Drug repurposing is a versatile strategy to improve current therapies. Disulfiram has long been used in the treatment of alcohol dependency and multiple clinical trials to evaluate its clinical value in oncology are ongoing. We have recently reported that the disulfiram metabolite diethyldithiocarbamate, when combined with copper (CuET), targets the NPL4 adapter of the p97VCP segregase to suppress the growth of a spectrum of cancer cell lines and xenograft models in vivo. CuET induces proteotoxic stress and genotoxic effects, however important issues concerning the full range of the CuET-evoked tumor cell phenotypes, their temporal order, and mechanistic basis have remained largely unexplored. Here, we have addressed these outstanding questions and show that in diverse human cancer cell models, CuET causes a very early translational arrest through the integrated stress response (ISR), later followed by features of nucleolar stress. Furthermore, we report that CuET entraps p53 in NPL4-rich aggregates leading to elevated p53 protein and its functional inhibition, consistent with the possibility of CuET-triggered cell death being p53-independent. Our transcriptomics profiling revealed activation of pro-survival adaptive pathways of ribosomal biogenesis (RiBi) and autophagy upon prolonged exposure to CuET, indicating potential feedback responses to CuET treatment. The latter concept was validated here by simultaneous pharmacological inhibition of RiBi and/or autophagy that further enhanced CuET's tumor cytotoxicity, using both cell culture and zebrafish in vivo preclinical models. Overall, these findings expand the mechanistic repertoire of CuET's anti-cancer activity, inform about the temporal order of responses and identify an unorthodox new mechanism of targeting p53. Our results are discussed in light of cancer-associated endogenous stresses as exploitable tumor vulnerabilities and may inspire future clinical applications of CuET in oncology, including combinatorial treatments and focus on potential advantages of using certain validated drug metabolites, rather than old, approved drugs with their, often complex, metabolic profiles.
- MeSH
- dánio pruhované metabolismus MeSH
- disulfiram * metabolismus MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádorový supresorový protein p53 genetika metabolismus MeSH
- nádory * metabolismus MeSH
- ribozomy metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Aldehyde dehydrogenase (ALDH) is a proposed biomarker and possible target to eradicate cancer stem cells. ALDH inhibition as a treatment approach is supported by anti-cancer effects of the alcohol-abuse drug disulfiram (DSF, Antabuse). Given that metabolic products of DSF, rather than DSF itself inhibit ALDH in vivo, and that DSF's anti-cancer activity is potentiated by copper led us to investigate the relevance of ALDH as the suggested molecular cancer-relevant target of DSF. Here we show that DSF does not directly inhibit ALDH activity in diverse human cell types, while DSF's in vivo metabolite, S-methyl-N,N-diethylthiocarbamate-sulfoxide inhibits ALDH activity yet does not impair cancer cell viability. Our data indicate that the anti-cancer activity of DSF does not involve ALDH inhibition, and rather reflects the impact of DSF's copper-containing metabolite (CuET), that forms spontaneously in vivo and in cell culture media, and kills cells through aggregation of NPL4, a subunit of the p97/VCP segregase. We also show that the CuET-mediated, rather than any ALDH-inhibitory activity of DSF underlies the preferential cytotoxicity of DSF towards BRCA1- and BRCA2-deficient cells. These findings provide evidence clarifying the confusing literature about the anti-cancer mechanism of DSF, a drug currently tested in clinical trials for repositioning in oncology.
- MeSH
- aldehyddehydrogenasa antagonisté a inhibitory MeSH
- antitumorózní látky metabolismus farmakologie MeSH
- buňky A549 MeSH
- buňky K562 MeSH
- disulfiram metabolismus farmakologie MeSH
- inhibitory acetaldehyd dehydrogenasy metabolismus farmakologie MeSH
- jaderné proteiny metabolismus MeSH
- kultivační média MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- cytochromy MeSH
- disulfiram aplikace a dávkování metabolismus moč MeSH
- dospělí MeSH
- finanční podpora výzkumu jako téma MeSH
- inhalační expozice MeSH
- krysa rodu rattus MeSH
- kyseliny mandlové moč MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci z povolání MeSH
- styren antagonisté a inhibitory metabolismus MeSH
- zvířata MeSH
- Check Tag
- dospělí MeSH
- krysa rodu rattus MeSH
- lidé středního věku MeSH
- lidé MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
- srovnávací studie MeSH
