NF-KAPPA-B AND SP1 REGULATE TRANSCRIPTION OF THE HUMAN MONOCYTE CHEMOATTRACTANT PROTEIN-1 GENE

Expression of the human monocyte chemoattractant protein-1 (hMCP-1) is ubiquitous in various cell types and is increased by a wide variety o f stimuli. We initially found that the effects of various stimuli, inc luding IL-1 beta, TNF-alpha, and 2-O-tetradecanoylphorbol 13-acetate, on the expression of hMCP-1 mRNA were quite different among A172 gliob lastoma cells, HT1080 fibrosarcoma cells, and SKLMS1 leiomyosarcoma ce lls. These findings suggested that hMCP-1 expression is regulated both in a stimulus-specific and a tissue-specific manner. To elucidate the mechanism underlying this stimulus-specific and tissue-specific regul ation, we isolated a hMCP-1 5'-flanking genomic DNA fragment and seque nced it extensively up to bp 3011 upstream from the transcriptional st art site. Among many putative cis-elements, we identified two cis-elem ents critical for the transcription of the hMCP-1 gene. The first elem ent is a remote kappa B binding site located far upstream between bp - 2612 and -2603 that was important for IL-1 beta-, TNF-alpha-, and 2-O- tetradecanoylphorbol 13-acetate-induced enhancer activity. Mutation at the kappa B consensus site resulted in a complete loss of these stimu lus-induced enhancer activities. The second element is a GC box locate d between bp -64 and -59 that was important for the maintenance of bas al transcriptional activity. Overexpression of rSp1 resulted in increa sed hMCP-1 transcriptional activity, possibly suggesting the role of S pl in controlling basal hMCP-1 transcription via this GC box. These re sults together indicate that hMCP-1 expression is controlled by at lea st two distinct regulatory elements: a kappa B Site and a GC box that seem to be associated with stimulus-specific and tissue-specific regul ation, respectively.