Alcohol-abuse drug Antabuse (disulfiram) kills cancer cells

What the report “Alcohol-abuse drug disulfiram targets cancer via p97 segregase adaptor NPL4” Nature 552, 6/14 Dec ’17 ⁽¹⁾ is all about

“Alcohol-abuse drug Antabuse kills cancer cells”, writes one of the scientists of an international team⁽¹⁾ in a media release of his university (Alcohol-abuse drug Antabuse kills cancer cells, Karolinska Institutet, 7/12 Dec ’17) about their just published report Alcohol-abuse drug disulfiram targets cancer via p97 segregase adaptor NPL4, Nature, 6/14 Dec ’17⁽¹⁾ and continues that the scientist found out, “that the alcohol-abuse drug Antabuse is effective against cancer [and] identifies a potential mechanism of action for the anti-tumour effect.”

The report is about three issues:

• The, highly interesting, progress in lab work on disufiram, which “fills an important knowledge gap regarding the anti-cancer mechanism of disulfiram and paves the way for future clinical trials,” as “[in] laboratory experiments, the team found that in mice and in the human body, disulfiram becomes metabolised into a molecule that causes a naturally occurring protein NPL4 to clump together with its partner, the body’s p97 enzyme. This process ‘freezes’ and thereby functionally disables the otherwise very mobile and tumour growth-supporting NPL4-p97 duo, resulting in cancer cell death…” (Jiří Bártek in the Karolinska media release)
  NOTE: the first clinical trial just began in Olomouc⁽²⁾
   
• Yet another analyses/report of the records/cases, this time “of cancer patients across Denmark” (over 3000 patients taking Antabuse of over 240,000 cases diagnosed between 2000 and 2013 in Denmark’s cancer registry). This, I think, may/should be “put into perspective” a bit more thoroughly and together with other cases⁽³⁾, at least as long as the clinical tests are on the way.
   
• The Nonprofit drugs issues, briefly mentioned by the authors. This theme, as a larger multidisciplinary project, is currently in preparation⁽⁴⁾.

Notes, quotes, further reading

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The countries and institutions of the international team…

• Czech Rep – Palacky University, Olomouc; Charles University, Prague; Psychiatric Hospital, Sternberk
• Denmark – Danish Cancer Society Research Center, Copenhagen
• Sweden – Karolinska Institute, Stockholm
• Switzerland – Kantonsspital St Gallen
• USA – Caltech, Pasadena, California; Wayne State University, Detroit, Michigan; Amgen, Thousand Oaks, California
• China – Guangzhou Medical University, Guangzhou

…and their report:

Alcohol-abuse drug disulfiram targets cancer via p97 segregase adaptor NPL4

Zdeněk Škrott⁺, Martin Mistrík⁺, Klaus Kaae Andersen, Søren Friis, Dušana Majera, Ján Gurský, Tomáš Oždian, Jiřina Bártková, Zsófia Turi, Pavel Moudrý, Marianne Kraus, Martina Michalová, Jana Václavková, Petr Džubák, Ivo Vrobel, Pavla Poučková, Jindřich Sedláček, Andrea Miklovičová, Anne Kutt, Jing Li, Jana Mattová, Christoph Driessen, Q. Ping Dou, Jørgen Olsen, Marián Hajdúch, Boris Cvek^*, Raymond J. Deshaies^*, Jiří Bártek^* (⁺contributed equally, ^*corresponding authors)
Nature 552, 194–199 (14 Dec 2017), doi:10.1038/nature25016, published online: 06 Dec 2017

Contributions – Zdeněk Škrott, Martin Mistrík, Boris Cvek, Raymond J. Deshaies and Jiří Bártek conceived the study. Zdeněk Škrott and Martin Mistrík performed most biochemical and microscopy experiments and wrote the manuscript. Dušana Majera established the expression cell lines and performed most cytotoxicity tests. Tomáš Oždian, Petr Džubák and Ivo Vrobel performed the HPLC experiments. Klaus Kaae Andersen, Søren Friis and Jørgen Olsen performed the epidemiological analyses. Jiří Bártek performed the immunohistochemical analyses. Jana Václavková and Petr Džubák performed DARTS experiments. Pavel Moudrý performed cell death analyses. Zsófia Turi performed cytotoxicity tests and heat-shock response analyses. Anne Kutt performed cytotoxicity tests. Andrea Miklovičová designed and performed phlebotomies of patients treated with Antabuse. Martina Michalová performed the ITC. Ján Gurský performed FACS analyses, cell death assays and cell sorting. Jindřich Sedláček performed 20S proteasome assays. Jing Li performed 26S proteasome assays. Marianne Kraus and Christoph Driessen performed the cytotoxicity experiments on myeloid- and patient-derived cell lines. Pavla Poučková, Jana Mattová and Marián Hajdúch performed mouse experiments. Jiří Bártek, Boris Cvek, Q. Ping Dou and Raymond J. Deshaies helped to design the experiments, interpreted the data and wrote/edited the manuscript. All authors approved the manuscript.

Acknowledgements, thanks – J. Škvor, M. Zadinová, J. Večerka and D. Doležal for help with animal experiments, Jana Vrbková for statistical analysis, David Friedecký and Tomáš Adam for help with HPLC, Iva Protivánková and M. Grønvig Nielsen for technical assistance.

The authors sum up their findings in the report’s last section:

Model of DSF anti-cancer activity in patients
Fig. 4f

DSF = disulfiram (tetraethylthiuram disulfide)
DTC = diethyldithiocarbamate
CuET = DTC–copper complex (bis (diethyldithiocarbamate)–copper)

Discussion
Our results help to explain the anti-cancer activity of the alcohol-abuse drug disulfiram.
We propose a model for DSF cytotoxic activity, featuring rapid conversion of DSF into CuET, which accumulates in tumours. After entering cells, CuET binds NPL4 and induces its aggregation, consequently disabling the vital p97–NPL4–UFD1 pathway and inducing a complex cellular phenotype leading to cell death (Fig. 4f). Supporting CuET as the active metabolite is the correlation of CuET concentrations (active in the nanomolar range) with the biological effects and functional impact on the targeted pathway(s) in vivo.
In addition, CuET is the only known metabolite of DSF containing copper ions, a metal that enhances the anti-tumour effects of DSF; it is unlikely that another DSF metabolite could represent the major anti-cancer agent as levels of non-CuET metabolites should be lowered by copper addition.
We also present a method for CuET detection in tissues and plasma, as well as data suggesting that preferential accumulation of CuET in tumours may contribute to cancer cell toxicity, consistent with the high therapeutic tolerability of DSF³, as documented even after years of daily administration at doses comparable to those we used in our mouse experiments.
Considering the numerous studies on DSF and diverse opinions about the potential target of its anti-cancer effects⁴⁴, identification of NPL4, a key component of the p97–NPL4–UFD1 segregase complex, as the molecular target of CuET is surprising. The CuET–NPL4 interaction leads to rapid formation of protein aggregates and immobilization of this otherwise very mobile multifunctional protein complex, resulting in a severe phenotype, induction of HSR and eventually cell death. While additional potential targets of CuET cannot be excluded, the malfunction of the p97 pathway due to the NPL4–p97 aggregate formation explains the major cell phenotypes and the consequent cell death.
Our work also reconciles the controversial studies^6,12, suggesting that the proteasome is the DSF target, by demonstrating that neither 20S nor 26S proteasome, but the processing of ubiquitylated proteins by the NPL4-dependent segregase, is targeted by CuET.
Our results support the notion that the p97–NPL4 pathway is a promising therapeutic target in oncology^45,46. Indeed, reports on p97 overabundance correlating with progression and metastasis of carcinomas of the breast, colon and prostate^47–49 are consistent with our present nationwide epidemiological analysis, which revealed an association between continued use of DSF and favourable prognosis, an intriguing finding that should be investigated further, particularly given the currently limited therapeutic options for patients with metastatic cancer.
From a broader perspective, our study illustrates the potential of multifaceted approaches to drug repurposing, providing novel mechanistic insights, identification of new cancer-relevant targets and encouragement for further clinical trials, here with DSF, an old, safe and public domain drug⁴ that might help to save lives of patients with cancer worldwide.

…
3. Iljin, K. et al. High-throughput cell-based screening of 4910 known drugs and drug-like small molecules identfies disulfiram as an inhibitor of prostate cancer cell growth. Clin. Cancer Res. 15, 6070–6078 (2009).
4. Cvek, B. Nonprofit drugs as the salvation of the world’s healthcare systems: the case of Antabuse (disulfiram). Drug Discov. Today 17, 409–412 (2012).
…
6. Chen, D., Cui, Q. C., Yang, H. & Dou, Q. P. Disulfiram, a clinically used anti-alcoholism drug and copper-binding agent, induces apoptotic cell death in breast cancer cultures and xenografts via inhibition of the proteasome activity. Cancer Res. 66, 10425–10433 (2006).
…
12. Lövborg, H. et al. Inhibition of proteasome activity, nuclear factor-κB translocation and cell survival by the antialcoholism drug disulfiram. Int. J. Cancer 118, 1577–1580 (2006).
…
44. Cvek, B. Targeting malignancies with disulfiram (Antabuse): multidrug resistance, angiogenesis, and proteasome. Curr. Cancer Drug Targets 11, 332–337 (2011).
45. Deshaies, R. J. Proteotoxic crisis, the ubiquitin–proteasome system, and cancer therapy. BMC Biol. 12, 94 (2014).
46. Anderson, D. J. et al. Targeting the AAA ATPase p97 as an approach to treat cancer through disruption of protein homeostasis. Cancer Cell 28, 653–665 (2015).
47. Cui, Y. et al. High expression of valosin-containing protein predicts poor prognosis in patients with breast carcinoma. Tumour Biol. 36, 9919–9927 (2015).
48. Yamamoto, S. et al. Expression of valosin-containing protein in colorectal carcinomas as a predictor for disease recurrence and prognosis. Clin. Cancer Res. 10, 651–657 (2004).
49. Tsujimoto, Y. et al. Elevated expression of valosin-containing protein (p97) is associated with poor prognosis of prostate cancer. Clin. Cancer Res. 10, 3007–3012 (2004).

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clinical tests in Olomouc:

• Phase II Trial of Disulfiram With Copper in Metastatic Breast Cancer (DISC), first posted: Oct 27, 2017, Marian Hajduch, M.D., Ph.D., University Hospital Olomouc, The Institute of Molecular and Translational Medicine, Czech Republic

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some previous, further cases, reports in:

• Disulfiram (Antabuse) against Cancer, Boris Cvek, Jan ’16

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on Nonprofit drugs see also:

• (in German) Ein zweiter Frühling für Medikamente (A second spring for medicines), Alan Niederer, NZZ 10.12.16
  

• Antabuse (disulfiram) as a pilot case of nonprofit drug, Boris Cvek et al.

• Drug discovery: Repurposing with a difference, Mark S. Boguski*, Kenneth D. Mandl, Vikas P. Sukhatme, Science 2009, Jun 12