SPOP mutation confers intrinsic BET inhibitor resistance in prostate cancer
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE88872 | GEO | 2017/07/21
SECONDARY ACCESSION(S): PRJNA348842
REPOSITORIES: GEO
Similar Datasets
Project description:Bromodomain and extraterminal domain (BET) protein inhibitors are emerging as promising therapeutics of cancers including prostate cancer. The E3 ubiquitin ligase adaptor protein speckle-type POZ protein (SPOP) is implicated in human prostate cancers due to its frequent mutation. Here we demonstrate that SPOP binds to the BET proteins BRD2, BRD3 and BRD4. Wild-type SPOP, but not prostate cancer-associated mutants, promotes polyubiquitination and proteasome degradation of BET proteins by recognizing a common degron motif. BET protein levels are highly elevated in SPOP-mutated prostate cancers in patients. Expression of cancer-derived SPOP mutants upregulates cholesterol biosynthesis genes and confers resistance to the BET inhibitor in cultured prostate cancer cells and tumors in mice, and this effect can be overcome by the AKT inhibitor. Our findings reveal BET proteins as proteolytic targets of SPOP and identify deregulated cholesterol biosynthesis as a downstream event of SPOP mutation-mediated tumorigenesis and therapy resistance in prostate cancer.
2017-07-24 | GSE88871 | GEO
Project description:Bromodomain and extraterminal domain (BET) protein inhibitors are emerging as promising therapeutics of cancers including prostate cancer. The E3 ubiquitin ligase adaptor protein speckle-type POZ protein (SPOP) is implicated in human prostate cancers due to its frequent mutation. Here we demonstrate that SPOP binds to the BET proteins BRD2, BRD3 and BRD4. Wild-type SPOP, but not prostate cancer-associated mutants, promotes polyubiquitination and proteasome degradation of BET proteins by recognizing a common degron motif. BET protein levels are highly elevated in SPOP-mutated prostate cancers in patients. Expression of cancer-derived SPOP mutants upregulates cholesterol biosynthesis genes and confers resistance to the BET inhibitor in cultured prostate cancer cells and tumors in mice, and this effect can be overcome by the AKT inhibitor. Our findings reveal BET proteins as proteolytic targets of SPOP and identify deregulated cholesterol biosynthesis as a downstream event of SPOP mutation-mediated tumorigenesis and therapy resistance in prostate cancer.
2017-07-24 | GSE78213 | GEO
Project description:Bromodomain and extraterminal domain (BET) protein inhibitors are emerging as promising therapeutics of cancers including prostate cancer. The E3 ubiquitin ligase adaptor protein speckle-type POZ protein (SPOP) is implicated in human prostate cancers due to its frequent mutation. Here we demonstrate that SPOP binds to the BET proteins BRD2, BRD3 and BRD4. Wild-type SPOP, but not prostate cancer-associated mutants, promotes polyubiquitination and proteasome degradation of BET proteins by recognizing a common degron motif. BET protein levels are highly elevated in SPOP-mutated prostate cancers in patients. Expression of cancer-derived SPOP mutants upregulates cholesterol biosynthesis genes and confers resistance to the BET inhibitor in cultured prostate cancer cells and tumors in mice, and this effect can be overcome by the AKT inhibitor. Our findings reveal BET proteins as proteolytic targets of SPOP and identify deregulated cholesterol biosynthesis as a downstream event of SPOP mutation-mediated tumorigenesis and therapy resistance in prostate cancer.
2018-03-08 | GSE98010 | GEO
Project description:SPOP mutation confers intrinsic BET inhibitor resistance in prostate cancer
| PRJNA348842 | ENA
Project description:Bromodomain and extraterminal domain (BET) protein inhibitors are emerging as promising anticancer therapies. The gene encoding the E3 ubiquitin ligase substrate-binding adaptor speckle-type POZ protein (SPOP) is the most frequently mutated in primary prostate cancer. Here we demonstrate that wild-type SPOP binds to and induces ubiquitination and proteasomal degradation of BET proteins (BRD2, BRD3 and BRD4) by recognizing a degron motif common among them. In contrast, prostate cancer-associated SPOP mutants show impaired binding to BET proteins, resulting in decreased proteasomal degradation and accumulation of these proteins in prostate cancer cell lines and patient specimens and causing resistance to BET inhibitors. Transcriptome and BRD4 cistrome analyses reveal enhanced expression of the GTPase RAC1 and cholesterol-biosynthesis-associated genes together with activation of AKT-mTORC1 signaling as a consequence of BRD4 stabilization. Our data show that resistance to BET inhibitors in SPOP-mutant prostate cancer can be overcome by combination with AKT inhibitors and further support the evaluation of SPOP mutations as biomarkers to guide BET-inhibitor-oriented therapy in patients with prostate cancer.
| S-EPMC5653288 | biostudies-literature
Project description:The bromodomain and extraterminal (BET) family of proteins comprises four members-BRD2, BRD3, BRD4 and the testis-specific isoform BRDT-that largely function as transcriptional coactivators and play critical roles in various cellular processes, including the cell cycle, apoptosis, migration and invasion. BET proteins enhance the oncogenic functions of major cancer drivers by elevating the expression of these drivers, such as c-Myc in leukemia, or by promoting the transcriptional activities of oncogenic factors, such as AR and ERG in prostate cancer. Pathologically, BET proteins are frequently overexpressed and are clinically linked to various types of human cancer; they are therefore being pursued as attractive therapeutic targets for selective inhibition in patients with cancer. To this end, a number of bromodomain inhibitors, including JQ1 and I-BET, have been developed and have shown promising outcomes in early clinical trials. Although resistance to BET inhibitors has been documented in preclinical models, the molecular mechanisms underlying acquired resistance are largely unknown. Here we report that cullin-3SPOP earmarks BET proteins, including BRD2, BRD3 and BRD4, for ubiquitination-mediated degradation. Pathologically, prostate cancer-associated SPOP mutants fail to interact with and promote the degradation of BET proteins, leading to their elevated abundance in SPOP-mutant prostate cancer. As a result, prostate cancer cell lines and organoids derived from individuals harboring SPOP mutations are more resistant to BET-inhibitor-induced cell growth arrest and apoptosis. Therefore, our results elucidate the tumor-suppressor role of SPOP in prostate cancer in which it acts as a negative regulator of BET protein stability and also provide a molecular mechanism for resistance to BET inhibitors in individuals with prostate cancer bearing SPOP mutations.
| S-EPMC5625299 | biostudies-literature
Project description:CULLIN3-based E3 ubiquitin ligase substrate-binding adaptor gene SPOP is frequently mutated in prostate cancer (PCa). PCa harboring SPOP hotspot mutants (e.g. F133V) are resistant to BET inhibitors because of aberrant elevation of BET proteins. Here, we identified a previously-unrecognized mutation Q165P at the edge of SPOP MATH domain in primary and metastatic PCa of a patient. The Q165P mutation causes structural changes in the MATH domain and impairs SPOP dimerization and substrate degradation. Different from F133V hotspot mutant tumors, Q165P mutant patient-derived xenografts (PDXs) and organoids were modestly sensitive to the BET inhibitor JQ1. Accordingly, protein levels of AR, BRD4 and downstream effectors such as RAC1 and phosphorylated AKT were not robustly elevated in Q165P mutant cells as in F133V mutant cells. However, NEO2734, a novel dual inhibitor of BET and CBP/p300, is active in both hotspot mutant (F133V) and non-hotspot mutant (Q165P) PCa cells in vitro and in vivo. These data provide a strong rationale to clinically investigate the anti-cancer efficacy of NEO2734 in SPOP-mutated PCa patients.
| S-SCDT-EMM-2019-10659 | biostudies-other
Project description:CULLIN3-based E3 ubiquitin ligase substrate-binding adaptor gene SPOP is frequently mutated in prostate cancer (PCa). PCa harboring SPOP hotspot mutants (e.g., F133V) are resistant to BET inhibitors because of aberrant elevation of BET proteins. Here, we identified a previously unrecognized mutation Q165P at the edge of SPOP MATH domain in primary and metastatic PCa of a patient. The Q165P mutation causes structural changes in the MATH domain and impairs SPOP dimerization and substrate degradation. Different from F133V hotspot mutant tumors, Q165P mutant patient-derived xenografts (PDXs) and organoids were modestly sensitive to the BET inhibitor JQ1. Accordingly, protein levels of AR, BRD4 and downstream effectors such as RAC1 and phosphorylated AKT were not robustly elevated in Q165P mutant cells as in F133V mutant cells. However, NEO2734, a novel dual inhibitor of BET and CBP/p300, is active in both hotspot mutant (F133V) and non-hotspot mutant (Q165P) PCa cells in vitro and in vivo. These data provide a strong rationale to clinically investigate the anti-cancer efficacy of NEO2734 in SPOP-mutated PCa patients.
| S-EPMC6835201 | biostudies-literature
Project description:Genomic instability is a fundamental feature of human cancer often resulting from impaired genome maintenance. In prostate cancer, structural genomic rearrangements are a common mechanism driving tumorigenesis. However, somatic alterations predisposing to chromosomal rearrangements in prostate cancer remain largely undefined. Here, we show that SPOP, the most commonly mutated gene in primary prostate cancer modulates DNA double strand break (DSB) repair, and that SPOP mutation is associated with genomic instability. In vivo, SPOP mutation results in a transcriptional response consistent with BRCA1 inactivation resulting in impaired homology-directed repair (HDR) of DSB. Furthermore, we found that SPOP mutation sensitizes to DNA damaging therapeutic agents such as PARP inhibitors. These results implicate SPOP as a novel participant in DSB repair, suggest that SPOP mutation drives prostate tumorigenesis in part through genomic instability, and indicate that mutant SPOP may increase response to DNA-damaging therapeutics.
| S-EPMC4621745 | biostudies-literature
Project description:Prostate cancer (PCa) is a leading adult malignant tumor. Recent research has shown that speckle-type BTB/POZ protein (SPOP) mutant is the top frequently mutated gene in PCa, which makes it an important biomarker. In this paper, we aimed at identifying critical genes and pathways related to SPOP mutation in PCa. Recent The Cancer Genome Atlas data showed that 12% of patients with PCa were SPOP mutant. There were 1,570 differentially expressed genes, and online enrichment analysis showed that these genes were mainly enriched in metabolism, pathways in cancer and reactive oxygen species. INS, GNG13, IL6, HTR5A, SAA1, PPY, CXCR5, CXCL13, CD19 and CCL20 were identified as hub genes. The lower SPOP expression level was associated with poor prognosis. In all, our findings showed that various pathways and genes could play critical roles in SPOP mutation in PCa, providing potential options for individualized treatment.
| S-EPMC7718645 | biostudies-literature