Changes in inducible nuclear factors with specific binding ability to c-myc gene fragments in peripheral blood mononuclear cells from systemic lupus erythematosus patients.

Using a gel retardation assay, we found new nuclear proteins of peripheral blood mononuclear cells (PBMC) from systemic lupus erythematosus (SLE) patients specifically binding to c-myc gene fragments. A different pattern could be detected between SLE patients and healthy controls for the c-myc exon I fragment, but both groups had similar patterns for the c-myc 5'-upper region fragment. For the c-myc exon I fragment, one DNA-protein complex was induced only in SLE patients and the other DNA-protein complex was amplified in SLE and normal PBMC with mitogen stimulation. It is suggested that abnormal c-myc protooncogene transcription in PBMC from SLE patients could be related to differences in nuclear specific binding proteins. These differences apparently play a key role in abnormal lymphocyte function in changes in gene regulation.