Blocking Fra-1 sensitizes triple-negative breast cancer to olaparib
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ABSTRACT:
PROVIDER: PRJNA629373 | ENA |
REPOSITORIES: ENA
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Project description:Fra-1 (FOSL1) is overexpressed in triple-negative breast cancer (TNBC). Fra-1 is a member of the activator protein 1 (AP-1) transcription factor complex, which plays crucial roles in tumor progression and treatment resistance. We have previously identified 118 proteins that interact with endogenous chromatin-bound Fra-1 in TNBC cells in a large screen, and these included PARP1(Poly (ADP-ribose) polymerase 1). PARP1 inhibitor olaparib is currently in clinical use for treatment of BRCA-mutated TNBC breast cancer. Here, we demonstrate that this interaction impacts the efficacy of olaparib treatment. We corroborate that PARP1 interacts with Fra-1, and we show that PARP1 downregulates Fra-1 and consequently reduces AP-1 transcriptional activity. Inhibition of PARP1, on the other hand, increases Fra-1 levels and enhances its transcriptional activity, which in turn can increase treatment resistance. However, by inhibiting Fra-1, we found that TNBC cells became sensitized to olaparib treatment. We compared Fra-1 chromatin binding sites with the Fra-1 and PARP1 regulated transcriptomes, and found that a large fraction of PARP1-regulated genes was dependent on Fra-1. We further show that PARP1 protein levels significantly correlate with Fra-1 in clinical breast cancer tumors, and we identify that high PARP1 expression is indicative of a poor clinical outcome in breast cancer patients overall, but not in basal-like tumors. In conclusion, by exploring the functionality of the Fra-1 and PARP1 interaction, we propose that targeting Fra-1 could serve as a therapeutic approach to improve olaparib treatment outcome for TNBC patients.
2022-04-21 | GSE149621 | GEO
Project description:PARP inhibitor and platinum based drugs such as cisplatin are promising therapies for triple negative breast cancer and exploit the deficiencies in BRCA1 or BRCA2, or homologous recombination repair defects. However, PARP inhibitor resistance is proven to be a major clinical problem. Acquired PARP inhibitor resistance has been linked with co-resistance to platinum-based drugs. To determine how acquired olaparib resistance affects cisplatin response and whether this is influenced by their BRCA1 status, we performed RNAseq transcriptome analysis of isogenic triple negative breast cancer models of olaparib resistance with normal and mutant BRCA1.
2021-07-22 | GSE165914 | GEO
Project description:This SuperSeries is composed of the SubSeries listed below. All the data are described in the article "Fra-1 regulates its target genes via binding to remote enhancers without exerting major control on chromatin architecture in triple negative breast cancers" by Bejjani et al.
2021-02-23 | GSE146825 | GEO
Project description:In the paper "Fra-1 regulates its target genes via binding to remote enhancers without exerting major control on chromatin architecture in triple negative breast cancers" by Bejjani et al., we identified Fra-1 and/or Fra-2 target genes in MDA-MB-231 cells. si RNA against Fra-1 and against Fra-2 were transfected in MDA-MB-231 cells either independenlty or simultaneously to identify genes regulated specifically by Fra-1 or Fra-2 and genes regulated redundantly or complementarily by Fra-1 and Fra-2 total RNA were purified and biotinylated sense-strand cDNA were produced. cDNA targets were used to probe Affymetrix GeneChip Human Gene 2.0 ST arrays
2021-02-23 | GSE146823 | GEO
Project description:Olaparib resistance and cisplatin responses in triple negative breast cancer
| PRJNA698566 | ENA
Project description:Fra-1, a member of the activator protein 1 (AP-1) family, is overexpressed in triple-negative breast cancer (TNBC) and plays crucial roles in tumor growth. Here we report the identification of 118 proteins interacting with endogenous chromatin-bound Fra-1 in TNBC cells, highlighting DDX5 as the most enriched Fra-1-interacting protein. DDX5, a previously unrecognized protein in the Fra-1 transcriptional network, shows extensive overlap with Fra-1 cistrome and transcriptome that are highly associated with the TNBC cell growth. We provide evidence that DDX5 expression enhances Fra-1 transcriptional activity and potentiates Fra-1-driven cell proliferation. Furthermore, we show that the DDX5 target gene signature predicts poor clinical outcome in breast cancer patients. DDX5 protein level was higher in triple-negative basal-like tumors than in non-basal-like tumors, including luminal A, luminal B, and HER2-enriched subtypes. Collectively, by combining proteomic and genomic approaches we reveal a role for DDX5 as a regulatory protein of Fra-1 signaling and suggest DDX5 as a potential therapeutic target for TNBC.
2019-09-03 | GSE112963 | GEO
Project description:Transcriptional regulation by Fra-1 in triple negative breast cancers
| PRJNA612051 | ENA
Project description:In the article "Fra-1 regulates its target genes via binding to remote enhancers without exerting major control on chromatin architecture in triple negative breast cancers" by Bejjani et al., we used NG Capture-C approach to identify regulatory elements interacting with the promoters of 35 Fra-1 regulated genes in the triple negative breast cancer cell line MDA-MB-231
2021-02-23 | GSE146824 | GEO
Project description:Fra-1, a member of the activator protein 1 (AP-1) family, is overexpressed in triple-negative breast cancer (TNBC) and plays crucial roles in tumor progression. However, a systematic analysis of the composition of the Fra-1 protein network specifically on chromatin is still missing. Here we performed endogenous purification of Fra-1 transcriptional complex under ChIP conditions, followed by mass spectrometry, to identify chromatin-bound partners of Fra-1 in TNBC cells. This study allowed the identification of 118 interactors, highlighting DDX5 as the high ranking of Fra-1 interacting proteins. DDX5, a previously unrecognized protein in the network, is recruited globally to Fra-1 binding sites and shares a substantial set of Fra-1 target genes required for the TNBC cell growth. We provide evidence that DDX5 expression enhances Fra-1 transcriptional activity, thereby enhancing Fra-1-driven tumorigenesis. By integrating ChIP-seq and RNA-seq, we show that DDX5 target gene signature predicts poor clinical outcome in breast cancer patients. DDX5 protein level was higher in triple-negative basal like tumors than in non-basal like tumors, including luminal A, luminal B and HER2-enriched subtypes. Collectively, this comprehensive Fra-1 interaction profiling provides a broad and deep view of Fra-1 chromatin interaction landscape, which will help in deciphering mechanisms of AP-1 regulation of gene expression.
2019-09-03 | GSE112962 | GEO