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Title: Cyclic-radiation response of murine fibrosarcoma cells grown as pulmonary nodules

Journal Article · · Int. J. Radiat. Oncol., Biol. Phys.; (United States)

The radiation age response of murine fibrosarcoma (FSa) cells grown as pulmonary nudules in C/sub 3/Hf/Kam mice was determined. FSa cells were irradiated in vivo either with 10 Gy as 14 day-old lung tumors (i.e., artifical micrometastases) following cell separation and synchronization by centrifugal elutriation. Flow microfluorometry (FMF) was used to determine cell-cycle parameters and the relative synchrony of the separated populations, as well as the percent contamination of normal diploid cells in each of the tumor cells populations. Tumor populations containing up to 90% G/sub 1/-, 60% S-, and 75% G/sub 2/+M-phase tumor cells were obtained. Cell clonogenicity, determined using a lung colony assay, ranged from 0.7 to 6% for control FSa cells from the various elutriator fractions. The radiation sensitivity of these separated cell populations varied by a factor of 6, regardless of whether the cells were irradiated as artifical micro or macro-metastases. In each experiment, tumor population most enriched in S-phase cells exhibited the greatest radiation sensitivity. To confirm that these populations were highly enriched in S-phase cells and to demonstrate that they were more radiosensitive than FSa cells in other parts of the cell cycle, the elutriated tumor population were exposed to either suicide labeling by high specific activity tritated thymidine or hydroxyurea. The resultant age response curves were qualitatively similar to those obtained following irradiation and reflected the S-phase sensitivity of FSa cells to these agents.

Research Organization:
The Univ. of Texas M.D. Anderson Hospital and Tumor Inst., Houston
OSTI ID:
5477036
Journal Information:
Int. J. Radiat. Oncol., Biol. Phys.; (United States), Vol. 8:10
Country of Publication:
United States
Language:
English