Reporter gene expression of different promoters in cell lines from various tissues. Two fragments (1,444 and 335 bp) of the cyclin A1 promoter, a 452-bp fragment of the cyclin A promoter, and the enhancerless SV40 promoter were transfected into 4 cell lines derived from myeloid cells (U937 and KCL22) or from solid carcinomas (PC3 and HeLa). The cyclin A1 promoter is active in each cell line, and its activity is inversely related to that of the cyclin A promoter. All experiments were performed in duplicates and independently performed at least 3 times.