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Background: Bleeding is a primary outcome for many transfusion-related trials in acute leukaemia (AL) patients, typically graded using the World Health Organisation (WHO) bleeding scale (clinically significant bleed (CSB) is ≥grade 2). This composite outcome fails to differentiate minor bleeds that may not be significant, poorly represents the total burden of bleeding and lacks input from healthcare providers (HCPs) and patients. As part of a multi-step project to create a better bleeding tool for trials, our objective was to identify HCPs' perspectives on the components of CSB in AL patients., Study Design and Methods: Using qualitative description, we interviewed 19 physicians and nurses who care for AL patients undergoing induction chemotherapy. Participants were recruited from professional organisations, networks and social media. An inductive approach to conventional content analysis was used., Results: HCPs identified features of CSB as the anatomical site of bleeding, amount of bleeding, need for intervention and changes in vital signs. Using these characteristics, bleeding events were categorised into three groups: clinically significant, could evolve into a CSB and not clinically significant. HCPs considered the patient's condition, bleeding history and clinical intuitions when deciding whether a bleed could escalate into serious bleeding., Discussion: Using data from HCPs, we categorised bleeds as clinically significant, could evolve into a CSB, and not significant. A study of patients' perspectives on the importance of different kinds of bleeding is the next step to creating a bleeding definition that is informed by evidence, clinicians and patients., (© 2024 The Author(s). Transfusion Medicine published by John Wiley & Sons Ltd on behalf of British Blood Transfusion Society.)

Aggressive double- and triple-hit (DH/TH) diffuse large B-cell lymphomas (DLBCLs) feature activation of Hsp90 stress pathways. Herein, we show that Hsp90 controls posttranscriptional dynamics of key messenger RNA (mRNA) species including those encoding BCL6, MYC, and BCL2. Using a proteomics approach, we found that Hsp90 binds to and maintains activity of eIF4E. eIF4E drives nuclear export and translation of BCL6, MYC, and BCL2 mRNA. eIF4E RNA-immunoprecipitation sequencing in DLBCL suggests that nuclear eIF4E controls an extended program that includes B-cell receptor signaling, cellular metabolism, and epigenetic regulation. Accordingly, eIF4E was required for survival of DLBCL including the most aggressive subtypes, DH/TH lymphomas. Indeed, eIF4E inhibition induces tumor regression in cell line and patient-derived tumorgrafts of TH-DLBCL, even in the presence of elevated Hsp90 activity. Targeting Hsp90 is typically limited by counterregulatory elevation of Hsp70B, which induces resistance to Hsp90 inhibitors. Surprisingly, we identify Hsp70 mRNA as an eIF4E target. In this way, eIF4E inhibition can overcome drug resistance to Hsp90 inhibitors. Accordingly, rational combinatorial inhibition of eIF4E and Hsp90 inhibitors resulted in cooperative antilymphoma activity in DH/TH DLBCL in vitro and in vivo., (© 2016 by The American Society of Hematology.)

Background Palliative care is not yet integrated into the health-care system in Saudi Arabia. King Faisal Specialist Hospital and Research Centre-Riyadh (KFSH&RC-Riyadh) is a tertiary care facility and regional cancer centre in Saudia Arabia with a highly multinational nursing workforce. Little is known about these nurses' knowledge of and attitudes towards palliative care. Aim To determine the palliative care knowledge and attitudes of the nursing workforce of KFSH&RC-Riyadh and any influencing factors. Method A questionnaire including demographic data, the Palliative Care Quiz for Nurses (PCQN), and Frommelt Attitude Toward Care of the Dying scale (FATCOD) was completed by 395 staff nurses from 19 countries. Results The nurses scored a mean of 111.66 out of 150 on the FATCOD scale and of 9.06 out of 20 on the PCQN. These scores indicate moderate attitudes towards but a knowledge deficit regarding palliative care. The nurses' palliative care training and years of nursing experience significantly affected the scores. The level of palliative care integration in the nurses' home countries was the most significant factor in multiple regression tests. Conclusion Palliative care integration into the health-care system of the country in which nurses train significantly influences their knowledge of and attitudes towards palliative care. Incorporating palliative care into nursing education might promote positive attitudes towards palliative care in nurses while enhancing their knowledge and skills.

The eukaryotic translation initiation factor eIF4E is highly elevated in human cancers including acute myeloid leukemia (AML). A potential anticancer agent, ribavirin, targets eIF4E activity in AML patients corresponding to clinical responses. To date, ribavirin is the only direct inhibitor of eIF4E to reach clinical trials. We showed that ribavirin acts as a competitive inhibitor of the methyl 7-guanosine (m(7)G) cap, the natural ligand of eIF4E. Here we examine the conformational changes occurring in human eIF4E upon binding the active metabolite of ribavirin, ribavirin triphosphate (RTP). Our NMR data revealed an unexpected concentration dependence on RTP affinity for eIF4E. We observed NMR spectra characteristic of tight binding at low micromolar concentrations (2-5 μM eIF4E) but much weaker affinity at more typical NMR concentrations (50- ). Comparison of chemical shift perturbation and line broadening suggest that the two eIF4E-RTP complexes differ in the precise positioning of RTP within the cap binding pocket, with the high affinity complex showing more extensive changes to the central β-sheet and dorsal surface of eIF4E, similar to m(7)G cap. The differences between high and low affinity complexes arise due to concentration dependent aggregation of eIF4E and RTP. Given the intracellular concentrations of eIF4E and RTP and the differential binding toward the W56A eIF4E mutant the high affinity complex is the most physiologically relevant. In summary, these findings demonstrate that RTP binds in the cap-binding site but also suggests new features of this pocket that should be considered in drug design efforts and reveal new insights into ligand eIF4E recognition., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Cancer drug resistance continues to be a major impediment in medical oncology. Clinically, resistance can arise prior to or as a result of cancer therapy. In this review, we discuss different mechanisms adapted by cancerous cells to resist treatment, including alteration in drug transport and metabolism, mutation and amplification of drug targets, as well as genetic rewiring which can lead to impaired apoptosis. Tumor heterogeneity may also contribute to resistance, where small subpopulations of cells may acquire or stochastically already possess some of the features enabling them to emerge under selective drug pressure. Making the problem even more challenging, some of these resistance pathways lead to multidrug resistance, generating an even more difficult clinical problem to overcome. We provide examples of these mechanisms and some insights into how understanding these processes can influence the next generation of cancer therapies.

Mechanotransduction refers to the transformation of physical forces into chemical signals. It generally involves stretch-sensitive channels or conformational change of cytoskeleton-associated proteins. Mechanotransduction is crucial for the physiology of several organs and for cell migration. The extent to which mechanical inputs contribute to development, and how they do this, remains poorly defined. Here we show that a mechanotransduction pathway operates between the body-wall muscles of Caenorhabditis elegans and the epidermis. This pathway involves, in addition to a Rac GTPase, three signalling proteins found at the hemidesmosome: p21-activated kinase (PAK-1), the adaptor GIT-1 and its partner PIX-1. The phosphorylation of intermediate filaments is one output of this pathway. Tension exerted by adjacent muscles or externally exerted mechanical pressure maintains GIT-1 at hemidesmosomes and stimulates PAK-1 activity through PIX-1 and Rac. This pathway promotes the maturation of a hemidesmosome into a junction that can resist mechanical stress and contributes to coordinating the morphogenesis of epidermal and muscle tissues. Our findings suggest that the C. elegans hemidesmosome is not only an attachment structure, but also a mechanosensor that responds to tension by triggering signalling processes. We suggest that similar pathways could promote epithelial morphogenesis or wound healing in other organisms in which epithelial cells adhere to tension-generating contractile cells.

Caenorhabditis elegans embryonic elongation depends on both epidermal and muscle cells. The hemidesmosome-like junctions, commonly called fibrous organelles (FOs), that attach the epidermis to the extracellular matrix ensure muscle anchoring to the cuticular exoskeleton and play an essential role during elongation. To further define how hemidesmosomes might control elongation, we searched for factors interacting with the core hemidesmosome component, the spectraplakin homolog VAB-10. Using the VAB-10 plakin domain as bait in a yeast two-hybrid screen, we identified the novel protein T17H7.4. We also identified T17H7.4 in an independent bioinformatic search for essential nematode-specific proteins that could define novel anti-nematode drug or vaccine targets. Interestingly, T17H7.4 corresponds to the C. elegans equivalent of the parasitic OvB20 antigen, and has a characteristic hemidesmosome distribution. We identified two mutations in T17H7.4, one of which defines the uncharacterized gene pat-12, previously identified in screens for genes required for muscle assembly. Using isoform-specific GFP constructs, we showed that one pat-12 isoform with a hemidesmosome distribution can rescue a pat-12 null allele. We further found that lack of pat-12 affects hemidesmosome integrity, with marked defects at the apical membrane. PAT-12 defines a novel component of C. elegans hemidesmosomes, which is required for maintaining their integrity. We suggest that PAT-12 helps maintaining VAB-10 attachment with matrix receptors., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Hemidesmosomes connect the extracellular matrix (ECM) to intermediate filaments through ECM receptors and plakins (plectin and BPAG1e). They affect tissue integrity, wound healing, and carcinoma invasion. Although biochemical and time-lapse studies indicate that alpha6beta4-integrin (ECM receptor) and plectin play a central role in modulating hemidesmosome disassembly, the mechanisms controlling hemidesmosome biogenesis in vivo remain poorly understood. The nematode C. elegans provides a powerful genetic model to address this issue. We performed a genome-wide RNA interference screen in C. elegans, searching for genes that decrease the viability of a weak VAB-10A/plakin mutant. We identified 14 genes that have human homologs with predicted roles in different cellular processes. We further characterized two genes encoding the chaperone CRT-1/calreticulin and the HECT domain E3 ubiquitin ligase EEL-1/HUWE1. CRT-1 controls by as little as 2-fold the abundance of UNC-52/perlecan, an essential hemidesmosome ECM ligand. Likewise, EEL-1 fine tunes by 2-fold the abundance of myotactin, the putative hemidesmosome ECM receptor. CRT-1 and EEL-1 activities, and by extension other genes identified in our screen, are essential during embryonic development to enable hemidesmosomes exposed to mechanical tension to mature into a tension-resistant form. Our findings should help understand how hemidesmosome dynamics are regulated in vertebrate systems., (Copyright 2010 Elsevier Ltd. All rights reserved.)

Myosin II plays a central role in epithelial morphogenesis; however, its role has mainly been examined in processes involving a single cell type. Here we analyze the structure, spatial requirement and regulation of myosin II during C. elegans embryonic elongation, a process that involves distinct epidermal cells and muscles. We developed novel GFP probes to visualize the dynamics of actomyosin remodeling, and found that the assembly of myosin II filaments, but not actin microfilaments, depends on the myosin regulatory light chain (MLC-4) and essential light chain (MLC-5, which we identified herein). To determine how myosin II regulates embryonic elongation, we rescued mlc-4 mutants with various constructs and found that MLC-4 is essential in a subset of epidermal cells. We show that phosphorylation of two evolutionary conserved MLC-4 serine and threonine residues is important for myosin II activity and organization. Finally, in an RNAi screen for potential myosin regulatory light chain kinases, we found that the ROCK, PAK and MRCK homologs act redundantly. The combined loss of ROCK and PAK, or ROCK and MRCK, completely prevented embryonic elongation, but a constitutively active form of MLC-4 could only rescue a lack of MRCK. This result, together with systematic genetic epistasis tests with a myosin phosphatase mutation, suggests that ROCK and MRCK regulate MLC-4 and the myosin phosphatase. Moreover, we suggest that ROCK and PAK regulate at least one other target essential for elongation, in addition to MLC-4.

Oculocutaneous albinism type 1 (OCA1) results from mutations in the tyrosinase gene, which lead to partial or complete loss of activity of the corresponding enzyme. A large number of mutations have been identified worldwide, providing insight into the pathogenesis of the disorder. We performed ophthalmic and dermatological exams on 30 Lebanese subjects with oculocutaneous albinism, then screened for mutations in the tyrosinase gene in an effort to establish the molecular basis of the disorder in our population and correlate it with phenotypic findings. The five exons of the gene together with the exon-intron boundaries and part of the promoter region were sequenced. Mutations were found in a total of 14 patients (47%) while no mutation was identified in the sequenced regions in 53% of patients. Fourteen different mutations were identified of which eight were novel while six had been previously reported. Mutations were mainly seen in patients with clinical findings, suggestive of OCA1A (64% of patients with OCA1A versus 25% of patients with OCA1B); therefore, the absence of mutations in some of the other patients may indicate the involvement of other genes.

Myotubularin is a ubiquitously expressed phosphatase that acts on phosphatidylinositol 3-monophosphate [PI(3)P], a lipid implicated in intracellular vesicle trafficking and autophagy. It is encoded by the MTM1 gene, which is mutated in X-linked myotubular myopathy (XLMTM), a muscular disorder characterized by generalized hypotonia and muscle weakness at birth leading to early death of most affected males. The disease was proposed to result from an arrest in myogenesis, as the skeletal muscle from patients contains hypotrophic fibers with centrally located nuclei that resemble fetal myotubes. To understand the physiopathological mechanism of XLMTM, we have generated mice lacking myotubularin by homologous recombination. These mice are viable, but their lifespan is severely reduced. They develop a generalized and progressive myopathy starting at around 4 weeks of age, with amyotrophy and accumulation of central nuclei in skeletal muscle fibers leading to death at 6-14 weeks. Contrary to expectations, we show that muscle differentiation in knockout mice occurs normally. We provide evidence that fibers with centralized myonuclei originate mainly from a structural maintenance defect affecting myotubularin-deficient muscle rather than a regenerative process. In addition, we demonstrate, through a conditional gene-targeting approach, that skeletal muscle is the primary target of murine XLMTM pathology. These mutant mice represent animal models for the human disease and will be a valuable tool for understanding the physiological role of myotubularin.