Chang Z F
Department of Biochemistry, Chang Gung Medical College, Tao-Yuan, Taiwan, R.O.C.
Biochem Biophys Res Commun. 1990 Jun 15;169(2):780-7. doi: 10.1016/0006-291x(90)90399-8.
The regulatory mechanism of human thymidine kinase (TK) gene expression was investigated in HL-60 promyelocytes during induction of monocytic differentiation with 12-O-tetradecanoyl phorbol-13-acetate (TPA). The steady-state levels of TK mRNA diminished gradually as cells were treated with TPA. The nuclear run-on experiments were performed and revealed that TPA treatment did not change TK gene activity in HL-60 cells. These findings suggested that the expression of TK mRNA was controlled by a post-transcriptional mechanism. The half-life of mature TK mRNA transcript was found to be more than 8 hours in both proliferating and differentiated HL-60 cells, which indicated that the stability of mature TK mRNA does not play a role in regulating TK gene expression. Analysis of poly(A-) TK mRNAs showed the high molecular weight precursors of TK mRNA which appeared in proliferating cells were not detectable in TPA-treated cells. This finding suggested that the TK mRNA processing event is implicated in the regulation of human TK gene expression in HL-60 cells during monocytic terminal differentiation.
在使用12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯（TPA）诱导HL - 60早幼粒细胞向单核细胞分化的过程中，对人胸苷激酶（TK）基因表达的调控机制进行了研究。随着用TPA处理细胞，TK mRNA的稳态水平逐渐降低。进行了核转录实验，结果显示TPA处理并未改变HL - 60细胞中TK基因的活性。这些发现表明，TK mRNA的表达受转录后机制控制。在增殖和分化的HL - 60细胞中，成熟TK mRNA转录本的半衰期均超过8小时，这表明成熟TK mRNA的稳定性在调节TK基因表达中不起作用。对聚腺苷酸缺失（poly(A-)）的TK mRNA的分析表明，在增殖细胞中出现的高分子量TK mRNA前体在经TPA处理的细胞中无法检测到。这一发现表明，在单核细胞终末分化过程中，TK mRNA加工事件与HL - 60细胞中人TK基因表达的调控有关。
