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An Orthotopic Murine Model of Human Prostate Cancer Metastasis
Published on: September 18, 2013
The p38 transduction pathway in prostatic neoplasia
M Ricote1, I García-Tuñón, F Bethencourt
1Department of Cell Biology and Genetics, University of Alcalá, Alcalá de Henares, Madrid, Spain.
The Journal of Pathology
|December 22, 2005
Summary
Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-alpha (IL-1-alpha) influence prostate cell proliferation via p38 activation. Overexpression of p38 pathway components in benign prostatic hyperplasia and prostate carcinoma enhances proliferation, suggesting p38 inhibition as a potential treatment.
Area of Science:
- Cellular and Molecular Biology
- Oncology
- Signal Transduction
Background:
- Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1-alpha (IL-1-alpha) are implicated in cellular responses, including cell death and proliferation, often mediated by p38 activation.
- The p38 signal transduction pathway plays a role in cellular proliferation and apoptosis, making it a relevant target for understanding prostate pathologies.
Purpose of the Study:
- To investigate the expression and activation of key components of the p38 signal transduction pathway, including alpha-PAK, MEK-6, Elk-1, and ATF-2.
- To compare the expression levels of these pathway components in normal prostate tissue, benign prostatic hyperplasia (BPH), and prostate carcinoma (PC).
Main Methods:
- Immunohistochemical and western blot analyses were conducted on tissue samples from normal prostate (n=20), BPH (n=47), and PC (n=27).
- Expression and localization of alpha-PAK, MEK-6, phosphorylated Elk-1 (p-Elk-1), and phosphorylated ATF-2 (p-ATF-2) were assessed in the different prostate tissue types.
Main Results:
- Normal prostates showed nuclear expression of p-Elk-1 and p-ATF-2, with no detectable alpha-PAK or MEK-6.
- Benign prostatic hyperplasia (BPH) exhibited cytoplasmic expression of alpha-PAK and MEK-6, with decreased proportions of lesions showing p-Elk-1 and p-ATF-2 immunoreactivity compared to normal tissue.
- Prostate carcinoma (PC) displayed increased percentages of cells expressing alpha-PAK and MEK-6, and significantly higher percentages of cells immunoreactive for p-Elk-1 and p-ATF-2 compared to BPH, indicating enhanced pathway activation.
Conclusions:
- Overexpression and activation of the p38 pathway components (alpha-PAK, MEK-6, p38, p-Elk-1, p-ATF-2) are associated with enhanced cell proliferation in BPH and PC.
- In BPH, proliferation is IL-1-driven and partially counteracted by TNF-alpha-induced apoptosis via AP-1. In PC, both IL-1 and TNF-alpha drive proliferation, with TNF-alpha signaling diverted to p38 activation.
- Given the increased expression of IL-1alpha and IL-1RI in PC and the role of p38 in proliferation and apoptosis, p38 inhibition presents a potential therapeutic strategy for prostate carcinoma.
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