[A sensitization effect of hematoporphyrin oligomer (HpO) and caffeine for X-ray radiation of skin cancer].
Human malignant melanoma cells (G-361) were irradiated with X-ray for different irradiation times. The amount of DNA damage was much increased by the treatment of the cells with HpO before X-ray irradiation. Furthermore, it was found that the caffeine inhibited effectively the repair of the damaged DNA. Furthermore, HpO was administered before X-ray irradiation of transplantable skin tumor in C3H mice and/or caffeine+ was to be given the mouse after X-ray irradiation. The growth of the tumor irradiated with HpO and/or caffeine was more inhibited and the necrotic area was more expanded than that of the tumor irradiated X-ray only. Labeling Index utilizing bromodeoxyuridine (BrdU) in the viable area of the treated tumor decreased when HpO and/or caffeine were administered. The amount of DNA damage more increased in the tumor cells irradiated with HpO than that irradiated only. And, the repair of the damaged DNA was more delayed in the tumor cells irradiated with HpO and caffeine than that irradiated with the other treatments. In conclusion, it was considered that HpO might be a radioactive sensitizer and caffeine enhanced the inhibition of the repair of DNA damaged. We hope that the treatment of X-ray radiation with HpO and caffeine is useful for clinical treatment of human malignant tumor.
Ishiguro
K
K
Department of Dermatology, Fukui Medical School.
Ueda
K
K
Miyoshi
N
N
Nakanishi
K
K
Fukuda
M
M
D000818:Animals; D002110:Caffeine / Q000494:pharmacology / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D004249:DNA Damage / Q000187:drug effects; D004273:DNA, Neoplasm / Q000187:drug effects; D006415:Hematoporphyrins / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D008545:Melanoma / Q000473:pathology / Q000532:radiotherapy*; D051379:Mice; D009368:Neoplasm Transplantation; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology / Q000627:therapeutic use*; D012878:Skin Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D014407:Tumor Cells, Cultured / Q000187:drug effects
D004273:DNA, Neoplasm; D006415:Hematoporphyrins; D011838:Radiation-Sensitizing Agents; D002110:Caffeine