Olaparib is effective in combination with, and as maintenance therapy after, first-line endocrine therapy in prostate cancer cells.

A number of prostate cancer (PCa)-specific genomic aberrations (denominated BRCAness genes) have been discovered implicating sensitivity to PARP inhibition within the concept of synthetic lethality. Recent clinical studies show favorable results for the PARP inhibitor olaparib used as single agent for treatment of metastatic castration-resistant PCa. Using 2D and 3D cell culture models mimicking the different treatment and progression stages of PCa, we evaluated a potential use for olaparib in combination with first-line endocrine treatments, androgen deprivation, and complete androgen blockade, and as a maintenance therapy following on from endocrine therapy.

Mechanistic rationale for MCL1 inhibition during androgen deprivation therapy.

Androgen deprivation therapy induces apoptosis or cell cycle arrest in prostate cancer (PCa) cells. Here we set out to analyze whether MCL1, a known mediator of chemotherapy resistance regulates the cellular response to androgen withdrawal. Analysis of MCL1 protein and mRNA expression in PCa tissue and primary cell culture specimens of luminal and basal origin, respectively, reveals higher expression in cancerous tissue compared to benign origin.