Publication Details (including relevant citation information):
Magn Reson Med. 2010 Sep 21. [Epub ahead of print]
Preclinical development of therapeutic agents against cancer could greatly benefit from noninvasive markers of tumor killing. Potentially, the intracellular partial pressure of oxygen (pO(2)) can be used as an early marker of antitumor efficacy. Here, the feasibility of measuring intracellular pO(2) of central nervous system glioma cells in vivo using (19)F magnetic resonance techniques is examined. Rat 9L glioma cells were labeled with perfluoro-15-crown-5-ether ex vivo and then implanted into the rat striatum. (19)F MRI was used to visualize tumor location in vivo. The mean (19)F T(1) of the implanted cells was measured using localized, single-voxel spectroscopy. The intracellular pO(2) in tumor cells was determined from an in vitro calibration curve. The basal pO(2) of 9L cells (day 3) was determined to be 45.3 ± 5 mmHg (n = 6). Rats were then treated with a 1× LD10 dose of bischloroethylnitrosourea intravenously and changes in intracellular pO(2) were monitored. The pO(2) increased significantly (P = 0.042, paired T-test) to 141.8 ± 3 mmHg within 18 h after bischloroethylnitrosourea treatment (day 4) and remained elevated (165 ± 24 mmHg) for at least 72 h (day 6). Intracellular localization of the perfluoro-15-crown-5-ether emulsion in 9L cells before and after bischloroethylnitrosourea treatment was confirmed by histological examination and fluorescence microscopy. Overall, noninvasive (19)F magnetic resonance techniques may provide a valuable preclinical tool for monitoring therapeutic response against central nervous system or other deep-seated tumors. Magn Reson Med, 2010. © 2010 Wiley-Liss, Inc.
Address (URL): http://www.ncbi.nlm.nih.gov/pubmed/20860007