Related Experiment Video

Updated: Jul 17, 2026

Knockdown of FAM83A to Verify Its Role in Cervical Cancer Cell Growth and Cisplatin Sensitivity
04:20

Knockdown of FAM83A to Verify Its Role in Cervical Cancer Cell Growth and Cisplatin Sensitivity

Published on: February 9, 2024

p21waf1/Cip1 partially mediates apoptosis in hepatocellular carcinoma cells

Irina Svechnikova1, Ole Ammerpohl, Tomas J Ekström

  • 1Department of Woman and Child Health, Pediatric Endocrinology Unit, Karolinska Institute & University Hospital, Q2:08, SE-171 76 Stockholm, Sweden. Irina.Svechnikova@ki.se

Biochemical and Biophysical Research Communications
|January 24, 2007
PubMed

Insights

This study demonstrates that p21waf1/Cip1 (p21) mediates the apoptosis induced by histone deacetylase inhibitors (HDACi) in liver cancer cells. Blocking p21 expression prevents cancer cell death, confirming its crucial role in HDACi treatment efficacy.

Area of Science:

  • Oncology
  • Molecular Biology
  • Biochemistry

Background:

  • p21waf1/Cip1 (p21) is a tumor suppressor gene implicated in apoptosis across various cancer types.
  • The precise role of p21 in mediating apoptosis induced by anti-cancer drugs, particularly histone deacetylase inhibitors (HDACi), remains debated due to limited direct evidence.

Purpose of the Study:

  • To investigate the role of p21 in mediating the apoptotic effects of HDAC inhibitors (4-phenylbutyrate and Trichostatin A) in hepatocellular carcinoma Hep3B cells.
  • To provide direct evidence for p21's involvement in HDACi-induced apoptosis.

Main Methods:

  • Hep3B cells were transfected with EGFP-p21 anti-sense or sense plasmids.
  • Apoptosis was induced using HDAC inhibitors (4-PB and TSA).
  • Apoptosis was assessed using the TUNEL assay.

Main Results:

  • Transfection with the p21 anti-sense construct significantly prevented apoptosis induced by HDAC inhibitors in Hep3B cells.
  • This indicates that p21 is essential for the apoptotic response to HDACi treatment.

Conclusions:

  • p21 plays a critical role in mediating the apoptotic effects of HDAC inhibitors in hepatocellular carcinoma cells.
  • These findings support the importance of p21 in the mechanism of action of HDAC inhibitors as anti-cancer agents.

More Related Videos

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c07:42

Activation of Apoptosis by Cytoplasmic Microinjection of Cytochrome c

Published on: June 29, 2011

Related Concept Videos

The Intrinsic Apoptotic Pathway01:31

The Intrinsic Apoptotic Pathway

Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
Inhibition of Cdk Activity02:34

Inhibition of Cdk Activity

The orderly progression of the cell cycle depends on the activation of Cdk protein by binding to its cyclin partner. However, the cell cycle must be restricted when undergoing abnormal changes. Most cancers correlate to the deregulated cell cycle, and since Cdks are a central component of the cell cycle, Cdk inhibitors are extensively studied to develop anticancer agents. For instance, cyclin D associates with several Cdks, such as Cdk 4/6, to form an active complex. The cyclin D-Cdk4/6 complex...
Apoptosis01:30

Apoptosis

Apoptosis is a combination of two Greek words, 'apo' and 'ptosis,' meaning separation and falling off, respectively. Hippocrates used this word to describe gangrene, which was caused due to bandaging of fractured bones. Apoptosis was distinguished from necrosis in 1970 when John Kerr reported observations of morphological changes occurring during apoptosis. During one experiment, he observed that the disruption of blood supply to the liver tissue resulted in a size reduction of the tissue.
The Extrinsic Apoptotic Pathway01:17

The Extrinsic Apoptotic Pathway

The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
Interactions Between Signaling Pathways01:19

Interactions Between Signaling Pathways

Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Anaphase Promoting Complex00:50

Anaphase Promoting Complex

The stepwise destruction of specific proteins is necessary for the progression and completion of the cell cycle. Such proteins are ubiquitinated by ubiquitin ligases and then subsequently destroyed by the proteasome. The SCF (Skp1/Cullin/F-box) and the anaphase-promoting complex (APC) are two important ubiquitin ligases involved in cell cycle progression. While SCF is active throughout the cell cycle, APC gets activated during metaphase to anaphase transition. Cdc20 or Cdh1 binds to APC and...