352 research outputs found

    Depannage and other maintenance strategies for transportation fleets

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    This paper addresses the problem of designing a depannage service network for freight transportation fleets in order to fill up an evident gap in Operations Management literature. As a matter of fact, breakdowns have a significant impact on service level and an efficient and effective assistance service is needed in order to guarantee competitive advantage. Aiming at laying the foundations for further research on modelling and solving the considered problem, a literature review is performed for identifying analogies with other problems, already approached in the past, and stating the problem. Finally, parameters, decision variables and objective function that should be considered for modelling and solving the problem are proposed, trying to stimulate the discussion on a new research theme and, more specifically, on the integration of decisions at strategic, tactical and operational level into a systemic model

    Dual inhibition of CDK4/6 and PI3K/AKT/mTOR signaling impairs energy metabolism in MPM cancer cells

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    Background: Malignant pleural mesothelioma (MPM) is an aggressive malignancy associated to asbestos exposure. One of the most frequent genetic alteration in MPM patients is CDKN2A/ARF loss, leading to aberrant activation of the Rb pathway. In MPM cells, we previously demonstrated the therapeutic efficacy of targeting this signaling with the CDK4/6 inhibitor palbociclib in combination with PI3K/mTOR inhibitors. Here, we investigated whether such combination may have an impact on cell energy metabolism. Methods: The study was performed in MPM cells of different histotypes; metabolic analyses were conducted by measuring GLUT-1 expression and glucose uptake/consumption, and by SeaHorse technologies. Results: MPM cell models differed for their ability to adapt to metabolic stress conditions, such as glucose starvation and hypoxia. Independently of these differences, combined treatments with palbociclib and PI3K/mTOR inhibitors inhibited cell proliferation more efficaciously than single agents. The drugs alone reduced glucose uptake/consumption as well as glycolysis, and their combination further enhanced these effects under both normoxic and hypoxic conditions. Moreover, the drug combinations significantly impaired mitochondrial respiration as compared with individual treatments. These metabolic effects were mediated by the concomitant inhibition of Rb/E2F/c-myc and PI3K/AKT/mTOR signaling. Conclusions: Dual blockade of glycolysis and respiration contributes to the anti-tumor efficacy of palbociclib-PI3K/mTOR inhibitors combination

    Simultaneous Combination of the CDK4/6 Inhibitor Palbociclib With Regorafenib Induces Enhanced Anti-tumor Effects in Hepatocarcinoma Cell Lines

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    Advanced hepatocarcinoma (HCC) is an aggressive malignancy with poor prognosis and limited treatment options. Alterations of the cyclin D-CDK4/6-Rb pathway occur frequently in HCC, providing the rationale for its targeting at least in a molecular subset of HCC. In a panel of HCC cell lines, we investigated whether the CDK4/6 inhibitor palbociclib might improve the efficacy of regorafenib, a powerful multi-kinase inhibitor approved as second-line treatment for advanced HCC after sorafenib failure and currently under clinical investigation as first-line therapy in combination with immunotherapy. In Rb-proficient cells, the simultaneous drug combination, but not the sequential schedules, inhibited cell proliferation, either in short or in long-term experiments, and induced cell death more strongly than individual treatments. Moreover, the combination significantly reduced spheroid cell growth and inhibited cell migration/invasion. The superior efficacy of palbociclib plus regorafenib emerged also under hypoxia and was associated with a significant down-regulation of CDK4/6-Rb-myc and mTORC1/p70S6K signaling. Moreover, regorafenib suppressed palbociclib-induced expression of cyclin D1 contributing to the cytotoxic effects of the combination. Besides these inhibitory effects on cell viability/proliferation, palbociclib and regorafenib reduced glucose uptake, although this effect was dependent on the cell model and on the oxygen availability (normoxia or hypoxia). Palbociclib and regorafenib combination impaired glucose uptake and utilization, down-regulating basal and hypoxia-induced expression of HIF-1α, HIF-2α, GLUT-1, and MCT4 proteins as well as the activity/expression of glycolytic enzymes (HK2, PFKP, aldolase A, PKM2). In addition, regorafenib alone reduced mitochondrial respiration. The combined treatment impaired glucose metabolism and respiration without enhancing the effects of the single agents. Our findings provide pre-clinical evidence for the effectiveness of palbociclib and regorafenib combination in HCC cell models

    Efficacy of the cdk4/6 dual inhibitor abemaciclib in egfr-mutated nsclc cell lines with different resistance mechanisms to osimertinib

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    Abemaciclib is an inhibitor of cyclin-dependent kinases (CDK) 4 and 6 that inhibits the transition from the G1 to the S phase of the cell cycle by blocking downstream CDK4/6-mediated phosphorylation of Rb. The effects of abemaciclib alone or combined with the third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) osimertinib were examined in a panel of PC9 and HCC827 osimertinib-resistant non-small cell lung cancer (NSCLC) cell lines carrying EGFR-dependent or-independent mechanisms of intrinsic or acquired resistance. Differently from sensitive cells, all the resistant cell lines analyzed maintained p-Rb, which may be considered as a biomarker of osimertinib resistance and a potential target for therapeutic intervention. In these models, abemaciclib inhibited cell growth, spheroid formation, colony formation, and induced senes-cence, and its efficacy was not enhanced in the presence of osimertinib. Interestingly, in osimertinib sensitive PC9, PC9T790M, and H1975 cells the combination of abemaciclib with osimertinib significantly inhibited the onset of resistance in long-term experiments. Our findings provide a preclinical support for using abemaciclib to treat resistance in EGFR mutated NSCLC patients progressed to osimertinib either as single treatment or combined with osimertinib, and suggest the combination of osimertinib with abemaciclib as a potential approach to prevent or delay osimertinib resistance in first-line treatment

    Pemetrexed enhances membrane PD-L1 expression and potentiates T cell-mediated cytotoxicity by anti-PD-L1 antibody therapy in non-small-cell lung cancer

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    Immunotherapy has significantly changed the treatment landscape for advanced non-small-cell lung cancer (NSCLC) with the introduction of drugs targeting programmed cell death protein-1 (PD-1) and programmed cell death ligand-1 (PD-L1). In particular, the addition of the anti-PD-1 antibody pembrolizumab to platinum-pemetrexed chemotherapy resulted in a significantly improved overall survival in patients with non-squamous NSCLC, regardless of PD-L1 expression. In this preclinical study, we investigated whether chemotherapy can modulate PD-L1 expression in non-squamous NSCLC cell lines, thus potentially affecting immunotherapy efficacy. Among different chemotherapeutic agents tested, only pemetrexed increased PD-L1 levels by activating both mTOR/P70S6K and STAT3 pathways. Moreover, it also induced the secretion of cytokines, such as IFN-γ and IL-2, by activated peripheral blood mononuclear cells PBMCs that further stimulated the expression of PD-L1 on tumor cells, as demonstrated in a co-culture system. The anti-PD-1/PD-L1 therapy enhanced T cell-mediated cytotoxicity of NSCLC cells treated with pemetrexed and expressing high levels of PD-L1 in comparison with untreated cells. These data may explain the positive results obtained with pemetrexed-based chemotherapy combined with pembrolizumab in PD-L1-negative NSCLC and can support pemetrexed as one of the preferable chemotherapy partners for immunochemotherapy combination regimens
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