Genomic rearrangement of the c-myc proto-oncogene in non-AIDS-related lymphoma in Japan.

Southern blot analysis was employed to analyze the structural alterations of the c-myc oncogene in genomic DNA derived from tumor specimens of 35 adults with pathologically classified and immunophenotyped non-AIDS-related, non-Hodgkin's lymphoma in Japan. In this study, seven cases (20%), including one peripheral T-cell lymphoma and six B-cell lymphomas of various histological types, were demonstrated to have additional c-myc fragments. An interesting feature is that c-myc rearrangements were found in three out of eight primary gastrointestinal lymphomas. Analyses with several restriction enzymes revealed that the breakpoints in these cases were clustered in a region spanning the first exon, first intron and nearby 5'-flanking sequences of the c-myc gene, suggesting that the alteration of this region may represent an important molecular event in activating the oncogenic potential of the c-myc gene.