The Genomic and Epigenomic Landscape of Double-Negative Metastatic Prostate Cancer

Area of Science:

• Oncology
• Genomics
• Molecular Biology

Background:

• Systemic therapies for prostate cancer target androgen signaling, but resistance leads to aggressive subtypes.
• Metastatic castration-resistant prostate cancer (mCRPC) can develop neuroendocrine (NE) or double-negative (AR-/NE-) features.
• The molecular underpinnings of the aggressive AR-/NE- mCRPC subtype remain poorly understood.

Purpose of the Study:

• To comprehensively characterize the molecular landscape of treatment-emergent mCRPC subtypes.
• To identify key molecular drivers and distinct features of the double-negative (AR-/NE-) mCRPC subtype.
• To uncover potential therapeutic targets for aggressive mCRPC.

Main Methods:

• Integrated analysis of matched RNA sequencing, whole-genome sequencing, and whole-genome bisulfite sequencing data from 210 mCRPC tumors.
• Comparative molecular and clinical analysis of different mCRPC subtypes, including AR-/NE-.
• Genome-wide methylation analysis to identify regulatory mechanisms and driver alterations.

Main Results:

• AR-/NE- mCRPC tumors were clinically and molecularly distinct, associated with the shortest survival.
• Amplification of the chromatin remodeler CHD7 and PTEN loss were identified in AR-/NE- tumors.
• Krüppel-like factor 5 (KLF5) was nominated as a driver of the AR-/NE- phenotype, linked to RB1 loss.

Conclusions:

• The AR-/NE- subtype represents a highly aggressive form of mCRPC with unique molecular drivers.
• Understanding these drivers, such as CHD7 and KLF5, is crucial for developing targeted therapies.
• This study provides insights into the molecular heterogeneity of mCRPC and identifies potential therapeutic avenues.