Normal expression of a rearranged and mutated c-myc oncogene after transfection into fibroblasts.

Expression of the c-myc oncogene is deregulated in a variety of malignancies. Rearrangement and mutation of the c-myc locus is a characteristic feature of human Burkitt's lymphoma. Whether deregulation is solely a result of mutation of c-myc or whether it is influenced by the transformed B cell context has not been determined. A translocated and mutated allele of c-myc was stably transfected into fibroblasts. The rearranged allele was expressed indistinguishably from a normal c-myc gene: it had serum-regulated expression, was transcribed with normal promoter preference, and was strongly attenuated. Thus mutations by themselves are insufficient to deregulate c-myc transcription.