[Effect of X-rays combined with ACNU and O6-ethylguanine on rat subcutaneous gliomas].
Rat gliomas of subcutaneously transplanted RGc-6 cells were irradiated with X-ray either alone, or combined with ACNU, and the cell-survival was assayed in vitro. Cell-survival curve composed of two components by X-irradiation alone indicated the presence of a hypoxic cell fraction. We have previously shown that combined treatment with ACNU apparently made the effect of X-ray on spheroids in vitro of the same cell line of RGc-6 more powerful. Although treatment of rat gliomas with ACNU administered at 2 hrs prior to X-irradiation was most effective, it resulted in only the additive effect of the independent action of the two agents. Further treatment by O6-ethylguanine prior to ACNU administration and X-irradiation apparently increased the strength of the effect of ACNU combined with X-ray to the dose-modifying factor for X-ray of 1.8. The result indicated that the combination of O6-ethylguanine prior to ACNU administration and X-irradiation may clinically enhance the effect of X-ray against apparent ACNU-resistant glioma cells such as RGc-6 cells.
Takahashi
K
K
Division of Neurosurgery, Tohoku University School of Medicine.
Katakura
R
R
Mashiyama
S
S
Yoshimoto
T
T
Suzuki
J
J
Sasaki
T
T
D000818:Animals; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D002470:Cell Survival / Q000187:drug effects / Q000528:radiation effects; D003131:Combined Modality Therapy; D005910:Glioma / Q000188:drug therapy / Q000532:radiotherapy / Q000628:therapy*; D006147:Guanine / Q000008:administration & dosage / Q000031:analogs & derivatives; D008297:Male; D009368:Neoplasm Transplantation; D015376:Nimustine / Q000008:administration & dosage; D051381:Rats; D011919:Rats, Inbred Strains; D012878:Skin Neoplasms / Q000188:drug therapy / Q000532:radiotherapy / Q000628:therapy*; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000473:pathology / Q000528:radiation effects
D015376:Nimustine; C007673:6-ethylguanine; D006147:Guanine