The response of hypoxic cells in SCCVII murine tumors to treatment with cisplatin and x rays.
Possible mechanisms of enhancement of radiation effects by cisplatin, including radiosensitization of hypoxic cells, drug-induced tumor reoxygenation, and inhibition of repair of sublethal radiation damage, were examined in the murine SCCVII model. Combination radiation/drug treatments were most effective when drug exposure preceded irradiation of animals breathing a reduced oxygen atmosphere, indicating that the primary interaction between the modalities was a cisplatin-induced increase in the oxygenation status of the acutely hypoxic cells in those tumors. Delivering cisplatin prior to or immediately after the first of two 5 Gy fractions was more effective than combinations with a single x-ray exposure, suggesting that proper sequences of the combined modalities may augment natural reoxygenation processes.
Yan
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Medical Biophysics Unit, B. C. Cancer Research Centre, Vancouver, Canada.
Durand
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RE
D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000188:drug therapy* / Q000503:physiopathology / Q000532:radiotherapy*; D015687:Cell Hypoxia / Q000187:drug effects* / Q000528:radiation effects*; D002945:Cisplatin / Q000627:therapeutic use*; D003131:Combined Modality Therapy; D004353:Drug Evaluation, Preclinical; D006801:Humans; D007223:Infant; D051379:Mice; D008809:Mice, Inbred C3H; D010101:Oxygen Consumption / Q000502:physiology; D011836:Radiation Tolerance / Q000187:drug effects; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000503:physiopathology / Q000532:radiotherapy*
D002945:Cisplatin