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The cytotoxicity of (−)-lomaiviticin A arises from induction of double-strand breaks in DNA

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Abstract

The metabolite (−)-lomaiviticin A, which contains two diazotetrahydrobenzo[b]fluorene (diazofluorene) functional groups, inhibits the growth of cultured human cancer cells at nanomolar–picomolar concentrations; however, the mechanism responsible for the potent cytotoxicity of this natural product is not known. Here we report that (−)-lomaiviticin A nicks and cleaves plasmid DNA by a pathway that is independent of reactive oxygen species and iron, and that the potent cytotoxicity of (−)-lomaiviticin A arises from the induction of DNA double-strand breaks (dsbs). In a plasmid cleavage assay, the ratio of single-strand breaks (ssbs) to dsbs is 5.3 ± 0.6:1. Labelling studies suggest that this cleavage occurs via a radical pathway. The structurally related isolates (−)-lomaiviticin C and (−)-kinamycin C, which contain one diazofluorene, are demonstrated to be much less effective DNA cleavage agents, thereby providing an explanation for the enhanced cytotoxicity of (−)-lomaiviticin A compared to that of other members of this family.

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Figure 1: Structures of the metabolites employed in this study and their proposed reaction pathways.
Figure 2: Analysis of nicked and cleaved plasmid pBR322 DNA by (−)-lomaiviticin A (1), (−)-lomaiviticin C (2) and (−)-kinamycin C (3).
Figure 3: Immunofluorescence imaging of γH2AX and 53BP1 foci in K562 cells treated with (−)-lomaiviticin A (1), (−)-lomaiviticin C (2) or (−)-kinamycin C (3).
Figure 4: Neutral comet unwinding assay of K562 cells treated with (−)-lomaiviticin A (1), (−)-lomaiviticin C (2) or (−)-kinamycin C (3).
Figure 5: Clonogenic survival curves and western blot analyses of cells treated with (−)-lomaiviticin A (1) or (−)-lomaiviticin C (2).
Figure 6: Relative reactivity studies and mechanistic pathways for the reduction of the diazofluorene.

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References

  1. He, H. et al. Lomaiviticins A and B, potent antitumor antibiotics from Micromonospora lomaivitiensis. J. Am. Chem. Soc. 123, 5362–5363 (2001).

    CAS  PubMed  Google Scholar 

  2. Woo, C. M., Beizer, N. E., Janso, J. E. & Herzon, S. B. Isolation of lomaiviticins C–E. Transformation of lomaiviticin C to lomaiviticin A, complete structure elucidation of lomaiviticin A, and structure–activity analyses. J. Am. Chem. Soc. 134, 15285–15288 (2012).

    CAS  PubMed  Google Scholar 

  3. Kersten, R. D. et al. Bioactivity-guided genome mining reveals the lomaiviticin biosynthetic gene cluster in Salinispora tropica. Chembiochem 14, 955–962 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  4. Ito, S., Matsuya, T., Ōmura, S., Otani, M. & Nakagawa, A. A new antibiotic, kinamycin. J. Antibiot. 23, 315–317 (1970).

    CAS  PubMed  Google Scholar 

  5. Hata, T., Ōmura, S., Iwai, Y., Nakagawa, A. & Otani, M. A new antibiotic, kinamycin: fermentation, isolation, purification and properties. J. Antibiot. 24, 353–359 (1971).

    CAS  PubMed  Google Scholar 

  6. Ōmura, S. et al. Structure of kinamycin C, and the structural relation among kinamycin A, B, C, and D. Chem. Pharm. Bull. 19, 2428–2430 (1971).

    Google Scholar 

  7. Furusaki, A. et al. Crystal and molecular structure of kinamycin C p-bromobenzoate. Israel J. Chem. 10, 173–187 (1972).

    CAS  Google Scholar 

  8. Ōmura, S., Nakagawa, A., Yamada, H., Hata, T. & Furusaki, A. Structures and biological properties of kinamycin A, B, C, and D. Chem. Pharm. Bull. 21, 931–940 (1973).

    PubMed  Google Scholar 

  9. Gould, S. J. Biosynthesis of the kinamycins. Chem. Rev. 97, 2499–2510 (1997).

    CAS  PubMed  Google Scholar 

  10. Marco-Contelles, J. & Molina, M. T. Naturally occurring diazo compounds: the kinamycins. Curr. Org. Chem. 7, 1433–1442 (2003).

    CAS  Google Scholar 

  11. Arya, D. P. Diazo and diazonium DNA cleavage agents: studies on model systems and natural product mechanisms of action. Top. Heterocycl. Chem. 2, 129–152 (2006).

    CAS  Google Scholar 

  12. Nawrat, C. C. & Moody, C. J. Natural products containing a diazo group. Nat. Prod. Rep. 28, 1426–1444 (2011).

    CAS  PubMed  Google Scholar 

  13. Herzon, S. B. & Woo, C. M. The diazofluorene antitumor antibiotics: structural elucidation, biosynthetic, synthetic, and chemical biological studies. Nat. Prod. Rep. 29, 87–118 (2012).

    CAS  PubMed  Google Scholar 

  14. O'Hara, K. A. et al. Mechanism of the cytotoxicity of the diazoparaquinone antitumor antibiotic kinamycin F. Free Radic. Biol. Med. 43, 1132–1144 (2007).

    CAS  PubMed  PubMed Central  Google Scholar 

  15. Heinecke, C. L. & Melander, C. Analysis of kinamycin D-mediated DNA cleavage. Tetrahedron Lett. 51, 1455–1458 (2010).

    CAS  Google Scholar 

  16. Laufer, R. S. & Dmitrienko, G. I. Diazo group electrophilicity in kinamycins and lomaiviticin A: potential insights into the molecular mechanism of antibacterial and antitumor activity. J. Am. Chem. Soc. 124, 1854–1855 (2002).

    CAS  PubMed  Google Scholar 

  17. Arya, D. P. & Jebaratnam, D. J. DNA cleaving ability of 9-diazofluorenes and diaryl diazomethanes: implications for the mode of action of the kinamycin antibiotics. J. Org. Chem. 60, 3268–3269 (1995).

    CAS  Google Scholar 

  18. Feldman, K. S. & Eastman, K. J. A proposal for the mechanism-of-action of diazoparaquinone natural products. J. Am. Chem. Soc. 127, 15344–15345 (2005).

    CAS  PubMed  PubMed Central  Google Scholar 

  19. Feldman, K. S. & Eastman, K. J. Studies on the mechanism of action of prekinamycin, a member of the diazoparaquinone family of natural products: evidence for both sp2 radical and orthoquinonemethide intermediates. J. Am. Chem. Soc. 128, 12562–12573 (2006).

    CAS  PubMed  PubMed Central  Google Scholar 

  20. Zeng, W. et al. Mimicking the biological activity of diazobenzo[b]fluorene natural products with electronically tuned diazofluorene analogs. Bioorg. Med. Chem. Lett. 16, 5148–5151 (2006).

    CAS  PubMed  Google Scholar 

  21. Ballard, T. E. & Melander, C. Kinamycin-mediated DNA cleavage under biomimetic conditions. Tetrahedron Lett. 49, 3157–3161 (2008).

    CAS  Google Scholar 

  22. Khdour, O. & Skibo, E. B. Quinone methide chemistry of prekinamycins: 13C-labeling, spectral global fitting and in vitro studies. Org. Biomol. Chem. 7, 2140–2154 (2009).

    CAS  PubMed  Google Scholar 

  23. Moore, H. W. Bioactivation as a model for drug design bioreductive alkylation. Science 197, 527–532 (1977).

    CAS  PubMed  Google Scholar 

  24. Mulcahy, S. P., Woo, C. M., Ding, W. D., Ellestad, G. A. & Herzon, S. B. Characterization of a reductively-activated elimination pathway relevant to the biological chemistry of the kinamycins and lomaiviticins. Chem. Sci. 3, 1070–1074 (2012).

    CAS  Google Scholar 

  25. Hasinoff, B. B. et al. Kinamycins A and C, bacterial metabolites that contain an unusual diazo group, as potential new anticancer agents: antiproliferative and cell cycle effects. Anti-Cancer Drugs 17, 825–837 (2006).

    CAS  PubMed  Google Scholar 

  26. O'Hara, K. A., Dmitrienko, G. I. & Hasinoff, B. B. Kinamycin F downregulates cyclin D3 in human leukemia K562 cells. Chem. Biol. Interact. 184, 396–402 (2010).

    CAS  PubMed  Google Scholar 

  27. Halliwell, B. & Gutteridge, J. M. C. in Methods in Enzymology Vol. 186 (eds Glazer, A. N. & Packer, L.) 1–85 (Academic Press, 1990).

    Google Scholar 

  28. Freifelder, D. & Trumbo, B. Matching of single-strand breaks to form double-strand breaks in DNA. Biopolymers 7, 681–693 (1969).

    CAS  Google Scholar 

  29. Povirk, L. F., Wübker, W., Köhnlein, W. & Hutchinson, F. DNA Double-strand breaks and alkali-labile bonds produced by bleomycin. Nucleic Acids Res. 4, 3573–3580 (1977).

    CAS  PubMed  PubMed Central  Google Scholar 

  30. Boger, D. L., Honda, T., Menezes, R. F. & Colletti, S. L. Total synthesis of bleomycin A2 and related agents. 3. Synthesis and comparative evaluation of deglycobleomycin A2, epideglycobleomycin A2, deglycobleomycin A1, and desacetamido-, descarboxamido-, desmethyl-, and desimidazolyldeglycobleomycin A2. J. Am. Chem. Soc. 116, 5631–5646 (1994).

    CAS  Google Scholar 

  31. Banath, J. P. & Olive, P. L. Expression of phosphorylated histone H2AX as a surrogate of cell killing by drugs that create DNA double-strand breaks. Cancer Res. 63, 4347–4350 (2003).

    CAS  PubMed  Google Scholar 

  32. Muslimovic, A., Ismail, I. H., Gao, Y. & Hammarsten, O. An optimized method for measurement of gamma-H2AX in blood mononuclear and cultured cells. Nature Protocols 3, 1187–1193 (2008).

    CAS  PubMed  Google Scholar 

  33. Schultz, L. B., Chehab, N. H., Malikzay, A. & Halazonetis, T. D. p53 binding protein 1 (53bp1) is an early participant in the cellular response to DNA double-strand breaks. J. Cell Biol. 151, 1381–1390 (2000).

    CAS  PubMed  PubMed Central  Google Scholar 

  34. Collins, A. The comet assay for DNA damage and repair. Mol. Biotechnol. 26, 249–261 (2004).

    CAS  PubMed  Google Scholar 

  35. Zein, N., McGahren, W. J., Morton, G. O., Ashcroft, J. & Ellestad, G. A. Exclusive abstraction of nonexchangeable protons from DNA by calicheamicin γ 1I. J. Am. Chem. Soc. 111, 6888–6890 (1989).

    CAS  Google Scholar 

  36. Roy, R., Chun, J. & Powell, S. N. BRCA1 and BRCA2: different roles in a common pathway of genome protection. Nature Rev. Cancer 12, 68–78 (2012).

    CAS  Google Scholar 

  37. Smith, J., Mun Tho, L., Xu, N. & Gillespie, D. A. in Advances in Cancer Research Vol. 108 (eds Vande Woude, G. F. & George, K.) 73–112 (Academic Press, 2010).

    Google Scholar 

  38. Schipler, A. & Iliakis, G. DNA double-strand-break complexity levels and their possible contributions to the probability for error-prone processing and repair pathway choice. Nucleic Acids Res. 41, 7589–7605 (2013).

    CAS  PubMed  PubMed Central  Google Scholar 

  39. Stadler, O. Zur Kenntniss der Merkaptane. Ber. Dtsch. Chem. Ges. 17, 2075–2081 (1884).

    CAS  Google Scholar 

  40. Ziegler, J. H. Ueber eine Methode zur Darstellung aromatischer Sulfide von bestimmter Constitution und das Thioxanthon. Ber. Dtsch. Chem. Ges. 23, 2469–2472 (1890).

    CAS  Google Scholar 

  41. Gannett, P. M. et al. C8-arylguanine and C8-aryladenine formation in calf thymus DNA from arenediazonium ions. Chem. Res. Toxicol. 12, 297–304 (1999).

    CAS  PubMed  Google Scholar 

  42. Hung, M. H. & Stock, L. M. Reactions of benzenediazonium ions with guanine and its derivatives. J. Org. Chem. 47, 448–453 (1982).

    CAS  Google Scholar 

  43. Wolkenberg, S. E. & Boger, D. L. Mechanisms of in situ activation for DNA-targeting antitumor agents. Chem. Rev. 102, 2477–2496 (2002).

    CAS  PubMed  Google Scholar 

  44. Borders, D. B. & Doyle, T. W. Enediyne Antibiotics as Antitumor Agents (Marcel Dekker, 1995).

    Google Scholar 

  45. Stubbe, J., Kozarich, J. W., Wu, W. & Vanderwall, D. E. Bleomycins: a structural model for specificity, binding, and double strand cleavage. Acc. Chem. Res. 29, 322–330 (1996).

    CAS  Google Scholar 

  46. Drak, J., Iwasawa, N., Danishefsky, S. & Crothers, D. M. The carbohydrate domain of calicheamicin γI1 determines its sequence specificity for DNA cleavage. Proc. Natl Acad. Sci. USA 88, 7464–7468 (1991).

    CAS  PubMed  Google Scholar 

  47. Irngartinger, H., Acker, R-D., Rebafka, W. & Staab, H. A. [2.2](2,5)Benzochinonophane: Struktur und Photochemie. Angew. Chem. 86, 705–706 (1974).

    CAS  Google Scholar 

  48. Wartini, A. R., Valenzuela, J., Staab, H. A. & Neugebauer, F. A. [2.2]Paracyclophane-4,7,12,15-tetrone, [2.2](1,4)naphthalenophane-4,7,14,17-tetrone, and 1,4,8,11-pentacenetetrone radical anions–a comparative ESR study. Eur. J. Org. Chem. 1998, 221–227 (1998).

    Google Scholar 

  49. Gómez, M., González, F. J. & González, I. Intra and intermolecular hydrogen bonding effects in the electrochemical reduction of α-phenolic-naphthoquinones. J. Electroanal. Chem. 578, 193–202 (2005).

    Google Scholar 

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Acknowledgements

The authors dedicate this paper to the memory of their colleague Donald M. Crothers. Financial support from the National Institute of General Medical Sciences (R01GM090000, S.B.H.), the National Institute of Environmental Health Sciences (R01ES005775, P.M.G.), the National Cancer Institute (R01CA168733, P.M.G.), the National Science Foundation (Graduate Research Fellowship to C.M.W.), the Searle Scholars Program (S.B.H.) and Yale University (S.B.H.) is gratefully acknowledged. S.B.H. acknowledges early-stage investigator awards from the David and Lucile Packard Foundation, the Alfred P. Sloan Foundation, the Camille and Henry Dreyfus Foundation, and the Research Corporation for Science Advancement. We thank T. Dymarz, J. Shen, D. Spiegel and T. Wang for assistance.

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L.C.C. and C.M.W. designed and performed the plasmid cleavage, immunofluorescence, comet and flow cytometry experiments. Z.L. and C.M.W. performed the in vitro reactivity studies. P.M.G. and D.A.H. designed, performed and analysed the clonogenic survival assays, pATM/pChk2/pATR/pChk1 western blots and comet assay employing BRCA2-deficient cells. S.B.H. conceived and designed the study, analysed the data and composed the manuscript.

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Correspondence to Seth B. Herzon.

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Colis, L., Woo, C., Hegan, D. et al. The cytotoxicity of (−)-lomaiviticin A arises from induction of double-strand breaks in DNA. Nature Chem 6, 504–510 (2014). https://doi.org/10.1038/nchem.1944

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