Anti-tumour activity of photodynamic therapy in combination with mitomycin C in nude mice with human colon adenocarcinoma

• Published in: British journal of cancer 1995-05, Vol.71 (5), p.950-956
• Main Authors: Ma, LW, Moan, J, Steen, HB, Iani, V
• Format: Article
• Language: English
• Subjects: Adenocarcinoma - drug therapy; Adenocarcinoma - metabolism; Animals; Antineoplastic agents; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cancer Research; Cell Cycle - drug effects; Cell Death - drug effects; Cell Death - physiology; Colonic Neoplasms - drug therapy; Colonic Neoplasms - metabolism; Combined Modality Therapy; Combined treatments (chemotherapy of immunotherapy associated with an other treatment); Drug Resistance; Drug Synergism; Epidemiology; experimental-oncology; Female; Hematoporphyrin Photoradiation; Hematoporphyrins - pharmacokinetics; Hematoporphyrins - pharmacology; Humans; Medical sciences; Mice; Mice, Inbred BALB C; Mice, Nude; Mitomycin - pharmacology; Molecular Medicine; Neoplasm Transplantation; Oncology; Pharmacology. Drug treatments; Transplantation, Heterologous
• ISSN: 0007-0920; 1532-1827
• DOI: 10.1038/bjc.1995.184

The interaction of photodynamic therapy (PDT) and a chemotherapeutic drug, mitomycin C (MMC), was investigated using WiDr human colon adenocarcinoma tumours implanted on Balb/c athymic nude mice. The WiDr tumours were treated with PDT alone, MMC alone or with both. It was found that the combined treatment produced a greater retardation in the growth of the WiDr tumour than monotherapy with MMC or PDT. The synergistic effect was especially prominent when PDT was used in combination with a low dose of MMC (1 mg kg-1), since treatment of 1 mg kg-1 MMC alone had no effect on the tumour. The anti-tumour activity of PDT was found to be increased with MMC of 5 mg kg-1. The response of normal skin on mice feet to PDT slightly greater when PDT was combined with 5 mg kg-1 MMC than when PDT was applied alone, while no detectable additional effect on skin photosensitivity was observed when PDT was combined with 1 mg kg-1 MMC. An enhanced uptake of Photofrin in tumours was found 12 h and 24 h after administration of MMC. The effect of MMC on the cell cycle distribution of cell dissociated directly from the tumours was studied. The results suggest that the increased susceptibility to photoinactivation of Photofrin-sensitised tumours may be due to MMC-induced accumulation of the tumour cells in S-phase.