Post-transcriptional suppression of human ornithine decarboxylase gene expression by phorbol esters in human keratinocytes.
Post-transcriptional suppression of human ornithine decarboxylase gene expression by phorbol esters in human keratinocytes.
复制标题
人角质形成细胞中佛波酯对人鸟氨酸脱羧酶基因表达的转录后抑制。
DOI：
10.1111/1523-1747.ep12398542
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Hickok,NJ
中科院分区：
文献类型：
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作者：
Ruhl,KK;Pomidor,MM;Rhim,JS;Tuan,RS;Hickok,NJ
The induction of ornithine decarboxylase levels by the phorbol ester 12-0-tetradecanoyl-phorbol- 13-acetate (TPA) in mouse skin has been shown to be integral to tumor promotion by TPA, and changes in ornithine decarboxylase activity indicate the proliferative state of many different cell types. However, in cultured human epidermal cells, TPA has been reported to be antiproliferative. Therefore, to elucidate pathways that TPA activates in cultured human skin cells, we have examined the levels at which TPA regulates ornithine decarboxylase gene expression in two immortalized human epidermal keratinocyte cell lines, and in normal neonatal keratinocytes. We have found that in cultured human keratinocytes, TPA causes a marked decrease in ornithine decarboxylase enzyme activity (50–90%), with no detectable effect on ornithine decarboxylase mRNA levels. TPA decreased steady-state levels of ornithine decarboxylase immunoreactive protein (∼ 50–67%), accounting for the 50–90% suppression of ornithine decarboxylase activity levels, as well as decreasing new synthesis of ornithine decarboxylase protein (48–50%). However, measurement of ornithine decarboxylase protein half-life showed no significant effect of TPA. Also, prolonged treatment of keratinocytes with phorbol esters abolished the suppression of ornithine decarboxylase activity by TPA. Our data, therefore, suggest that phorbol esters suppress ornithine decarboxylase gene expression predominantly by decreasing ornithine decarboxylase mRNA translatability.
