Abundance of the primary transcript and its processed product of growth-related genes in normal and leukemic cells during proliferation and differentiation.
Abundance of the primary transcript and its processed product of growth-related genes in normal and leukemic cells during proliferation and differentiation.
复制标题
正常和白血病细胞在增殖和分化过程中生长相关基因的初级转录本及其加工产物的丰度。
作者：
S. Ferrari;E. Tagliafico;R. Manfredini;A. Grande;E. Rossi;P. Zucchini;G. Torelli;U. Torelli
在静息和有丝分裂原刺激的淋巴细胞、增殖和终末分化的 HL-60 细胞以及白血病母细胞中，进行逆转录酶-聚合酶链反应和 Northern 印迹分析后，通过光密度测定 c-myc、钙环蛋白、S14 核糖体蛋白和 rRNA 基因的初级转录物和成熟 mRNA 的相对丰度。 c-myc 和 rRNA 基因转录物的转录和加工在有丝分裂原刺激后成比例增加，而在 S14 基因的情况下，这些过程与细胞周期状态无关。正常淋巴细胞显示出出乎意料的大量钙周期蛋白基因的初级转录本，而相应的 mRNA 却检测不到。与增殖细胞相比，终末分化的 HL-60 细胞中 c-myc、钙周期蛋白和 S14 mRNA 的丰度急剧下降。这种减少反映了转录后调节，因为前体的丰度基本保持不变。 HL-60分化后，32S rRNA水平保持相对较高，而45S初级转录物几乎消失。白血病母细胞表现出 c-myc、钙周期蛋白和 S14 基因的前体/mRNA 比率高度可变，但 32S 与 45S RNA 的比率始终较高，表明这些细胞中 32S rRNA 的裂解率急剧降低，导致该分子的积累。这些结果表明有效加工初级转录物以产生足够的功能性 mRNA 从而调节基因表达的重要性。此外，在终末分化细胞和白血病母细胞中，可以观察到初级转录物在没有有效加工的情况下的稳定。径流转录结果进一步支持了初级转录物在终末分化中的稳定作用，表明在视黄酸/二甲基亚砜处理的HL-60细胞中c-myc和钙周期蛋白转录率急剧下降。
The relative abundance of primary transcript and mature mRNA of the c-myc, calcyclin, S14 ribosomal protein, and rRNA genes was determined densitometrically after reverse transcriptase-polymerase chain reaction and Northern blotting analysis in resting and mitogen-stimulated lymphocytes, proliferating and terminally differentiated HL-60 cells, and leukemic blast cells. Transcription and processing of c-myc and rRNA gene transcripts increased proportionally after mitogen stimulation, whereas these processes were independent of cell cycling status in the case of the S14 gene. Normal lymphocytes showed an unexpectedly large amount of primary transcript of the calcyclin gene, whereas the corresponding mRNA was undetectable. The abundance of c-myc, calcyclin, and S14 mRNA in terminally differentiated HL-60 cells decreased sharply, compared to their proliferating counterparts. This decrease reflected post-transcriptional modulation, since the abundance of precursor remained essentially unchanged. After HL-60 differentiation, the 32S rRNA levels remained relatively high, whereas the 45S primary transcript almost disappeared. Leukemic blast cells displayed highly variable precursor/mRNA ratios of c-myc, calcyclin, and S14 genes but consistently high ratios of 32S to 45S RNA, suggesting that the cleavage rate of the 32S rRNA was sharply reduced in these cells, resulting in an accumulation of this molecule. These results suggest the importance of efficient processing of primary transcript to generate adequate functional mRNA, thus regulating gene expression. Furthermore, in terminally differentiated cells and leukemic blast cells a stabilization of the primary transcript without efficient processing can be observed. The role of the stabilization of the primary transcript in terminal differentiation is further supported by the results of run-off transcription, indicating a sharp decrease of c-myc and calcyclin transcription rate in retinoic acid/dimethyl sulfoxide-treated HL-60 cells.
DOI：
10.1016/s0021-9258(18)47567-9
发表时间：
1987-06
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
S. Ferrari;B. Calabretta;J. K. Deriel;R. Battini;F. Ghezzo;E. Lauret;C. Griffin;B. Emanuel;F. Gurrieri;R. Baserga
通讯作者：
S. Ferrari;B. Calabretta;J. K. Deriel;R. Battini;F. Ghezzo;E. Lauret;C. Griffin;B. Emanuel;F. Gurrieri;R. Baserga
影响因子：
56.9
作者：
BLACKWOOD, EM;EISENMAN, RN
通讯作者：
EISENMAN, RN
DNA 合成开始时胸苷激酶 mRNA 的核转录后加工。
DOI：
10.1073/pnas.85.13.4705
发表时间：
1988
影响因子：
11.1
作者：
Gudas,JM;Knight,GB;Pardee,AB
通讯作者：
Pardee,AB