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Updated: Jan 30, 2026

Preparation of Cell-lines for Conditional Knockdown of Gene Expression and Measurement of the Knockdown Effects on E4orf4-Induced Cell Death
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Preparation of Cell-lines for Conditional Knockdown of Gene Expression and Measurement of the Knockdown Effects on E4orf4-Induced Cell Death

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PDCD4 Knockdown Induces Senescence in Hepatoma Cells by Up-Regulating the p21 Expression

Jing Guo1, Iwata Ozaki1,2, Jinghe Xia1

  • 1Division of Hepatology, Diabetology and Endocrinology, Department of Internal Medicine, Saga Medical School, Saga University, Saga, Japan.

Frontiers in Oncology
|January 29, 2019
PubMed

Insights

Programmed cell death 4 (PDCD4) knockdown inhibits hepatoma cell growth by affecting cell cycle regulators. This study reveals PDCD4

Area of Science:

  • Hepatocellular carcinoma research
  • Cell cycle regulation
  • Tumor suppressor genes

Background:

  • Over-expression of programmed cell death 4 (PDCD4) induces apoptosis.
  • Recent findings indicate PDCD4 knockdown also triggers apoptosis.
  • The role of PDCD4 in hepatoma cell cycle regulation requires further investigation.

Purpose of the Study:

  • To investigate the contribution of PDCD4 to cell cycle regulation in hepatoma cells.
  • To examine cell cycle regulators affected by PDCD4 knockdown.
  • To explore PDCD4 as a potential therapeutic target for hepatocellular carcinoma.

Main Methods:

  • Utilized three hepatoma cell lines: HepG2, Huh7, and Hep3B.
  • Performed PDCD4 knockdown experiments.
  • Analyzed cell cycle regulators including Rb, CDKs, and p21.
  • Assessed apoptosis and cellular senescence (β-galactosidase staining).

Main Results:

  • PDCD4 knockdown suppressed hepatoma cell growth across all tested cell lines.
  • Inhibition of Rb phosphorylation was observed, linked to down-regulated Rb/CDK expression and up-regulated p21.
  • Apoptosis occurred in a p53-dependent manner in HepG2 cells, with a different mechanism in p53-deficient Hep3B cells.
  • PDCD4 knockdown induced cellular senescence, which was rescued by p21 knockdown.

Conclusions:

  • PDCD4 plays a crucial role in regulating the cell cycle of hepatoma cells.
  • PDCD4 knockdown impacts Rb phosphorylation and p21 expression through a p53-independent pathway.
  • PDCD4 is implicated in inducing both apoptosis and senescence in hepatoma cells.
  • PDCD4 represents a potential therapeutic target for hepatocellular carcinoma treatment.
Keywords:
PDCD4apoptosishepatoma cellsp21senescence

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