A negative regulatory factor is missing in a human metastatic breast cancer cell line.
The intermediate filament protein, vimentin, is differentially expressed in various tissues and stages of development and in metastatic versus nonmetastatic breast cancer cell lines. Previously, we have shown vimentin expression to be regulated at least in part by a silencer element which binds a M(r) 95,000 protein and an overriding, antisilencer element which binds a M(r) 140,000 protein. Southwestern blot (DNA-protein) analyses indicate that silencer protein binding activity is missing in the metastatic breast cancer cell line (MDA-MB-231), where vimentin is highly expressed, but is present in the nonmetastatic breast cancer cell line, MCF-7, where vimentin is not expressed. This suggests that the absence of a functional silencer protein may lead to expression of vimentin as well as other genes which contribute to the metastatic state.
Stover
D M
DM
Department of Biochemistry and Molecular Biophysics, Medical College of Virginia/Virginia Commonwealth University, Richmond 23298.
Carey
I
I
Garzon
R J
RJ
Zehner
Z E
ZE
D000818:Animals; D001483:Base Sequence; D001943:Breast Neoplasms / Q000235:genetics* / Q000473:pathology*; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D004273:DNA, Neoplasm / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D017353:Gene Deletion; D015972:Gene Expression Regulation, Neoplastic; D005809:Genes, Regulator; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009362:Neoplasm Metastasis; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D014162:Transfection; D014407:Tumor Cells, Cultured; D014746:Vimentin / Q000235:genetics*
D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D014746:Vimentin; D015500:Chloramphenicol O-Acetyltransferase