Dataset Information

BETting on next-generation bromodomain inhibitors.

ABSTRACT: Within the last decade, bromodomain and extraterminal (BET) domain inhibitors were introduced as the first in a wave of new agents known as bromodomain inhibitors. These original examples exhibited anti-inflammatory and anticancer properties, and some have progressed to human clinical trials. BET proteins and their conserved N-terminal bromodomains, BD1 and BD2, have been implicated in the regulation of transcription. The early-generation BET inhibitors showed equal affinity for BD1 and BD2, and therefore the differential roles of BD1 and BD2 remain poorly understood. A recent study published in Science by Gilan et al. outlines the transcriptional and phenotypic effects of inhibiting BD1 and BD2 individually, specifically in the context of cancer and immunoinflammatory pathologies. These findings suggest that BD1 and BD2 have separate and distinct roles in transcriptional regulation, and that BD1- and BD2-selective agents may exhibit higher clinical efficacies in solid tumors, such as prostate cancer, with fewer off-target side effects seen with early generation compounds.

SUBMITTER: Collins MK

PROVIDER: S-EPMC7486540 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

BETting on next-generation bromodomain inhibitors.

Collins Matthew K MK Chau Cindy H CH Price Douglas K DK Figg William D WD

American journal of clinical and experimental urology 20200815 4

Within the last decade, bromodomain and extraterminal (BET) domain inhibitors were introduced as the first in a wave of new agents known as bromodomain inhibitors. These original examples exhibited anti-inflammatory and anticancer properties, and some have progressed to human clinical trials. BET proteins and their conserved N-terminal bromodomains, BD1 and BD2, have been implicated in the regulation of transcription. The early-generation BET inhibitors showed equal affinity for BD1 and BD2, and ...[more]

PMID: 32929408

Similar Datasets

Project description:Oncogenic protein tyrosine phosphatases (PTPs) are overexpressed in numerous human cancers but they have been challenging pharmacological targets. The emblematic oncogenic PTP4A tyrosine phosphatase family regulates many fundamental malignant processes. 7-Imino-2-phenylthieno[3,2-c]pyridine-4,6(5H,7H)-dione (JMS-053) is a novel, potent, and selective PTP4A inhibitor but its mechanism of action has not been fully elucidated, nor has the chemotype been fully investigated. Because tyrosine phosphatases are notoriously susceptible to oxidation, we interrogated JMS-053 and three newly synthesized analogs with specific attention on the role of oxidation. JMS-053 and its three analogs were potent in vitro PTP4A3 inhibitors, but 7-imino-5-methyl-2-phenylthieno[3,2-c]pyridine-4,6(5H,7H)-dione (NRT-870-59) appeared unique among the thienopyridinediones with respect to its inhibitory specificity for PTP4A3 versus both a PTP4A3 A111S mutant and an oncogenic dual specificity tyrosine phosphatase, CDC25B. Like JMS-053, NRT-870-59 was a reversible PTP4A3 inhibitor. All of the thienopyridinediones retained cytotoxicity against human ovarian and breast cancer cells grown as pathologically relevant three-dimensional spheroids. Inhibition of cancer cell colony formation by NRT-870-59, like JMS-053, required PTP4A3 expression. JMS-053 failed to generate significant detectable reactive oxygen species in vitro or in cancer cells. Mass spectrometry results indicated no disulfide bond formation or oxidation of the catalytic Cys104 after in vitro incubation of PTP4A3 with JMS-053 or NRT-870-59. Gene expression profiling of cancer cells exposed to JMS-053 phenocopied many of the changes seen with the loss of PTP4A3 and did not indicate oxidative stress. These data demonstrate that PTP4A phosphatases can be selectively targeted with small molecules that lack prominent reactive oxygen species generation and encourage further studies of this chemotype. SIGNIFICANCE STATEMENT: Protein tyrosine phosphatases are emerging as important contributors to human cancers. We report on a new class of reversible protein phosphatase small molecule inhibitors that are cytotoxic to human ovarian and breast cancer cells, do not generate significant reactive oxygen species in vitro and in cells, and could be valuable lead molecules for future studies of PTP4A phosphatases.

Project description:The first generation CDK2/7/9 inhibitor seliciclib (CYC202) causes multipolar anaphase and apoptosis in lung cancer cells with supernumerary centrosomes (known as anaphase catastrophe). We investigated a new and potent CDK2/9 inhibitor, CCT68127 (Cyclacel). CCT68127 was studied in lung cancer cells (three murine and five human) and control murine pulmonary epithelial and human immortalized bronchial epithelial cells. Robotic CCT68127 cell-based proliferation screens were used. Cells undergoing multipolar anaphase and inhibited centrosome clustering were scored. Reverse phase protein arrays (RPPAs) assessed CCT68127 effects on signaling pathways. The function of PEA15, a growth regulator highlighted by RPPAs, was analyzed. Syngeneic murine lung cancer xenografts (n = 4/group) determined CCT68127 effects on tumorigenicity and circulating tumor cell levels. All statistical tests were two-sided. CCT68127 inhibited growth up to 88.5% (SD = 6.4%, P < .003) at 1 μM, induced apoptosis up to 42.6% (SD = 5.5%, P < .001) at 2 μM, and caused G1 or G2/M arrest in lung cancer cells with minimal effects on control cells (growth inhibition at 1 μM: 10.6%, SD = 3.6%, P = .32; apoptosis at 2 μM: 8.2%, SD = 1.0%, P = .22). A robotic screen found that lung cancer cells with KRAS mutation were particularly sensitive to CCT68127 ( P = .02 for IC 50 ). CCT68127 inhibited supernumerary centrosome clustering and caused anaphase catastrophe by 14.1% (SD = 3.6%, P < .009 at 1 μM). CCT68127 reduced PEA15 phosphorylation by 70% (SD = 3.0%, P = .003). The gain of PEA15 expression antagonized and its loss enhanced CCT68127-mediated growth inhibition. CCT68127 reduced lung cancer growth in vivo ( P < .001) and circulating tumor cells ( P = .004). Findings were confirmed with another CDK2/9 inhibitor, CYC065. Next-generation CDK2/9 inhibition elicits marked antineoplastic effects in lung cancer via anaphase catastrophe and reduced PEA15 phosphorylation.

Dataset Information

BETting on next-generation bromodomain inhibitors.

Publications

BETting on next-generation bromodomain inhibitors.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets