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The nongenotoxic carcinogens naphthalene and para-dichlorobenzene suppress apoptosis in Caenorhabditis elegans

Nature Chemical Biology volume 2, pages 338–345 (2006)Cite this article

Abstract

Naphthalene (1) and para-dichlorobenzene (PDCB, 2), which are widely used as moth repellents and air fresheners, cause cancer in rodents and are potential human carcinogens. However, their mechanisms of action remain unclear. Here we describe a novel method for delivering and screening hydrophobic chemicals in C. elegans and apply this technique to investigate the ways in which naphthalene and PDCB may promote tumorigenesis in mammals. We show that naphthalene and PDCB inhibit apoptosis in C. elegans, a result that suggests a cellular mechanism by which these chemicals may promote the survival and proliferation of latent tumor cells. In addition, we find that a naphthalene metabolite directly inactivates caspases by oxidizing the active site cysteine residue; this suggests a molecular mechanism by which these chemicals suppress apoptosis. Naphthalene and PDCB are the first small-molecule apoptosis inhibitors identified in C. elegans. The power of C. elegans molecular genetics, in combination with the possibility of carrying out large-scale chemical screens in this organism, makes C. elegans an attractive and economic animal model for both toxicological studies and drug screens.

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Figure 1: Naphthalene and PDCB cause nonheritable apoptosis suppression in C. elegans.
Figure 2: The inhibitory activity of naphthalene and PDCB toward apoptosis in different solvents.
Figure 3: Naphthalene and PDCB suppress apoptosis in different genetic backgrounds and in multiple cell types in C. elegans.
Figure 4: Naphthalene treatment suppresses activated CED-3 (acCED-3)-induced apoptosis in the absence of CED-4.
Figure 5: A naphthalene metabolite, 1,4-naphthoquinone, inhibits the activities of CED-3 and caspase-3 in vitro.
Figure 6: Kinetics of human caspase-3 inactivation by 1,4-naphthoquinone.
Figure 7: vMALDI-LTQ mass spectra of trypsin digests of caspase-3 treated with 1,4-naphthoquinone (1,4-NQ) and mock.

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References

  1. Tomatis, L. Cancer: causes, occurrence and control. IARC Sci. Publ. 100, 1–352 (1990).

    Google Scholar 

  2. Balmain, A., Gray, J. & Ponder, B. The genetics and genomics of cancer. Nat. Genet. 33, 238–244 (2003).

    CAS  PubMed  Google Scholar 

  3. Ashby, J. Use of short-term tests in determining the genotoxicity or nongenotoxicity of chemicals. IARC Sci. Publ. 116, 135–164 (1992).

    CAS  Google Scholar 

  4. Balmain, A. Cancer genetics: from Boveri and Mendel to microarrays. Nat. Rev. Cancer 1, 77–82 (2001).

    CAS  PubMed  Google Scholar 

  5. Silva Lima, B. & Van der Laan, J.W. Mechanisms of nongenotoxic carcinogenesis and assessment of the human hazard. Regul. Toxicol. Pharmacol. 32, 135–143 (2000).

    CAS  PubMed  Google Scholar 

  6. Thompson, C.B. Apoptosis in the pathogenesis and treatment of disease. Science 267, 1456–1462 (1995).

    CAS  PubMed  Google Scholar 

  7. Johnstone, R.W., Ruefli, A.A. & Lowe, S.W. Apoptosis: a link between cancer genetics and chemotherapy. Cell 108, 153–164 (2002).

    CAS  PubMed  Google Scholar 

  8. ATSDR. Toxicological Profile for Naphthalene (draft). (Agency for Toxic Substances and Disease Registry, Atlanta, 2003). http://www.atsdr.cdc.gov/toxprofiles/tp67.html.

  9. ATSDR. Toxological Profile for Dichlorobenzenes (draft). (Agency for Toxic Substances and Disease Registry, Atlanta, 2003). http://www.atsdr.cdc.gov/toxprofiles/tp10.html.

  10. IARC. Some traditional herbal medicines, some mycotoxins, naphthalene and styrene. IARC Monogr. Eval. Carcinog. Risks Hum. 82, 1–556 (2002).

  11. Sulston, J.E. & Horvitz, H.R. Post-embryonic cell lineages of the nematode, Caenorhabditis elegans. Dev. Biol. 56, 110–156 (1977).

    CAS  PubMed  Google Scholar 

  12. Sulston, J.E., Schierenberg, E., White, J.G. & Thomson, J.N. The embryonic cell lineage of the nematode Caenorhabditis elegans. Dev. Biol. 100, 64–119 (1983).

    CAS  PubMed  Google Scholar 

  13. Gartner, A., Milstein, S., Ahmed, S., Hodgkin, J. & Hengartner, M.O. A conserved checkpoint pathway mediates DNA damage–induced apoptosis and cell cycle arrest in C. elegans. Mol. Cell 5, 435–443 (2000).

    CAS  PubMed  Google Scholar 

  14. Metzstein, M.M., Stanfield, G.M. & Horvitz, H.R. Genetics of programmed cell death in C. elegans: past, present and future. Trends Genet. 14, 410–416 (1998).

    CAS  PubMed  Google Scholar 

  15. Metzstein, M.M. & Horvitz, H.R. The C. elegans cell death specification gene ces-1 encodes a snail family zinc finger protein. Mol. Cell 4, 309–319 (1999).

    CAS  PubMed  Google Scholar 

  16. Metzstein, M.M., Hengartner, M.O., Tsung, N., Ellis, R.E. & Horvitz, H.R. Transcriptional regulator of programmed cell death encoded by Caenorhabditis elegans gene ces-2. Nature 382, 545–547 (1996).

    CAS  PubMed  Google Scholar 

  17. Zhou, Z., Hartwieg, E. & Horvitz, H.R. CED-1 is a transmembrane receptor that mediates cell corpse engulfment in C. elegans. Cell 104, 43–56 (2001).

    CAS  PubMed  Google Scholar 

  18. Reddien, P.W. & Horvitz, H.R. CED-2/CrkII and CED-10/Rac control phagocytosis and cell migration in Caenorhabditis elegans. Nat. Cell Biol. 2, 131–136 (2000).

    CAS  PubMed  Google Scholar 

  19. Stanfield, G.M. & Horvitz, H.R. The ced-8 gene controls the timing of programmed cell deaths in C. elegans. Mol. Cell 5, 423–433 (2000).

    CAS  PubMed  Google Scholar 

  20. Wu, Y.C., Stanfield, G.M. & Horvitz, H.R. NUC-1, a Caenorhabditis elegans DNase II homolog, functions in an intermediate step of DNA degradation during apoptosis. Genes Dev. 14, 536–548 (2000).

    CAS  PubMed  PubMed Central  Google Scholar 

  21. Parrish, J. et al. Mitochondrial endonuclease G is important for apoptosis in C. elegans. Nature 412, 90–94 (2001).

    CAS  PubMed  Google Scholar 

  22. Horvitz, H.R. Worms, life, and death (Nobel lecture). ChemBioChem 4, 697–711 (2003).

    CAS  PubMed  Google Scholar 

  23. Earnshaw, W.C., Martins, L.M. & Kaufmann, S.H. Mammalian caspases: structure, activation, substrates, and functions during apoptosis. Annu. Rev. Biochem. 68, 383–424 (1999).

    CAS  PubMed  Google Scholar 

  24. Xue, D., Shaham, S. & Horvitz, H.R. The Caenorhabditis elegans cell-death protein CED-3 is a cysteine protease with substrate specificities similar to those of the human CPP32 protease. Genes Dev. 10, 1073–1083 (1996).

    CAS  PubMed  Google Scholar 

  25. Xue, D. & Horvitz, H.R. Inhibition of the Caenorhabditis elegans cell-death protease CED-3 by a CED-3 cleavage site in baculovirus p35 protein. Nature 377, 248–251 (1995).

    CAS  PubMed  Google Scholar 

  26. Aballay, A. & Ausubel, F.M. Programmed cell death mediated by ced-3 and ced-4 protects Caenorhabditis elegans from Salmonella typhimurium-mediated killing. Proc. Natl. Acad. Sci. USA 98, 2735–2739 (2001).

    CAS  PubMed  PubMed Central  Google Scholar 

  27. Lackner, M.R. et al. Chemical genetics identifies Rab geranylgeranyl transferase as an apoptotic target of farnesyl transferase inhibitors. Cancer Cell 7, 325–336 (2005).

    CAS  PubMed  Google Scholar 

  28. Parrish, J., Metters, H., Chen, L. & Xue, D. Demonstration of the in vivo interaction of key cell death regulators by structure-based design of second-site suppressors. Proc. Natl. Acad. Sci. USA 97, 11916–11921 (2000).

    CAS  PubMed  PubMed Central  Google Scholar 

  29. Yan, N. et al. Structural, biochemical, and functional analyses of CED-9 recognition by the proapoptotic proteins EGL-1 and CED-4. Mol. Cell 15, 999–1006 (2004).

    CAS  PubMed  Google Scholar 

  30. Reddien, P.W., Cameron, S. & Horvitz, H.R. Phagocytosis promotes programmed cell death in C. elegans. Nature 412, 198–202 (2001).

    CAS  PubMed  Google Scholar 

  31. Conradt, B. & Horvitz, H.R. The TRA-1A sex determination protein of C. elegans regulates sexually dimorphic cell deaths by repressing the egl-1 cell death activator gene. Cell 98, 317–327 (1999).

    CAS  PubMed  Google Scholar 

  32. Yan, N. et al. Structure of the CED-4-CED-9 complex provides insights into programmed cell death in Caenorhabditis elegans. Nature 437, 831–837 (2005).

    CAS  PubMed  Google Scholar 

  33. Ellis, H.M. & Horvitz, H.R. Genetic control of programmed cell death in the nematode C. elegans. Cell 44, 817–829 (1986).

    CAS  PubMed  Google Scholar 

  34. Cerniglia, C.E. & Gibson, D.T. Metabolism of naphthalene by Cunninghamella elegans. Appl. Environ. Microbiol. 34, 363–370 (1977).

    CAS  PubMed  PubMed Central  Google Scholar 

  35. Miller, M.G., Rodgers, A. & Cohen, G.M. Mechanisms of toxicity of naphthoquinones to isolated hepatocytes. Biochem. Pharmacol. 35, 1177–1184 (1986).

    CAS  PubMed  Google Scholar 

  36. Xue, D. & Horvitz, H.R. Caenorhabditis elegans CED-9 protein is a bifunctional cell-death inhibitor. Nature 390, 305–308 (1997).

    CAS  PubMed  Google Scholar 

  37. Bisswanger, H. Enzyme Kinetics: Principles and Methods (Wiley-VCH, Weinheim, Germany, 2002).

    Google Scholar 

  38. Hanahan, D. & Weinberg, R.A. The hallmarks of cancer. Cell 100, 57–70 (2000).

    CAS  PubMed  Google Scholar 

  39. Jacks, T. & Weinberg, R.A. Taking the study of cancer cell survival to a new dimension. Cell 111, 923–925 (2002).

    CAS  PubMed  Google Scholar 

  40. Reed, J.C. Dysregulation of apoptosis in cancer. J. Clin. Oncol. 17, 2941–2953 (1999).

    CAS  PubMed  Google Scholar 

  41. Perera, F.P. Environment and cancer: who are susceptible? Science 278, 1068–1073 (1997).

    CAS  PubMed  Google Scholar 

  42. Worner, W. & Schrenk, D. Influence of liver tumor promoters on apoptosis in rat hepatocytes induced by 2-acetylaminofluorene, ultraviolet light, or transforming growth factor beta 1. Cancer Res. 56, 1272–1278 (1996).

    CAS  PubMed  Google Scholar 

  43. Bayly, A.C., Roberts, R.A. & Dive, C. Suppression of liver cell apoptosis in vitro by the non-genotoxic hepatocarcinogen and peroxisome proliferator nafenopin. J. Cell Biol. 125, 197–203 (1994).

    CAS  PubMed  Google Scholar 

  44. Schrenk, D., Schmitz, H.J., Bohnenberger, S., Wagner, B. & Worner, W. Tumor promoters as inhibitors of apoptosis in rat hepatocytes. Toxicol. Lett. 149, 43–50 (2004).

    CAS  PubMed  Google Scholar 

  45. Dorit, A. et al. Cysteine Protease Inhibitors. US patent 2,004,198,716 (2004).

  46. Brenner, S. The genetics of Caenorhabditis elegans. Genetics 77, 71–94 (1974).

    CAS  PubMed  PubMed Central  Google Scholar 

  47. Mello, C.C., Kramer, J.M., Stinchcomb, D. & Ambros, V. Efficient gene transfer in C. elegans: extrachromosomal maintenance and integration of transforming sequences. EMBO J. 10, 3959–3970 (1991).

    CAS  PubMed  PubMed Central  Google Scholar 

  48. Gu, T., Orita, S. & Han, M. Caenorhabditis elegans SUR-5, a novel but conserved protein, negatively regulates LET-60 Ras activity during vulval induction. Mol. Cell. Biol. 18, 4556–4564 (1998).

    CAS  PubMed  PubMed Central  Google Scholar 

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Acknowledgements

We thank T. Blumenthal, M. Han, M. Stowell, S. Copley and members of the Xue lab for comments and discussions and H.R. Horvitz and P. Sternberg for strains. This work was supported by the US National Institutes of Health R01 grants (GM59083 and GM66262) and a Burroughs Wellcome Fund Career Award (D.X.).

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Authors and Affiliations

  1. Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, 80309-0347, Colorado, USA

    David Kokel & Ding Xue

  2. Department of Biochemistry, Baylor College of Medicine, Houston, 77030, Texas, USA

    Yehua Li & Jun Qin

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Correspondence to Ding Xue.

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Kokel, D., Li, Y., Qin, J. et al. The nongenotoxic carcinogens naphthalene and para-dichlorobenzene suppress apoptosis in Caenorhabditis elegans. Nat Chem Biol 2, 338–345 (2006). https://doi.org/10.1038/nchembio791

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