HSD3B1 status as a biomarker of androgen deprivation resistance and implications for prostate cancer

Area of Science:

• Oncology
• Genetics
• Pharmacology

Background:

• Advanced prostate cancer often becomes resistant to androgen deprivation therapy (ADT).
• Intratumoral androgen synthesis, particularly via 3β-hydroxysteroid dehydrogenase/Δ5→4 isomerase 1 (3β-HSD1) encoded by HSD3B1, is a key mechanism of resistance.
• A specific HSD3B1 gene variant (1245A>C) leads to increased enzyme levels and androgen synthesis from extragonadal precursors.

Purpose of the Study:

• To investigate the clinical implications of the HSD3B1 gene variant in advanced prostate cancer patients undergoing ADT.
• To evaluate the HSD3B1 variant as a predictive biomarker for treatment response.
• To explore how the HSD3B1 variant influences response to different therapeutic agents, including CYP17A1 inhibitors and abiraterone.

Main Methods:

• Analysis of clinical study data correlating HSD3B1 variant status with patient outcomes after ADT.
• Examination of the role of 3β-HSD1 in androgen synthesis from adrenal precursors.
• Investigation of the metabolic pathway of steroidal drugs like abiraterone involving 3β-HSD1.

Main Results:

• Patients with the HSD3B1 variant allele show significantly worse outcomes following ADT compared to those without the variant.
• The HSD3B1 variant is associated with extended responses to CYP17A1 inhibition, suggesting increased tumor reliance on extragonadal androgens.
• Metabolism of abiraterone by 3β-HSD1 produces 5α-abiraterone, which can activate the androgen receptor and potentially drive progression.

Conclusions:

• HSD3B1 variant status is a predictive biomarker for ADT response in advanced prostate cancer.
• The HSD3B1 variant highlights increased tumor dependence on extragonadal androgens.
• Current treatment strategies may need modification for patients with the HSD3B1 variant to optimize outcomes.