Dual glutathione-S-transferase-θ1 and -μ1 gene deletions determine imatinib failure in chronic myeloid leukemia

Area of Science:

• Pharmacogenomics
• Oncology
• Molecular Biology

Background:

• Approximately 40% of chronic myeloid leukemia (CML) patients exhibit imatinib treatment failure.
• Glutathione-S-transferase (GST) gene variations, including deletions in GSTT1 and GSTM1 and a specific SNP in GSTP1 (Ile105Val), are associated with CML risk.
• The impact of these GST variations on imatinib treatment outcomes in CML patients remains unclear.

Purpose of the Study:

• To investigate the association between genetic variations in GSTT1, GSTM1, and GSTP1 and imatinib treatment outcomes in CML patients.
• To determine if specific GST gene deletions or polymorphisms predict imatinib failure in CML.

Main Methods:

• Genotyping analysis was performed on 193 CML patients undergoing imatinib therapy.
• Assessed deletions in GSTT1 and GSTM1 genes.
• Evaluated the GSTP1 Ile105Val (GSTP1*B) single-nucleotide polymorphism (SNP).
• Correlated GST genotypes with imatinib treatment failure rates.

Main Results:

• Deletion of the GSTT1 gene significantly increased the likelihood of imatinib failure (P = 0.021).
• Combined deletion of both GSTT1 and GSTM1 genes strongly correlated with imatinib failure (P < 0.001).
• The GSTP1 Ile105Val (GSTP1*B) SNP showed no significant association with time to imatinib failure.

Conclusions:

• Loss of GSTT1 and/or GSTM1 genes are significant determinants of imatinib treatment failure in CML.
• Genetic screening for GSTT1 and GSTM1 deletions at diagnosis could identify CML patients who may benefit from alternative therapies.
• These findings highlight the potential of pharmacogenetic markers to personalize CML treatment strategies.