title: Serum signaling factors and spheroids.
abstract: Normal epithelial cells grow as a sheet-like structure. Upon malignant transformation, epithelial cells grow as multicell aggregates. Adopted in tissue culture, most tumor cells revert to adherent monolayer. In tissue culture, as early as 1958, anchorage-independent multicellular spheroid cancer cells have been shown to revert to adherent monolayer in response to extracellular serum signaling factors. Such serum signaling factors have not yet been characterized. Recent studies reveal that the conversion of adherent monolayer to multicellular spheroids is also mediated by serum signaling factors such as carcinoembryonal antigen, interferon-gamma, insulin-like growth factor-II, heregulin beta1 and plasmin. The reports provide a new approach to investigate the regulatory system of tumor cell growth pattern as well as the effect of the change in growth pattern on various cellular functions.
authors.affiliation: Bioeast, New York, NY 10128, USA. chun01@sprynet.com
authors.forename: M H
authors.initials: MH
authors.lastname: Chun
mesh_terms: D001798:Blood Proteins / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods; D002471:Cell Transformation, Neoplastic; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D015398:Signal Transduction; D018874:Spheroids, Cellular / Q000378:metabolism / Q000473:pathology*
chemical_list: D001798:Blood Proteins