Oxygenation status and tumor response during fractionated irradiation in two murine tumor cell lines of same origin but different intrinsic radiosensitivities.
Two murine tumor cell lines derived from the same origin and having different intrinsic radiosensitivities, one radiosensitive, SHA3K4-Ic (Ic), and the other relatively radioresistant, SHA3K4-III19 (III19), were compared in vivo regarding oxygenation, proliferation, and tumor response during fractionated irradiation. Tumors transplanted into nude mice were irradiated five times a week with a fraction size of 3 Gy up to a total dose of 30 Gy. Oxygenation status was analyzed using a non-invasive system with near infrared reflection spectroscopy. Proliferation status was quantified as the percentage of bromodeoxyuridine-labelled tumor cells and the percentage of necrotic area. All parameters were compared between untreated and irradiated tumors of the two lines. The oxygenation status in the untreated tumors did not correlate with tumor response. However, for the radioresponsive line, Ic, O2 saturation was significantly higher in irradiated than in untreated tumors, suggesting the existence of reoxygenation following fractionated irradiation. On the other hand, oxygenation status remained almost unchanged for the non-radioresponsive line, III19. Proliferation status did not correlate with tumor response. The results indicate that comprehensive investigations, including oxygen measurements, are necessary to understand the various intrinsic and extrinsic factors determining in vivo tumor radioresponse.
Institut fuer Medizinische Strahlenbiologie, Universitaetsklinikum Essen.
Y
Y
Mariya
F
F
Seinberg
C
C
Streffer
C
C
Fuhrmann
Y
Y
Abe
D000818:Animals; D001973:Bromodeoxyuridine / Q000378:metabolism; D002455:Cell Division; D002470:Cell Survival; D019583:Dose Fractionation, Radiation; D051379:Mice; D008819:Mice, Nude; D009336:Necrosis; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000378:metabolism / Q000473:pathology / Q000532:radiotherapy*; D010101:Oxygen Consumption; D011836:Radiation Tolerance; D019265:Spectroscopy, Near-Infrared; D014407:Tumor Cells, Cultured
D001973:Bromodeoxyuridine