Angiogenic Activity of Breast Cancer Patients’ Monocytes Reverted by Combined Use of Systems Modeling and Experimental Approaches

Angiogenesis plays a key role in tumor growth and cancer progression. TIE-2-expressing monocytes (TEM) have been reported to critically account for tumor vascularization and growth in mouse tumor experimental models, but the molecular basis of their pro-angiogenic activity are largely unknown. Moreover, differences in the pro-angiogenic activity between blood circulating and tumor infiltrated TEM in human patients has not been established to date, hindering the identification of specific targets for therapeutic intervention. In this work, we investigated these differences and the phenotypic reversal of breast tumor pro-angiogenic TEM to a weak pro-angiogenic phenotype by combining Boolean modelling and experimental approaches. Firstly, we show that in breast cancer patients the pro-angiogenic activity of TEM increased drastically from blood to tumor, suggesting that the tumor microenvironment shapes the highly pro-angiogenic phenotype of TEM. Secondly, we predicted in silico all minimal perturbations transitioning the highly pro-angiogenic phenotype of tumor TEM to the weak pro-angiogenic phenotype of blood TEM and vice versa. In silico predicted perturbations were validated experimentally using patient TEM. In addition, gene expression profiling of TEM transitioned to a weak pro-angiogenic phenotype confirmed that TEM are plastic cells and can be reverted to immunological potent monocytes. Finally, the relapse-free survival analysis showed a statistically significant difference between patients with tumors with high and low expression values for genes encoding transitioning proteins detected in silico and validated on patient TEM. In conclusion, the inferred TEM regulatory network accurately captured experimental TEM behavior and highlighted crosstalk between specific angiogenic and inflammatory signaling pathways of outstanding importance to control their pro-angiogenic activity. Results showed the successful in vitro reversion of such an activity by perturbation of in silico predicted target genes in tumor derived TEM, and indicated that targeting tumor TEM plasticity may constitute a novel valid therapeutic strategy in breast cancer.     

Oncolytic parvoviruses as cancer therapeutics

The experimental infectivity and excellent tolerance of some rodent autonomous parvoviruses in humans, together with their oncosuppressive effects in preclinical models, speak for the inclusion of these agents in the arsenal of oncolytic viruses under consideration for cancer therapy. In particular, wild-type parvovirus H-1PV can achieve a complete cure of various tumors in animal models and kill tumor cells that resist conventional anticancer treatments. There is growing evidence that H-1PV oncosuppression involves an immune component in addition to the direct viral oncolytic effect. This article summarizes the recent assessment of H-1PV antineoplastic activity in glioma, pancreatic ductal adenocarcinoma, and non-Hodgkin lymphoma models, laying the foundation for the present launch of a first phase I/IIa clinical trial on glioma patients.     

Dietary diversification and variations in the number of labrum sensilla in grasshoppers: Which came first?

The diversity of the diet of grasshoppers (Acrididae, Orthoptera) is related to multiple factors, including the chemoreceptors on the antennae, palps and on the epipharyngeal face of the labrum. In the present study, we sought to understand the nature of the diet of 12 Moroccan acridian species and to try to relate various aspects of their diet to the number of labrum sensilla. If the effect of the labrum size on the number of sensilla is removed, four groups of species are recorded: (i) polyphagous species with a broad diet and numerous sensilla; (ii) polyphagous species with a graminivorous diet and numerous sensilla; (iii) oligophagous species feeding exclusively on Poaceae and with a medium number of sensilla; and (iv) strictly monophagous species feeding on a single plant species and with the smallest number of sensilla. These observations show the close relationship between the diet and the number of labrum sensilla. However, Sphingonotus rubescens, a polyphagous species, is an exception to this trend as it harbours a medium number of sensilla. We propose that the modification in the number of labrum sensilla is a result of a progressive adaptation to a different diet and does not represent its cause.     

Prediction of physical performance through muscle enzymes activity

Physical performance deteriorates during strenuous exercise as manifested by a decrease in maximal aerobic power and increased activity of serum muscle enzymes. The relationship between these parameters was investigated in 41 trained subjects during 24 h marches and the following recovery period. Peak O2 uptake and serum activity of creatine phosphokinase (CPK) and glutamic oxalacetic transaminase (GOT) were measured. During the marches there was a simultaneous, significant elevation in serum CPK and GOT activity and a significant reduction in peak O2 uptake. During the early recovery period (24 h) no significant changes occurred in muscle enzyme activity and peak O2 uptake; thereafter (up to 72 h after the end of the march), a gradual decline in enzyme activity levels with a concomitant increase in peak O2 uptake was observed, reaching pre-march values. A "mirror image" relationship between muscle enzyme activity and peak O2 uptake was found during three clearly distinguished phases: a) 24 h march, b) early recovery stage and c) late recovery stage. These findings suggest that muscle enzyme leakage from muscle cells is closely related to the decline in muscular function and aerobic power. Thus, muscle enzyme activity might be a practical measure of physical performance capacity during the early and late stages of recovery from prolonged endurance exercise.     

Plasma-cortisol levels in experimental heatstroke in dogs

The effect of external heat-load, exercise and dehydration on dynamic changes in plasma cortisol during the development of heatstroke was investigated. Thirty-three unanesthetized dogs were tested under two sets of climatic conditions: comfort conditions and hot-dry climatic conditions, half of them while exercising. Half of the dogs in each group were rehydrated. None of the dogs that were investigated at room temperature suffered heatstroke. Of the dogs exposed to high ambient temperature, all of the exercising, as well as five out of six non-hydrated dogs and one rehydrated non-exercising dog suffered heatstroke. Significant dehydration (6%–7% of body weight), occurred only under hgh ambient temperature. Plasma cortisol levels of all dogs that suffered heatstroke rose conspicuously for at least 5 h and returned to normal levels 24 h later. Cortisol levels of dogs who did not experience heatstroke remained within the normal range. Cortisol levels correlated with the severity of the stress leading to heatstroke. High and rising levels of cortisol, several hours after body temperature returns to normal, may support the diagnosis of heatstroke.     

Phosphoinositides in insulin action on GLUT4 dynamics: not just PtdIns(3,4,5)P3

Accumulated evidence over the last several years indicates that insulin regulates multiple steps in the overall translocation of GLUT4 vesicles to the fat/muscle cell surface, including formation of an intracellular storage pool of GLUT4 vesicles, its movement to the proximity of the cell surface, and the subsequent docking/fusion with the plasma membrane. Insulin-stimulated formation of phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P(3); and in some cases, of its catabolite PtdIns(3,4)P(2)] plays a pivotal role in this process. PtdIns(3,4,5)P(3) is synthesized by the activated wortmannin-sensitive class IA phosphoinositide (PI) 3-kinase and controls the rate-limiting cell surface terminal stages of the GLUT4 journey. However, recent research is consistent with the conclusion that signals by each of the remaining five PIs, i.e., PtdIns(3)P, PtdIns(4)P, PtdIns(5)P, PtdIns(3,5)P(2), and PtdIns(4,5)P(2), may act in concert with that of PtdIns(3,4,5)P(3) in integrating the insulin receptor-issued signals with GLUT4 surface translocation and glucose transport activation. This review summarizes the experimental evidence supporting the complementary function of these PIs in insulin responsiveness of fat and muscle cells, with particular reference to mechanistic insights and functional significance in the regulation of overall GLUT4 vesicle dynamics.     

Estrogenic endocrine disruptive components interfere with calcium handling and differentiation of human trophoblast cells

During development, calcium (Ca) is actively transported by placental trophoblasts to meet fetal nutritional and the skeletal mineralization needs. Maternal exposure to estrogenic pesticides, such as 1,1-bis(p-chlorophenyl)-2,2,2-trichloroethane (DDT) and methoxychlor (MTC), has been shown to result in reproductive disorders and/or abnormal fetal development. In this study, we have examined the effects of exposure of trophoblastic cells to MTC and DTT, in comparison to 17beta-estradiol (E2) and diethylstilbestrol (DES), to test the hypothesis that cellular Ca handling is a target for these endocrine disruptive components. Treatment with DDT, MTC, DES, or E2 increased cellular Ca uptake, and the expression of trophoblast-specific human Ca binding protein (HCaBP) was down-regulated by both MTC and DDT. Treatment with MTC, DDT, and DES inhibited cell proliferation, induced apoptosis, and suppressed expression of several trophoblast differentiation marker genes. These effects were reversed by overexpression of metallothionein IIa, a gene highly responsive to cadmium and other metals. These results strongly suggest that trophoblast Ca handling functions are endocrinally modulated, and that their alteration by candidate endocrine disruptors, such as MTC and DDT, constitutes a possible pathway of the harmful effects of these components on fetal development.     

Characterization of aerobic and anaerobic vegetative growth of the food-borne pathogen Bacillus cereus F4430/73 strain

The Gram-positive bacterium Bacillus cereus is a facultative anaerobe that is still poorly characterized metabolically. In this study, the aerobic vegetative growth and anaerobic vegetative growth of the food-borne pathogen B. cereus F4430/73 strain were compared with those of the genome-sequenced ATCC14579 strain using glucose and glycerol as fermentative and nonfermentative carbon sources, respectively. Uncontrolled batch cultures on several defined media showed that B. cereus strains had high amino acid or pyruvate requirements for anaerobic fermentative growth. In addition, growth performance was considerably improved by maintaining the pH of the culture medium near neutrality. Spectra of fermentation by-products were typically (per mole of glucose) 0.2-0.4 acetate, 1.1-1.4 L-lactate, 0.3-0.4 formate, and 0.05-0.2 ethanol with only traces of succinate, pyruvate, and 2,3-butanediol. These spectra were drastically changed in the presence of 20 mmol nitrate x L(-1), which stimulated anaerobic growth. During anaerobic and aerobic respiration, the persistent production of acetate and other by-products indicated overflow metabolisms. This was especially true in glucose-grown cells for which respiratory complex III made only a minor contribution to growth. Surprisingly, oxygen uptake rates linked to the cytochrome c and quinol branches of the respiratory chain were maintained at high levels in anaerobic, respiring, or fermenting cells. Growth and metabolic features of B. cereus F4430/73 are discussed using biochemical and genomic data.     

Myotubularin regulates the function of the late endosome through the gram domain-phosphatidylinositol 3,5-bisphosphate interaction

Myotubularin and related proteins constitute a large and highly conserved family possessing phosphoinositide 3-phosphatase activity, although not all members possess this activity. This family contains a conserved region called the GRAM domain that is found in a variety of proteins associated with membrane-coupled processes and signal transduction. Mutations of myotubularin are found in X-linked myotubular myopathy, a severe muscle disease. Mutations in the GRAM domain are responsible for this condition, suggesting crucial roles for this region. Here, we show that the GRAM domain of myotubularin binds to phosphoinositide with the highest affinity to phosphatidylinositol 3,5-bisphosphate (PtdIns(3,5)P(2)). In patients with myotubular myopathy, mutations in the myotubularin GRAM domain eliminate this binding, indicating that the PtdIns(3,5)P(2) binding ability of the GRAM (glucosyltransferases, Rablike GTPase activators and myotubularin) domain is crucial for the functions of myotubularin in vivo. Stimulation of epidermal growth factor recruits myotubularin to the late endosomal compartment in a manner dependent on the phosphoinositide binding. Overexpression of myotubularin inhibits epidermal growth factor receptor trafficking from late endosome to lysosome and induces the large endosomal vacuoles. Thus, our data suggest that myotubularin phosphatase physiologically functions in late endosomal trafficking and vacuolar morphology through interaction with PtdIns(3,5)P(2).