DOI: 10.1073/pnas.94.21.11557. The role of polyamine catabolism in polyamine analogue-induced programmed cell death

The role of polyamine catabolism in polyamine analogue-induced programmed cell death

10.1073/pnas.94.21.11557

Crossref journal-article

Proceedings of the National Academy of Sciences

Proceedings of the National Academy of Sciences (341)

Abstract

N1-ethyl-N11-[(cyclopropyl)methyl]-4,8,-diazaundecane (CPENSpm) is a polyamine analogue that represents a new class of antitumor agents that demonstrate phenotype-specific cytotoxic activity. However, the precise mechanism of its selective cytotoxic activity is not known. CPENSpm treatment results in the superinduction of the polyamine catabolic enzyme spermidine/spermineN1-acetyltransferase (SSAT) in sensitive cell types and has been demonstrated to induce programmed cell death (PCD). The catalysis of polyamines by the SSAT/polyamine oxidase (PAO) pathway produces H2O2as one product, suggesting that PCD produced by CPENSpm may be, in part, due to oxidative stress as a result of H2O2production. In the sensitive human nonsmall cell line H157, the coaddition of catalase significantly reduces high molecular weight (HMW) DNA (≥50 kb) and nuclear fragmentation. Important to note, specific inhibition of PAO byN,N′-bis(2,3-butadienyl)-1,4-butane-diamine results in a significant reduction of the formation of HMW DNA and nuclear fragmentation. In contrast, the coaddition of catalase or PAO inhibitor has no effect on reducing HMW DNA fragmentation induced byN1-ethyl-N11-[(cycloheptyl)methyl]-4,8,-diazaundecane, which does not induce SSAT and does not deplete intracellular polyamines. These results strongly suggest that H2O2production by PAO has a role in CPENSpm cytotoxicity in sensitive cells via PCD and demonstrate a potential basis for differential sensitivity to this promising new class of antineoplastic agents. Furthermore, the data suggest a general mechanism by which, under certain stimuli, cells can commit suicide through catabolism of the ubiquitous intracellular polyamines.

Bibliography

Ha, H. C., Woster, P. M., Yager, J. D., & Casero, R. A. (1997). The role of polyamine catabolism in polyamine analogue-induced programmed cellâdeath. Proceedings of the National Academy of Sciences, 94(21), 11557â11562.

Authors 4

Hyo Chol Ha (first)
Patrick M. Woster (additional)
James D. Yager (additional)
Robert A. Casero (additional)

References 44 Referenced 212

10.1038/bjc.1972.33
10.1016/S0074-7696(08)62312-8
G Majno, I Joris Am J Pathol 146, 3–15 (1995). / Am J Pathol by Majno G (1995)
10.1146/annurev.cb.07.110191.003311
10.1126/science.7878463
10.1073/pnas.93.6.2239
10.1006/taap.1994.1195
A E Pegg Cancer Res 48, 759–774 (1988). / Cancer Res by Pegg A E (1988)
10.1146/annurev.pa.35.040195.000415
10.3109/07853899109148056
C W Porter, R J Bernacki, J Miller, R J Bergeron Cancer Res 53, 581–586 (1993). / Cancer Res by Porter C W (1993)
10.1021/jm00401a019
10.1096/fasebj.7.8.8500690
M A Desiderio, E Grassilli, E Bellesia, P Salomoni, C Franceschi Cell Growth Diff 6, 505–513 (1995). / Cell Growth Diff by Desiderio M A (1995)
10.1042/bj3110723
10.1016/S0021-9258(18)43849-5
K E Tobias, C Kahana Cell Growth Diff 6, 1279–1285 (1995). / Cell Growth Diff by Tobias K E (1995)
10.1128/mcb.14.9.5741-5747.1994
10.1002/jcp.1041650320
10.1006/bbrc.1995.2679
D E McCloskey, J Yang, P M Woster, N E Davidson, R A Casero Clin Cancer Res 2, 441–446 (1996). / Clin Cancer Res by McCloskey D E (1996)
D E McCloskey, R A Casero, P M Woster, N E Davidson Cancer Res 55, 3233–3236 (1995). / Cancer Res by McCloskey D E (1995)
D E McCloskey, L J Prestigiacomo, P M Woster, R A Casero, N E Davidson Proc Am Assoc Can Res 37, 400, (abstr.). (1996). / Proc Am Assoc Can Res by McCloskey D E (1996)
10.1007/BF00685735
10.1016/S0079-6123(08)61229-7
P M Woster Polyamines: Regulation and Molecular InteractionR A Casero, ed R A Casero (Landes, Austin, TX), pp. 171–186 (1995). / Polyamines: Regulation and Molecular Interaction by Woster P M (1995)
D G Hoyt, R J Mannix, J M Rusnak, B R Pitt, J S Lazo Am J Physiol 269, L171–L177 (1995). / Am J Physiol by Hoyt D G (1995)
10.1016/S0022-2836(75)80083-0
10.1016/0092-8674(93)80066-N
10.1177/30.9.6182188
A Al-Mehdi, H Shuman, A B Fisher Lab Invest 70, 579–587 (1994). / Lab Invest by Al-Mehdi A (1994)
10.1126/science.270.5234.296
10.1042/bj2690329
10.1002/cyto.990160407
10.1007/BF00686190
R A Casero, B Go, H W Theiss, J Smith, S B Baylin, G D Luk Cancer Res 47, 3964–3967 (1987). / Cancer Res by Casero R A (1987)
10.1042/bj2910131
10.1073/pnas.86.10.3654
10.1073/pnas.87.11.4340
R E Parchment, G B Pierce Cancer Res 49, 6680–6686 (1989). / Cancer Res by Parchment R E (1989)
R E Parchment Int J Dev Biol 37, 75–83 (1993). / Int J Dev Biol by Parchment R E (1993)
G Packhamn, R A Ashmun, J L Cleveland J Immunol 156, 2792–2800 (1996). (10.4049/jimmunol.156.8.2792) / J Immunol by Packhamn G (1996)
R A Casero, A R Mank, L Xiao, J Smith, R J Bergeron, P Celano Cancer Res 52, 5359–5363 (1992). / Cancer Res by Casero R A (1992)
N W Shappell, J T Miller, R J Bergeron, C W Porter Anticancer Res 12, 1083–1090 (1992). / Anticancer Res by Shappell N W (1992)

Dates

Type	When
Created	23 years, 1 month ago (July 26, 2002, 10:42 a.m.)
Deposited	2 years, 4 months ago (April 22, 2023, 8:33 a.m.)
Indexed	3 weeks, 1 day ago (Aug. 7, 2025, 4:41 p.m.)
Issued	27 years, 10 months ago (Oct. 14, 1997)
Published	27 years, 10 months ago (Oct. 14, 1997)
Published Online	27 years, 10 months ago (Oct. 14, 1997)
Published Print	27 years, 10 months ago (Oct. 14, 1997)

Funders 0

None

BibTeX

@article{Ha_1997, title={The role of polyamine catabolism in polyamine analogue-induced programmed cell death}, volume={94}, ISSN={1091-6490}, url={http://dx.doi.org/10.1073/pnas.94.21.11557}, DOI={10.1073/pnas.94.21.11557}, number={21}, journal={Proceedings of the National Academy of Sciences}, publisher={Proceedings of the National Academy of Sciences}, author={Ha, Hyo Chol and Woster, Patrick M. and Yager, James D. and Casero, Robert A.}, year={1997}, month=oct, pages={11557–11562} }

JSON

{
  "indexed": {
    "date-parts": [
      [
        2025,
        8,
        7
      ]
    ],
    "date-time": "2025-08-07T20:41:03Z",
    "timestamp": 1754599263790
  },
  "reference-count": 44,
  "publisher": "Proceedings of the National Academy of Sciences",
  "issue": "21",
  "content-domain": {
    "domain": [
      "www.pnas.org"
    ],
    "crossmark-restriction": true
  },
  "published-print": {
    "date-parts": [
      [
        1997,
        10,
        14
      ]
    ]
  },
  "abstract": "<jats:p><jats:italic>N</jats:italic><jats:sup>1</jats:sup>-ethyl-<jats:italic>N</jats:italic><jats:sup>11</jats:sup>-[(cyclopropyl)methyl]-4,8,-diazaundecane (CPENSpm) is a polyamine analogue that represents a new class of antitumor agents that demonstrate phenotype-specific cytotoxic activity. However, the precise mechanism of its selective cytotoxic activity is not known. CPENSpm treatment results in the superinduction of the polyamine catabolic enzyme spermidine/spermine<jats:italic>N</jats:italic><jats:sup>1</jats:sup>-acetyltransferase (SSAT) in sensitive cell types and has been demonstrated to induce programmed cell death (PCD). The catalysis of polyamines by the SSAT/polyamine oxidase (PAO) pathway produces H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>as one product, suggesting that PCD produced by CPENSpm may be, in part, due to oxidative stress as a result of H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>production. In the sensitive human nonsmall cell line H157, the coaddition of catalase significantly reduces high molecular weight (HMW) DNA (\u226550 kb) and nuclear fragmentation. Important to note, specific inhibition of PAO by<jats:italic>N</jats:italic>,<jats:italic>N</jats:italic>\u2032-bis(2,3-butadienyl)-1,4-butane-diamine results in a significant reduction of the formation of HMW DNA and nuclear fragmentation. In contrast, the coaddition of catalase or PAO inhibitor has no effect on reducing HMW DNA fragmentation induced by<jats:italic>N</jats:italic><jats:sup>1</jats:sup>-ethyl-<jats:italic>N</jats:italic><jats:sup>11</jats:sup>-[(cycloheptyl)methyl]-4,8,-diazaundecane, which does not induce SSAT and does not deplete intracellular polyamines. These results strongly suggest that H<jats:sub>2</jats:sub>O<jats:sub>2</jats:sub>production by PAO has a role in CPENSpm cytotoxicity in sensitive cells via PCD and demonstrate a potential basis for differential sensitivity to this promising new class of antineoplastic agents. Furthermore, the data suggest a general mechanism by which, under certain stimuli, cells can commit suicide through catabolism of the ubiquitous intracellular polyamines.</jats:p>",
  "DOI": "10.1073/pnas.94.21.11557",
  "type": "journal-article",
  "created": {
    "date-parts": [
      [
        2002,
        7,
        26
      ]
    ],
    "date-time": "2002-07-26T14:42:40Z",
    "timestamp": 1027694560000
  },
  "page": "11557-11562",
  "update-policy": "http://dx.doi.org/10.1073/pnas.cm10313",
  "source": "Crossref",
  "is-referenced-by-count": 212,
  "title": "The role of polyamine catabolism in polyamine analogue-induced programmed cell\u2009death",
  "prefix": "10.1073",
  "volume": "94",
  "author": [
    {
      "given": "Hyo Chol",
      "family": "Ha",
      "sequence": "first",
      "affiliation": [
        {
          "name": "Division of Toxicological Sciences, Department of Environmental Health Sciences, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205; The Oncology Center Research Laboratories, Johns Hopkins University School of Medicine, Baltimore, MD 21231; and Wayne State University, Detroit, MI 48202"
        }
      ]
    },
    {
      "given": "Patrick M.",
      "family": "Woster",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "Division of Toxicological Sciences, Department of Environmental Health Sciences, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205; The Oncology Center Research Laboratories, Johns Hopkins University School of Medicine, Baltimore, MD 21231; and Wayne State University, Detroit, MI 48202"
        }
      ]
    },
    {
      "given": "James D.",
      "family": "Yager",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "Division of Toxicological Sciences, Department of Environmental Health Sciences, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205; The Oncology Center Research Laboratories, Johns Hopkins University School of Medicine, Baltimore, MD 21231; and Wayne State University, Detroit, MI 48202"
        }
      ]
    },
    {
      "suffix": "Jr.",
      "given": "Robert A.",
      "family": "Casero",
      "sequence": "additional",
      "affiliation": [
        {
          "name": "Division of Toxicological Sciences, Department of Environmental Health Sciences, Johns Hopkins School of Hygiene and Public Health, Baltimore, MD 21205; The Oncology Center Research Laboratories, Johns Hopkins University School of Medicine, Baltimore, MD 21231; and Wayne State University, Detroit, MI 48202"
        }
      ]
    }
  ],
  "member": "341",
  "published-online": {
    "date-parts": [
      [
        1997,
        10,
        14
      ]
    ]
  },
  "reference": [
    {
      "key": "e_1_3_3_1_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1038/bjc.1972.33"
    },
    {
      "key": "e_1_3_3_2_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1016/S0074-7696(08)62312-8"
    },
    {
      "key": "e_1_3_3_3_2",
      "first-page": "3",
      "volume": "146",
      "author": "Majno G",
      "year": "1995",
      "unstructured": "G Majno, I Joris Am J Pathol 146, 3\u201315 (1995).",
      "journal-title": "Am J Pathol"
    },
    {
      "key": "e_1_3_3_4_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1146/annurev.cb.07.110191.003311"
    },
    {
      "key": "e_1_3_3_5_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1126/science.7878463"
    },
    {
      "key": "e_1_3_3_6_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1073/pnas.93.6.2239"
    },
    {
      "key": "e_1_3_3_7_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1006/taap.1994.1195"
    },
    {
      "key": "e_1_3_3_8_2",
      "first-page": "759",
      "volume": "48",
      "author": "Pegg A E",
      "year": "1988",
      "unstructured": "A E Pegg Cancer Res 48, 759\u2013774 (1988).",
      "journal-title": "Cancer Res"
    },
    {
      "key": "e_1_3_3_9_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1146/annurev.pa.35.040195.000415"
    },
    {
      "key": "e_1_3_3_10_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.3109/07853899109148056"
    },
    {
      "key": "e_1_3_3_11_2",
      "first-page": "581",
      "volume": "53",
      "author": "Porter C W",
      "year": "1993",
      "unstructured": "C W Porter, R J Bernacki, J Miller, R J Bergeron Cancer Res 53, 581\u2013586 (1993).",
      "journal-title": "Cancer Res"
    },
    {
      "key": "e_1_3_3_12_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1021/jm00401a019"
    },
    {
      "key": "e_1_3_3_13_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1096/fasebj.7.8.8500690"
    },
    {
      "key": "e_1_3_3_14_2",
      "first-page": "505",
      "volume": "6",
      "author": "Desiderio M A",
      "year": "1995",
      "unstructured": "M A Desiderio, E Grassilli, E Bellesia, P Salomoni, C Franceschi Cell Growth Diff 6, 505\u2013513 (1995).",
      "journal-title": "Cell Growth Diff"
    },
    {
      "key": "e_1_3_3_15_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1042/bj3110723"
    },
    {
      "key": "e_1_3_3_16_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1016/S0021-9258(18)43849-5"
    },
    {
      "key": "e_1_3_3_17_2",
      "first-page": "1279",
      "volume": "6",
      "author": "Tobias K E",
      "year": "1995",
      "unstructured": "K E Tobias, C Kahana Cell Growth Diff 6, 1279\u20131285 (1995).",
      "journal-title": "Cell Growth Diff"
    },
    {
      "key": "e_1_3_3_18_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1128/mcb.14.9.5741-5747.1994"
    },
    {
      "key": "e_1_3_3_19_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1002/jcp.1041650320"
    },
    {
      "key": "e_1_3_3_20_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1006/bbrc.1995.2679"
    },
    {
      "key": "e_1_3_3_21_2",
      "first-page": "441",
      "volume": "2",
      "author": "McCloskey D E",
      "year": "1996",
      "unstructured": "D E McCloskey, J Yang, P M Woster, N E Davidson, R A Casero Clin Cancer Res 2, 441\u2013446 (1996).",
      "journal-title": "Clin Cancer Res"
    },
    {
      "key": "e_1_3_3_22_2",
      "first-page": "3233",
      "volume": "55",
      "author": "McCloskey D E",
      "year": "1995",
      "unstructured": "D E McCloskey, R A Casero, P M Woster, N E Davidson Cancer Res 55, 3233\u20133236 (1995).",
      "journal-title": "Cancer Res"
    },
    {
      "key": "e_1_3_3_23_2",
      "first-page": "400",
      "volume": "37",
      "author": "McCloskey D E",
      "year": "1996",
      "unstructured": "D E McCloskey, L J Prestigiacomo, P M Woster, R A Casero, N E Davidson Proc Am Assoc Can Res 37, 400, (abstr.). (1996).",
      "journal-title": "Proc Am Assoc Can Res"
    },
    {
      "key": "e_1_3_3_24_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1007/BF00685735"
    },
    {
      "key": "e_1_3_3_25_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1016/S0079-6123(08)61229-7"
    },
    {
      "key": "e_1_3_3_26_2",
      "first-page": "171",
      "volume-title": "Polyamines: Regulation and Molecular Interaction",
      "author": "Woster P M",
      "year": "1995",
      "unstructured": "P M Woster Polyamines: Regulation and Molecular InteractionR A Casero, ed R A Casero (Landes, Austin, TX), pp. 171\u2013186 (1995)."
    },
    {
      "key": "e_1_3_3_27_2",
      "first-page": "L171",
      "volume": "269",
      "author": "Hoyt D G",
      "year": "1995",
      "unstructured": "D G Hoyt, R J Mannix, J M Rusnak, B R Pitt, J S Lazo Am J Physiol 269, L171\u2013L177 (1995).",
      "journal-title": "Am J Physiol"
    },
    {
      "key": "e_1_3_3_28_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1016/S0022-2836(75)80083-0"
    },
    {
      "key": "e_1_3_3_29_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1016/0092-8674(93)80066-N"
    },
    {
      "key": "e_1_3_3_30_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1177/30.9.6182188"
    },
    {
      "key": "e_1_3_3_31_2",
      "first-page": "579",
      "volume": "70",
      "author": "Al-Mehdi A",
      "year": "1994",
      "unstructured": "A Al-Mehdi, H Shuman, A B Fisher Lab Invest 70, 579\u2013587 (1994).",
      "journal-title": "Lab Invest"
    },
    {
      "key": "e_1_3_3_32_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1126/science.270.5234.296"
    },
    {
      "key": "e_1_3_3_33_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1042/bj2690329"
    },
    {
      "key": "e_1_3_3_34_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1002/cyto.990160407"
    },
    {
      "key": "e_1_3_3_35_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1007/BF00686190"
    },
    {
      "key": "e_1_3_3_36_2",
      "first-page": "3964",
      "volume": "47",
      "author": "Casero R A",
      "year": "1987",
      "unstructured": "R A Casero, B Go, H W Theiss, J Smith, S B Baylin, G D Luk Cancer Res 47, 3964\u20133967 (1987).",
      "journal-title": "Cancer Res"
    },
    {
      "key": "e_1_3_3_37_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1042/bj2910131"
    },
    {
      "key": "e_1_3_3_38_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1073/pnas.86.10.3654"
    },
    {
      "key": "e_1_3_3_39_2",
      "doi-asserted-by": "publisher",
      "DOI": "10.1073/pnas.87.11.4340"
    },
    {
      "key": "e_1_3_3_40_2",
      "first-page": "6680",
      "volume": "49",
      "author": "Parchment R E",
      "year": "1989",
      "unstructured": "R E Parchment, G B Pierce Cancer Res 49, 6680\u20136686 (1989).",
      "journal-title": "Cancer Res"
    },
    {
      "key": "e_1_3_3_41_2",
      "first-page": "75",
      "volume": "37",
      "author": "Parchment R E",
      "year": "1993",
      "unstructured": "R E Parchment Int J Dev Biol 37, 75\u201383 (1993).",
      "journal-title": "Int J Dev Biol"
    },
    {
      "key": "e_1_3_3_42_2",
      "doi-asserted-by": "crossref",
      "first-page": "2792",
      "DOI": "10.4049/jimmunol.156.8.2792",
      "volume": "156",
      "author": "Packhamn G",
      "year": "1996",
      "unstructured": "G Packhamn, R A Ashmun, J L Cleveland J Immunol 156, 2792\u20132800 (1996).",
      "journal-title": "J Immunol"
    },
    {
      "key": "e_1_3_3_43_2",
      "first-page": "5359",
      "volume": "52",
      "author": "Casero R A",
      "year": "1992",
      "unstructured": "R A Casero, A R Mank, L Xiao, J Smith, R J Bergeron, P Celano Cancer Res 52, 5359\u20135363 (1992).",
      "journal-title": "Cancer Res"
    },
    {
      "key": "e_1_3_3_44_2",
      "first-page": "1083",
      "volume": "12",
      "author": "Shappell N W",
      "year": "1992",
      "unstructured": "N W Shappell, J T Miller, R J Bergeron, C W Porter Anticancer Res 12, 1083\u20131090 (1992).",
      "journal-title": "Anticancer Res"
    }
  ],
  "container-title": "Proceedings of the National Academy of Sciences",
  "original-title": [],
  "language": "en",
  "link": [
    {
      "URL": "https://pnas.org/doi/pdf/10.1073/pnas.94.21.11557",
      "content-type": "unspecified",
      "content-version": "vor",
      "intended-application": "similarity-checking"
    }
  ],
  "deposited": {
    "date-parts": [
      [
        2023,
        4,
        22
      ]
    ],
    "date-time": "2023-04-22T12:33:25Z",
    "timestamp": 1682166805000
  },
  "score": 1,
  "resource": {
    "primary": {
      "URL": "https://pnas.org/doi/full/10.1073/pnas.94.21.11557"
    }
  },
  "subtitle": [],
  "short-title": [],
  "issued": {
    "date-parts": [
      [
        1997,
        10,
        14
      ]
    ]
  },
  "references-count": 44,
  "journal-issue": {
    "issue": "21",
    "published-print": {
      "date-parts": [
        [
          1997,
          10,
          14
        ]
      ]
    }
  },
  "alternative-id": [
    "10.1073/pnas.94.21.11557"
  ],
  "URL": "http://dx.doi.org/10.1073/pnas.94.21.11557",
  "relation": {},
  "ISSN": [
    "0027-8424",
    "1091-6490"
  ],
  "subject": [],
  "container-title-short": "Proc. Natl. Acad. Sci. U.S.A.",
  "published": {
    "date-parts": [
      [
        1997,
        10,
        14
      ]
    ]
  },
  "assertion": [
    {
      "value": "1997-07-09",
      "order": 0,
      "name": "received",
      "label": "Received",
      "group": {
        "name": "publication_history",
        "label": "Publication History"
      }
    },
    {
      "value": "1997-08-19",
      "order": 1,
      "name": "accepted",
      "label": "Accepted",
      "group": {
        "name": "publication_history",
        "label": "Publication History"
      }
    },
    {
      "value": "1997-10-14",
      "order": 2,
      "name": "published",
      "label": "Published",
      "group": {
        "name": "publication_history",
        "label": "Publication History"
      }
    }
  ]
}