title: Constitutive and regulated secretion of epidermal growth factor and transforming growth factor-beta1 in MDA-MB-231 breast cancer cell line in 11-day cultures.
abstract: Epidermal growth factor (EGF) and transforming growth factor type beta1 (TGF-beta1) exert opposite effects in most cells. A potential regulation between the two factors has been studied at a transcriptional level, but never at a protein level. MDA-MB-231 is a breast carcinoma cell line which possesses large quantities of membrane receptors and expresses high activities for both factors. In this study, conditioned mediums (CM) of 11-day cultures of these cells were collected to measure EGF and TGF-beta1 by immunochemical assays. Four types of cultures were tested: (1) controls; (2) after treatment with 17-beta-estradiol; (3) treated with EGF; and (4) treated with TGF-beta1. These cells secreted constitutively quantifiable concentrations of both factors to the CM. EGF treatment inhibited TGF-beta1 levels in CM throughout the study period (P = 0.002), while EGF levels diminished after TGF-beta1 treatment (P = 0.05). This finding suggests a dual regulation between EGF and TGF-beta1, at a protein level, in this cell line.
authors.affiliation: Biochemistry Department, Ciutat Sanitària i Universitària de Bellvitge, Barcelona, Spain.
authors.forename: P A
authors.initials: PA
authors.lastname: Martínez-Carpio
authors.forename: C
authors.initials: C
authors.lastname: Mur
authors.forename: P
authors.initials: P
authors.lastname: Rosel
authors.forename: M A
authors.initials: MA
authors.lastname: Navarro
mesh_terms: D001943:Breast Neoplasms / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D005260:Female; D006801:Humans; D013997:Time Factors; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor