Isaacs, J. T. | bioRxiv Science

bioRxiv2024

LSD1 inhibition suppresses ASCL1 and de-represses YAP1 to drive potent activity against neuroendocrine prostate cancer

Progression to lethal metastatic castration-resistant prostate cancer (mCRPC) is driven in part by epigenetic modulators such as LSD1 (KDM1A), a lysine-specific demethylase. Yet, mCRPC is increasingly recognized as a highly heterogeneous disease whose classification into subtypes is defined by the extent of androgen receptor (AR) and/or neuroendocrine (NE) characteristics. Meanwhile, the role of LSD1 in driving the different subtypes of mCRPC has remained unclear. Here, we assess the necessity of LSD1 in driving progression of mCRPC subtypes including AR+/NE- (ARPC), AR-/NE+ (NEPC), AR+/NE+ (amphicrine; AMPC), and AR-/NE- (double-negative; DNPC) through the use of LSD1 inhibitors in clinical development. LSD1 inhibition (LSD1i) was observed to be highly effective in restricting growth of NEPC, and efficacy was associated with TP53 loss-of-function. Mice bearing NEPC patient-derived xenografts treated with the LSD1 inhibitors, bomedemstat (MK-3543) or iadademstat (ORY-1001), exhibited suppression of the NE transcriptional profile, including ASCL1. LSD1i also induced expression and activity of YAP1, a non-NE transcription factor canonically silenced in NEPC (YAPOFF cancer), thereby switching NEPC from a YAPOFF to a YAPON cancer class. Therapeutically-induced YAPON NEPC tumors exhibited cell cycle arrest and repression of proliferative transcriptional programs. Importantly, the LSD1i-mediated YAPON state induced sensitivity to an inhibitor of YAP/TEAD function, IAG933, which extended antitumor efficacy against NEPC. Altogether, these findings indicate that patients diagnosed with NEPC may obtain greater relative benefit from LSD1-targeted therapies compared to those with other mCRPC subtypes and that dual inhibition of LSD1 and YAP/TEAD function demonstrates a promising treatment strategy potentially extending to other YAPOFF cancers. SignificanceAcross prostate cancer subtypes, NEPC is exceptionally responsive to LSD1 inhibition and this response is enhanced in combination with a YAP/TEAD disruptor which may improve patient selection and outcomes. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=171 HEIGHT=200 SRC="FIGDIR/small/576106v2_ufig1.gif" ALT="Figure 1"> View larger version (53K): org.highwire.dtl.DTLVardef@77332eorg.highwire.dtl.DTLVardef@1c127d0org.highwire.dtl.DTLVardef@1cec77org.highwire.dtl.DTLVardef@e87ed7_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2022

Polo-like kinase-1 Inhibitors and the Antiandrogen Abiraterone Synergistically Disrupt Mitosis and Kill Cancer Cells of Disparate Origin Independently of Androgen Receptor Signaling

Abiraterone, a standard treatment for metastatic castrate-resistant prostate cancer (mCRPC), slows disease progression by abrogating androgen synthesis and antagonizing the androgen receptor (AR). We report that inhibitors of the mitotic kinase Plk1, including the clinically active third-generation Plk1 inhibitor onvansertib, when co-administered with abiraterone, synergistically kill cancer cells from a wide variety of tumor types in an androgen-independent manner, both in vitro and in vivo. Abiraterone treatment alone results in defects in mitotic spindle orientation, failure of complete chromosome condensation, and upregulation of mitosis and mitotic-spindle related gene sets independently of its effects on AR signaling. These effects, while mild following abiraterone monotherapy, result in profound sensitization to the anti-mitotic effects of Plk1 inhibition, leading to spindle assembly checkpoint-dependent mitotic cell death and entosis. In a murine PDX model of mCRPC, combined onvansertib and abiraterone resulted in enhanced mitotic arrest and dramatic inhibition of tumor cell growth compared to either agent alone. STATEMENT OF SIGNIFICANCEA phase 2 clinical trial is underway (NCT03414034) testing combined Plk1 inhibitor onvansertib and abiraterone in mCRPC patients with nascent abiraterone resistance. Our work establishes a mechanistic basis for that trial and indicates that combined abiraterone and onvansertib co-treatment may have broad utility for cancer treatment beyond mCRPC.

cancer biology↗