title: Breast cancer cell lines grown in vivo: what goes in isn't always the same as what comes out.
abstract: Human cell lines constitute powerful model systems for the in vitro and in vivo analysis of cancer. Cancer lines that are invasive in culture often form tumors and metastases in immune deficient mice. It is generally assumed that, in such cases, the principal population of cancer cells in culture corresponds to the tumor-forming cells in vivo. Here, we high-light a recent functional proteomics investigation that suggests the contrary. In this study, cells derived from orthotopic xenograft tumors formed by the invasive breast cancer line MDA-MB-231 were found to exhibit profound differences in their enzyme activity profiles and increased tumor growth rates and metastasis when compared to the parental line. These findings suggest that the in vivo microenvironment of the mouse mammary fat pad cultivates the growth of human breast cancer cells with elevated tumorigenic properties. Characterization of the unique molecular properties of these tumor-forming cells may reveal new strategies for the diagnosis and treatment of breast cancer.
authors.affiliation: The Skaggs Institute for Chemical Biology, Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037, USA.
authors.forename: Nadim
authors.initials: N
authors.lastname: Jessani
authors.forename: Sherry
authors.initials: S
authors.lastname: Niessen
authors.forename: Barbara M
authors.initials: BM
authors.lastname: Mueller
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Cravatt
mesh_terms: D000818:Animals; D001943:Breast Neoplasms / Q000201:enzymology* / Q000473:pathology* / Q000503:physiopathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008321:Mammary Glands, Animal / Q000201:enzymology / Q000473:pathology / Q000503:physiopathology; D051379:Mice; D016513:Mice, SCID; D009361:Neoplasm Invasiveness; D009362:Neoplasm Metastasis / Q000473:pathology*; D009368:Neoplasm Transplantation; D025221:Phosphofructokinases / Q000235:genetics / Q000378:metabolism; D040901:Proteomics; D010959:Tissue Plasminogen Activator / Q000235:genetics / Q000378:metabolism; D014183:Transplantation, Heterologous; D014568:Urokinase-Type Plasminogen Activator / Q000235:genetics / Q000378:metabolism
chemical_list: D025221:Phosphofructokinases; D010959:Tissue Plasminogen Activator; D014568:Urokinase-Type Plasminogen Activator