Reference - Detail
|Author||Saitoh J, Sakurai H, Suzuki Y, Muramatsu H, Ishikawa H, Kitamoto Y, Akimoto T, Hasegawa M, Mitsuhashi N, Nakano T.|
|Title||Correlations between in vivo tumor weight, oxygen pressure, 31P NMR spectroscopy, hypoxic microenvironment marking by beta-D-iodinated azomycin galactopyranoside (beta-D-IAZGP), and radiation sensitivity.|
|Journal||Int. J. Radiat. Oncol. Biol. Phys.|
PURPOSE:The purpose of this study is to evaluate the amount of hypoxic fraction in a rodent tumor by means of polarographic oxygen electrode, phosphorus-31 magnetic resonance spectroscopy (31P-MRS), and a newly synthesized hypoxic marker, beta-D-iodinated azomycin galactopyranoside (beta-D-IAZGP). We also investigated the radiosensitivity for tumors of different weights.
METHODS AND MATERIALS:Murine mammary carcinoma cells, FM3A, were subcutaneously implanted into the back of 5-week-old male C3H/He mice. beta-D-IAZGP radiolabeled with 123I or with 125I was injected intravenously into tumor-bearing mice, and marker distribution was measured by nuclear medicine procedures. Radiosensitivity of the tumor was measured by the in vivo/in vitro clonogenic assay. Tumor oxygenation status was also measured directly by polarographic oxygen electrodes and indirectly estimated from 31P-MR spectra.
RESULTS:Higher accumulation of 123I-beta-D-IAZGP was observed in the tumors than in normal tissues at 24 h after administration. As to biodistribution of 125I-beta-D-IAZGP, the tumor/blood ratio varied widely, but correlated significantly with tumor weight. Mean oxygen pressure (pO2) values and ratios of nucleoside triphosphate beta to inorganic phosphate (beta-ATP/Pi) and of phosphocreatine to inorganic phosphate (PCr/Pi) decreased significantly with the increase in tumor volume. As tumor volume increased, the surviving fraction of cells from tumors irradiated in vivo increased significantly.
CONCLUSIONS:The increase in tumor volume was significantly correlated with a reduction in mean pO2, a decrease in the ratios of beta-ATP/Pi or PCr/Pi, an increase in uptake of beta-D-IAZGP, and an increase in radioresistance. Because the uptake of beta-D-IAZGP can be measured noninvasively by nuclear medicine techniques, it could be clinically useful for monitoring hypoxia in human tumors.
|MeSH||Animals Biomarkers Cell Hypoxia* Female Magnetic Resonance Spectroscopy Male Mammary Neoplasms, Animal / metabolism* Mammary Neoplasms, Animal / pathology* Mammary Neoplasms, Animal / radiotherapy Mice Mice, Inbred C3H Monosaccharides / pharmacokinetics Nitroimidazoles / pharmacokinetics Organ Size Oxygen / analysis* Partial Pressure Radiation Tolerance*|
|WOS Category||RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING ONCOLOGY|
|Human and Animal Cells|