ABSTRACT
Resistance to androgen receptor (AR) blockade in castration-resistant prostate cancer (CRPC) is associated with sustained AR signaling, including through alternative splicing of AR (AR-SV). Inhibitors of transcriptional coactivators that regulate AR activity, including the paralog histone acetyltransferase proteins p300 and CBP, are attractive therapeutic targets for lethal prostate cancer. Herein, we validate targeting p300/CBP as a therapeutic strategy for lethal prostate cancer and describe CCS1477, a novel small-molecule inhibitor of the p300/CBP conserved bromodomain. We show that CCS1477 inhibits cell proliferation in prostate cancer cell lines and decreases AR- and C-MYC-regulated gene expression. In AR-SV-driven models, CCS1477 has antitumor activity, regulating AR and C-MYC signaling. Early clinical studies suggest that CCS1477 modulates KLK3 blood levels and regulates CRPC biopsy biomarker expression. Overall, CCS1477 shows promise for the treatment of patients with advanced prostate cancer. SIGNIFICANCE: Treating CRPC remains challenging due to persistent AR signaling. Inhibiting transcriptional AR coactivators is an attractive therapeutic strategy. CCS1477, an inhibitor of p300/CBP, inhibits growth and AR activity in CRPC models, and can affect metastatic CRPC target expression in serial clinical biopsies.See related commentary by Rasool et al., p. 1011.This article is highlighted in the In This Issue feature, p. 995.
Subject(s)
Androgen Receptor Antagonists/therapeutic use , Imidazoles/therapeutic use , Oxazoles/therapeutic use , Prostatic Neoplasms, Castration-Resistant/drug therapy , p300-CBP Transcription Factors/antagonists & inhibitors , Androgen Receptor Antagonists/pharmacology , Animals , Cell Line, Tumor/drug effects , Cell Proliferation/drug effects , Humans , Imidazoles/pharmacology , Male , Mice , Oxazoles/pharmacology , Xenograft Model Antitumor AssaysABSTRACT
The SAR of a series of novel pyrido[3,4-d]pyramid-4-ylamine mGluR1 antagonists is described. The multiple of the unbound K(i) in cerebrospinal fluid necessary to give morphine like analgesic effects in an electromyograph pinch model in rodents is determined and the effect of structure on CNS penetration examined.
Subject(s)
Excitatory Amino Acid Antagonists/chemical synthesis , Receptors, Metabotropic Glutamate/antagonists & inhibitors , Animals , Electromyography/methods , Excitatory Amino Acid Antagonists/chemistry , Excitatory Amino Acid Antagonists/pharmacology , Pain Measurement/drug effects , Pain Measurement/methods , Rats , Receptors, Metabotropic Glutamate/physiology , Structure-Activity RelationshipABSTRACT
A series of novel mGluR1 antagonists have been prepared. Incorporation of fragments derived from weak lead matter into a library led to enhanced potency in a new chemical series. A chemistry driven second library iteration, covering a greatly enhanced area of chemical space, maintained good potency and introduced metabolic stability.
