Expression of NF-κB-related proteins and their modulation during TNF-α-provoked apoptosis in prostate cancer cells
Article first published online: 25 APR 2011
Copyright © 2011 Wiley Periodicals, Inc.
Volume 72, Issue 1, pages 40–50, January 2012
How to Cite
Rodríguez-Berriguete, G., Fraile, B., Paniagua, R., Aller, P. and Royuela, M. (2012), Expression of NF-κB-related proteins and their modulation during TNF-α-provoked apoptosis in prostate cancer cells. Prostate, 72: 40–50. doi: 10.1002/pros.21404
- Issue published online: 24 NOV 2011
- Article first published online: 25 APR 2011
- Manuscript Accepted: 25 MAR 2011
- Manuscript Received: 23 FEB 2011
- Ministerio de Educación y Ciencia, Spain. Grant Numbers: SAF2007-61928, SAF2007-64721
- (Plan Nacional de Investigación Científica; Desarrollo e Innovación Tecnológica; Dirección General de Investigación)
- Mutua Madrileña de Automóviles Foundation. Grant Number: AP76182010
- Consejo Superior de Investigaciones Científicas. Grant Number: 201020E037
- prostate cancer;
The involvement of TNF-α in cancer development is controversial, since this cytokine was reported to act either as tumor promoter or suppressor. TNF-α may activate signaling pathways critical for life/death decisions, such as mitogen-activated protein kinases (MAPKs) and the anti-apoptotic NF-κB pathway. In this work, we investigate the activation status of NF-κB-related proteins in human prostate cancerous versus normal epithelium, and the alterations in the NF-κB pathway in relation to cell death in TNF-α-treated LNCaP (androgen-independent cells) and PC3 (androgen-independent) prostate cancer cell lines.
The expression of phospho-p38-MAPK, phospho-IKK-α/β and phospho-IκB-α, total IκB-α, and p65- and p50-NF-κB, were analyzed by immunohistochemistry in cancerous and normal prostate samples. The toxicity of TNF-α in LNCaP and PC3 cells, with or without kinase and NF-κB inhibitors, was assessed by changes on viability (MTT assay) and apoptosis (loss of DNA, annexin-V binding, and caspase cleavage/activation). Expression of NF-κB-related proteins in these cell lines was measured by Western blot.
Phospho-IκB-α, phospho-IKK-α/β and phospho-p38 levels, cytoplasmic p50 to IκB-α ratio, and nuclear p50 and p65, levels, were increased in cancerous epithelium, suggesting activation of the NF-κB pathway in prostatic malignance. TNF-α caused apoptosis with higher efficacy in LNCaP cells, and this response was potentiated by p38-MAPK inhibitor (LNCaP cells) and IKK-β inhibitor (both cell lines). However, the protective action of IKK-β was mediated by NF-κB only in LNCaP cells.
IKK-β mediates both NF-κB-dependent and -independent anti-apoptotic functions in prostate cancerous epithelium. IKK-β and p38-MAPK may represent useful therapeutic targets against prostate cancer. Prostate 72:40–50, 2012. © 2011 Wiley Periodicals, Inc.