Weigel R J, deConinck E C
Department of Surgery, Stanford University, California 94305.
Cancer Res. 1993 Aug 1;53(15):3472-4.
The mechanisms which control estrogen receptor (ER) expression in breast carcinoma have not been elucidated. The MCF-7 (ER-positive) and MDA-MB-231 (ER-negative) breast carcinoma cell lines have been used to examine ER gene expression. Northern blot analysis of mRNA isolated from these two cell lines demonstrates that MCF-7 cells express an expected 6.5-kilobase ER mRNA whereas MDA-MB-231 do not make detectable ER message. Reverse polymerase chain reaction, which offers greater sensitivity, confirms these Northern blot results. The nuclear run-on assay was used to examine directly transcription in these two cell lines. MCF-7 cells actively transcribe the ER gene whereas no ER transcription is detected in MDA-MB-231. Southern analysis of genomic DNA confirms that the ER gene is present in MDA-MB-231. We conclude that the ER gene is controlled transcriptionally in this ER-negative breast carcinoma line.
控制乳腺癌中雌激素受体（ER）表达的机制尚未阐明。MCF-7（ER阳性）和MDA-MB-231（ER阴性）乳腺癌细胞系已被用于研究ER基因表达。对从这两种细胞系中分离出的mRNA进行Northern印迹分析表明，MCF-7细胞表达预期的6.5千碱基的ER mRNA，而MDA-MB-231细胞则未检测到可检测的ER信息。具有更高灵敏度的逆转录聚合酶链反应证实了这些Northern印迹结果。核转录分析用于直接检测这两种细胞系中的转录情况。MCF-7细胞积极转录ER基因，而在MDA-MB-231中未检测到ER转录。对基因组DNA的Southern分析证实ER基因存在于MDA-MB-231中。我们得出结论，在这种ER阴性乳腺癌细胞系中，ER基因是受转录调控的。
