Aromatase gene is amplified in MCF-7 human breast cancer cells.
Aromatase gene is amplified in MCF-7 human breast cancer cells.
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芳香酶基因在 MCF-7 人乳腺癌细胞中扩增。
DOI：
10.1016/0960-0760(93)90289-9
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Chen,S
中科院分区：
文献类型：
--
作者：
Zhou,D;Wang,J;Chen,E;Murai,J;Siiteri,PK;Chen,S
研究了芳香化酶基因在MCF-7人乳腺癌细胞和另外7个培养细胞中的表达水平。以正常人包皮成纤维细胞为对照，以人胎盘芳香化酶cDNA为探针，通过Southern和DNA槽印迹分析发现，芳香化酶基因在MCF-7细胞中扩增。然而，基于DNA凹槽印迹分析的结果，MCF-7细胞中没有扩增到启动子I.1和芳香酶基因的第一个外显子，该分析使用的寡核苷酸探针的序列来源于人类芳香酶基因的这些区域。Northern blot检测芳香化酶mRNA水平、免疫沉淀检测芳香化酶蛋白水平、芳香化酶活性测定结果表明，该细胞系芳香化酶表达水平极低。此外，通过PCR技术对MCF-7细胞的芳香化酶cDNA进行核苷酸序列分析，发现与胎盘中表达的酶没有序列差异。这些结果使我们得出结论，MCF-7细胞中芳香化酶的表达受到一个不寻常的启动子的控制，芳香化酶基因的表达在这些细胞的转录水平上受到抑制。
The levels of the aromatase gene and its expression in MCF-7 human breast cancer cells and seven additional cultured cells were investigated. Using normal human foreskin fibroblasts as the control, the aromatase gene appeared to be amplified in MCF-7 cells as shown by Southern and DNA slot blot analyses utilizing human placental aromatase cDNA as the probe. However, the promoter I.1 and the first exon of the aromatase gene were not amplified in MCF-7 cells based on results obtained from DNA slot blot analysis using oligonucleotide probes having sequences derived from those regions of human aromatase gene. Aromatase was expressed at a very low level in this cell line as indicated by Northern blot analysis to measure the level of aromatase mRNA, immunoprecipitation analysis to measure the level of aromatase protein, and aromatase activity measurement. Furthermore, nucleotide sequence analysis of the aromatase cDNA obtained from MCF-7 cells by PCR techniques, revealed no sequence difference from that of the enzyme expressed in placenta. These results lead us to conclude that the expression of aromatase in MCF-7 cells is under the control of an unusual promoter and aromatase gene expression is repressed at the transcriptional level in these cells.