- Paper Report
- Open Access
Activin can activate p38 MAPK
- Elena Neumann1
© Biomed Central Ltd 2001
- Received: 20 August 2001
- Accepted: 20 August 2001
- Published: 1 December 2001
- Activin, cell growth, growth arrest, p38 MAPK, signaling, Smad
Activin, a member of the transforming growth factor (TGF)? family of growth factors, is known to be a potential growth inhibitor in various tissues and a potential regulator of inflammation by downregulation of proinflammatory cytokines, like interleukin (IL)-1 and IL-6. Activin is overexpressed in several diseases, e.g. in the synovium of rheumatoid arthritis, which is characterized by inflammation and hyperplasia. Intracellular signaling of cellular growth arrest mediated by activin involves Smad proteins, but other molecular pathways still have to be clarified. The aim of this study was to characterize the intracellular signaling of activin that leads to cell growth inhibition.
The authors analyzed the signaling of activin in a breast cancer cell line (T47D), which showed a strong decrease of cell growth after treatment with activin. By analyzing the activation of several transcription factors and signaling cascades, the authors showed that in addition to the induction of Smads the p38 mitogen-activated protein kinases (MAPK) pathway was activated in T47D cells after activin-induced inhibition of cell growth. The mRNA levels for two cyclin-dependent kinase inhibitors (p15INK4B and p21CIP1/WAF1) increased following stimulation with activin.
Proliferation assay, transfection by electroporation and reporter assay, RNase protection assay, western blotting