Cathepsin D gene of human MCF7 cells contains estrogen-responsive sequences in its 5' proximal flanking region.
Cathepsin D is a lysosomal protease produced and secreted in excess by most human breast cancer cells. In MCF7 cells, estrogens stimulate cathepsin D expression at the mRNA level via a mechanism independent of de novo protein synthesis. We have isolated the human cathepsin D gene and its 5' flanking sequences from a MCF7 genomic library. To demonstrate its transcriptional estrogen regulation, we constructed chimeric recombinants bearing different fragments of the cathepsin D gene 5' proximal region inserted in front of the bacterial chloramphenicol acetyl transferase reporter gene. By transient cotransfection with the estrogen receptor expression vector into MCF7 cells, we showed that a 240 bp fragment located in the 5' proximal region of the gene was able to mediate transcriptional estrogen activation. This induction was concentration-dependent and suppressed by the antiestrogen ICI 164, 384.
Cavailles
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V
Unité Hormones et Cancer (U 148) INSERM, Université de Montpellier I, France.
Augereau
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P
Rochefort
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H
D001943:Breast Neoplasms; D002402:Cathepsin D / Q000235:genetics*; D002460:Cell Line; D004273:DNA, Neoplasm / Q000235:genetics / Q000302:isolation & purification; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D015723:Gene Library; D005796:Genes; D006801:Humans; D007700:Kinetics; D015183:Restriction Mapping; D014158:Transcription, Genetic / Q000187:drug effects*; D014162:Transfection
D004273:DNA, Neoplasm; D004958:Estradiol; D002402:Cathepsin D