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Summary Benzoporphyrin derivative monoacid (BPD-MA) photosensitization was examined for its effects on cellular adhesion of a human ovarian cancer cell line, OVCAR 3, to extracellular matrix (ECM) components. Mild BPD-MA photosensitization (~ 85% cell survival) of OVCAR 3 transiently decreased adhesion to collagen IV, fibronectin, laminin and vitronectin to a greater extent than could be attributed to cell death. The loss in adhesiveness was accompanied by a loss of β 1 integrin-containing focal adhesion plaques (FAPs), although β 1 subunits were still recognized by monoclonal antibody directed against human β 1 subunits. In vivo BPD-MA photosensitization decreased OVCAR 3 adhesiveness as well. Photosensitized adhesion was reduced in the presence of sodium azide and enhanced in deuterium oxide, suggesting mediation by singlet oxygen. Co-localization studies of BPD-MA and Rhodamine 123 showed that the photosensitizer was largely mitochondrial, but also exhibited extramitochondrial, intracellullar, diffuse cytosolic fluorescence. Taken together, these data show that intracellular damage mediated by BPD-PDT remote from the FAP site can affect cellular-ECM interactions and result in loss of FAP formation. This may have an impact on long-term effects of photodynamic therapy. The topic merits further investigation.

Epithelial ovarian carcinoma is the leading cause o f death from gynecologic malignancy and the 4th most frcqucnt cause of cancer death among women in the United States, where approximately 1 in 70 women will develop ovarian cancer in their lifetime. If current trends persist, more than half of these patients will present with advanced stages of disease, with an associated 5-year survival of approximately 21% (Parker et al., 1996). To expedite the search for new therapeutic and diagnostic regimens, in vitro and in vivo experimental models need to be developed since previous systems are often compromised by their inherent limitations (Pratesi et al., 1995; Hamilton et al., 1984a).Our primary objective was to develop a new in vivo model system of advanced ovarian carcinoma, in which the predominant clinical manifestation is diffuse, macroscopic i.p. disease. To more closely parallel the human disease process, a model in which carcinomatosis preceded any significant ascitcs production was sought. Tumor progression and the gross, histological, immunocytochemical and cytogenetic characteristics of a new xenograft model using the human ovarian cancer cell line N1H:OVCAR-5 are described. Because of the important role that cellular interactions with extracellular matrix (ECM) molecules play in tumorigenesis and metastasis (Hynes, 1992), data on binding of N1H:OVCAR-5 cells to 4 ECM proteins are also presented. The previously established N1H:OVCAR-5 cell line was derived from a patient with epithelial ovarian carcinoma, who had received no prior cytotoxic therapy (Hamilton et al., 19846). Although utilized in earlier in vitro investigations, thcrc are no reports of detailed characterization of the N1H:OVCAR-5 cell line or of its use in a previously described i.p. xenograft model. The specific goals of this study were to (i) Tumor cellsN1H:OVCAR-5 cells were obtained from the Fox Chase Cancer Institute (Philadelphia, PA). Cells were grown in RPMI-1640 media supplemented with 10% heat-inactivated FCS, 100 U/ml penicillin and 100 pg/ml streptomycin and maintained in an incubator at 37°C in an atmosphere of 5% COz. Cells were harvested for injection during the log growth phase, when 80-85% confluent. For harvest and transplantation, cells were trypsinized (trypsin-EDTA; GIBCO, Grand Island, NY), centrifuged at 20°C for 10 min at 148g (model RT6000, Sorvall; Dupont, Wilmington, DE), resuspended in RPMI without FCS (GIBCO), and counted using a hemocytometer. In vitro growth kineticsThe log growth curve and relative population doubling time of the N1H:OVCAR-5 cells grown in culture were evaluated. For each time point, 1 x lo4 cells were sccded in triplicate in 25 cm? tissue culture flasks (Corning, Corning, NY) and incubated under standard conditions as described above. A cell count was taken on days 2-6 after culture initiation, and the total number of viable cells (Trypan blue exclusion) was plotted to obtain the growth curve. Culture of NIH:OVCARJ tumor cells ex vivoSingle-cell suspensions were prepared from N1H:OVCAR-5 x...