title: Autocrine interleukin-1 beta regulates both proliferation and apoptosis in EL4-6.1 thymoma cells.
abstract: We demonstrate here that EL4-6.1 cells, a mouse thymoma that expresses high levels of membrane interleukin (IL)-1 receptors, produce IL-1 beta as an autocrine regulatory factor. Endogenous IL-1 beta sustains both proliferation and apoptosis: during the exponential phase, it mainly promotes proliferation, while during the plateau phase of cell growth, it induces death by apoptosis. Additionally, we show that exogenous IL-1 beta added to EL4-6.1 cells in lag phase induces apoptosis in a portion of the cells and proliferation in the remaining cells. Therefore, IL-1 beta can exert two completely opposite effects on a single cell type, depending on the state of the target cell.
authors.affiliation: Istituto di Richerche Farmacologiche Mario Negri, Milan, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Fratelli
authors.forename: V
authors.initials: V
authors.lastname: Gagliardini
authors.forename: G
authors.initials: G
authors.lastname: Galli
authors.forename: P
authors.initials: P
authors.lastname: Gnocchi
authors.forename: P
authors.initials: P
authors.lastname: Ghiara
authors.forename: P
authors.initials: P
authors.lastname: Ghezzi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002452:Cell Count / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D007375:Interleukin-1 / Q000378:metabolism* / Q000494:pharmacology; D051379:Mice; D015398:Signal Transduction; D013945:Thymoma / Q000378:metabolism* / Q000473:pathology*; D014407:Tumor Cells, Cultured
chemical_list: D007375:Interleukin-1