Photodynamic therapy and tumor imaging of hypericin-treated squamous cell carcinoma

Christian S. Head, Quang Luu, Joel Sercarz, Romaine Saxton

Research output: Contribution to journalArticle

23 Citations (Scopus)

Abstract

Background: Conventional cancer therapy including surgery, radiation, and chemotherapy often are physically debilitating and largely ineffective in previously treated patients with recurrent head and neck squamous cell carcinoma (SCC). A natural photochemical, hypericin, could be a less invasive method for laser photodynamic therapy (PDT) of these recurrent head and neck malignancies. Hypericin has powerful photo-oxidizing ability, tumor localization properties, and fluorescent imaging capabilities as well as minimal dark toxicity. The current study defined hypericin PDT in vitro with human SCC cells before the cells were grown as tumor transplants in nude mice and tested as a model for hypericin induced tumor fluorescence and PDT via laser fiberoptics. Methods: SNU squamous carcinoma cells were grown in tissue culture, detached from monolayers with trypsin, and incubated with 0.1 μg to 10 μg/ml of hypericin before exposure to laser light at 514, 550, or 593 nm to define optimal dose, time, and wavelength for PDT of tumor cells. The SCC cells also were injected subcutaneously in nude mice and grown for 6 8 weeks to form tumors before hypericin injection and insertion of fiberoptics from a KTP532 surgical laser to assess the feasibility of this operating room instrument in stimulating fluorescence and PDT of tumors. Results: In vitro testing revealed a hypericin dose of 0.2 0.5 μg/ml was needed for PDT of the SCC cells with an optimal tumoricidal response seen at the 593 nm light absorption maximum. In vivo tumor retention of injected hypericin was seen for 7 to10 days using KTP532 laser induced fluorescence and biweekly PDT via laser fiberoptics led to regression of SCC tumor transplants under 0.4 cm2 diameter, but resulted in progression of larger size tumors in the nude mice. Conclusion: In this preclinical study, hypericin was tested for 514 593 nm dye laser PDT of human SCC cells in vitro and for KTP532 surgical laser targeting of SCC tumors in mice. The results suggest hypericin is a potent tumor imaging agent using this surgical laser that may prove useful in defining tumor margins and possibly in sterilizing post-resection margins. Deeply penetrating pulsed infrared laser emissions will be needed for PDT of larger and more inaccessible tumors.

Original languageEnglish (US)
Article number1477
Pages (from-to)1-10
Number of pages10
JournalWorld Journal of Surgical Oncology
Volume4
DOIs
StatePublished - Dec 5 2006

Fingerprint

Photochemotherapy
Squamous Cell Carcinoma
Lasers
Neoplasms
Nude Mice
Fluorescence
hypericin
Laser Therapy
Dye Lasers
Transplants
Operating Rooms
Trypsin

ASJC Scopus subject areas

  • Oncology
  • Surgery

Cite this

Photodynamic therapy and tumor imaging of hypericin-treated squamous cell carcinoma. / Head, Christian S.; Luu, Quang; Sercarz, Joel; Saxton, Romaine.

In: World Journal of Surgical Oncology, Vol. 4, 1477, 05.12.2006, p. 1-10.

Research output: Contribution to journalArticle

Head, Christian S. ; Luu, Quang ; Sercarz, Joel ; Saxton, Romaine. / Photodynamic therapy and tumor imaging of hypericin-treated squamous cell carcinoma. In: World Journal of Surgical Oncology. 2006 ; Vol. 4. pp. 1-10.
@article{e5129862544b49e59e750c7794bb4906,
title = "Photodynamic therapy and tumor imaging of hypericin-treated squamous cell carcinoma",
abstract = "Background: Conventional cancer therapy including surgery, radiation, and chemotherapy often are physically debilitating and largely ineffective in previously treated patients with recurrent head and neck squamous cell carcinoma (SCC). A natural photochemical, hypericin, could be a less invasive method for laser photodynamic therapy (PDT) of these recurrent head and neck malignancies. Hypericin has powerful photo-oxidizing ability, tumor localization properties, and fluorescent imaging capabilities as well as minimal dark toxicity. The current study defined hypericin PDT in vitro with human SCC cells before the cells were grown as tumor transplants in nude mice and tested as a model for hypericin induced tumor fluorescence and PDT via laser fiberoptics. Methods: SNU squamous carcinoma cells were grown in tissue culture, detached from monolayers with trypsin, and incubated with 0.1 μg to 10 μg/ml of hypericin before exposure to laser light at 514, 550, or 593 nm to define optimal dose, time, and wavelength for PDT of tumor cells. The SCC cells also were injected subcutaneously in nude mice and grown for 6 8 weeks to form tumors before hypericin injection and insertion of fiberoptics from a KTP532 surgical laser to assess the feasibility of this operating room instrument in stimulating fluorescence and PDT of tumors. Results: In vitro testing revealed a hypericin dose of 0.2 0.5 μg/ml was needed for PDT of the SCC cells with an optimal tumoricidal response seen at the 593 nm light absorption maximum. In vivo tumor retention of injected hypericin was seen for 7 to10 days using KTP532 laser induced fluorescence and biweekly PDT via laser fiberoptics led to regression of SCC tumor transplants under 0.4 cm2 diameter, but resulted in progression of larger size tumors in the nude mice. Conclusion: In this preclinical study, hypericin was tested for 514 593 nm dye laser PDT of human SCC cells in vitro and for KTP532 surgical laser targeting of SCC tumors in mice. The results suggest hypericin is a potent tumor imaging agent using this surgical laser that may prove useful in defining tumor margins and possibly in sterilizing post-resection margins. Deeply penetrating pulsed infrared laser emissions will be needed for PDT of larger and more inaccessible tumors.",
author = "Head, {Christian S.} and Quang Luu and Joel Sercarz and Romaine Saxton",
year = "2006",
month = "12",
day = "5",
doi = "10.1186/1477-7819-4-1",
language = "English (US)",
volume = "4",
pages = "1--10",
journal = "World Journal of Surgical Oncology",
issn = "1477-7819",
publisher = "BioMed Central",

}

TY - JOUR

T1 - Photodynamic therapy and tumor imaging of hypericin-treated squamous cell carcinoma

AU - Head, Christian S.

AU - Luu, Quang

AU - Sercarz, Joel

AU - Saxton, Romaine

PY - 2006/12/5

Y1 - 2006/12/5

N2 - Background: Conventional cancer therapy including surgery, radiation, and chemotherapy often are physically debilitating and largely ineffective in previously treated patients with recurrent head and neck squamous cell carcinoma (SCC). A natural photochemical, hypericin, could be a less invasive method for laser photodynamic therapy (PDT) of these recurrent head and neck malignancies. Hypericin has powerful photo-oxidizing ability, tumor localization properties, and fluorescent imaging capabilities as well as minimal dark toxicity. The current study defined hypericin PDT in vitro with human SCC cells before the cells were grown as tumor transplants in nude mice and tested as a model for hypericin induced tumor fluorescence and PDT via laser fiberoptics. Methods: SNU squamous carcinoma cells were grown in tissue culture, detached from monolayers with trypsin, and incubated with 0.1 μg to 10 μg/ml of hypericin before exposure to laser light at 514, 550, or 593 nm to define optimal dose, time, and wavelength for PDT of tumor cells. The SCC cells also were injected subcutaneously in nude mice and grown for 6 8 weeks to form tumors before hypericin injection and insertion of fiberoptics from a KTP532 surgical laser to assess the feasibility of this operating room instrument in stimulating fluorescence and PDT of tumors. Results: In vitro testing revealed a hypericin dose of 0.2 0.5 μg/ml was needed for PDT of the SCC cells with an optimal tumoricidal response seen at the 593 nm light absorption maximum. In vivo tumor retention of injected hypericin was seen for 7 to10 days using KTP532 laser induced fluorescence and biweekly PDT via laser fiberoptics led to regression of SCC tumor transplants under 0.4 cm2 diameter, but resulted in progression of larger size tumors in the nude mice. Conclusion: In this preclinical study, hypericin was tested for 514 593 nm dye laser PDT of human SCC cells in vitro and for KTP532 surgical laser targeting of SCC tumors in mice. The results suggest hypericin is a potent tumor imaging agent using this surgical laser that may prove useful in defining tumor margins and possibly in sterilizing post-resection margins. Deeply penetrating pulsed infrared laser emissions will be needed for PDT of larger and more inaccessible tumors.

AB - Background: Conventional cancer therapy including surgery, radiation, and chemotherapy often are physically debilitating and largely ineffective in previously treated patients with recurrent head and neck squamous cell carcinoma (SCC). A natural photochemical, hypericin, could be a less invasive method for laser photodynamic therapy (PDT) of these recurrent head and neck malignancies. Hypericin has powerful photo-oxidizing ability, tumor localization properties, and fluorescent imaging capabilities as well as minimal dark toxicity. The current study defined hypericin PDT in vitro with human SCC cells before the cells were grown as tumor transplants in nude mice and tested as a model for hypericin induced tumor fluorescence and PDT via laser fiberoptics. Methods: SNU squamous carcinoma cells were grown in tissue culture, detached from monolayers with trypsin, and incubated with 0.1 μg to 10 μg/ml of hypericin before exposure to laser light at 514, 550, or 593 nm to define optimal dose, time, and wavelength for PDT of tumor cells. The SCC cells also were injected subcutaneously in nude mice and grown for 6 8 weeks to form tumors before hypericin injection and insertion of fiberoptics from a KTP532 surgical laser to assess the feasibility of this operating room instrument in stimulating fluorescence and PDT of tumors. Results: In vitro testing revealed a hypericin dose of 0.2 0.5 μg/ml was needed for PDT of the SCC cells with an optimal tumoricidal response seen at the 593 nm light absorption maximum. In vivo tumor retention of injected hypericin was seen for 7 to10 days using KTP532 laser induced fluorescence and biweekly PDT via laser fiberoptics led to regression of SCC tumor transplants under 0.4 cm2 diameter, but resulted in progression of larger size tumors in the nude mice. Conclusion: In this preclinical study, hypericin was tested for 514 593 nm dye laser PDT of human SCC cells in vitro and for KTP532 surgical laser targeting of SCC tumors in mice. The results suggest hypericin is a potent tumor imaging agent using this surgical laser that may prove useful in defining tumor margins and possibly in sterilizing post-resection margins. Deeply penetrating pulsed infrared laser emissions will be needed for PDT of larger and more inaccessible tumors.

UR - http://www.scopus.com/inward/record.url?scp=70449624968&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70449624968&partnerID=8YFLogxK

U2 - 10.1186/1477-7819-4-1

DO - 10.1186/1477-7819-4-1

M3 - Article

AN - SCOPUS:70449624968

VL - 4

SP - 1

EP - 10

JO - World Journal of Surgical Oncology

JF - World Journal of Surgical Oncology

SN - 1477-7819

M1 - 1477

ER -