2010年2月
Influence of manipulating hypoxia in solid tumors on the radiation dose-rate effect in vivo, with reference to that in the quiescent cell population
JAPANESE JOURNAL OF RADIOLOGY
- 巻
- 28
- 号
- 2
- 開始ページ
- 132
- 終了ページ
- 142
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1007/s11604-009-0397-1
- 出版者・発行元
- SPRINGER
Purpose. The aim of this study was to clarify the effect of manipulating intratumor hypoxia on radiosensitivity under reduced dose-rate (RDR) irradiation.
Materials and methods. Tumor-bearing mice were continuously given 5-bromo-2'-deoxyuridine ( BrdU) to label all proliferating ( P) cells. They received.-rays or accelerated carbon-ion beams at high dose-rate (HDR) or RDR with or without tumor clamping to induce hypoxia. Some mice without clamping received nicotin-amide, an acute hypoxia-releasing agent or misonidazole, a hypoxic cell radio-sensitizer before irradiation. The responses of quiescent ( Q) and total (=P + Q) cells were assessed by the micronucleus frequency using immunofluorescence staining for BrdU.
Results. The clearer decrease in radiosensitivity in Q than total cells after RDR gamma-ray irradiation was suppressed with carbon-ion beams, especially with a higher linear energy transfer value. Repressing the decrease in the radiosensitivity under RDR irradiation through keeping tumors hypoxic during irradiation and enhancing the decrease in the radiosensitivity by nicotinamide were clearer with gamma-rays and in total cells than with carbon-ion beams and in Q cells, respectively. Inhibiting the decrease in the radiosensitivity by misonidazole was clearer with gamma-rays and in Q cells than with carbon-ion beams and in total cells, respectively.
Conclusion. Manipulating hypoxia during RDR as well as HDR irradiation influences tumor radiosensitivity, especially with gamma-rays.
Materials and methods. Tumor-bearing mice were continuously given 5-bromo-2'-deoxyuridine ( BrdU) to label all proliferating ( P) cells. They received.-rays or accelerated carbon-ion beams at high dose-rate (HDR) or RDR with or without tumor clamping to induce hypoxia. Some mice without clamping received nicotin-amide, an acute hypoxia-releasing agent or misonidazole, a hypoxic cell radio-sensitizer before irradiation. The responses of quiescent ( Q) and total (=P + Q) cells were assessed by the micronucleus frequency using immunofluorescence staining for BrdU.
Results. The clearer decrease in radiosensitivity in Q than total cells after RDR gamma-ray irradiation was suppressed with carbon-ion beams, especially with a higher linear energy transfer value. Repressing the decrease in the radiosensitivity under RDR irradiation through keeping tumors hypoxic during irradiation and enhancing the decrease in the radiosensitivity by nicotinamide were clearer with gamma-rays and in total cells than with carbon-ion beams and in Q cells, respectively. Inhibiting the decrease in the radiosensitivity by misonidazole was clearer with gamma-rays and in Q cells than with carbon-ion beams and in total cells, respectively.
Conclusion. Manipulating hypoxia during RDR as well as HDR irradiation influences tumor radiosensitivity, especially with gamma-rays.
- リンク情報
- ID情報
-
- DOI : 10.1007/s11604-009-0397-1
- ISSN : 1867-108X
- Web of Science ID : WOS:000274946800007