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Proceedings Paper

Photochemical internalization (PCI) of bleomycin induces T-cell activation of importance for curative effect and systemic anti-tumor immunity (Conference Presentation)
Author(s): Kristian Berg; Ane Sofie Fremstedal; Anette Weyergang; Jakub Golab; Ole-Jacob Norum

Paper Abstract

Photochemical internalization (PCI) is a technology to enhance intracellular drug delivery by light-induced translocation of endocytosed therapeutics into the cytosol. The aim of this study was to explore the efficacy of PCI-based delivery of bleomycin and the impact on systemic anti-tumor immunity. Mouse colon carcinoma cells (CT26.CL25), stably expressing the bacterial β-galactosidase, were inoculated into the legs of athymic or immuno-competent BALB/c mice strains. The mice were injected with the photosensitizer AlPcS2a and bleomycin (BLM) prior to tumor light exposure from a 670 nm diode laser. Photochemical activation of BLM was found to induce synergistic inhibition of tumor growth as compared to the sum of the individual treatments. However, a curative effect was not observed in the athymic mice exposed to 30 J/cm2 of light while more than 90% of the thymic mice were cured after exposure to only 15 J/cm2 light. Cured thymic mice, re-challenged with CT26.CL25 tumor cells on the contralateral leg, rejected 57-100% of the tumor cells inoculated immediately and up to 2 months after the photochemical treatment. T-cells from the spleen of PCI-treated mice were found to inhibit the growth of CT26.CL25 cells in naïve thymic mice with a 60% rejection rate. The results show that treatment of CT26.CL25 tumors in thymic mice by PCI of BLM induces a systemic anti-tumor immunity.

Paper Details

Date Published: 14 August 2019
Proc. SPIE 11070, 17th International Photodynamic Association World Congress, 110702P (14 August 2019); doi: 10.1117/12.2526088
Show Author Affiliations
Kristian Berg, Oslo Univ. Hospital (Norway)
Ane Sofie Fremstedal, Oslo Univ. Hospital (Norway)
Anette Weyergang, Oslo Univ. Hospital (Norway)
Jakub Golab, Medical Univ. of Warsaw (Poland)
Ole-Jacob Norum, Oslo Univ. Hospital (Norway)

Published in SPIE Proceedings Vol. 11070:
17th International Photodynamic Association World Congress
Tayyaba Hasan, Editor(s)

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