PEA3, AP-1, and a unique repetitive sequence all are involved in transcriptional regulation of the breast cancer-associated gene, mammaglobin.
The breast cancer-associated gene mammaglobin is a member of the secretoglobin protein family and has demonstrated its utility as a breast cancer marker. However, the transcriptional regulation of mammaglobin has not been well-characterized. In this report, we used luciferase reporter assays to identify the 200 bp directly 5' of the transcriptional start site as the minimal promoter region of mammaglobin. Sequence scanning indicated that two PEA3 transcription sites were possibly involved in mammaglobin transcription. By transfecting a PEA3 expression vector into breast cancer cell lines MDA-MB-415 and MCF-7, we determined that exogenous PEA3 was able to drive transcription. Mutational analysis indicated that each PEA3 site was functional. Our reporter system and electrophorectic mobility shift assays (EMSAs) also identified the involvement of a unique repetitive element in mammaglobin transcription. Finally, AP-1 was determined via luciferase assays to be involved in regulating non-PEA3 dependent transcription. Elucidating these cis-acting elements will impact our understanding of transcription of normal breast and breast cancer-associated genes.
Hesselbrock
Diane R
DR
Department of Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA.
Kurpios
Natasza
N
Hassell
John A
JA
Watson
Mark A
MA
Fleming
Timothy P
TP
D001940:Breast / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D060785:Mammaglobin A; D009154:Mutation; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics*; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D024363:Transcription Initiation Site; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D014598:Uteroglobin / Q000235:genetics* / Q000378:metabolism
D060785:Mammaglobin A; D009363:Neoplasm Proteins; C556448:SCGB2A2 protein, human; D018808:Transcription Factor AP-1; D014157:Transcription Factors; C065788:transcription factor PEA3; D014598:Uteroglobin; D008156:Luciferases