232 research outputs found
In vivo confinement promotes collective migration of neural crest cells
Collective cell migration is fundamental throughout development and in many diseases. Spatial confinement using micropatterns has been shown to promote collective cell migration in vitro, but its effect in vivo remains unclear. Combining computational and experimental approaches, we show that the in vivo collective migration of neural crest cells (NCCs) depends on such confinement. We demonstrate that confinement may be imposed by the spatiotemporal distribution of a nonpermissive substrate provided by versican, an extracellular matrix molecule previously proposed to have contrasting roles: barrier or promoter of NCC migration. We resolve the controversy by demonstrating that versican works as an inhibitor of NCC migration and also acts as a guiding cue by forming exclusionary boundaries. Our model predicts an optimal number of cells in a given confinement width to allow for directional migration. This optimum coincides with the width of neural crest migratory streams analyzed across different species, proposing an explanation for the highly conserved nature of NCC streams during development
Visceral Leishmaniasis: Epidemiology, Diagnosis, and Treatment Regimens in Different Geographical Areas with a Focus on Pediatrics
Visceral Leishmaniasis (VL) is a vector-borne disease caused by an intracellular protozoa of the genus Leishmania that can be lethal if not treated. VL is caused by Leishmania donovani in Asia and in Eastern Africa, where the pathogens’ reservoir is represented by humans, and by Leishmania infantum in Latin America and in the Mediterranean area, where VL is a zoonotic disease and dog is the main reservoir. A part of the infected individuals become symptomatic, with irregular fever, splenomegaly, anemia or pancytopenia, and weakness, whereas others are asymptomatic. VL treatment has made progress in the last decades with the use of new drugs such as liposomal amphotericin B, and with new therapeutic regimens including monotherapy or a combination of drugs, aiming at shorter treatment duration and avoiding the development of resistance. However, the same treatment protocol may not be effective all over the world, due to differences in the infecting Leishmania species, so depending on the geographical area. This narrative review presents a comprehensive description of the clinical picture of VL, especially in children, the diagnostic approach, and some insight into the most used pharmacological therapies available worldwide
Mutations in TIMM50 compromise cell survival in OxPhos-dependent metabolic conditions
TIMM50 is an essential component of the TIM23 complex, the mitochondrial inner membrane machinery that imports cytosolic proteins containing a mitochondrial targeting presequence into the mitochondrial inner compartment. Whole exome sequencing (WES) identified compound heterozygous pathogenic mutations in TIMM50 in an infant patient with rapidly progressive, severe encephalopathy. Patient fibroblasts presented low levels of TIMM50 and other components of the TIM23 complex, lower mitochondrial membrane potential, and impaired TIM23-dependent protein import. As a consequence, steady-state levels of several components of mitochondrial respiratory chain were decreased, resulting in decreased respiration and increased ROS production. Growth of patient fibroblasts in galactose shifted energy production metabolism toward oxidative phosphorylation (OxPhos), producing an apparent improvement in most of the above features but also increased apoptosis. Complementation of patient fibroblasts with TIMM50 improved or restored these features to control levels. Moreover, RNASEH1 and ISCU mutant fibroblasts only shared a few of these features with TIMM50 mutant fibroblasts. Our results indicate that mutations in TIMM50 cause multiple mitochondrial bioenergetic dysfunction and that functional TIMM50 is essential for cell survival in OxPhos-dependent conditions
Synergistic cytotoxic effects of bortezomib and CK2 inhibitor CX-4945 in acute lymphoblastic leukemia: turning offthe prosurvival ER chaperone BIP/Grp78 and turning on the proapoptotic NF-ÎşB
The proteasome inhibitor bortezomib is a new targeted treatment option for refractory or relapsed acute lymphoblastic leukemia (ALL) patients. However, a limited efficacy of bortezomib alone has been reported. A terminal pro-apoptotic endoplasmic reticulum (ER) stress/unfolded protein response (UPR) is one of the several mechanisms of bortezomib-induced apoptosis. Recently, it has been documented that UPR disruption could be considered a selective anti-leukemia therapy. CX- 4945, a potent casein kinase (CK) 2 inhibitor, has been found to induce apoptotic cell death in T-ALL preclinical models, via perturbation of ER/UPR pathway. In this study, we analyzed in T- and B-ALL preclinical settings, the molecular mechanisms of synergistic apoptotic effects observed after bortezomib/CX-4945 combined treatment. We demonstrated that, adding CX-4945 after bortezomib treatment, prevented leukemic cells from engaging a functional UPR in order to buffer the bortezomibmediated proteotoxic stress in ER lumen. We documented that the combined treatment decreased pro-survival ER chaperon BIP/Grp78 expression, via reduction of chaperoning activity of Hsp90. Bortezomib/CX-4945 treatment inhibited NF-ÎşB signaling in T-ALL cell lines and primary cells from T-ALL patients, but, intriguingly, in B-ALL cells the drug combination activated NF-ÎşB p65 pro-apoptotic functions. In fact in B-cells, the combined treatment induced p65-HDAC1 association with consequent repression of the anti-apoptotic target genes, Bcl-xL and XIAP. Exposure to NEMO (IKKÎł)-binding domain inhibitor peptide reduced the cytotoxic effects of bortezomib/CX-4945 treatment. Overall, our findings demonstrated that CK2 inhibition could be useful in combination with bortezomib as a novel therapeutic strategy in both T- and B-ALL
Synergistic cytotoxic effects of bortezomib and CK2 inhibitor CX-4945 in acute lymphoblastic leukemia: turning off the prosurvival ER chaperone BIP/Grp78 and turning on the proapoptotic NF-κB
Multicenter randomized, double-blind controlled trial to evaluate the efficacy of laser therapy for the treatment of severe oral mucositis induced by chemotherapy in children: laMPO RCT
Objectives: To demonstrate the efficacy of laser photobiomodulation (PBM) compared to that of placebo on severe oral mucositis (OM) in pediatric oncology patients. The primary objective was the reduction of OM grade (World Health Organization [WHO] scale) 7 days after starting PBM. Secondary objectives were reduction of pain, analgesic consumption, and incidence of side effects. Methods: One hundred and one children with WHO grade\ua0>\ua02 chemotherapy-induced OM were enrolled in eight Italian hospitals. Patients were randomized to either PBM or sham treatment for four consecutive days (days +1 to +4). On days +4, +7, and +11, OM grade, pain (following a 0\u201310 numeric pain rating scale, NRS) and need for analgesics were evaluated by an operator blinded to treatment. Results: Fifty-one patients were allocated to the PBM group, and 50 were allocated to the sham group. In total, 93.7% of PBM patients and 72% of sham patients had OM grade\ua0<\ua03 WHO on day +7 (P\ua0=\ua00.01). A significant reduction of pain was registered on day +7 in the PBM versus sham group (NRS 1 [0\u20133] vs. 2.5 [1\u20135], P\ua0<\ua00.006). Reduced use of analgesics was reported in the PBM group, although it was not statistically significant. No significant adverse events attributable to treatment were recorded. Conclusions: PBM is a safe, feasible, and effective treatment for children affected by chemotherapy-induced OM, as it accelerates mucosal recovery and reduces pain
Toxicity and Clinical Results after Proton Therapy for Pediatric Medulloblastoma: A Multi-Centric Retrospective Study
Medulloblastoma is the most common malignant brain tumor in children. Even if current treatment dramatically improves the prognosis, survivors often develop long-term treatment-related sequelae. The current radiotherapy standard for medulloblastoma is craniospinal irradiation with a boost to the primary tumor site and to any metastatic sites. Proton therapy (PT) has similar efficacy compared to traditional photon-based radiotherapy but might achieve lower toxicity rates. We report on our multi-centric experience with 43 children with medulloblastoma (median age at diagnosis 8.7 years, IQR 6.6, M/F 23/20; 26 high-risk, 14 standard-risk, 3 ex-infant), who received active scanning PT between 2015 and 2021, with a focus on PT-related acute-subacute toxicity, as well as some preliminary data on late toxicity. Most acute toxicities were mild and manageable with supportive therapy. Hematological toxicity was limited, even among HR patients who underwent hematopoietic stem-cell transplantation before PT. Preliminary data on late sequelae were also encouraging, although a longer follow-up is needed
Ongoing outbreak of visceral leishmaniasis in Bologna Province, Italy, November 2012 to May 2013
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Therapeutic targeting of Polo-like kinase-1 and Aurora kinases in T-cell acute lymphoblastic leukemia
AMP-dependent kinase/mammalian target of rapamycin complex 1 signaling in T-cell acute lymphoblastic leukemia: therapeutic implications.
The mammalian target of rapamycin (mTOR) serine/threonine
kinase is the catalytic subunit of two multi-protein complexes,
referred to as mTORC1 and mTORC2. Signaling downstream
of mTORC1 has a critical role in leukemic cell biology by
controlling mRNA translation of genes involved in both cell
survival and proliferation. mTORC1 activity can be downmodulated
by upregulating the liver kinase B1/AMP-activated
protein kinase (LKB1/AMPK) pathway. Here, we have explored
the therapeutic potential of the anti-diabetic drug, metformin
(an LKB1/AMPK activator), against both T-cell acute lymphoblastic
leukemia (T-ALL) cell lines and primary samples
from T-ALL patients displaying mTORC1 activation. Metformin
affected T-ALL cell viability by inducing autophagy and
apoptosis. However, it was much less toxic against proliferating
CD4Ăľ T-lymphocytes from healthy donors. Western blot
analysis demonstrated dephosphorylation of mTORC1 downstream
targets. Unlike rapamycin, we found a marked inhibition
of mRNA translation in T-ALL cells treated with metformin.
Remarkably, metformin targeted the side population of T-ALL
cell lines as well as a putative leukemia-initiating cell subpopulation
(CD34Ăľ/CD7/CD4) in patient samples. In conclusion,
metformin displayed a remarkable anti-leukemic activity,
which emphasizes future development of LKB1/AMPK activators
as clinical candidates for therapy in T-ALL.
Leukemia (2012) 26, 91–100; doi:10.1038/leu.2011.269;
published online 4 October 201
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