Presented as a poster at the Combined Otolaryngological Spring Meeting (COSM), San Diego, California, April 25–29, 2007.
Photodynamic therapy of cottontail rabbit papillomavirus-induced papillomas in a severe combined immunodeficient mouse xenograft system†
Article first published online: 20 JAN 2010
Copyright © 2010 The American Laryngological, Rhinological, and Otological Society, Inc.
Volume 120, Issue 3, pages 618–624, March 2010
How to Cite
Lee, R. G., Vecchiotti, M. A., Heaphy, J., Panneerselvam, A., Schluchter, M. D., Oleinick, N. L., Lavertu, P., Alagramam, K. N., Arnold, J. E. and Sprecher, R. C. (2010), Photodynamic therapy of cottontail rabbit papillomavirus-induced papillomas in a severe combined immunodeficient mouse xenograft system. The Laryngoscope, 120: 618–624. doi: 10.1002/lary.20709
- Issue published online: 16 FEB 2010
- Article first published online: 20 JAN 2010
- Manuscript Accepted: 12 MAY 2009
- Manuscript Revised: 7 MAY 2009
- Manuscript Received: 27 JAN 2009
- Rainbow Board of Trustees through the Rainbow Surgical Specialists and by NCI. Grant Number: P01CA48735
- Recurrent respiratory papillomatosis;
- photodynamic therapy;
To evaluate the efficacy of photodynamic therapy (PDT) with the phthalocyanine photosensitizer Pc 4 for treating an animal model of recurrent respiratory papillomatosis (RRP).
Rabbit skin was grafted onto the dorsum of severe combined immunodeficient mice, two xenografts per animal. After the graft healed, it was inoculated with cottontail rabbit papillomavirus (CRPV). When papillomas developed, Pc 4 (0.6 or 1.0 mg/kg) was administered systemically, and 48 hours later, one papilloma of the two on each animal was exposed to 675-nm photoactivating light at either 100 or 150 J/cm2. In addition to the contralateral tumors, which received Pc 4 but no light, other controls included animals receiving light only or neither agent. Response was assessed by measuring papilloma size with a caliper. Some papillomas and residual skin were harvested for histological assessment.
For the lower-dose PDT regimens, papilloma growth rates were not significantly different from the controls. In contrast, 13 of 15 papillomas receiving the higher Pc 4 dose (1.0 mg/kg) and the higher light fluence (150 J/cm2) regressed completely and did not regrow within the observation period of up to 79 days. The response of these papillomas was significantly different from the controls (P < .001). Histological analysis confirmed the absence of residual tumor following complete response and replacement with near-normal epithelium.
Pc 4-PDT is highly effective in treating virally induced (CRPV) papillomas in a murine model of RRP, and thus warrants further study as a treatment for HPV-induced papillomas. Laryngoscope, 2010