Autocrine interleukin-1 beta regulates both proliferation and apoptosis in EL4-6.1 thymoma cells.
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.
Fratelli
M
M
Istituto di Richerche Farmacologiche Mario Negri, Milan, Italy.
Gagliardini
V
V
Galli
G
G
Gnocchi
P
P
Ghiara
P
P
Ghezzi
P
P
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
D007375:Interleukin-1