GSTM5 as a Potential Biomarker for Treatment Resistance in Prostate Cancer

Area of Science:

• Oncology
• Genetics
• Pharmacogenomics

Background:

• Androgen deprivation therapy (ADT) is a cornerstone for prostate cancer (PC) management.
• Treatment resistance to ADT is a significant clinical hurdle.
• The role of Glutathione S-transferase Mu 5 (GSTM5) in ADT resistance is not well-defined.

Purpose of the Study:

• To investigate the association of the GSTM5 rs3768490 polymorphism with early ADT resistance in prostate cancer.
• To evaluate the combined predictive value of GSTM5 genotype and clinical variables for ADT response.
• To explore the relationship between GSTM5 expression, rs3768490 genotype, and ADT response.

Main Methods:

• In silico analyses of GSTM5 interactions and pathways.
• Genotyping of the rs3768490 polymorphism in 354 PC patients.
• Logistic regression to assess associations between genotype, clinical factors, and ADT response.
• Analysis of GSTM5 expression in 129 prostate tissue samples.

Main Results:

• The T/T genotype of rs3768490 was significantly associated with a reduced likelihood of early ADT resistance (OR=0.18, p=0.0359).
• High D'Amico risk classification strongly predicted early progression (OR>5.4, p<0.0004).
• Combined genotype and clinical risk improved patient stratification for ADT response.
• GSTM5 expression was slightly elevated in T/T carriers, suggesting a protective effect.

Conclusions:

• The rs3768490 T/T genotype may confer protection against ADT resistance in prostate cancer, potentially via modulation of GSTM5 expression.
• Integrating genetic biomarkers like rs3768490 with clinical data may enhance personalized treatment strategies for PC.
• Further research is warranted to validate these preliminary findings and their clinical utility.