Project description:Analysis of enzalutamide- and/or olaparib-responsive gene expression in prostate cancer cells. The hypothesis tested in the present study was that enzalutamide influences the expression of genes that are involved in important bioprocesses in prostate cance rcells, including DNA damage response genes and this effect may synergize with poly(ADP-ribose) polymerase inhibitor olaparib in cytotoxicity to prstate cancer cells. prostate cancer cells were pretreated with enzalutamide or vehicle control DMSO for 24 h, followed by treatment with enzalutamide, olaparib, enzalutamide+olaparib, or vehicle control DMSO for 48 h. Gene expression in enzalutamide+olaparib-treated cells was compared with taht in vehicle control- and single agent-treated cells.
Project description:Sequencing of olaparib-resistant PEO1 derivatives (C4, C5, C10 and C18) and parental PEO1 (P1 and P2) cells was performed in order to determine mechanisms of acquired resistance in the resistant cell lines. PEO1 parental cell lines were authenticated prior to sequencing. PEO1 parental were confirmed to be BRCA2-mutated (5139C>G). Olaparib PEO1 resistant cells were generated through a step-wise escalation of olaparib (10nM to 8uM olaparib). In olaparib resistant lines an increase canonical Wnt signaling and loss of of non-canonical Wnt signaling was observed.
Project description:Acquisition of resistance to the PARP inhibitor, Olaparib, constitutes a major challenge for the treatment of advanced prostate cancer. The purpose of this study was to identify molecular targets responsible for the development of acquired Olaparib resistance in advanced prostate cancer. Towards this goal, next-generation sequencing (NGS)-based gene expression profiling (RNA-Sequencing; RNA-Seq) was performed on castration-sensitive prostate cancer (CSPC)/Olaparib-sensitive LNCaP cells, castration-sensitive prostate cancer (CSPC)/Olaparib-resistant LN-OlapR cells, castration-resistant prostate cancer (CSPC)/Olaparib-sensitive C4-2B cells, and castration-resistant prostate cancer (CSPC)/Olaparib-resistant 2B-OlapR cells.
Project description:To investigate the effect of olaparib or MNA on macrophage, we treated bone marrow with olaparib or MNA during BMDM induction for 6 days.
Project description:In this study, a population of knockout cells was generated using the GeCKO v2 sgRNA library. The population of knockout cells was treated with the PARP inhibitor olaparib for 14 days. Over this time, knockout cells that were sensitive to olaparib treatment would die and a population of knockout cells that was resistant to olaparib treatment remained. Cells from olaparib and DMSO conditions and the sgRNA cassette in the knockout cells was amplified and sequenced to identify synthetic lethal or suppressor interactions with olaparib treatment.
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.
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.
Project description:Analysis of enzalutamide- and/or olaparib-responsive gene expression in prostate cancer cells. The hypothesis tested in the present study was that enzalutamide influences the expression of genes that are involved in important bioprocesses in prostate cance rcells, including DNA damage response genes and this effect may synergize with poly(ADP-ribose) polymerase inhibitor olaparib in cytotoxicity to prstate cancer cells.
Project description:PARP inhibitors (PARPi) resistance is not well understood in prostate cancer (PC). The aim of the study was to identify new resistance mechanisms in PC by developing acquired olaparib-resistance PC cell lines.
Project description:The poly-ADP-ribose polymerase (PARP) is a protein from the family of ADP-ribosyltransferases that catalyzes poly adenosine diphosphate ribose (ADPR) formation in order to attract the DNA repair machinery to DNA damage sites. Inhibition of PARP activity by olaparib can cause cell death which is of clinical relevance in some tumor types. This demonstrates that quantification of PARP activity in the context of living cells is of great importance. In this work we present the design, synthesis and biological evaluation of photo-activatable affinity probes inspired by the olaparib molecule which are equipped with a diazirine for covalent attachment upon activation by UV light and a ligation handle for the addition of a reporter group of choice. SDS-PAGE, western blotting and label-free LC-MS/MS quantification analysis show that the probes target the PARP-1 protein and are selectively outcompeted by olaparib suggesting binding in the same enzymatic pocket.