PARP-targeted auger therapy in p53 mutant colon cancer xenograft mouse models Journal Article


Authors: Wilson, T.; Pirovano, G.; Xiao, G.; Samuels, Z.; Roberts, S.; Viray, T.; Guru, N.; Zanzonico, P.; Gollub, M.; Pillarsetty, N. V. K.; Reiner, T.; Bargonetti, J.
Article Title: PARP-targeted auger therapy in p53 mutant colon cancer xenograft mouse models
Abstract: Despite Auger electrons being highly appealing due to their short-range and high linear energy transfer to surrounding tissues, the progress in the field has been limited due to the challenge in delivering a therapeutic dose within the close proximity of cancer cell's DNA. Here, we demonstrate that the PARP inhibitor 123I-MAPi is a viable agent for the systemic administration and treatment of p53 mutant cancers. Significantly, minimal off-site toxicity was observed in mice administered with up to 74 MBq of 127I-PARPi. Taken together, these results lay the foundation for future clinical evaluation and broader preclinical investigations. By harnessing the scaffold of the PARP inhibitor Olaparib, we were able to deliver therapeutic levels of Auger radiation to the site of human colorectal cancer xenograft tumors after systemic administration. In-depth toxicity studies analyzed blood chemistry levels and markers associated with specific organ toxicity. Finally, p53+/+ and p53-/- human colorectal cancer cell lines were evaluated for the ability of 123I-MAPi to induce tumor growth delay. Toxicity studies demonstrate that both 123I-MAPi and its stable isotopologue, 127I-PARPi, have no significant off-site toxicity when administered systemically. Analysis following 123I-MAPi treatment confirmed its ability to induce DNA damage at the site of xenograft tumors when administered systemically. Finally, we demonstrate that 123I-MAPi generates a therapeutic response in p53-/-, but not p53+/+, subcutaneous xenograft tumors in mouse models. Taken together, these results represent the first example of a PARP Auger theranostic agent capable of delivering a therapeutic dose to xenograft human colorectal cancer tumors upon systemic administration without causing significant toxicity to surrounding mouse organs. Moreover, it suggests that a PARP Auger theranostic can act as a targeted therapeutic for cancers with mutated p53 pathways. This landmark goal paves the way for clinical evaluation of 123I-MAPi for pan cancer therapeutics. © 2021 American Chemical Society.
Keywords: p53; p21; parp; auger; 123i-mapi
Journal Title: Molecular Pharmaceutics
Volume: 18
Issue: 9
ISSN: 1543-8384
Publisher: American Chemical Society  
Date Published: 2021-09-06
Start Page: 3418
End Page: 3428
Language: English
DOI: 10.1021/acs.molpharmaceut.1c00323
PUBMED: 34318678
PROVIDER: scopus
PMCID: PMC8686831
DOI/URL:
Notes: Article -- Export Date: 1 October 2021 -- Source: Scopus
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MSK Authors
  1. Marc J Gollub
    208 Gollub
  2. Pat B Zanzonico
    355 Zanzonico
  3. Thomas Reiner
    136 Reiner
  4. Sheryl Roberts
    23 Roberts
  5. Navjot Guru
    13 Guru
  6. Thomas Charles Wilson
    6 Wilson
  7. Zachary Samuels
    17 Samuels
  8. Tara Viray
    12 Viray
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