Childhood acute lymphoblastic leukemia in the Middle East and neighboring countries: A prospective multi-institutional international collaborative study (CALLME1) by the Middle East Childhood Cancer Alliance (MECCA)

Background: Little is known about childhood ALL in the Middle East. This study was undertaken by MECCA as initial efforts in collaborative data collection to provide clinical and demographic information on children with ALL in the Middle East. Procedure: Clinical and laboratory data for patients with ALL between January 2008 and April 2012 were prospectively collected from institutions in 14 Middle East countries and entered into a custom-built-database during induction phase. All laboratory studies including cytogenetics were done at local institutions. Results: The 1,171 voluntarily enrolled patients had a mean age of 6.1±3.9 years and 59.2 were boys. T-ALL represented 14.8 and 84.2 had B-precursor ALL. At diagnosis, 5.6 had CNS disease. The distribution of common genetic abnormalities reflected a similar percentage of hyperdiploidy (25.6), but a lower percentage of ETV6-RUNX1 translocation (14.7) compared to large series reported from Western populations. By clinical criteria, 47.1 were low/standard risk, 16.9 were intermediate risk, and 36 were high risk. Most patients received all their care at the same unit (96.9). Patients had excellent induction response to chemotherapy with an overall complete remission rate of 96. Induction toxicities were acceptable. Conclusions: This first collaborative study has established a process for prospective data collection and future multinational collaborative research in the Middle East. Despite the limitations of an incomplete population-based study, it provides the first comprehensive baseline data on clinical characteristics, laboratory evaluation, induction outcome, and toxicity. Further work is planned to uncover possible biologic differences of ALL in the region and to improve diagnosis and management. Pediatr Blood Cancer 2014; 61:1403-1410. © 2014 Wiley Periodicals, Inc

Phenotypic screening reveals TNFR2 as a promising target for cancer immunotherapy.

Antibodies that target cell-surface molecules on T cells can enhance anti-tumor immune responses, resulting in sustained immune-mediated control of cancer. We set out to find new cancer immunotherapy targets by phenotypic screening on human regulatory T (Treg) cells and report the discovery of novel activators of tumor necrosis factor receptor 2 (TNFR2) and a potential role for this target in immunotherapy. A diverse phage display library was screened to find antibody mimetics with preferential binding to Treg cells, the most Treg-selective of which were all, without exception, found to bind specifically to TNFR2. A subset of these TNFR2 binders were found to agonise the receptor, inducing iκ-B degradation and NF-κB pathway signalling in vitro. TNFR2 was found to be expressed by tumor-infiltrating Treg cells, and to a lesser extent Teff cells, from three lung cancer patients, and a similar pattern was also observed in mice implanted with CT26 syngeneic tumors. In such animals, TNFR2-specific agonists inhibited tumor growth, enhanced tumor infiltration by CD8+ T cells and increased CD8+ T cell IFN-γ synthesis. Together, these data indicate a novel mechanism for TNF-α-independent TNFR2 agonism in cancer immunotherapy, and demonstrate the utility of target-agnostic screening in highlighting important targets during drug discovery.GW, BM, SG, JC-U, AS, AG-M, CB, JJ, RL, AJL, SR, RS, LJ, VV-A, RM and RWW were funded by MedImmune; JP and VB were funded by AstraZeneca PLC; JW, RSA-L and JB were funded by NIHR Cambridge Biomedical Research Centre and Kidney Research UK; JS and JF were funded by Retrogenix Ltd

Plasmodium falciparum Adhesion on Human Brain Microvascular Endothelial Cells Involves Transmigration-Like Cup Formation and Induces Opening of Intercellular Junctions

Cerebral malaria, a major cause of death during malaria infection, is characterised by the sequestration of infected red blood cells (IRBC) in brain microvessels. Most of the molecules implicated in the adhesion of IRBC on endothelial cells (EC) are already described; however, the structure of the IRBC/EC junction and the impact of this adhesion on the EC are poorly understood. We analysed this interaction using human brain microvascular EC monolayers co-cultured with IRBC. Our study demonstrates the transfer of material from the IRBC to the brain EC plasma membrane in a trogocytosis-like process, followed by a TNF-enhanced IRBC engulfing process. Upon IRBC/EC binding, parasite antigens are transferred to early endosomes in the EC, in a cytoskeleton-dependent process. This is associated with the opening of the intercellular junctions. The transfer of IRBC antigens can thus transform EC into a target for the immune response and contribute to the profound EC alterations, including peri-vascular oedema, associated with cerebral malaria

DR3 Signaling Protects against Cisplatin Nephrotoxicity Mediated by Tumor Necrosis Factor

The expression of death receptor 3 (DR3), a member of the tumor necrosis factor (TNF) receptor superfamily, is up-regulated in human tubular epithelial cells (TECs) during renal injury, but its function in this setting remains unknown. We used cisplatin to induce renal injury in wild-type (DR3(+/+)) or congenitally deficient DR3(-/-) mice to examine the in vivo role of DR3. Cisplatin induced the expression of DR3, its ligand, TNF-like ligand 1A (TL1A), and TNF in TECs, as observed in human renal injury. Cisplatin increased apoptotic death of DR3(-/-) TECs by twofold compared with DR3(+/+) TECs, whereas it reduced the number of tubules expressing phospho-NF-κBp65(Ser276) by 50% at 72 hours. Similar degrees of induction of DR3, TL1A, and TNF, and changes in apoptosis and phospho-NF-κBp65(Ser276), were obtained in mouse kidney organ cultures treated with cisplatin for 3 hours, suggesting a direct effect on TECs. TNF was implicated in mediating cisplatin-induced tubular damage given that the in vivo co-administration of GM6001, an inhibitor of TNF maturation and release, significantly reduced TNF production and tubular damage. Moreover, TNF exacerbated, whereas TL1A reduced, cisplatin-induced apoptosis in the DR3(+/+) mouse proximal tubule cell line, TKPTS. Our data demonstrate that cisplatin-induced nephrotoxicity is mitigated by DR3 signaling, suggesting that this occurs by antagonizing pro-apoptotic signals induced by TNF. Therefore, activating DR3 may be beneficial in reducing acute kidney injury

Hyponatraemia in a Lao paediatric intensive care unit: Prevalence, associations and intravenous fluid use

AIM: Hyponatraemia is a common and potentially deadly complication affecting hospitalised children world-wide. Hypotonic intravenous fluids can be a significant exacerbating factor. Exclusive use of isotonic fluids, coupled with rigorous blood monitoring, has proven effective in reducing hyponatraemia in developed settings. In developing countries, where hyponatraemia is often more common and severe, different factors may contribute to its incidence and detection. We aimed to determine the prevalence and disease associations of hyponatraemia and describe the intravenous maintenance fluid prescribing practices in a Lao paediatric intensive care unit. METHODS: We conducted a cross-sectional study of 164 children aged 1 month to 15 years admitted to intensive care at a tertiary centre in Lao People's Democratic Republic (PDR) and recorded their serum sodium and clinical data at admission and on two subsequent days. RESULTS: Hyponatraemia was detected in 41% (67/164, confidence interval 34-48%) of children, the majority of which was mild (34%, 56/164) and present at admission (35%, 55/158). Hyponatraemia was more common in malnourished children (odds ratio (OR) 2.3, P = 0.012) and females (OR 1.9, P = 0.045). Hyponatraemia correlated with death or expected death after discharge (OR 2.2, P = 0.015); 88% received maintenance intravenous fluids, with 67% of those receiving a hypotonic solution. Electrolyte testing was only performed in 20% (9/46) of patients outside the study protocol. CONCLUSIONS: Hyponatraemia is highly prevalent in critically ill children in Lao PDR, as is the continued use of hypotonic intravenous fluids. With financial and practical barriers to safely detecting and monitoring electrolyte disorders in this setting, this local audit can help promote testing and has already encouraged changes to fluid prescribing

DR3 signaling protects against cisplatin nephrotoxicity mediated by tumor necrosis factor

The expression of death receptor 3 (DR3), a member of the tumor necrosis factor (TNF) receptor superfamily, is up-regulated in human tubular epithelial cells (TECs) during renal injury, but its function in this setting remains unknown. We used cisplatin to induce renal injury in wild-type (DR3(+/+)) or congenitally deficient DR3(-/-) mice to examine the in vivo role of DR3. Cisplatin induced the expression of DR3, its ligand, TNF-like ligand 1A (TL1A), and TNF in TECs, as observed in human renal injury. Cisplatin increased apoptotic death of DR3(-/-) TECs by twofold compared with DR3(+/+) TECs, whereas it reduced the number of tubules expressing phospho-NF-κBp65(Ser276) by 50% at 72 hours. Similar degrees of induction of DR3, TL1A, and TNF, and changes in apoptosis and phospho-NF-κBp65(Ser276), were obtained in mouse kidney organ cultures treated with cisplatin for 3 hours, suggesting a direct effect on TECs. TNF was implicated in mediating cisplatin-induced tubular damage given that the in vivo co-administration of GM6001, an inhibitor of TNF maturation and release, significantly reduced TNF production and tubular damage. Moreover, TNF exacerbated, whereas TL1A reduced, cisplatin-induced apoptosis in the DR3(+/+) mouse proximal tubule cell line, TKPTS. Our data demonstrate that cisplatin-induced nephrotoxicity is mitigated by DR3 signaling, suggesting that this occurs by antagonizing pro-apoptotic signals induced by TNF. Therefore, activating DR3 may be beneficial in reducing acute kidney injury

Smad-dependent and smad-independent induction of id1 by prostacyclin analogues inhibits proliferation of pulmonary artery smooth muscle cells in vitro and in vivo

RATIONALE: Mutations in the bone morphogenetic protein type II receptor (BMPR-II) are responsible for the majority of cases of heritable pulmonary arterial hypertension (PAH). Mutations lead to reduced Smad1/5-driven expression of inhibitor of DNA binding protein 1 (Id1) and loss of the growth suppressive effects of BMPs. The impact of existing PAH therapies on BMP signaling is lacking. OBJECTIVE: Because prostacyclin analogues are effective treatments for clinical PAH, we hypothesized that these agents enhance Smad1/Id1 signaling. METHODS AND RESULTS: Iloprost alone induced Id1 expression in human pulmonary artery smooth muscle cells (PASMCs), an effect that was independent of Smad1/5 activation but dependent on a cAMP-responsive element in the Id1 promoter. In addition, iloprost and treprostinil enhanced BMP-induced phosphorylation of Smad1/5 and Id1 expression in a cAMP-dependent manner. The mechanism involved suppression of inhibitory Smad, Smad6. Furthermore, iloprost rescued the deficit in Smad1/5 phosphorylation and Id gene expression in PASMCs harboring mutations in BMPR-II and restored growth suppression to BMP4 in mutant PASMCs. We confirmed a critical role for Id1 in PASMC proliferation. Reduced expression of Id1 was observed in concentric intimal lesions of heritable PAH cases. In the monocrotaline rat model of PAH, associated with reduced BMPR-II expression, we confirmed that treprostinil inhibited smooth muscle cell proliferation and prevented progression of PAH while enhancing Smad1/5 phosphorylation and Id1 gene expression. CONCLUSIONS: Prostacyclin analogues enhance Id1 expression in vitro and in vivo and restore deficient BMP signaling in BMPR-II mutant PASMCs