title: Effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin on growth factor expression in the human breast cancer cell line MCF-7.
abstract: The aim of this study was to examine whether changes in growth factor or cytokine expression could be responsible for the growth inhibitory effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the human breast cancer MCF-7 cell line. Treatment of MCF-7 cells with 10 nM TCDD for 7 days reduced the cell growth to 60% of control; this effect was partly abolished by cotreatment of the cells with 100 nM 17 beta-estradiol (E2). The inhibition of cell growth by TCDD was accompanied by an enhanced secretion of transforming growth factor-beta (TGF-beta) and the TGF-beta content in cell culture supernatants was 2-fold higher than in controls. Using reverse transcription polymerase chain reaction (RT-PCR), the effect of TCDD on the expression of TGF-beta isoforms, transforming growth factor-alpha (TGF-alpha), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) was investigated. It was demonstrated that incubation with 1, 10 and 100 nM TCDD for 24 h increased mRNA levels of TGF-alpha, TNF-alpha and IL-1 beta. The strongest effect was found on IL-1 beta, the mRNA level of which was dose-dependently increased. TCDD had a minor effect on TGF-alpha and TNF-alpha mRNA. The mRNA levels were significantly increased after treatment with 10 and 100 nM TCDD. The mRNA expression of TGF-beta 1 and TGF-beta 2 was unchanged, whereas the TGF-beta 3 mRNA level was enhanced 2 to 3-fold after TCDD treatment. From the results, we suggest that TCDD-induced growth inhibition in MCF-7 cells is related to the growth inhibitory action of a set of growth factors and cytokines which have a contextual action on MCF-7 cell proliferation.
authors.affiliation: Heinrich-Heine University of Düsseldorf, Department of Toxicology, Düsseldorf, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Vogel
authors.forename: J
authors.initials: J
authors.lastname: Abel
mesh_terms: D000704:Analysis of Variance; D001943:Breast Neoplasms / Q000503:physiopathology*; D016207:Cytokines / Q000096:biosynthesis* / Q000187:drug effects; D006133:Growth Substances / Q000096:biosynthesis*; D006801:Humans; D007375:Interleukin-1 / Q000096:biosynthesis; D008175:Lung Neoplasms / Q000503:physiopathology; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D016211:Transforming Growth Factor alpha / Q000096:biosynthesis; D016212:Transforming Growth Factor beta / Q000096:biosynthesis; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
chemical_list: D016207:Cytokines; D006133:Growth Substances; D007375:Interleukin-1; D000072317:Polychlorinated Dibenzodioxins; D016211:Transforming Growth Factor alpha; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha