Genomic alterations and enormous monoclonal immunoglobulin production cause multiple myeloma to heavily depend on proteostasis mechanisms, including protein folding and degradation. These findings support the use of proteasome inhibitors for treating multiple myeloma and mantle cell lymphoma. Myeloma treatment has evolved, especially with the availability of new drugs, such as proteasome inhibitors, into therapeutic strategies for both frontline and relapsed/refractory disease settings. However, proteasome inhibitors are generally not effective enough to cure most patients. Natural resistance and eventual acquired resistance led to relapsed/refractory disease and poor prognosis. Advances in the understanding of cellular proteostasis and the development of innovative drugs that also target other proteostasis network components offer opportunities to exploit the intrinsic vulnerability of myeloma cells. This review outlines recent findings on the molecular mechanisms regulating cellular proteostasis pathways, as well as resistance, sensitivity, and escape strategies developed against proteasome inhibitors and provides a rationale and examples for novel combinations of proteasome inhibitors with FDA-approved drugs and investigational drugs targeting the NRF1 (NFE2L1)-mediated proteasome bounce-back response, redox homeostasis, heat shock response, unfolding protein response, autophagy, and VCP/p97 to increase proteotoxic stress, which can improve the efficacy of antimyeloma therapy based on proteasome inhibitors.

• Klíčová slova
• Autophagy, Heat shock response, Proteasome bounce-back response, Redox homeostasis, UPR, VCP/p97,
• MeSH
• chemorezistence MeSH
• homeostáze proteinů * účinky léků   MeSH
• inhibitory proteasomu * terapeutické užití   farmakologie   MeSH
• lidé MeSH
• mnohočetný myelom * farmakoterapie   metabolismus   MeSH
• protinádorové látky * terapeutické užití   farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• inhibitory proteasomu * MeSH
• protinádorové látky * MeSH

Despite several approved therapeutic modalities, multiple myeloma (MM) remains an incurable blood malignancy and only a small fraction of patients achieves prolonged disease control. The common anti-MM treatment targets proteasome with specific inhibitors (PI). The resulting interference with protein degradation is particularly toxic to MM cells as they typically accumulate large amounts of toxic proteins. However, MM cells often acquire resistance to PIs through aberrant expression or mutations of proteasome subunits such as PSMB5, resulting in disease recurrence and further treatment failure. Here we propose CuET-a proteasome-like inhibitor agent that is spontaneously formed in-vivo and in-vitro from the approved alcohol-abuse drug disulfiram (DSF), as a readily available treatment effective against diverse resistant forms of MM. We show that CuET efficiently kills also resistant MM cells adapted to proliferate under exposure to common anti-myeloma drugs such as bortezomib and carfilzomib used as the first-line therapy, as well as to other experimental drugs targeting protein degradation upstream of the proteasome. Furthermore, CuET can overcome also the adaptation mechanism based on reduced proteasome load, another clinically relevant form of treatment resistance. Data obtained from experimental treatment-resistant cellular models of human MM are further corroborated using rather unique advanced cytotoxicity experiments on myeloma and normal blood cells obtained from fresh patient biopsies including newly diagnosed as well as relapsed and treatment-resistant MM. Overall our findings suggest that disulfiram repurposing particularly if combined with copper supplementation may offer a promising and readily available treatment option for patients suffering from relapsed and/or therapy-resistant multiple myeloma.

• MeSH
• bortezomib farmakologie   terapeutické užití   MeSH
• chemorezistence MeSH
• disulfiram farmakologie   MeSH
• inhibitory proteasomu farmakologie   terapeutické užití   MeSH
• lidé MeSH
• lokální recidiva nádoru farmakoterapie   MeSH
• mnohočetný myelom * patologie   MeSH
• nádorové buněčné linie MeSH
• přehodnocení terapeutických indikací léčivého přípravku MeSH
• proteasomový endopeptidasový komplex metabolismus   MeSH
• protinádorové látky * farmakologie   terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• bortezomib MeSH
• disulfiram MeSH
• inhibitory proteasomu MeSH
• proteasomový endopeptidasový komplex MeSH
• protinádorové látky * MeSH

Despite proteotoxic stress and heat shock being implicated in diverse pathologies, currently no methodology to inflict defined, subcellular thermal damage exists. Here, we present such a single-cell method compatible with laser-scanning microscopes, adopting the plasmon resonance principle. Dose-defined heat causes protein damage in subcellular compartments, rapid heat-shock chaperone recruitment, and ensuing engagement of the ubiquitin-proteasome system, providing unprecedented insights into the spatiotemporal response to thermal damage relevant for degenerative diseases, with broad applicability in biomedicine. Using this versatile method, we discover that HSP70 chaperone and its interactors are recruited to sites of thermally damaged proteins within seconds, and we report here mechanistically important determinants of such HSP70 recruitment. Finally, we demonstrate a so-far unsuspected involvement of p97(VCP) translocase in the processing of heat-damaged proteins. Overall, we report an approach to inflict targeted thermal protein damage and its application to elucidate cellular stress-response pathways that are emerging as promising therapeutic targets.

• MeSH
• analýza jednotlivých buněk metody   MeSH
• kovové nanočástice chemie   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• povrchová plasmonová rezonance MeSH
• proteasomový endopeptidasový komplex metabolismus   MeSH
• protein obsahující valosin genetika   metabolismus   MeSH
• proteiny tepelného šoku HSP70 metabolismus   MeSH
• reakce na tepelný šok * MeSH
• stříbro chemie   MeSH
• ubikvitin metabolismus   MeSH
• vysoká teplota škodlivé účinky   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• proteasomový endopeptidasový komplex MeSH
• protein obsahující valosin MeSH
• proteiny tepelného šoku HSP70 MeSH
• stříbro MeSH
• ubikvitin MeSH
• VCP protein, human MeSH Prohlížeč

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

• Klíčová slova
• Autophagosome, LC3, cancer, flux, lysosome, macroautophagy, neurodegeneration, phagophore, stress, vacuole,
• MeSH
• autofagie * fyziologie   MeSH
• autofagozomy MeSH
• biologické markery MeSH
• biotest normy   MeSH
• lidé MeSH
• lyzozomy MeSH
• proteiny spojené s autofagií metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• směrnice MeSH
• Názvy látek
• biologické markery MeSH
• proteiny spojené s autofagií MeSH

Cancer incidence is rising and this global challenge is further exacerbated by tumour resistance to available medicines. A promising approach to meet the need for improved cancer treatment is drug repurposing. Here we highlight the potential for repurposing disulfiram (also known by the trade name Antabuse), an old alcohol-aversion drug that has been shown to be effective against diverse cancer types in preclinical studies. Our nationwide epidemiological study reveals that patients who continuously used disulfiram have a lower risk of death from cancer compared to those who stopped using the drug at their diagnosis. Moreover, we identify the ditiocarb-copper complex as the metabolite of disulfiram that is responsible for its anti-cancer effects, and provide methods to detect preferential accumulation of the complex in tumours and candidate biomarkers to analyse its effect on cells and tissues. Finally, our functional and biophysical analyses reveal the molecular target of disulfiram's tumour-suppressing effects as NPL4, an adaptor of p97 (also known as VCP) segregase, which is essential for the turnover of proteins involved in multiple regulatory and stress-response pathways in cells.

• MeSH
• alkoholismus farmakoterapie   epidemiologie   MeSH
• cílená molekulární terapie MeSH
• disulfiram chemie   farmakologie   terapeutické užití   MeSH
• dospělí MeSH
• jaderné proteiny chemie   metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• měď chemie   MeSH
• myši MeSH
• nádory farmakoterapie   metabolismus   mortalita   patologie   MeSH
• odvykací prostředky alkoholu * farmakologie   terapeutické užití   MeSH
• přehodnocení terapeutických indikací léčivého přípravku * MeSH
• proteinové agregáty MeSH
• proteolýza účinky léků   MeSH
• protinádorové látky * farmakologie   terapeutické užití   MeSH
• reakce na tepelný šok účinky léků   MeSH
• vazba proteinů účinky léků   MeSH
• zvířata MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Dánsko epidemiologie   MeSH
• Názvy látek
• disulfiram MeSH
• jaderné proteiny MeSH
• měď MeSH
• NPLOC4 protein, human MeSH Prohlížeč
• odvykací prostředky alkoholu * MeSH
• proteinové agregáty MeSH
• protinádorové látky * MeSH