Histone deacetylases inhibition by SAHA/Vorinostat normalizes the glioma microenvironment via xCT equilibration

Area of Science:

• Neuro-oncology
• Molecular Biology
• Pharmacology

Background:

• Malignant gliomas cause neurodegeneration by disrupting glutamate homeostasis.
• Increased expression of the glutamate transporter xCT (solute carrier family 7 member 11) is crucial for glioma progression.
• Targeting xCT is challenging due to its essential physiological role and ubiquitous expression.

Purpose of the Study:

• To investigate the effect of the HDAC-inhibitor SAHA on xCT transporter expression in malignant gliomas.
• To determine if SAHA can specifically target xCT in tumor cells while sparing healthy brain tissue.
• To evaluate the therapeutic potential of SAHA in normalizing the tumor microenvironment.

Main Methods:

• Treatment of glioma cells and brain tissue with SAHA.
• Analysis of xCT transporter expression and its correlation with ATF4.
• Assessment of reactive oxygen species (ROS) levels.
• Measurement of extracellular glutamate levels and neuronal cell death.

Main Results:

• SAHA specifically inhibits xCT transporter expression in malignant gliomas.
• SAHA treatment leads to increased tumor cell stress (ROS) and correlates with reduced ATF4 expression.
• SAHA normalizes xCT levels specifically in malignant brain tumors, not in healthy brain parenchyma.
• Reduced extracellular glutamate levels result in decreased neuronal cell death and a normalized tumor microenvironment.

Conclusions:

• SAHA demonstrates specific efficacy against malignant gliomas by targeting the xCT transporter.
• SAHA normalizes glutamate homeostasis within the tumor microenvironment, mitigating neurotoxicity.
• SAHA represents a potential therapeutic agent for managing malignant gliomas by specifically targeting tumor-associated xCT expression.