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PIAS1-modulated Smad2/4 complex activation is involved in zinc-induced cancer cell apoptosis

N Yang1, B Zhao, A Rasul

  • 1The Key Laboratory of Molecular Epigenetics of MOE, Institute of Genetics and Cytology, Northeast Normal University, Changchun 130024, China.

Cell Death & Disease
|September 21, 2013
PubMed

Insights

Zinc supplementation induces apoptosis in prostate cancer cells by activating the p21(WAF1/Cip1) gene. This process involves the Smad2/4/PIAS1 complex, offering a new target for cancer prevention strategies.

Area of Science:

  • Oncology
  • Molecular Biology
  • Nutritional Science

Background:

  • Prostate cancer is a leading cancer diagnosis in men, with diet playing a key role in prevention.
  • Zinc is a nutrient with known roles in modulating apoptosis, but its precise mechanism in prostate cancer chemoprevention is unclear.

Purpose of the Study:

  • To investigate the therapeutic potential of zinc in prostate cancer chemoprevention.
  • To elucidate the molecular mechanisms underlying zinc-mediated apoptosis in prostate cancer cells.

Main Methods:

  • Investigated zinc's effect on apoptosis and p21(WAF1/Cip1) transactivation in prostate cancer cells.
  • Analyzed protein expression, interactions (Smad2, Smad4, PIAS1), and promoter binding.
  • Utilized gene silencing (siRNA) and exogenous expression techniques, alongside colony formation assays.

Main Results:

  • Zinc exposure induced apoptosis and p21(WAF1/Cip1) transactivation in a Smad-dependent, p53-independent manner.
  • Zinc upregulated Smad2 and PIAS1, enhancing Smad2/4 and PIAS1 interactions and forming a transcriptional complex.
  • This complex bound to the p21(WAF1/Cip1) promoter, mediating zinc-induced apoptosis, a mechanism observed across multiple cancer cell lines.

Conclusions:

  • Zinc promotes apoptosis in prostate cancer cells by forming a Smad2/4/PIAS1 complex that activates the p21(WAF1/Cip1) gene.
  • This study reveals a novel mechanism for zinc-induced apoptosis, highlighting the roles of PIAS1, Smad2, and Smad4.
  • Findings suggest potential for zinc-based chemoprevention strategies targeting this molecular pathway.

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