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Messenger RNA (mRNA) has become a promising tool in therapeutic cancer vaccine strategies. Owing to its flexible design and rapid production, mRNA is an attractive antigen delivery format for cancer vaccines targeting mutated peptides expressed in a tumor-the so-called neoantigens. These neoantigens are rarely shared between patients, and inclusion of these antigens in a vaccine requires the production of individual batches of patient-tailored mRNA. The authors have developed MIDRIX NEO , a personalized mRNA-loaded dendritic cell vaccine targeting tumor neoantigens, which is currently being evaluated in a phase 1 clinical study in lung cancer patients. To facilitate this study, the authors set up a Good Manufacturing Practice (GMP)-compliant production process for the manufacture of small batches of personalized neoantigen-encoding mRNA. In this article, the authors describe the complete mRNA production process and the extensive quality assessment to which the mRNA is subjected. Validation runs have shown that the process delivers mRNA of reproducible, high quality. This process is now successfully applied for the production of neoantigen-encoding mRNA for the clinical evaluation of MIDRIX NEO . To the authors' knowledge, this is the first time that a GMP-based production process of patient-tailored neoantigen mRNA has been described., Competing Interests: Declaration of Competing Interest The authors have no commercial, proprietary or financial interest in the products or companies described in this article., (Copyright © 2021 International Society for Cell & Gene Therapy. Published by Elsevier Inc. All rights reserved.)

Nanoparticle-sensitized photoporation is an upcoming approach for the intracellular delivery of biologics, combining high efficiency and throughput with excellent cell viability. However, as it relies on close contact between nanoparticles and cells, its translation towards clinical applications is hampered by safety and regulatory concerns. Here we show that light-sensitive iron oxide nanoparticles embedded in biocompatible electrospun nanofibres induce membrane permeabilization by photothermal effects without direct cellular contact with the nanoparticles. The photothermal nanofibres have been successfully used to deliver effector molecules, including CRISPR-Cas9 ribonucleoprotein complexes and short interfering RNA, to adherent and suspension cells, including embryonic stem cells and hard-to-transfect T cells, without affecting cell proliferation or phenotype. In vivo experiments furthermore demonstrated successful tumour regression in mice treated with chimeric antibody receptor T cells in which the expression of programmed cell death protein 1 (PD1) is downregulated after nanofibre photoporation with short interfering RNA to PD1. In conclusion, cell membrane permeabilization with photothermal nanofibres is a promising concept towards the safe and more efficient production of engineered cells for therapeutic applications, including stem cell or adoptive T cell therapy., (© 2021. The Author(s), under exclusive licence to Springer Nature Limited.)

Systemic toxicities have severely limited the clinical application of tumor necrosis factor (TNF) as an anticancer agent. Activity-on-Target cytokines (AcTakines) are a novel class of immunocytokines with improved therapeutic index. A TNF-based AcTakine targeted to CD13 enables selective activation of the tumor neovasculature without any detectable toxicity in vivo. Upregulation of adhesion markers supports enhanced T-cell infiltration leading to control or elimination of solid tumors by, respectively, CAR T cells or a combination therapy with CD8-targeted type I interferon AcTakine. Co-treatment with a CD13-targeted type II interferon AcTakine leads to very rapid destruction of the tumor neovasculature and complete regression of large, established tumors. As no tumor markers are needed, safe and efficacious elimination of a broad range of tumor types becomes feasible., (© 2020 The Authors. Published under the terms of the CC BY 4.0 license.)

The serine/threonine protein phosphatase-1 (PP1) complex is a key regulator of the cell cycle. However, the redundancy of PP1 isoforms and the lack of specific inhibitors have hampered studies on the global role of PP1 in cell cycle progression in vertebrates. Here, we show that the overexpression of nuclear inhibitor of PP1 (NIPP1; also known as PPP1R8) in HeLa cells culminated in a prometaphase arrest, associated with severe spindle-formation and chromosome-congression defects. In addition, the spindle assembly checkpoint was activated and checkpoint silencing was hampered. Eventually, most cells either died by apoptosis or formed binucleated cells. The NIPP1-induced mitotic arrest could be explained by the inhibition of PP1 that was titrated away from other mitotic PP1 interactors. Consistent with this notion, the mitotic-arrest phenotype could be rescued by the overexpression of PP1 or the inhibition of the Aurora B kinase, which acts antagonistically to PP1. Finally, we demonstrate that the overexpression of NIPP1 also hampered colony formation and tumor growth in xenograft assays in a PP1-dependent manner. Our data show that the selective inhibition of PP1 can be used to induce cancer cell death through mitotic catastrophe., (© 2015. Published by The Company of Biologists Ltd.)