Involving service users in trials: developing a standard operating procedure

<p>BACKGROUND: Many funding bodies require researchers to actively involve service users in research to improve relevance, accountability and quality. Current guidance to researchers mainly discusses general principles. Formal guidance about how to involve service users operationally in the conduct of trials is lacking. We aimed to develop a standard operating procedure (SOP) to support researchers to involve service users in trials and rigorous studies.</p> <p>METHODS: Researchers with experience of involving service users and service users who were contributing to trials collaborated with the West Wales Organisation for Rigorous Trials in Health, a registered clinical trials unit, to develop the SOP. Drafts were prepared in a Task and Finish Group, reviewed by all co-authors and amendments made.</p> <p>RESULTS: We articulated core principles, which defined equality of service users with all other research team members and collaborative processes underpinning the SOP, plus guidance on how to achieve these. We developed a framework for involving service users in research that defined minimum levels of collaboration plus additional consultation and decision-making opportunities. We recommended service users be involved throughout the life of a trial, including planning and development, data collection, analysis and dissemination, and listed tasks for collaboration. We listed people responsible for involving service users in studies and promoting an inclusive culture. We advocate actively involving service users as early as possible in the research process, with a minimum of two on all formal trial groups and committees. We propose that researchers protect at least 1% of their total research budget as a minimum resource to involve service users and allow enough time to facilitate active involvement.</p> <p>CONCLUSIONS: This SOP provides guidance to researchers to involve service users successfully in developing and conducting clinical trials and creating a culture of actively involving service users in research at all stages. The UK Clinical Research Collaboration should encourage clinical trials units actively to involve service users and research funders should provide sufficient funds and time for this in research grants.</p&gt

Inhibition of Plasmepsin V activity demonstrates its essential role in protein export, PfEMP1 display, and survival of malaria parasites

The malaria parasite Plasmodium falciparum exports several hundred proteins into the infected erythrocyte that are involved in cellular remodeling and severe virulence. The export mechanism involves the Plasmodium export element (PEXEL), which is a cleavage site for the parasite protease, Plasmepsin V (PMV). The PMV gene is refractory to deletion, suggesting it is essential, but definitive proof is lacking. Here, we generated a PEXEL-mimetic inhibitor that potently blocks the activity of PMV isolated from P. falciparum and Plasmodium vivax. Assessment of PMV activity in P. falciparum revealed PEXEL cleavage occurs cotranslationaly, similar to signal peptidase. Treatment of P. falciparum-infected erythrocytes with the inhibitor caused dose-dependent inhibition of PEXEL processing as well as protein export, including impaired display of the major virulence adhesin, PfEMP1, on the erythrocyte surface, and cytoadherence. The inhibitor killed parasites at the trophozoite stage and knockdown of PMV enhanced sensitivity to the inhibitor, while overexpression of PMV increased resistance. This provides the first direct evidence that PMV activity is essential for protein export in Plasmodium spp. and for parasite survival in human erythrocytes and validates PMV as an antimalarial drug target

Colorectal cancer cell line proteomes are representative of primary tumors and predict drug sensitivity

Proteomics holds promise for individualizing cancer treatment. We analyzed to what extent the proteomic landscape of human colorectal cancer (CRC) is maintained in established CRC cell lines and the utility of proteomics for predicting therapeutic responses. Proteomic and transcriptomic analyses were performed on 44 CRC cell lines, compared against primary CRCs (n=95) and normal tissues (n=60), and integrated with genomic and drug sensitivity data. Cell lines mirrored the proteomic aberrations of primary tumors, in particular for intrinsic programs. Tumor relationships of protein expression with DNA copy number aberrations and signatures of post-transcriptional regulation were recapitulated in cell lines. The 5 proteomic subtypes previously identified in tumors were represented among cell lines. Nonetheless, systematic differences between cell line and tumor proteomes were apparent, attributable to stroma, extrinsic signaling, and growth conditions. Contribution of tumor stroma obscured signatures of DNA mismatch repair identified in cell lines with a hypermutation phenotype. Global proteomic data showed improved utility for predicting both known drug-target relationships and overall drug sensitivity as compared with genomic or transcriptomic measurements. Inhibition of targetable proteins associated with drug responses further identified corresponding synergistic or antagonistic drug combinations. Our data provide evidence for CRC proteomic subtype-specific drug responses. Proteomes of established CRC cell line are representative of primary tumors. Proteomic data tend to exhibit improved prediction of drug sensitivity as compared with genomic and transcriptomic profiles. Our integrative proteogenomic analysis highlights the potential of proteome profiling to inform personalized cancer medicine

Oval Cell Numbers in Human Chronic Liver Diseases Are Directly Related to Disease Severity

The risk of developing hepatocellular carcinoma is significantly increased in patients with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C infection. The precise mechanisms underlying the development of hepatocellular carcinoma in these conditions are not well understood. Stem cells within the liver, termed oval cells, are involved in the pathogenesis of hepatocellular carcinoma in animal models and may be important in the development of hepatocellular carcinoma in human chronic liver diseases. The aims of this study were to determine whether oval cells could be detected in the liver of patients with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C, and whether there is a relationship between the severity of the liver disease and the number of oval cells. Oval cells were detected using histology and immunohistochemistry in liver biopsies from patients with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C. Oval cells were not observed in normal liver controls. Oval cell numbers increased significantly with the progression of disease severity from mild to severe in each of the diseases studied. We conclude that oval cells are frequently found in subjects with genetic hemochromatosis, alcoholic liver disease, or chronic hepatitis C. There is an association between severity of liver disease and increase in the number of oval cells consistent with the hypothesis that oval cell proliferation is associated with increased risk for development of hepatocellular carcinoma in chronic liver disease

\u3b2TrCP- and Rsk1/2-Mediated Degradation of BimEL Inhibits Apoptosis

The BimEL tumor suppressor is a potent proapop- totic BH3-only protein. We found that, in response to survival signals, BimEL was rapidly phosphory- lated on three serine residues in a conserved degron, facilitating binding and degradation via the F box protein bTrCP. Phosphorylation of the BimEL degron was executed by Rsk1/2 and promoted by the Erk1/2-mediated phosphorylation of BimEL on Ser69. Compared to wild-type BimEL, a BimEL phos- phorylation mutant unable to bind bTrCP was stabi- lized and consequently potent at inducing apoptosis by the intrinsic mitochondrial pathway. Moreover, although non-small cell lung cancer (NSCLC) cells often become resistant to gefitinib (a clinically rele- vant tyrosine kinase inhibitor that induces apoptosis through BimEL), silencing of either bTrCP or Rsk1/2 resulted in BimEL-mediated apoptosis of both gefiti- nib-sensitive and gefitinib-insensitive NSCLC cells. Our findings reveal that bTrCP promotes cell survival in cooperation with the ERK-RSK pathway by target- ing BimEL for degradation

Structure activity refinement of phenylsulfonyl piperazines as antimalarials that block erythrocytic invasion

The emerging resistance to combination therapies comprised of artemisinin derivatives has driven a need to identify new antimalarials with novel mechanisms of action. Central to the survival and proliferation of the malaria parasite is the invasion of red blood cells by Plasmodium merozoites, providing an attractive target for novel therapeutics. A screen of the Medicines for Malaria Venture Pathogen Box employing transgenic P. falciparum parasites expressing the nanoluciferase bioluminescent reporter identified the phenylsulfonyl piperazine class as a specific inhibitor of erythrocyte invasion. Here, we describe the optimization and further characterization of the phenylsulfonyl piperazine class. During the optimization process we defined the functionality required for P. falciparum asexual stage activity and determined the alpha-carbonyl S-methyl isomer was important for antimalarial potency. The optimized compounds also possessed comparable activity against multidrug resistant strains of P. falciparum and displayed weak activity against sexual stage gametocytes. We determined that the optimized compounds blocked erythrocyte invasion consistent with the asexual activity observed and therefore the phenylsulfonyl piperazine analogues described could serve as useful tools for studying Plasmodium erythrocyte invasion.William Nguyena, Madeline G. Dansc, Anna Ngoa, Maria R. Ganchevaf, Ornella Romeof, Sandra Duffy ... et al

Transition State Mimetics of the Plasmodium Export Element Are Potent Inhibitors of Plasmepsin V from P. falciparum and P. vivax

Following erythrocyte invasion, malaria parasites export a catalogue of remodeling proteins into the infected cell that enable parasite development in the human host. Export is dependent on the activity of the aspartyl protease, plasmepsin V (PMV), which cleaves proteins within the Plasmodium export element (PEXEL; RxL↓xE/Q/D) in the parasite’s endoplasmic reticulum. Here, we generated transition state mimetics of the native PEXEL substrate that potently inhibit PMV isolated from Plasmodium falciparum and Plasmodium vivax. Through optimization, we identified that the activity of the mimetics was completely dependent on the presence of P₁ Leu and P₃ Arg. Treatment of P. falciparum-infected erythrocytes with a set of optimized mimetics impaired PEXEL processing and killed the parasites. The striking effect of the compounds provides a clearer understanding of the accessibility of the PMV active site and reaffirms the enzyme as an attractive target for the design of future antimalarials