Transforming growth factor-beta1 regulation of ATF-3 and identification of ATF-3 target genes in breast cancer cells.
Transforming growth factor-beta1 (TGF-beta1) is a crucial molecule for stimulation of breast cancer invasion and formation of bone metastases. The molecular mechanisms of how TGF-beta1 mediates these effects have yet to be completely determined. We have found that activating transcription factor-3 (ATF-3) is strongly stimulated and its level is sustained by TGF-beta1 in highly invasive and metastatic human breast cancer (MDA-MB231) and in mouse mammary pad tumor cells (r3T). ATF-3 is also overexpressed in human primary breast cancer tissue. Overexpression of ATF-3 increased normal human mammary epithelial cell number and DNA synthesis suggesting a role for ATF-3 in cell proliferation. The functional role of ATF-3 in breast cancer progression was determined by the RNA interference technique. Knockdown of ATF-3 by ATF-3 shRNA in MDA-MB231 cells decreased expression of cell cycle gene, cyclin A1 in MDA-MB231 cells. ATF-3 shRNA also decreased expression of an invasive and metastatic gene, matrix metalloproteinase-13 (MMP-13; collagenase-3) in these cells. Chromatin immunoprecipitation experiments identified the direct physical interaction of ATF-3 protein on the human MMP-13 promoter. Thus, the dysregulation of ATF-3 by TGF-beta1 is likely to activate cyclin A1 and MMP-13 genes in breast cancer cells and that would be key to the subsequent cancer cell invasion and metastasis.
Kwok
Sukyee
S
Department of Physiology and Biophysics, UMDNJ-Robert Wood Johnson Medical School, Piscataway, New Jersey 08854, USA.
Rittling
Susan R
SR
Partridge
Nicola C
NC
Benson
Chellakkan S
CS
Thiyagaraj
Mayuranathan
M
Srinivasan
Narasimhan
N
Selvamurugan
Nagarajan
N
D051700:Activating Transcription Factor 3 / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001940:Breast / Q000166:cytology / Q000378:metabolism; D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D047369:Chromatin Immunoprecipitation; D056750:Cyclin A1 / Q000235:genetics* / Q000378:metabolism; D016213:Cyclins / Q000378:metabolism; D004268:DNA-Binding Proteins; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D015674:Mammary Neoplasms, Animal / Q000378:metabolism; D053509:Matrix Metalloproteinase 13 / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D009361:Neoplasm Invasiveness / Q000235:genetics; D009362:Neoplasm Metastasis / Q000235:genetics; D011401:Promoter Regions, Genetic; D034622:RNA Interference; D046888:Tissue Array Analysis; D014162:Transfection; D053773:Transforming Growth Factor beta1 / Q000008:administration & dosage / Q000235:genetics* / Q000378:metabolism
D051700:Activating Transcription Factor 3; D056750:Cyclin A1; D016213:Cyclins; D004268:DNA-Binding Proteins; D053773:Transforming Growth Factor beta1; D053509:Matrix Metalloproteinase 13