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Fluorescence-based Monitoring of PAD4 Activity via a Pro-fluorescence Substrate Analog
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Published on: November 5, 2014

Tumour-suppression activity of the proapoptotic regulator Par4

Isabel García-Cao1, Angeles Duran, Manuel Collado

  • 1Spanish National Cancer Center (CNIO), 3 Melchor Fernandez Almagro Street, Madrid 28029, Spain.

EMBO Reports
|May 7, 2005
PubMed

Insights

Mice lacking the Par4 (prostate apoptosis response 4) gene developed tumors, especially in the endometrium and prostate. Par4 deficiency promotes cancer by increasing the apoptosis inhibitor XIAP.

Area of Science:

  • Oncology
  • Molecular Biology
  • Genetics

Background:

  • The proapoptotic protein Par4 (prostate apoptosis response 4) is recognized for its role in tumor suppression, particularly within the prostate.
  • Studies suggest Par4 influences cancer development, but its specific functions in various tissues remain under investigation.

Purpose of the Study:

  • To investigate the role of Par4 in spontaneous and carcinogen-induced tumor development.
  • To examine the impact of Par4 deficiency on endometrial and prostate tissues.
  • To elucidate the molecular mechanisms underlying Par4's tumor-suppressive function.

Main Methods:

  • Generation and analysis of Par4-null mice.
  • Histopathological examination of endometrial and prostate tissues.
  • Assessment of apoptosis-related protein levels, including XIAP (X-chromosome-linked inhibitor of apoptosis).

Main Results:

  • Par4-null mice exhibited increased susceptibility to spontaneous and carcinogen-induced tumors.
  • Significant incidences of endometrial hyperplasia (80%) and adenocarcinoma (36%) were observed in female Par4-null mice.
  • Male Par4-null mice showed high rates of prostate hyperplasia and prostatic intraepithelial neoplasias, with heightened sensitivity to testosterone.
  • Elevated XIAP levels were detected in the uterus and prostate of young Par4-null mice.

Conclusions:

  • Par4 plays a critical role in tumor suppression, with notable importance in the endometrium and prostate.
  • Par4 deficiency promotes proliferative lesions and cancer development in these tissues.
  • The tumor-suppressive function of Par4 may involve the inhibition of the (zeta)PKC-NF-(kappa)B-XIAP pathway.

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