CHANGES IN CHROMATIN CONFORMATION REGULATE THE 5-LIPOXYGENASE GENE-EXPRESSION DURING DIFFERENTIATION OF HL60 CELLS

The HL60 cell line does not express the 5-lipoxygenase gene prior to d ifferentiation with various agents. In this paper we have shown by DNa se I sensitivity that the chromatin conformation of the 5-lipoxygenase gene changes following differentiation of HL60 cells with dimethyl su lfoxide (DMSO). Moreover, run-on analysis suggests that transcription of the 5-lipoxygenase gene is enhanced after differentiation. We propo sed that the chromatin conformation represses the expression of the 5- lipoxygenase gene in HL60 cell line and that differentiation of these cells with DMSO changes the chromatin conformation, which allows the e xpression of the 5-lipoxygenase gene. The HeLa cells which, like the H L60 cells, do not express the 5-lipoxygenase, were insensitive to DNas e I treatment. These results suggest that chromatin structure might re present a form of regulation for the 5-lipoxygenase gene.