effective and low cost) methods and devices for CPA removal with minimum cell loss and damage remains an unfilled need.

The gon-1 gene is required for gonadal morphogenesis in Caenorhabditis elegans

In wild-type Caenorhabditis elegans, the gonad is a complex epithelial tube that consists of long arms composed predominantly of germline tissue as well as somatic structures specialized for particular reproductive functions. In gon-1 mutants, the adult gonad is severely disorganized with essentially no arm extension and no recognizable somatic structure. The developmental defects in gon-1 mutants are limited to the gonad; other cells, tissues, and organs appear to develop normally. Previous work defined the regulatory "leader" cells as crucial for extension of the gonadal arms (J. E. Kimble and J. G. White, 1981, Dev. Biol. 81, 208-219). In gon-1 mutants, the leader cells are specified correctly, but they fail to migrate and gonadal arms are not generated. In addition, gon-1 is required for morphogenesis of the gonadal somatic structures. This second role appears to be independent of that required for leader migration. Parallel studies have shown that gon-1 encodes a secreted metalloprotease (R. Blelloch and J. Kimble, 1999, Nature 399, 586-590). We discuss how a metalloprotease may control two aspects of gonadal morphogenesis.

Interactions of intrathecally administered ziconotide, a selective blocker of neuronal N-type voltage-sensitive calcium channels, with morphine on nociception in rats

Ziconotide is a selective, potent and reversible blocker of neuronal N-type voltage-sensitive calcium channels (VSCCs). Morphine is an agonist of mu-opioid receptors and inhibits N-type VSCC channels via a G-protein coupling mechanism. Both agents are antinociceptive when they are administered intrathecally (spinally). The present study investigated the acute and chronic (7-day) interactions of intrathecally administered ziconotide and morphine on nociception in several animal models of pain. In the acute study, intrathecal bolus injections of morphine and ziconotide alone produced dose-dependent inhibition of formalin-induced tonic flinch responses and withdrawal responses to paw pressure. The combination of ziconotide and morphine produced an additive inhibition of formalin-induced tonic flinch responses and a significant leftward shift of the morphine dose-response curve in the paw pressure test. After chronic (7-day) intrathecal infusion, ziconotide enhanced morphine analgesia in the formalin test. In contrast, chronic intrathecal morphine infusion produced tolerance to analgesia, but did not affect ziconotide antinociception. Antinociception produced by ziconotide alone was the same as that observed when the compound was co-administered with morphine to morphine-tolerant rats. In the hot-plate and tail immersion tests, chronic intrathecal infusion of morphine lead to rapid tolerance whereas ziconotide produced sustained analgesia with no loss of potency throughout the infusion period. Although ziconotide in combination with morphine produced an apparent synergistic analgesic effects during the initial phase of continuous infusion, it did not prevent morphine tolerance to analgesia. These results demonstrate that (1) acute intrathecal administrations of ziconotide and morphine produce additive or synergistic analgesic effects; (2) chronic intrathecal morphine infusion results in tolerance to analgesia but does not produce cross-tolerance to ziconotide; (3) chronic intrathecal ziconotide administration produces neither tolerance nor cross-tolerance to morphine analgesia; (4) intrathecal ziconotide does not prevent or reverse morphine tolerance.

Lysophosphatidylcholine increases the secretion of matrix metalloproteinase 2 through the activation of NADH/NADPH oxidase in cultured aortic endothelial cells

Matrix metalloproteinases (MMPs) play a pivotal role in angiogenesis, atherogenesis, vascular remodeling after vascular injury, and instability of atherosclerotic plaque. The present study was undertaken to investigate the effect of lysophosphatidylcholine, a major component of oxidized low density lipoprotein (LDL), on the regulation of MMPs in cultured bovine aortic endothelial cells (BAECs). Furthermore, we explored the potential role of oxidative stress in the regulation of MMP. LPC increased the secretion of gelatinolytic activity, as well as, protein of MMP-2 from BAECs. The stimulation of BAEC with superoxide increased the production of MMP-2 and it also induced its activation. Electron spin resonance (ESR) with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as spin trap agent demonstrated that lysophosphatidycholine (LPC) induced generation of reactive oxygen (ROS) species from BAECs. The inhibition of NADH/NADPH oxidase, one of the potential sources of superoxide in endothelial cells, attenuated the effect of LPC. Our findings suggest that LPC might activate the endothelial NADH/NADPH oxidase to enhance superoxide production, and it might, in turn, enhance MMP-2 induction.

Enhanced ZAG production by subcutaneous adipose tissue is linked to weight loss in gastrointestinal cancer patients

Background:

Profound loss of adipose tissue is a hallmark of cancer cachexia. Zinc-α2-glycoprotein (ZAG), a recently identified adipokine, is suggested as a candidate in lipid catabolism.

Methods:

In the first study, eight weight-stable and 17 cachectic cancer patients (weight loss ⩾5% in previous 6 months) were recruited. Zinc-α2-glycoprotein mRNA and protein expression were assessed in subcutaneous adipose tissue (SAT), subcutaneous adipose tissue morphology was examined and serum ZAG concentrations were quantified. In the second cohort, ZAG release by SAT was determined in 18 weight-stable and 15 cachectic cancer patients. The effect of ZAG on lipolysis was evaluated in vitro.

Results:

Subcutaneous adipose tissue remodelling in cancer cachexia was evident through shrunken adipocytes with increased fibrosis. In cachectic cancer patients, ZAG mRNA was upregulated (2.7-fold, P=0.028) while leptin mRNA decreased (2.2-fold, P=0.018); serum ZAG levels were found to be unaffected. Zinc-α2-glycoprotein mRNA correlated positively with weight loss (r=0.51, P=0.01) and serum glycerol levels (r=0.57, P=0.003). Zinc-α2-glycoprotein release by SAT was also elevated in cachectic patients (1.5-fold, P=0.024) and correlated with weight loss (r=0.50, P=0.003). Recombinant ZAG stimulated lipolysis in human adipocytes.

Conclusions:

Zinc-α2-glycoprotein expression and secretion by adipose tissue is enhanced in cachectic cancer patients. Given its lipid-mobilising effect, ZAG may contribute to adipose atrophy associated with cancer cachexia in human beings.

Effects of intrathecal administration of ziconotide, a selective neuronal N-type calcium channel blocker, on mechanical allodynia and heat hyperalgesia in a rat model of postoperative pain

Ziconotide (SNX-111), a selective blocker of neuronal N-type voltage-sensitive calcium channels, is antinociceptive when it is administered intrathecally. It is currently under clinical investigation for the treatment of malignant and non-malignant pain syndromes. The present study was undertaken to compare and contrast antinociceptive properties of ziconotide, morphine and clonidine in a rat model of post-operative pain. Post-operative pain was produced by making a longitudinal incision through the skin, fascia, and muscle of the plantar aspect of the left hindpaw. This procedure produced immediate (0.5 h after surgery) and long-lasting (4-7 days post-surgery) heat hyperalgesia and mechanical allodynia in the injured hindpaw. Pain thresholds in the contralateral hindpaw were unaffected. Administered one day after incisional surgery, intrathecal ziconotide blocked established heat hyperalgesia in the injured hindpaw in a dose-dependent manner yielding an ED(50)4 h) but reversible (<24 h) blockade of established mechanical allodynia. Administered one day after surgery, intrathecal bolus injection of morphine dose-dependently blocked heat hyperalgesia in the injured hindpaw with an ED(50) of 1.6 microg (2.1 nmol) and heat nociceptive responses in the normal hindpaw with an ED(50) of 2.7 microg (3.6 nmol). The effects were immediate and short-lasting (</=1 h). Intravenous bolus injection of 3 mg/kg (1.1 micromol/kg) ziconotide, administered either before or after incisional surgery, had no effect on thermal pain thresholds measured in either the injured or normal hindpaw. In contrast, intraperitoneal injections of 2 mg/kg (2.6 micromol/kg) morphine and 2.5 mg/kg (9.4 micromol/kg) clonidine blocked heat hyperalgesia in the injured hindpaw; morphine, but not clonidine, also elevated thermal (heat) nociceptive response thresholds in the normal hindpaw. The results of this study show that intrathecal ziconotide is antinociceptive in a rat incisional model of post-operative pain and is more potent, longer acting, and more specific in its actions than intrathecal morphine.

tau binds and organizes Escherichia coli replication proteins through distinct domains. Domain IV, located within the unique C terminus of tau, binds the replication fork, helicase, DnaB

Interaction between the tau subunit of the DNA polymerase III holoenzyme and the DnaB helicase is critical for coupling the replicase and the primosomal apparatus at the replication fork (Kim, S., Dallmann, H. G., McHenry, C. S., and Marians, K. J. (1996) Cell 84, 643-650). In the preceding manuscript, we reported the identification of five putative structural domains within the tau subunit (Gao, D., and McHenry, C. (2000) J. Biol. Chem. 275, 4433-4440). As part of our systematic effort to assign functions to each of these domains, we expressed a series of truncated, biotin-tagged tau fusion proteins and determined their ability to bind DnaB by surface plasmon resonance on streptavidin-coated surfaces. Only tau fusion proteins containing domain IV bound DnaB. The DnaB-binding region was further limited to a highly basic 66-amino acid residue stretch within domain IV. Unlike the binding of immobilized tau(4) to the DnaB hexamer, the binding of monomeric domain IV to DnaB(6) was dependent upon the density of immobilized domain IV, indicating that DnaB(6) is bound by more than one tau protomer. This observation implies that both the leading and lagging strand polymerases are tethered to the DnaB helicase via dimeric tau. These double tethers of the leading and lagging strand polymerases proceeding through the tau-tau link and an additional tau-DnaB link are likely important for the dynamic activities of the replication fork.

Integrated genomic analyses identify WEE1 as a critical mediator of cell fate and a novel therapeutic target in acute myeloid leukemia

Acute myeloid leukemia (AML) remains a therapeutic challenge despite increasing knowledge about the molecular origins of the disease, as the mechanisms of AML cell escape from chemotherapy remain poorly defined. We hypothesized that AML cells are addicted to molecular pathways in the context of chemotherapy and used complementary approaches to identify these addictions. Using novel molecular and computational approaches, we performed genome-wide shRNA screens to identify proteins that mediate AML cell fate after cytarabine exposure, gene expression profiling of AML cells exposed to cytarabine to identify genes with induced expression in this context, and examination of existing gene expression data from primary patient samples. The integration of these independent analyses strongly implicates cell cycle checkpoint proteins, particularly WEE1, as critical mediators of AML cell survival after cytarabine exposure. Knockdown of WEE1 in a secondary screen confirmed its role in AML cell survival. Pharmacologic inhibition of WEE1 in AML cell lines and primary cells is synergistic with cytarabine. Further experiments demonstrate that inhibition of WEE1 prevents S-phase arrest induced by cytarabine, broadening the functions of WEE1 that may be exploited therapeutically. These data highlight the power of integrating functional and descriptive genomics, and identify WEE1 as potential therapeutic target in AML.

tau binds and organizes Escherichia coli replication through distinct domains. Partial proteolysis of terminally tagged tau to determine candidate domains and to assign domain V as the alpha binding domain

The tau subunit dimerizes Escherichia coli DNA polymerase III core through interactions with the alpha subunit. In addition to playing critical roles in the structural organization of the holoenzyme, tau mediates intersubunit communications required for efficient replication fork function. We identified potential structural domains of this multifunctional subunit by limited proteolysis of C-terminal biotin-tagged tau proteins. The cleavage sites of each of eight different proteases were found to be clustered within four regions of the tau subunit. The second susceptible region corresponds to the hinge between domain II and III of the highly homologous delta' subunit, and the third region is near the C-terminal end of the tau-delta' alignment (Guenther, B., Onrust, R., Sali, A., O'Donnell, M., and Kuriyan, J. (1997) Cell 91, 335-345). We propose a five-domain structure for the tau protein. Domains I and II are based on the crystallographic structure of delta' by Guenther and colleagues. Domains III-V are based on our protease cleavage results. Using this information, we expressed biotin-tagged tau proteins lacking specific protease-resistant domains and analyzed their binding to the alpha subunit by surface plasmon resonance. Results from these studies indicated that the alpha binding site of tau lies within its C-terminal 147 residues (domain V).

IGF2 is critical for tumorigenesis by synovial sarcoma oncoprotein SYT-SSX1

Synovial sarcoma is an aggressive soft tissue tumor characterized by a specific chromosomal translocation between chromosome 18 and X. This translocation can generate a fusion transcript encoding SYT-SSX1, a transforming oncoprotein. We present evidence that SYT-SSX1 induces insulin-like growth factor II expression in fibroblast cells. SYT-SSX2, a fusion also frequently found in synovial sarcoma, is necessary for maintaining Igf2 expression in the synovial sarcoma cell line, and the increased IGF2 synthesis protects cells from anoikis and is required for tumor formation in vivo. We also found a loss of imprinting (LOI) for Igf2 in a limited number of primary synovial sarcomas despite demethylation of CpG dinucleotides critical for maintaining imprinting. These findings suggest that inhibition of the IGF2/IGF1-R signaling pathway may represent a significant therapeutic modality for treating synovial sarcoma.

Functional domains of LAG-2, a putative signaling ligand for LIN-12 and GLP-1 receptors in Caenorhabditis elegans

The LAG-2 membrane protein is a putative signaling ligand for the LIN-12 and GLP-1 receptors of Caenorhabditis elegans. LAG-2, like its Drosophila homologues Delta and Serrate, acts in a conserved signal transduction pathway to regulate cell fates during development. In this article, we investigate the functional domains of LAG-2. For the most part, mutants were constructed in vitro and assayed for activity in transgenic animals. We find a functional role for all major regions except one. Within the extracellular domain, the N-terminal region, which bears no known motif, and the DSL domain are both required. By contrast, the region bearing epidermal growth factor-like repeats can be deleted with no apparent reduction in rescuing activity. The intracellular region is not required for activity but instead plays a role in down-regulating LAG-2 function. Finally, membrane association is critical for mutant rescue.

Downregulation of zinc-{alpha}2-glycoprotein in adipose tissue and liver of obese ob/ob mice and by tumour necrosis factor-alpha in adipocytes

Zinc-alpha2-glycoprotein (ZAG, also listed as AZGP1 in the MGI Database), a lipid-mobilising factor, has recently been suggested as a potential candidate in the modulation of body weight. We investigated the effect of increased adiposity on ZAG expression in adipose tissue and the liver and on plasma levels in obese (ob/ob) mice compared with lean siblings. The study also examined the effect of the pro-inflammatory cytokine tumour necrosis factor-alpha (TNFalpha) on ZAG expression in adipocytes. Zag mRNA levels were significantly reduced in subcutaneous (fourfold) and epididymal (eightfold) fat of ob/ob mice. Consistently, ZAG protein content was decreased in both fat depots of ob/ob mice. In the liver of obese animals, steatosis was accompanied by the fall of both Zag mRNA (twofold) and ZAG protein content (2.5-fold). Plasma ZAG levels were also decreased in obese mice. In addition, Zag mRNA was reduced in epididymal (fivefold) and retroperitoneal (fivefold) adipose tissue of obese (fa/fa) Zucker rats. In contrast to Zag expression, Tnfalpha mRNA levels were elevated in adipose tissue (twofold) and the liver (2.5-fold) of ob/ob mice. Treatment with TNFalpha reduced Zag gene expression in differentiated adipocytes, and this inhibition was chronic, occurring at 24 and 48 h following TNFalpha treatment. It is concluded that ZAG synthesis in adipose tissue and the liver is downregulated, as are its circulating levels, in ob/ob mice. The reduced ZAG production may advance the susceptibility to lipid accumulation in these tissues in obesity, and this could be at least in part attributable to the inhibitory effect of TNFalpha.