310 research outputs found

    Mathematical modeling of the formation of apoptosome in intrinsic pathway of apoptosis

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    Caspase-9 is the protease that mediates the intrinsic pathway of apoptosis, a type of cell death. Activation of caspase-9 is a multi-step process that requires dATP or ATP and involves at least two proteins, cytochrome c and Apaf-1. In this study, we mathematically model caspase-9 activation by using a system of ordinary differential equations (an ODE model) generated by a systems biology tool Simpathica—a simulation and reasoning system, developed to study biological pathways. A rudimentary version of “model checking” based on comparing simulation data with that obtained from a recombinant system of caspase-9 activation, provided several new insights into regulation of this protease. The model predicts that the activation begins with binding of dATP to Apaf-1, which initiates the interaction between Apaf-1 and cytochrome c, thus forming a complex that oligomerizes into an active caspase-9 holoenzyme via a linear binding model with cooperative interaction rather than through network formation

    Primary tumor sidedness and benefit from FOLFOXIRI plus bevacizumab as initial therapy for metastatic colorectal cancer. Retrospective analysis of the TRIBE trial by GONO

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    Right-sided metastatic colorectal cancer (mCRC) patients have poor prognosis and achieve limited benefit from first-line doublets plus a targeted agent. In this unplanned analysis of the TRIBE study, we investigated the prognostic and predictive impact of primary tumor sidedness in mCRC patients and the differential impact of the intensification of the chemotherapy in subgroups defined according to both primary tumor sidedness and RAS and BRAF mutational status

    KRAS and BRAF genotyping of synchronous colorectal carcinomas.

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    Abstract. v‑Ki‑ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) genotyping is required prior to anti‑epidermal growth factor receptor monoclonal antibody therapy administered in cases of metastatic colorectal carcinoma (CRC). Thus, KRAS mutation screening is required for patient management. The present study reported the experience of KRAS/v‑raf murine sarcoma viral oncogene homolog B1 (BRAF) mutational screening on synchronous CRC pairs from 26 patients, which were defined as index lesions (ILs) and concurrent lesions (CLs) on the basis of tumor grade and dimension and their respective lymph node and distant metastases. Overall, KRAS mutations were present in 38.4% of patients, whereas BRAF mutations were present at a frequency of 11.5%. The genotyping of paired synchronous carcinomas indicated that 11 patients (42.3%) exhibited discordant KRAS mutational statuses in terms of the presence of a mutation in only one lesion of the pair or of two different mutations harbored by each lesion. BRAF mutations were present in the synchronous tumors of two cases, whereas in two other cases, only the IL or CL harbored mutant BRAF. Overall, the mutational statuses of distant and lymph node metastases confirm the genetic heterogeneity of synchronous primary tumors. These results highlighted the fact that adequate sampling and comprehensive testing, when feasible, is likely to optimize the decision‑making process for treatment approaches, even in the relatively rare event of multiple synchronous lesions

    Apocynin Derivatives Interrupt Intracellular Signaling Resulting in Decreased Migration in Breast Cancer Cells

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    Cancer cells are defined by their ability to divide uncontrollably and metastasize to secondary sites in the body. Consequently, tumor cell migration represents a promising target for anticancer drug development. Using our high-throughput cell migration assay, we have screened several classes of compounds for noncytotoxic tumor cell migration inhibiting activity. One such compound, apocynin (4-acetovanillone), is oxidized by peroxidases to yield a variety of oligophenolic and quinone-type compounds that are recognized inhibitors of NADPH oxidase and may be inhibitors of the small G protein Rac1 that controls cell migration. We report here that while apocynin itself is not effective, apocynin derivatives inhibit migration of the breast cancer cell line MDA-MB-435 at subtoxic concentrations; the migration of nonmalignant MCF10A breast cells is unaffected. These compounds also cause a significant rearrangement of the actin cytoskeleton, cell rounding, and decreased levels of active Rac1 and its related G protein Cdc42. These results may suggest a promising new route to the development of novel anticancer therapeutics

    Aflibercept Plus FOLFIRI in the Real-life Setting: Safety and Quality of Life Data From the Italian Patient Cohort of the Aflibercept Safety and Quality-of-Life Program Study

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    The Italian subset of the real-life Aflibercept Safety and Quality-of-Life Program study evaluated the safety and health-related quality of life (HRQL) of aflibercept plus FOLFIRI (folinic acid, 5-fluorouracil, irinotecan) in 200 patients with pretreated metastatic colorectal cancer (mCRC). No significant worsening of HRQL occurred, and the safety profile was consistent with the reported data. The combination was well tolerated as second-line treatment for patients with mCRC in a real-life setting. Background: Aflibercept combined with FOLFIRI (folinic acid, 5-fluorouracil, irinotecan) as second-line treatment of metastatic colorectal cancer (mCRC) significantly improved survival compared with FOLFIRI alone in the pivotal VELOUR (aflibercept vs. placebo in combination with irinotecan and 5-fluorouracil in the treatment of patients with metastatic colorectal cancer after failure of an oxaliplatin-based regimen) trial. No quality-of-life assessment was performed in VELOUR; therefore, the ASQoP (Aflibercept Safety and Quality-of-Life Program) trial was designed to capture the safety and health-related quality of life (HRQL). Patients and Methods: ASQoP was an international, open-label, single-arm trial evaluating the safety and HRQL of aflibercept combined with FOLFIRI administered in a real-life setting to 781 patients with mCRC, pretreated with an oxaliplatin-based regimen with or without bevacizumab. The Italian subset of ASQoP enrolled 200 patients from 28 institutions. The primary endpoint was safety; HRQL was a secondary endpoint, assessed by validated questionnaires (European quality of life 5-dimension instrument 3-level; European Organization for Research and Treatment for Cancer Quality of Life Questionnaire Core 30, version 3; and EORTC-CR29) at baseline, during treatment, and at the end of treatment. Results: The median age of the Italian ASQoP population was 63 years; the median number of aflibercept and FOLFIRI cycles was 7. Treatment-emergent adverse events were reported in 97.5% of patients. Hypertension (28.5%), neutropenia (27.5%; from laboratory data), asthenic conditions (20.0%), diarrhea (17.0%), and stomatitis (13.0%) were the most frequent (incidence, ≥ 5%) grade 3/4 toxicities. One toxic death occurred during the study period due to sepsis, without neutropenic complications. No significant worsening of HRQL was shown during treatment. Conclusion: Aflibercept combined with FOLFIRI was well tolerated when administered as second-line treatment for patients with mCRC in a real-life setting. It did not affect HRQL and showed similar rates of treatment-emergent adverse events as those observed in the VELOUR trial. No new safety signals were identified

    SiO2nanoparticles modulate the electrical activity of neuroendocrine cells without exerting genomic effects

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    Engineered silica nanoparticles (NPs) have attracted increasing interest in several applications, and particularly in the field of nanomedicine, thanks to the high biocompatibility of this material. For their optimal and controlled use, the understanding of the mechanisms elicited by their interaction with the biological target is a prerequisite, especially when dealing with cells particularly vulnerable to environmental stimuli like neurons. Here we have combined different electrophysiological approaches (both at the single cell and at the population level) with a genomic screening in order to analyze, in GT1-7 neuroendocrine cells, the impact of SiO2NPs (50\u2009\ub1\u20093\u2009nm in diameter) on electrical activity and gene expression, providing a detailed analysis of the impact of a nanoparticle on neuronal excitability. We find that 20\u2009\ub5g\u2009mL-1NPs induce depolarization of the membrane potential, with a modulation of the firing of action potentials. Recordings of electrical activity with multielectrode arrays provide further evidence that the NPs evoke a temporary increase in firing frequency, without affecting the functional behavior on a time scale of hours. Finally, NPs incubation up to 24\u2009hours does not induce any change in gene expression
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