Related Experiment Video

Updated: Jul 2, 2026

Real Time Detection of In Vitro Tumor Cell Apoptosis Induced by CD8+ T Cells to Study Immune Suppressive Functions of Tumor-infiltrating Myeloid Cells
09:57

Real Time Detection of In Vitro Tumor Cell Apoptosis Induced by CD8+ T Cells to Study Immune Suppressive Functions of Tumor-infiltrating Myeloid Cells

Published on: January 29, 2019

Vorinostat and sorafenib synergistically kill tumor cells via FLIP suppression and CD95 activation

Guo Zhang1, Margaret A Park, Clint Mitchell

  • 1Department of Biochemistry, Virginia Commonwealth University, Richmond, Virginia 23298-0035, USA.

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research
|September 4, 2008
PubMed
Abstract

Insights

Sorafenib and vorinostat synergistically kill cancer cells by downregulating anti-apoptotic proteins and activating cell death pathways. This combination therapy targets hepatic, renal, and pancreatic adenocarcinomas, offering a promising therapeutic strategy.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pharmacology

Background:

  • Sorafenib is a multikinase inhibitor, and vorinostat is a histone deacetylase inhibitor.
  • Understanding drug interactions is crucial for developing effective cancer therapies.

Purpose of the Study:

  • To define the mechanisms by which sorafenib and vorinostat interact to induce cancer cell death.
  • To investigate the role of apoptosis pathways in the combined drug effect.

Main Methods:

  • In vitro synergistic assays using low doses of sorafenib and vorinostat.
  • Cell viability and colony formation assays.
  • Analysis of apoptosis-related protein expression and signaling pathway activation.
  • Inhibition and knockdown studies targeting specific proteases and signaling molecules.

Main Results:

  • Sorafenib and vorinostat demonstrated synergistic cancer cell killing in hepatic, renal, and pancreatic adenocarcinoma cells.
  • Cell death was mediated through the CD95 extrinsic apoptotic pathway and lysosomal proteases, involving caspase-8 and cathepsins.
  • Combined treatment led to decreased expression of anti-apoptotic proteins (e.g., BCL-2, MCL-1) and increased expression of pro-apoptotic proteins (e.g., BIM).
  • Suppression of c-FLIP-s was identified as a critical event in mediating cell death.

Conclusions:

  • Combined sorafenib and vorinostat treatment effectively kills cancer cells by modulating apoptotic pathways.
  • The interaction involves downregulation of anti-apoptotic proteins and activation of CD95-mediated apoptosis.
  • Targeting c-FLIP-s suppression is key to the pro-apoptotic signaling cascade initiated by this drug combination.

Related Concept Videos

Combination Therapies and Personalized Medicine02:50

Combination Therapies and Personalized Medicine

Combining two or more treatment methods increases the life span of cancer patients while reducing damage to vital organs or tissue from the overuse of a single treatment. Combination therapy also targets different cancer-inducing pathways, thus reducing the chances of developing resistance to treatment.
The combination of the drug acetazolamide and sulforaphane is a good example of combination therapy to treat cancer. The cells in the interior of a large tumor often die due to the hypoxic and...
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...
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...
Combined Effects of Drugs: Synergism01:27

Combined Effects of Drugs: Synergism

Synergism is a useful mechanism where combining two or more drugs is more effective than each constituent used alone. Such combinations are also called supra-additive interactions. The drugs collectively enhance the final therapeutic effect by acting on different targets. Another advantage is that the low dose of each constituent drug is sufficient to achieve the desired effect. This helps reduce the duration of therapy and lower the adverse effects of these drugs.
Such synergistic combinations...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
mTOR Signaling and Cancer Progression03:03

mTOR Signaling and Cancer Progression

The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...