DNA fingerprinting analysis of radiation-induced rat skin tumors.

DNA fingerprinting analysis was performed on rat skin tumors induced by high linear energy transfer neon ion radiation. Most of these tumors (13/15) showed DNA-fingerprint variability between independently isolated tumors from the same animal. These changes include multiple band shifts and extra bands. Comparisons of DNA fingerprints were also made on successive biopsy samples from the same tumor. Each of 3 neon-induced tumors and 2 of 8 electron (low LET) induced tumors showed progressive loss of amplified sequences, gain of amplified sequences, deletions, band shifts, and the appearance of extra bands in progressive biopsies. These results provide evidence for LET-specific effects on genomic instability in radiation-induced rat skin tumors.