185 research outputs found

    Vitamin C inhibits endothelial cell apoptosis in congestive heart failure

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    Background - Proinflammatory cytokines like tumor necrosis factor- and oxidative stress induce apoptotic cell death in endothelial cells (ECs). Systemic inflammation and increased oxidative stress in congestive heart failure (CHF) coincide with enhanced EC apoptosis and the development of endothelial dysfunction. Therefore, we investigated the effects of antioxidative vitamin C therapy on EC apoptosis in CHF patients. Methods and Results - Vitamin C dose dependently suppressed the induction of EC apoptosis by tumor necrosis factor- and angiotensin II in vitro as assessed by DNA fragmentation, DAPI nuclear staining, and MTT viability assay. The antiapoptotic effect of vitamin C was associated with reduced cytochrome C release from mitochondria and the inhibition of caspase-9 activity. To assess EC protection by vitamin C in CHF patients, we prospectively randomized CHF patients in a double-blind trial to vitamin C treatment versus placebo. Vitamin C administration to CHF patients markedly reduced plasma levels of circulating apoptotic microparticles to 32±8% of baseline levels, whereas placebo had no effect (87±14%, P<0.005). In addition, vitamin C administration suppressed the proapoptotic activity on EC of the serum of CHF patients (P<0.001). Conclusions - Administration of vitamin C to CHF patients suppresses EC apoptosis in vivo, which might contribute to the established functional benefit of vitamin C supplementation on endothelial function

    Constitutive cytoplasmic localization of p21Waf1/Cip1 affects the apoptotic process in monocytic leukaemia

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    In the present study, we analysed the expression and localization of p21Waf1/Cip1 in normal and malignant haematopoietic cells. We demonstrate that in normal monocytic cells, protein kinase C (PKC)-induced p21 gene activation, which is nuclear factor-κB (NF-κB) independent, results in predominantly cytoplasmic localized p21 protein. In acute monocytic leukaemia (M4, M5), monocytic blasts (N=12) show constitutive cytoplasmic p21 expression in 75% of the cases, while in myeloid leukaemic blasts (N=10), low nuclear and cytoplasmic localization of p21 could be detected, which is also PKC dependent. Constitutive p21 expression in monocytic leukaemia might have important antiapoptotic functions. This is supported by the finding that in U937 cells overexpressing p21, VP16-induced apoptosis is significantly reduced (20.0±0.9 vs 55.8±3.8%, P<0.01, N=5), reflected by a reduced phosphorylation of p38 and JNK. Similarly, AML blasts with high cytoplasmic p21 were less sensitive to VP16-induced apoptosis as compared to AML cases with low or undetectable p21 expression (42.25 vs 12.3%, P<0.01). Moreover, complex formation between p21 and ASK1 could be demonstrated in AML cells, by means of coimmunoprecipitation. In summary, these results indicate that p21 has an antiapoptotic role in monocytic leukaemia, and that p21 expression is regulated in a PKC-dependent and NF-κB independent manner.

    Increased S-nitrosylation and proteasomal degradation of caspase-3 during infection contribute to the persistence of adherent invasive escherichia coli (AIEC) in immune cells

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    Adherent invasive Escherichia coli (AIEC) have been implicated as a causative agent of Crohn's disease (CD) due to their isolation from the intestines of CD sufferers and their ability to persist in macrophages inducing granulomas. The rapid intracellular multiplication of AIEC sets it apart from other enteric pathogens such as Salmonella Typhimurium which after limited replication induce programmed cell death (PCD). Understanding the response of infected cells to the increased AIEC bacterial load and associated metabolic stress may offer insights into AIEC pathogenesis and its association with CD. Here we show that AIEC persistence within macrophages and dendritic cells is facilitated by increased proteasomal degradation of caspase-3. In addition S-nitrosylation of pro- and active forms of caspase-3, which can inhibit the enzymes activity, is increased in AIEC infected macrophages. This S-nitrosylated caspase-3 was seen to accumulate upon inhibition of the proteasome indicating an additional role for S-nitrosylation in inducing caspase-3 degradation in a manner independent of ubiquitination. In addition to the autophagic genetic defects that are linked to CD, this delay in apoptosis mediated in AIEC infected cells through increased degradation of caspase-3, may be an essential factor in its prolonged persistence in CD patients

    Lenvatinib with etoposide plus ifosfamide in patients with refractory or relapsed osteosarcoma (ITCC-050): a multicentre, open-label, multicohort, phase 1/2 study

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    Background: Tyrosine kinase inhibitors have shown activity in osteosarcoma and might enhance the efficacy of chemotherapy. We aimed to determine the recommended phase 2 dose and antitumour activity of lenvatinib with etoposide plus ifosfamide in patients with refractory or relapsed osteosarcoma. // Methods: This multicentre, open-label, multicohort, phase 1/2 trial was done at 17 hospitals in six countries. Eligible patients were aged 2–25 years, had relapsed or refractory osteosarcoma, measurable or evaluable disease per Response Evaluation Criteria in Solid Tumors version 1.1, Lansky play–performance score or Karnofsky performance score of 50% or higher, up to one previous VEGF or VEGF receptor-targeted therapy, and a life expectancy of at least 3 months. This study includes a combination dose-finding phase 1 part (cohort 3A) and a phase 2 combination expansion in patients with osteosarcoma (cohort 3B). Lenvatinib was administered orally at a starting dose of 11 mg/m2 per day, capped at 24 mg per day, and etoposide (100 mg/m2 per day) plus ifosfamide (3000 mg/m2 per day) were administered intravenously on days 1–3 of each 21-day cycle for a maximum of five cycles. Lenvatinib monotherapy continued after these five cycles until disease progression, toxic effects, or patient choice to discontinue. The phase 1 primary endpoint was to determine the recommended phase 2 dose by evaluating dose-limiting toxicity and the phase 2 primary endpoint was progression-free survival at 4 months. Progression-free survival was measured in the full analysis set, which included all patients enrolled for efficacy outcomes; safety was assessed in all patients who received any study drug. This study is registered with ClinicalTrials.gov, NCT02432274. // Findings: 30 patients were screened for enrolment into cohort 3A between May 9, 2016, and June 3, 2019, and 22 patients for enrolment into cohort 3B between Sept 13, 2018, and July 18, 2019. Eight patients from cohort 3A and two from cohort 3B were ineligible for enrolment in the study. In phase 1, dose-limiting toxicities were observed in three patients (one in the lenvatinib 11 mg/m2 combination group and two in the 14 mg/m2 combination group) and the recommended phase 2 dose was determined as lenvatinib 14 mg/m2 per day (with daily dose cap of 24 mg) and etoposide 100 mg/m2 per day plus ifosfamide 3000 mg/m2 per day administered intravenously on days 1–3 of each 21-day cycle for a maximum of five cycles. 35 patients from phase 1 (cohort 3A; n=15) and phase 2 (cohort 3B; n=20) were treated at the recommended phase 2 dose and their results were pooled. Progression-free survival at 4 months was 51% (95% CI 34–69) in 18 of 35 patients per the binomial estimate. The most common grade 3–4 treatment-emergent adverse events were neutropenia (27 [77%] of 35), thrombocytopenia (25 [71%]), anaemia (19 [54%]), and decreased white blood cell count (19 [54%]). 26 [74%] of 35 patients had serious treatment-emergent adverse events and no treatment-related deaths occurred. // Interpretation: Lenvatinib with etoposide plus ifosfamide shows promising antitumour activity with no new safety signals in patients with refractory and relapsed osteosarcoma. These findings warrant further investigation in an ongoing randomised phase 2 study (NCT04154189)

    Phase I/II study of single-agent lenvatinib in children and adolescents with refractory or relapsed solid malignancies and young adults with osteosarcoma (ITCC-050)

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    Background: We report results from the phase I dose-finding and phase II expansion part of a multicenter, open-label study of single-agent lenvatinib in pediatric and young adult patients with relapsed/refractory solid tumors, including osteosarcoma and radioiodine-refractory differentiated thyroid cancer (RR-DTC) (NCT02432274). // Patients and methods: The primary endpoint of phase I was to determine the recommended phase II dose (RP2D) of lenvatinib in children with relapsed/refractory solid malignant tumors. Phase II primary endpoints were progression-free survival rate at 4 months (PFS-4) for patients with relapsed/refractory osteosarcoma; and objective response rate/best overall response for patients with RR-DTC at the RP2D. // Results: In phase I, 23 patients (median age, 12 years) were enrolled. With lenvatinib 14 mg/m2, three dose-limiting toxicities (hypertension, n = 2; increased alanine aminotransferase, n = 1) were reported, establishing 14 mg/m2 as the RP2D. In phase II, 31 patients with osteosarcoma (median age, 15 years) and 1 patient with RR-DTC (age 17 years) were enrolled. For the osteosarcoma cohort, PFS-4 (binomial estimate) was 29.0% [95% confidence interval (CI) 14.2% to 48.0%; full analysis set: n = 31], PFS-4 by Kaplan–Meier estimate was 37.8% (95% CI 20.0% to 55.4%; full analysis set) and median PFS was 3.0 months (95% CI 1.8-5.4 months). The objective response rate was 6.7% (95% CI 0.8% to 22.1%). The patient with RR-DTC had a best overall response of partial response. Some 60.8% of patients in phase I and 22.6% of patients in phase II (with osteosarcoma) had treatment-related treatment-emergent adverse events of grade ≥3. // Conclusions: The lenvatinib RP2D was 14 mg/m2. Single-agent lenvatinib showed activity in osteosarcoma; however, the null hypothesis could not be rejected. The safety profile was consistent with previous tyrosine kinase inhibitor studies. Lenvatinib is currently being investigated in osteosarcoma in combination with chemotherapy as part of a randomized, controlled trial (NCT04154189), in pediatric solid tumors in combination with everolimus (NCT03245151), and as a single agent in a basket study with enrollment ongoing (NCT04447755)

    Phase I/II intra-patient dose escalation study of vorinostat in children with relapsed solid tumor, lymphoma, or leukemia

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    Background: Until today, adult and pediatric clinical trials investigating single-agent or combinatorial HDAC inhibitors including vorinostat in solid tumors have largely failed to demonstrate efficacy. These results may in part be explained by data from preclinical models showing significant activity only at higher concentrations compared to those achieved with current dosing regimens. In the current pediatric trial, we applied an intra-patient dose escalation design. The purpose of this trial was to determine a safe dose recommendation (SDR) of single-agent vorinostat for intra-patient dose escalation, pharmacokinetic analyses (PK), and activity evaluation in children (3-18 years) with relapsed or therapy-refractory malignancies. Results: A phase I intra-patient dose (de)escalation was performed until individual maximum tolerated dose (MTD). The starting dose was 180 mg/m(2)/day with weekly dose escalations of 50 mg/m(2) until DLT/maximum dose. After MTD determination, patients seamlessly continued in phase II with disease assessments every 3 months. PK and plasma cytokine profiles were determined. Fifty of 52 patients received treatment. n = 27/50 (54%) completed the intra-patient (de)escalation and entered phase II. An SDR of 130 mg/m(2)/day was determined (maximum, 580 mg/m(2)/day). n = 46/50 (92%) patients experienced treatment-related AEs which were mostly reversible and included thrombocytopenia, fatigue, nausea, diarrhea, anemia, and vomiting. n = 6/50 (12%) had treatment-related SAEs. No treatment-related deaths occurred. Higher dose levels resulted in higher C-max. Five patients achieved prolonged disease control (> 12 months) and showed a higher C-max (> 270 ng/mL) and MTDs. Best overall response (combining PR and SD, no CR observed) rate in phase II was 6/27 (22%) with a median PFS and OS of 5.3 and 22.4 months. Low levels of baseline cytokine expression were significantly correlated with favorable outcome. Conclusion: An SDR of 130 mg/m(2)/day for individual dose escalation was determined. Higher drug exposure was associated with responses and long-term disease stabilization with manageable toxicity. Patients with low expression of plasma cytokine levels at baseline were able to tolerate higher doses of vorinostat and benefited from treatment. Baseline cytokine profile is a promising potential predictive biomarker

    Dexamethasone vs prednisone in induction treatment of pediatric ALL: results of the randomized trial AIEOP-BFM ALL 2000

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    Induction therapy for childhood acute lymphoblastic leukemia (ALL) traditionally includes prednisone; yet, dexamethasone may have higher antileukemic potency, leading to fewer relapses and improved survival. After a 7-day prednisone prephase, 3720 patients enrolled on trial Associazione Italiana di Ematologia e Oncologia Pediatrica and Berlin-Frankfurt-Münster (AIEOP-BFM) ALL 2000 were randomly selected to receive either dexamethasone (10 mg/m(2) per day) or prednisone (60 mg/m(2) per day) for 3 weeks plus tapering in induction. The 5-year cumulative incidence of relapse (± standard error) was 10.8 ± 0.7% in the dexamethasone and 15.6 ± 0.8% in the prednisone group (P &lt; .0001), showing the largest effect on extramedullary relapses. The benefit of dexamethasone was partially counterbalanced by a significantly higher induction-related death rate (2.5% vs 0.9%, P = .00013), resulting in 5-year event-free survival rates of 83.9 ± 0.9% for dexamethasone and 80.8 ± 0.9% for prednisone (P = .024). No difference was seen in 5-year overall survival (OS) in the total cohort (dexamethasone, 90.3 ± 0.7%; prednisone, 90.5 ± 0.7%). Retrospective analyses of predefined subgroups revealed a significant survival benefit from dexamethasone only for patients with T-cell ALL and good response to the prednisone prephase (prednisone good-response [PGR]) (dexamethasone, 91.4 ± 2.4%; prednisone, 82.6 ± 3.2%; P = .036). In patients with precursor B-cell ALL and PGR, survival after relapse was found to be significantly worse if patients were previously assigned to the dexamethasone arm. We conclude that, for patients with PGR in the large subgroup of precursor B-cell ALL, dexamethasone especially reduced the incidence of better salvageable relapses, resulting in inferior survival after relapse. This explains the lack of benefit from dexamethasone in overall survival that we observed in the total cohort except in the subset of T-cell ALL patients with PGR. This trial was registered at www.clinicaltrials.gov (BFM: NCT00430118, AIEOP: NCT00613457)

    Driving vascular endothelial cell fate of human multipotent Isl1+ heart progenitors with VEGF modified mRNA

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    Distinct families of multipotent heart progenitors play a central role in the generation of diverse cardiac, smooth muscle and endothelial cell lineages during mammalian cardiogenesis. The identification of precise paracrine signals that drive the cell-fate decision of these multipotent progenitors, and the development of novel approaches to deliver these signals in vivo, are critical steps towards unlocking their regenerative therapeutic potential. Herein, we have identified a family of human cardiac endothelial intermediates located in outflow tract of the early human fetal hearts (OFT-ECs), characterized by coexpression of Isl1 and CD144/vWF. By comparing angiocrine factors expressed by the human OFT-ECs and non-cardiac ECs, vascular endothelial growth factor (VEGF)-A was identified as the most abundantly expressed factor, and clonal assays documented its ability to drive endothelial specification of human embryonic stem cell (ESC)-derived Isl1+ progenitors in a VEGF receptor-dependent manner. Human Isl1-ECs (endothelial cells differentiated from hESC-derived ISL1+ progenitors) resemble OFT-ECs in terms of expression of the cardiac endothelial progenitor- and endocardial cell-specific genes, confirming their organ specificity. To determine whether VEGF-A might serve as an in vivo cell-fate switch for human ESC-derived Isl1-ECs, we established a novel approach using chemically modified mRNA as a platform for transient, yet highly efficient expression of paracrine factors in cardiovascular progenitors. Overexpression of VEGF-A promotes not only the endothelial specification but also engraftment, proliferation and survival (reduced apoptosis) of the human Isl1+ progenitors in vivo. The large-scale derivation of cardiac-specific human Isl1-ECs from human pluripotent stem cells, coupled with the ability to drive endothelial specification, engraftment, and survival following transplantation, suggest a novel strategy for vascular regeneration in the heart

    Histone Deacetylase Inhibition Enhances Self Renewal and Cardioprotection by Human Cord Blood-Derived CD34+ Cells

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    Abstract BACKGROUND: Use of peripheral blood- or bone marrow-derived progenitors for ischemic heart repair is a feasible option to induce neo-vascularization in ischemic tissues. These cells, named Endothelial Progenitors Cells (EPCs), have been extensively characterized phenotypically and functionally. The clinical efficacy of cardiac repair by EPCs cells remains, however, limited, due to cell autonomous defects as a consequence of risk factors. The devise of "enhancement" strategies has been therefore sought to improve repair ability of these cells and increase the clinical benefit. PRINCIPAL FINDINGS: Pharmacologic inhibition of histone deacetylases (HDACs) is known to enhance hematopoietic stem cells engraftment by improvement of self renewal and inhibition of differentiation in the presence of mitogenic stimuli in vitro. In the present study cord blood-derived CD34(+) were pre-conditioned with the HDAC inhibitor Valproic Acid. This treatment affected stem cell growth and gene expression, and improved ischemic myocardium protection in an immunodeficient mouse model of myocardial infarction. CONCLUSIONS: Our results show that HDAC blockade leads to phenotype changes in CD34(+) cells with enhanced self renewal and cardioprotection

    Rho Kinase Inhibition by Fasudil Ameliorates Diabetes-Induced Microvascular Damage

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    OBJECTIVE—Leukocyte adhesion in retinal microvasuculature substantially contributes to diabetic retinopathy. Involvement of the Rho/Rho kinase (ROCK) pathway in diabetic microvasculopathy and therapeutic potential of fasudil, a selective ROCK inhibitor, are investigated
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