FIGURE 4.

MYCN regulates transcription from ABC promoters in a transient transfection assay. A, firefly luciferase activity was determined following transfection of reporter constructs into TET21/N cells, in the presence (+tet) or absence (−tet) of MYCN. Bent arrow, transcription start site. The cloned DNA region (bp) is indicated below the promoter map. B, luciferase assay of wt and mutated ABCC3 reporter vectors. The results are the means ± S.E. of three independent transfections. Fragment coordinates are expressed relative to the transcription start point.