High-throughput identification of genotype-specific cancer vulnerabilities in mixtures of barcoded tumor cell lines.

Hundreds of genetically characterized cell lines are available for the discovery of genotype-specific cancer vulnerabilities. However, screening large numbers of compounds against large numbers of cell lines is currently impractical, and such experiments are often difficult to control. Here we report a method called PRISM that allows pooled screening of mixtures of cancer cell lines by labeling each cell line with 24-nucleotide barcodes. PRISM revealed the expected patterns of cell killing seen in conventional (unpooled) assays. In a screen of 102 cell lines across 8,400 compounds, PRISM led to the identification of BRD-7880 as a potent and highly specific inhibitor of aurora kinases B and C. Cell line pools also efficiently formed tumors as xenografts, and PRISM recapitulated the expected pattern of erlotinib sensitivity in vivo

Mesothelial cell differentiation into osteoblast- and adipocyte-like cells

Serosal pathologies including malignant mesothelioma (MM) can show features of osseous and/or cartilaginous differentiation although the mechanism for its formation is unknown. Mesothelial cells have the capacity to differentiate into cells with myofibroblast, smooth muscle and endothelial cell characteristics. Whether they can differentiate into other cell types is unclear. This study tests the hypothesis that mesothelial cells can differentiate into cell lineages of the embryonic mesoderm including osteoblasts and adipocytes. To examine this, a functional assay of bone formation and an adipogenic assay were performed in vitro with primary rat and human mesothelial cells maintained in osteogenic or adipogenic medium (AM) for 0–26 days. Mesothelial cells expressed increasing levels of alkaline phosphatase, an early marker of the osteoblast phenotype, and formed mineralized bone-like nodules. Mesothelial cells also accumulated lipid indicative of a mature adipocyte phenotype when cultured in AM. All cells expressed several key osteoblast and adipocyte markers, including osteoblast-specific runt-related transcription factor 2, and demonstrated changes in mRNA expression consistent with epithelial-to-mesenchymal transition. In conclusion, these studies confirm that mesothelial cells have the capacity to differentiate into osteoblast- and adipocyte-like cells, providing definitive evidence of their multipotential nature. These data strongly support mesothelial cell differentiation as the potential source of different tissue types in MM tumours and other serosal pathologies, and add support for the use of mesothelial cells in regenerative therapies

Parent and child agreement for acute stress disorder, post-traumatic stress disorder and other psychopathology in a prospective study of children and adolescents exposed to single-event trauma

Examining parent-child agreement for Acute Stress Disorder (ASD) and Post-Traumatic Stress Disorder (PTSD) in children and adolescents is essential for informing the assessment of trauma-exposed children, yet no studies have examined this relationship using appropriate statistical techniques. Parent-child agreement for these disorders was examined by structured interview in a prospective study of assault and motor vehicle accident (MVA) child survivors, assessed at 2-4 weeks and 6 months post-trauma. Children were significantly more likely to meet criteria for ASD, as well as other ASD and PTSD symptom clusters, based on their own report than on their parent's report. Parent-child agreement for ASD was poor (Cohen's κ = -.04), but fair for PTSD (Cohen's κ = .21). Agreement ranged widely for other emotional disorders (Cohen's κ = -.07-.64), with generalised anxiety disorder found to have superior parent-child agreement (when assessed by phi coefficients) relative to ASD and PTSD. The findings support the need to directly interview children and adolescents, particularly for the early screening of posttraumatic stress, and suggest that other anxiety disorders may have a clearer presentation post-trauma

DSP107 combines inhibition of CD47/SIRPα axis with activation of 4-1BB to trigger anticancer immunity

BACKGROUND: Treatment of Diffuse Large B Cell Lymphoma (DLBCL) patients with rituximab and the CHOP treatment regimen is associated with frequent intrinsic and acquired resistance. However, treatment with a CD47 monoclonal antibody in combination with rituximab yielded high objective response rates in patients with relapsed/refractory DLBCL in a phase I trial. Here, we report on a new bispecific and fully human fusion protein comprising the extracellular domains of SIRPα and 4-1BBL, termed DSP107, for the treatment of DLBCL. DSP107 blocks the CD47:SIRPα ‘don’t eat me’ signaling axis on phagocytes and promotes innate anticancer immunity. At the same time, CD47-specific binding of DSP107 enables activation of the costimulatory receptor 4-1BB on activated T cells, thereby, augmenting anticancer T cell immunity. METHODS: Using macrophages, polymorphonuclear neutrophils (PMNs), and T cells of healthy donors and DLBCL patients, DSP107-mediated reactivation of immune cells against B cell lymphoma cell lines and primary patient-derived blasts was studied with phagocytosis assays, T cell activation and cytotoxicity assays. DSP107 anticancer activity was further evaluated in a DLBCL xenograft mouse model and safety was evaluated in cynomolgus monkey. RESULTS: Treatment with DSP107 alone or in combination with rituximab significantly increased macrophage- and PMN-mediated phagocytosis and trogocytosis, respectively, of DLBCL cell lines and primary patient-derived blasts. Further, prolonged treatment of in vitro macrophage/cancer cell co-cultures with DSP107 and rituximab decreased cancer cell number by up to 85%. DSP107 treatment activated 4-1BB-mediated costimulatory signaling by HT1080.4-1BB reporter cells, which was strictly dependent on the SIRPα-mediated binding of DSP107 to CD47. In mixed cultures with CD47-expressing cancer cells, DSP107 augmented T cell cytotoxicity in vitro in an effector-to-target ratio-dependent manner. In mice with established SUDHL6 xenografts, the treatment with human PBMCs and DSP107 strongly reduced tumor size compared to treatment with PBMCs alone and increased the number of tumor-infiltrated T cells. Finally, DSP107 had an excellent safety profile in cynomolgus monkeys. CONCLUSIONS: DSP107 effectively (re)activated innate and adaptive anticancer immune responses and may be of therapeutic use alone and in combination with rituximab for the treatment of DLBCL patients. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13046-022-02256-x

Functional molecules in mesothelial to mesenchymal transition revealed by transcriptome analyses

Peritoneal fibrosis is a common complication of abdominal and pelvic surgery, and can also be triggered by peritoneal dialysis, resulting in treatment failure. In these settings, fibrosis is driven by activated myofibroblasts that are considered to be partly derived by mesothelial‐to‐mesenchymal transition (MMT). We hypothesized that, if the molecular signature of MMT could be better defined, these insights could be exploited to block this pathological cellular transition. Rat peritoneal mesothelial cells were purified by the use of an antibody against HBME1, a protein present on mesothelial cell microvilli, and streptavidin nanobead technology. After exposure of sorted cells to a well‐known mediator of MMT, transforming growth factor (TGF)‐β1, RNA sequencing was undertaken to define the transcriptomes of mesothelial cells before and during early‐phase MMT. MMT was associated with dysregulation of transcripts encoding molecules involved in insulin‐like growth factor (IGF) and bone morphogenetic protein (BMP) signalling. The application of either recombinant BMP4 or IGF‐binding protein 4 (IGFBP4) ameliorated TGF‐β1‐induced MMT in culture, as judged from the retention of epithelial morphological and molecular phenotypes, and reduced migration. Furthermore, peritoneal tissue from peritoneal dialysis patients showed less prominent immunostaining than control tissue for IGFBP4 and BMP4 on the peritoneal surface. In a mouse model of TGF‐β1‐induced peritoneal thickening, BMP4 immunostaining on the peritoneal surface was attenuated as compared with healthy controls. Finally, genetic lineage tracing of mesothelial cells was used in mice with peritoneal injury. In this model, administration of BMP4 ameliorated the injury‐induced shape change and migration of mesothelial cells. Our findings demonstrate a distinctive MMT signature, and highlight the therapeutic potential for BMP4, and possibly IGFBP4, to reduce MMT

Diversity-Oriented Synthesis Yields a Novel Lead for the Treatment of Malaria

Here, we describe the discovery of a novel antimalarial agent using phenotypic screening of Plasmodium falciparum asexual blood-stage parasites. Screening a novel compound collection created using diversity-oriented synthesis (DOS) led to the initial hit. Structure–activity relationships guided the synthesis of compounds having improved potency and water solubility, yielding a subnanomolar inhibitor of parasite asexual blood-stage growth. Optimized compound 27 has an excellent off-target activity profile in erythrocyte lysis and HepG2 assays and is stable in human plasma. This compound is available via the molecular libraries probe production centers network (MLPCN) and is designated ML238.Chemistry and Chemical Biolog

Non-Neoplastic and Neoplastic Pleural Endpoints Following Fiber Exposure

Exposure to asbestos fibers is associated with non-neoplastic pleural diseases including plaques, fibrosis, and benign effusions, as well as with diffuse malignant pleural mesothelioma. Translocation and retention of fibers are fundamental processes in understanding the interactions between the dose and dimensions of fibers retained at this anatomic site and the subsequent pathological reactions. The initial interaction of fibers with target cells in the pleura has been studied in cellular models in vitro and in experimental studies in vivo. The proposed biological mechanisms responsible for non-neoplastic and neoplastic pleural diseases and the physical and chemical properties of asbestos fibers relevant to these mechanisms are critically reviewed. Understanding mechanisms of asbestos fiber toxicity may help us anticipate the problems from future exposures both to asbestos and to novel fibrous materials such as nanotubes. Gaps in our understanding have been outlined as guides for future research

Aleglitazar, a balanced PPARα/γ agonist, has no clinically relevant pharmacokinetic interaction with high-dose atorvastatin or rosuvastatin

Background: Aleglitazar, a dual PPAR-α/γ agonist, combines the lipid benefits of fibrates and the insulin-sensitizing benefits of thiazolidinediones. Objective: To investigate the pharmacokinetic effects of co-administration of atorvastatin or rosuvastatin with aleglitazar. Research design and methods: In a two-cohort, open-label, randomised, three-period crossover study, 44 healthy subjects received once-daily oral doses of aleglitazar 300 μg, statin (atorvastatin 80 mg or rosuvastatin 40 mg) and aleglitazar co-administered with each statin for 7 days. Plasma concentrations of each drug were measured and pharmacokinetic parameters determined on day 7 in each period. Main outcome measures: Peak observed plasma concentration (Cmax) and total exposures (AUC0 24) of aleglitazar, atorvastatin and rosuvastatin. Results: Cmax and AUC0 24 to aleglitazar were similar, whether administered alone or in combination with a statin. Total exposure to either statin was unaffected by co-administration with aleglitazar. Cmax treatment ratios for both statins exceeded the conventional no-effect boundary (1.25) when administered with aleglitazar. Conclusions: Co-administration of aleglitazar with a statin does not alter the pharmacokinetic profile of either drug. © 2011 Informa UK, Ltd

Peritoneal dialysis fluid-induced changes of the peritoneal membrane are reversible after peritoneal rest in rats

BACKGROUND: Peritoneal dialysis (PD) is associated with functional and structural alterations of the peritoneal membrane. However, the (ir)reversibility of these pathological changes of the peritoneum is not understood fully. METHODS: In an experimental PD model, rats (n = 15) received daily 10 ml conventional glucose containing PD fluid, via peritoneal catheters connected to implanted subcutaneous mini vascular access ports. After 5 weeks of treatment, the first group of animals (PDF; n = 10) was sacrificed, while peritoneal catheters of the remaining group of rats (PD-rest; n = 5) were removed 1 week later. The latter group (PD-rest) was sacrificed 12 weeks after removing catheters. At both time points, untreated rats were included as controls. Cellular and morphological parameters were analysed by light and electron microscopy. RESULTS: Rats exposed to PD fluid for 5 weeks showed a severe angiogenesis in various peritoneal tissues. Peritoneal rest resulted in a significant reduction in blood vessel density in visceral (mesentery, P<0.05), but not in parietal peritoneum. Five weeks' exposure to PD fluid resulted in a profound fibrosis in the parietal peritoneum, whereas the degree of fibrosis was significantly reduced in the PD-rest group (P<0.02). Daily exposure to PD fluid induced a higher number of mast cells in the omentum compared with untreated rats, whereas peritoneal rest normalized the increased mast cell density completely (P<0.03). Likewise, continued PD fluid instillation evoked a strong omental milky spot response, which was returned to the control level after peritoneal rest (P<0.009). Furthermore, the number of mesothelial cells on the liver was significantly increased in rats treated with PD fluid, whereas animals from the PD-rest group had a lower number of mesothelial cells, although this was not statistically significant (P = 0.08). Finally, as evidenced by electron microscopy, daily exposure to PD fluid resulted in severe damage to the mesothelial cell layer covering the peritoneum, whereas this cell layer was completely recovered after peritoneal rest. CONCLUSIONS: We show that PD fluid-induced cellular and morphological alterations of the peritoneal membrane are generally reversible

Evidence for incorporation of free-floating mesothelial cells as a mechanism of serosal healing

Regeneration of the mesothelium is unlike that of other epithelial-like surfaces, as healing does not occur solely by centripetal migration of cells from the wound edge. The mechanism of repair of mesothelium is controversial,but it is widely accepted, without compelling evidence, that pluripotent cells beneath the mesothelium migrate to the surface and differentiate into mesothelial cells. In this study we examined an alternative hypothesis, using in vivo cell-tracking studies, that repair involves implantation,proliferation and incorporation of free-floating mesothelial cells into the regenerating mesothelium. Cultured mesothelial cells, fibroblasts and peritoneal lavage cells were DiI- or PKH26-PCL-labelled and injected into rats immediately following mesothelial injury. Implantation of labelled cells was assessed on mesothelial imprints using confocal microscopy, and cell proliferation was determined by proliferating cell nuclear antigen immunolabelling. Incorporation of labelled cells, assessed by the formation of apical junctional complexes, was shown by confocal imaging of zonula occludens-1 protein. Labelled cultured mesothelial and peritoneal lavage cells, but not cultured fibroblasts, implanted onto the wound surface 3, 5 and 8 days after injury. These cells proliferated and incorporated into the regenerated mesothelium, as demonstrated by nuclear proliferating cell nuclear antigen staining and membrane-localised zonula occludens-1 expression,respectively. Furthermore, immunolocalisation of the mesothelial cell marker HBME-1 demonstrated that the incorporated, labelled lavage-derived cells were mesothelial cells and not macrophages as it had previously been suggested. This study has clearly shown that serosal healing involves implantation,proliferation and incorporation of free-floating mesothelial cells into the regenerating mesothelium