348 research outputs found

    Predicting risk of school refusal: examining the incremental role of trait EI beyond personality and emotion regulation

    Get PDF
    Research has not yet been deepened in the link between personality factors and risk of school refusal. Furthermore, previous studies fail to verify the direct relation between trait EI and the risk of school refusal. The present study examined personality traits, emotion regulation and trait EI for the contributory role they may play in predicting the risk of school refusal. The sample consisted of 311 participants, 112 males (36%) and 199 females (64%) with an average age of 14.19 (SD = .60), from a high school in the city of Messina (Sicily, Italy). Results show that the risk of school refusal is positively related to neuroticism and maladaptive emotion regulation strategies, while it is negatively related to the extroversion, agreeableness and conscientiousness and trait EI. Moreover, trait EI can be considered as a strong incremental negative predictor of risk of school refusal over and above personality traits and emotion regulation

    Learned Helplessness and Learning Goals: Role played in School Refusal. A Study on Italian Students.

    Get PDF
    Literature on school refusal has shown a link between school refusal and poor school performance. However, there has been little investigation into the individual underlying factors, and specifically factors directly related to the learning process, such as the learning goals of students and their expectations of success and/or failure. The main purpose of the present study is to investigate the influence of Learned Helplessness (LH) and learning goals on school refusal. We hypothesized that LH and learning goals exert a unique role in predicting school refusal above and beyond the roles of academic achievement, age, and gender. The sample consisted of 201 Italian students with an average age of 11.93, with both low (57.2 % of students) and high (42.8 %) academic achievement. School refusal, LH, and learning goals were measured by means of questionnaires. The results confirm the hypothesis of this study; in fact, we found that learning goals and, above all, LH play a more predictive role of school refusal than academic achievement. These results extend previous studies on school refusal and, for the first time, they provide additional knowledge about this problem, analyzing the relationship between school refusal, learning goals, and LH, still neglected in the literature. Implications on the psychological well-being of students are discussed

    Identifying the optimal donor for natural killer cell adoptive therapy to treat paediatric B- and T-cell acute lymphoblastic leukaemia.

    Get PDF
    Objectives: Natural killer (NK) cells are an attractive source of cells for an 'off the shelf' cellular therapy because of their innate capacity to target malignant cells, and ability to be transferred between donors and patients. However, since not all NK cells are equally effective at targeting cancer, selecting the right donor for cellular therapy is critical for the success of the treatment. Recently, cellular therapies utilising NK cells from cytomegalovirus (CMV)-seropositive donors have been explored. However, whether these NK cells are the best source to treat paediatric acute lymphoblastic leukaemia (ALL) remains unclear. Methods: Using a panel of patient-derived paediatric B- and T-ALL, we assessed the ability of NK cells from 49 healthy donors to mount an effective functional response against these two major subtypes of ALL. Results: From this cohort, we have identified a pool of donors with superior activity against multiple ALL cells. While these donors were more likely to be CMV+, we identified multiple CMVneg donors within this group. Furthermore, NK cells from these donors recognised B- and T-ALL through different activating receptors. Dividing functional NK cells into 29 unique subsets, we observed that within each individual the same NK cell subsets dominated across all ALL cells. Intriguingly, this occurred despite the ALL cells in our panel expressing different combinations of NK cell ligands. Finally, we can demonstrate that cellular therapy products derived from these superior donors significantly delayed leukaemia progression in preclinical models of ALL. Conclusions: We have identified a pool of superior donors that are effective against a range of ALL cells, representing a potential pool of donors that can be used as an adoptive NK cell therapy to treat paediatric ALL

    The Association of AMPK with ULK1 Regulates Autophagy

    Get PDF
    Autophagy is a highly orchestrated intracellular bulk degradation process that is activated by various environmental stresses. The serine/threonine kinase ULK1, like its yeast homologue Atg1, is a key initiator of autophagy that is negatively regulated by the mTOR kinase. However, the molecular mechanism that controls the inhibitory effect of mTOR on ULK1-mediated autophagy is not fully understood. Here we identified AMPK, a central energy sensor, as a new ULK1-binding partner. We found that AMPK binds to the PS domain of ULK1 and this interaction is required for ULK1-mediated autophagy. Interestingly, activation of AMPK by AICAR induces 14-3-3 binding to the AMPK-ULK1-mTORC1 complex, which coincides with raptor Ser792 phosphorylation and mTOR inactivation. Consistently, AICAR induces autophagy in TSC2-deficient cells expressing wild-type raptor but not the mutant raptor that lacks the AMPK phosphorylation sites (Ser722 and Ser792). Taken together, these results suggest that AMPK association with ULK1 plays an important role in autophagy induction, at least in part, by phosphorylation of raptor to lift the inhibitory effect of mTOR on the ULK1 autophagic complex

    Activation of β-Catenin by Oncogenic PIK3CA and EGFR Promotes Resistance to Glucose Deprivation by Inducing a Strong Antioxidant Response

    Get PDF
    Glucose is an essential fuel for cell survival and its availability limits aberrant cellular proliferation. We have hypothesized that specific cancer mutations regulate metabolic response(s) to glucose deprivation (GD). By means of somatic knock-in cellular models, we have analyzed the response to glucose deprivation in cells carrying the frequent delE746-A750EGFR, G13DKRAS or E545KPIK3CA cancer alleles. We demonstrate that, in mammary epithelial cells, glucose has an essential antioxidant function and that these cells are very sensitive to GD. Conversely, isogenic cells carrying the delE746-A750EGFR or the E545KPIK3CA, but not the G13DKRAS allele, display high tolerance to GD by stimulating the expression of anti-oxidant genes (MnSOD and catalase). This adaptive transcriptional response is mediated by the activation of WNT/β-catenin and FOXO4 signalling. Our data highlights a new functional synergism between oncogenic EGFR and PIK3CA with WNT/β-catenin conferring high tolerance to oxidative stress generated by nutrient deprivation

    Metformin inhibits melanoma development through autophagy and apoptosis mechanisms

    Get PDF
    Metformin is the most widely used antidiabetic drug because of its proven efficacy and limited secondary effects. Interestingly, recent studies have reported that metformin can block the growth of different tumor types. Here, we show that metformin exerts antiproliferative effects on melanoma cells, whereas normal human melanocytes are resistant to these metformin-induced effects. To better understand the basis of this antiproliferative effect of metformin in melanoma, we characterized the sequence of events underlying metformin action. We showed that 24 h metformin treatment induced a cell cycle arrest in G0/G1 phases, while after 72 h, melanoma cells underwent autophagy as demonstrated by electron microscopy, immunochemistry, and by quantification of the autolysosome-associated LC3 and Beclin1 proteins. In addition, 96 h post metformin treatment we observed robust apoptosis of melanoma cells. Interestingly, inhibition of autophagy by knocking down LC3 or ATG5 decreased the extent of apoptosis, and suppressed the antiproliferative effect of metformin on melanoma cells, suggesting that apoptosis is a consequence of autophagy. The relevance of these observations were confirmed in vivo, as we showed that metformin treatment impaired the melanoma tumor growth in mice, and induced autophagy and apoptosis markers. Taken together, our data suggest that metformin has an important impact on melanoma growth, and may therefore be beneficial in patients with melanoma

    Oxygen Consumption Can Regulate the Growth of Tumors, a New Perspective on the Warburg Effect

    Get PDF
    The unique metabolism of tumors was described many years ago by Otto Warburg, who identified tumor cells with increased glycolysis and decreased mitochondrial activity. However, "aerobic glycolysis" generates fewer ATP per glucose molecule than mitochondrial oxidative phosphorylation, so in terms of energy production, it is unclear how increasing a less efficient process provides tumors with a growth advantage.We carried out a screen for loss of genetic elements in pancreatic tumor cells that accelerated their growth as tumors, and identified mitochondrial ribosomal protein L28 (MRPL28). Knockdown of MRPL28 in these cells decreased mitochondrial activity, and increased glycolysis, but paradoxically, decreased cellular growth in vitro. Following Warburg's observations, this mutation causes decreased mitochondrial function, compensatory increase in glycolysis and accelerated growth in vivo. Likewise, knockdown of either mitochondrial ribosomal protein L12 (MRPL12) or cytochrome oxidase had a similar effect. Conversely, expression of the mitochondrial uncoupling protein 1 (UCP1) increased oxygen consumption and decreased tumor growth. Finally, treatment of tumor bearing animals with dichloroacetate (DCA) increased pyruvate consumption in the mitochondria, increased total oxygen consumption, increased tumor hypoxia and slowed tumor growth.We interpret these findings to show that non-oncogenic genetic changes that alter mitochondrial metabolism can regulate tumor growth through modulation of the consumption of oxygen, which appears to be a rate limiting substrate for tumor proliferation
    corecore