Photodynamic Effects In Vitro in Fresh GynecologicTumors Analyzed with a Bioluminescence Method

Abstract

Photodynamic therapy (PDT) is a promising alternative method for clinical cancer treatment. In the present study, cells from four breast carcinomas, seven ovarian carcinomas of various stages of differentiation, and ascites from a diffuse metastatic tumor were treated by PDT in vitro. Tetra(m-hydroxyphenyl)-chlorin (m-THPC) was used as the photosensitizer. Surviving cell rate was evaluated by the ATP-Cell-Viability-Assay (ATP-CVA), which measures light production as an interaction of intracellular ATP with the luciferin-luciferase complex. The most effective PDT of the tumor cells was achieved at an m-THPC concentration of 0.2 microgram/ml following incubation of the cells with photosensitizer for 24 hours. PDT toxicity resulted in a cell survival rate of 1% to 42% compared to untreated control cells (survival rate of control = 100%). The inhibitor concentration IC50 of m-THPC was determined both in the dark (dark toxicity) and in combination with laser irradiation. IC50 was defined as the concentration of photosensitizer which caused 50% of cell death. The IC50 values were heterogeneous in all tumor specimens examined. IC50 values for dark toxicity were on average 0.14 microgram m-THPC/ml for primary ovarian carcinoma, 2.16 micrograms m-THPC ml for refractory ovarian carcinoma and 0.3 microgram m-THPC/ml for breast carcinoma. After PDT, average IC50 value for refractory ovarian carcinoma was 0.04 microgram m-THPC/ml, for primary ovarian carcinoma 0.05 microgram m-THPC/ml and for breast carcinoma 0.03 microgram m-THPC/ml. These data might indicate that clinical PDT of gynecological carcinoma requires individual treatment conditions to achieve optimal results.

Temoporfin (Foscan®, 5,10,15,20‐Tetra(m‐hydroxyphenyl)chlorin)—A Second‐generation Photosensitizer†,‡

“…(316). Relevant in vitro and ex vivo tests have been described above (231). The use of m THPC in gynecological cancers was initiated by Wierrani et al.…”

“…For general reviews on the use and utility of PDT in this area see Gannon and Brown (408), Allison et al (299) and Hillemanns et al (316). Relevant in vitro and ex vivo tests have been described above (231). The use of mTHPC in gynecological cancers was initiated by Wierrani et al, who reported success in a small group of women suffering from recurrent intraperitoneal carcinoma of the ovary (409).…”

“…For the MCF‐7 cell line a more pronounced localization in lysosomes in the drug resistant strain was discussed (229,230). In vitro tests have also been performed with freshly prepared human gynecological tumors (breast, ovary and ascites) and indicated that individual treatment protocols might be required (231). Cell tests also indicated the utility of Foscan (and Foslip) for perihilar cholangiocarcinoma.…”

In-vivoluminescence model for the study of tumor regression and regrowth following combination regimens with differentiation-promoting agents and photodynamic therapy

“…Moreover, the light intensity will be proportional to the number of live Luc-gene transfected cancer cells present in the tumor 13 . Schlosser et al 14 and Hamblin et al 15,16 have demonstrated a good correlation between the bioluminescence signal and the number of viable cells. Because of the nontoxic nature of luciferin, tumor growth and its response to our treatment protocol can be studied in same cohort of mice longitudinally by administering luciferin at certain time points of our interest.…”

Bioluminescence Imaging of the Response of Rat Gliosarcoma to ALA‐PpIX‐mediated Photodynamic Therapy¶

“…Schlosser et al . (36) used luminometry to measure the responses of four different ovarian cancer cell lines in vitro after meso ‐tetrahydroxyphenyl chlorin (mTHPC)‐mediated PDT. The intracellular ATP level was measured as a way to assess cell viability after PDT, and a good correlation between the bioluminescence signal and the number of viable cells was observed.…”