Redox-Mediated Suberoylanilide Hydroxamic Acid Sensitivity in Breast Cancer

Area of Science:

• Oncology
• Pharmacology
• Molecular Biology

Background:

• Vorinostat (SAHA) is an approved histone deacetylase inhibitor (HDACi) for T-cell lymphoma with potential in breast cancer.
• Investigating SAHA responsiveness in human breast tumors and cell lines is crucial for understanding treatment efficacy.

Purpose of the Study:

• To investigate breast cancer cell and tumor responsiveness to Vorinostat (SAHA).
• To identify biomarkers predicting sensitivity or resistance to SAHA treatment.
• To explore mechanisms of SAHA resistance, focusing on redox pathways.

Main Methods:

• Differential gene expression analysis in SAHA-sensitive and resistant breast cancer cell lines.
• Validation of gene expression findings in human breast primary tumors.
• Assessing the impact of buthionine sulfoximine (BSO) on SAHA-induced cytotoxicity.

Main Results:

• Differential responses to SAHA were observed in breast cancer cell lines and primary tumors.
• Genes in cell adhesion and redox pathways, especially glutathione metabolism, were differentially expressed in resistant versus sensitive cell lines.
• Buthionine sulfoximine (BSO) significantly enhanced SAHA cytotoxicity in both cell lines and primary tumors, suggesting glutathione's role in resistance.

Conclusions:

• Redox pathway gene expression, particularly antioxidant genes, may predict breast cancer resistance to SAHA.
• Evaluating antioxidant gene expression could inform clinical application of epigenetic drugs like HDACis.
• Targeting glutathione metabolism presents a potential strategy to overcome SAHA resistance in breast cancer.