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Updated: Aug 11, 2026

Focus Formation: A Cell-based Assay to Determine the Oncogenic Potential of a Gene
Published on: December 31, 2014
The ras oncogenes increase the intrinsic resistance of NIH 3T3 cells to ionizing radiation
1Department of Radiation Oncology, University of Michigan Medical School, Ann Arbor 48109.
Abstract:
Identification of genes that function to protect cells from radiation damage is an essential step in understanding the molecular mechanisms by which mammalian cells cope with ionizing radiation. The intrinsic radiation resistance (D0) of NIH 3T3 cells was markedly and significantly increased by transformation with ras oncogenes activated by missense mutations. This radiobiologic activity appeared to be a specific consequence of the ras mutations rather than of transformation, since revertant cells that contained functional ras genes (but were no longer phenotypically transformed) retained their increased D0's.
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