[(18)F] PARPi imaging is not affected by HPV status in vitro Journal Article


Authors: Guru, N.; De Souza França, P. D.; Pirovano, G.; Huang, C.; Patel, S. G.; Reiner, T.
Article Title: [(18)F] PARPi imaging is not affected by HPV status in vitro
Abstract: Background. Human papillomavirus- (HPV-) associated oropharyngeal squamous cell carcinomas (OPSCCs) are clinically and pathologically distinct from HPV-negative tumors. Here, we explore whether HPV affects functional biomarkers, including γH2AX, RAD51, and PARP1. Moreover, the role of [18F]PARPi as a broadly applicable imaging tool for head and neck carcinomas is investigated. Methods. HPV-positive and HPV-negative cell lines were used to evaluate the γH2AX, RAD51, and PARP1 expression with immunoblotting and immunofluorescence. Effects of external beam ionizing radiation were investigated in vitro, and survival was investigated via colony-formation assay. [18F]PARPi uptake experiments were performed on HPV-negative and HPV-positive cell lines to quantify PARP1 expression. PARP1 IHC and γH2AX foci were quantified using patient-derived oropharyngeal tumor specimens. Results. Differences in DNA repair were detected, showing higher RAD51 and γH2AX expression in HPV-positive cell lines. Clonogenic assays confirm HPV-positive cell lines to be significantly more radiosensitive. PARP1 expression levels were similar, irrespective of HPV status. Consequently, [18F]PARPi uptake assays demonstrated that this tracer is internalized in cell lines independently from their HPV status. Conclusion. The HPV status, often used clinically to stratify patients, did not affect PARP1 levels, suggesting that PARP imaging can be performed in both HPV-positive and HPV-negative patients. This study confirms that the PET imaging agent [18F]PARPi could serve as a general clinical tool for oropharyngeal cancer patients. © 2021 Navjot Guru et al.
Keywords: squamous cell carcinoma; cell culture; radiation effects; tumors; immunoblotting; ionizing radiation; cells; human papillomavirus; colony formation; clinical tools; expression levels; oropharyngeal cancer; clonogenic assays
Journal Title: Molecular Imaging
Volume: 2021
ISSN: 1535-3508
Publisher: Sage Publications, Inc.  
Date Published: 2021-01-20
Start Page: 6641397
Language: English
DOI: 10.1155/2021/6641397
PROVIDER: scopus
PMCID: PMC8205605
PUBMED: 34194286
DOI/URL:
Notes: Article -- Export Date: 3 May 2021 -- Source: Scopus
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  1. Snehal G Patel
    411 Patel
  2. Thomas Reiner
    136 Reiner
  3. Navjot Guru
    13 Guru
  4. Cien Huang
    2 Huang