scholarly journals EZH2 contributes to the response to PARP inhibitors through its PARP-mediated poly-ADP ribosylation in breast cancer

Oncogene ◽  
2017 ◽  
Vol 37 (2) ◽  
pp. 208-217 ◽  
Author(s):  
H Yamaguchi ◽  
Y Du ◽  
K Nakai ◽  
M Ding ◽  
S-S Chang ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Parp Inhibitors ◽  
Adp Ribosylation

scholarly journals Cytoplasmic ADP-ribosylation levels correlate with markers of patient outcome in distinct human cancers

2021 ◽  
Author(s):  
Fabio Aimi ◽  
Holger Moch ◽  
Peter Schraml ◽  
Michael O. Hottiger
Keyword(s):  
Breast Cancer ◽  
Patient Outcome ◽  
Overall Survival ◽  
Lymph Node ◽  
Tumor Stage ◽  
Parp Inhibitors ◽  
Breast Adenocarcinoma ◽  
Lymph Node Status ◽  
Adp Ribosylation ◽  
Tumor Types

AbstractADP-ribosylation (ADPR) is a posttranslational modification whose importance in oncology keeps increasing due to frequent use of PARP inhibitors (PARPi) to treat different tumor types. Due to the lack of suitable tools to analyze cellular ADPR levels, ADPR’s significance for cancer progression and patient outcome is unclear. In this study, we assessed ADPR levels by immunohistochemistry using a newly developed anti-ADP-ribose (ADPr) antibody, which is able to detect both mono- and poly-ADPR. Tissue microarrays containing brain (n = 103), breast (n = 1108), colon (n = 236), lung (n = 138), ovarian (n = 142), and prostate (n = 328) cancers were used to correlate ADPR staining intensities to clinico-pathological data, including patient overall survival (OS), tumor grade, tumor stage (pT), lymph node status (pN), and the presence of distant metastasis (pM). While nuclear ADPR was detected only in a minority of the samples, cytoplasmic ADPR (cyADPR) staining was observed in most tumor types. Strong cyADPR intensities were significantly associated with better overall survival in invasive ductal breast cancer (p < 0.0001), invasive lobular breast cancer (p < 0.005), and high grade serous ovarian cancer patients (p < 0.01). Furthermore, stronger cytoplasmic ADPR levels significantly correlated with early tumor stage in colorectal and in invasive ductal breast adenocarcinoma (p < 0.0001 and p < 0.01, respectively) and with the absence of regional lymph node metastasis in colorectal adenocarcinoma (p < 0.05). No correlation to cyADPR was found for prostate and lung cancer or brain tumors. In conclusion, our new anti-ADP-ribose antibody revealed heterogeneous ADPR staining patterns with predominant cytoplasmic ADPR staining in most tumor types. Different cyADPR staining patterns could help to better understand variable response rates to PARP inhibitors in the future.

scholarly journals PARP7 and Mono-ADP-Ribosylation Negatively Regulate Estrogen Receptor α Signaling in Human Breast Cancer Cells

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 623
Author(s):  
Marit Rasmussen ◽  
Susanna Tan ◽  
Venkata S. Somisetty ◽  
David Hutin ◽  
Ninni Elise Olafsen ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Protein Modification ◽  
Target Genes ◽  
Estrogen Receptor Α ◽  
Transactivation Domain ◽  
Adp Ribosylation ◽  
Protein Levels ◽  
17Β Estradiol ◽  
Mcf 7

ADP-ribosylation is a post-translational protein modification catalyzed by a family of proteins known as poly-ADP-ribose polymerases. PARP7 (TIPARP; ARTD14) is a mono-ADP-ribosyltransferase involved in several cellular processes, including responses to hypoxia, innate immunity and regulation of nuclear receptors. Since previous studies suggested that PARP7 was regulated by 17β-estradiol, we investigated whether PARP7 regulates estrogen receptor α signaling. We confirmed the 17β-estradiol-dependent increases of PARP7 mRNA and protein levels in MCF-7 cells, and observed recruitment of estrogen receptor α to the promoter of PARP7. Overexpression of PARP7 decreased ligand-dependent estrogen receptor α signaling, while treatment of PARP7 knockout MCF-7 cells with 17β-estradiol resulted in increased expression of and recruitment to estrogen receptor α target genes, in addition to increased proliferation. Co-immunoprecipitation assays revealed that PARP7 mono-ADP-ribosylated estrogen receptor α, and mass spectrometry mapped the modified peptides to the receptor’s ligand-independent transactivation domain. Co-immunoprecipitation with truncated estrogen receptor α variants identified that the hinge region of the receptor is required for PARP7-dependent mono-ADP-ribosylation. These results imply that PARP7-mediated mono-ADP-ribosylation may play an important role in estrogen receptor positive breast cancer.

PARP inhibitors stumble in breast cancer

2011 ◽  
Vol 29 (5) ◽  
pp. 373-374 ◽  
Author(s):  
Malini Guha
Keyword(s):  
Breast Cancer ◽  
Parp Inhibitors

Efficacy of DAN-222, a novel investigational polymeric nanoparticle with topoisomerase I inhibitor, as monotherapy in breast cancer models and when combined with PARP inhibitor.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 1081-1081
Author(s):  
Ashley P Wright ◽  
Jodi D Bradley ◽  
Timothy Hagerty ◽  
Emily A Wyatt
Keyword(s):  
Breast Cancer ◽  
Tumor Growth ◽  
Growth Inhibition ◽  
Tumor Cells ◽  
Topoisomerase I ◽  
Parp Inhibitor ◽  
Parp Inhibitors ◽  
Topoisomerase I Inhibitor ◽  
Polymeric Nanoparticle ◽  
Cancer Tumor

1081 Background: Patients with BRCA-positive HER2-negative breast cancer benefit from PARP inhibitor therapy, but additional benefit is still desired. PARP inhibition alone does not prevent all mechanisms for repairing damage to DNA such as homologous recombination repair. An attractive combination for treating such patients would be combining a topoisomerase I inhibitor with a PARP inhibitor given the dual mechanism this would provide for DNA damage and inhibited repair, leading to tumor cell death. This combination has been tried in multiple phase 1 studies, but myelotoxicity prevented the combination from being evaluated further. DAN-222 is a novel investigational polymeric nanoparticle conjugated with camptothecin, a topoisomerase I inhibitor, that provides significant accumulation of drug in tumor tissues via the enhanced permeability and retention (EPR) effect and significantly reduced bone marrow exposure compared to native chemotherapy. These observations underscore the potential advantages of DAN-222 alone as well as in combination with other agents such as PARP inhibitors in solid tumors. Here, we report the effects of DAN-222 monotherapy and in combination with a PARP inhibitor on the growth inhibition in an HRD+ TNBC breast cancer (MDA-MB-436) and an HRD- ovarian (OVCAR3) xenograft mouse model. Methods: HRD+ breast cancer tumor cells (MDA-MB-436) were implanted into female NCr nu/nu mice and HRD- ovarian cancer tumor cells (OVCAR3) were implanted into female CB.17 SCID mice. Mice were randomized to vehicle or treatment arms until tumors reached 2000 mm3 or day 45 (MDA-MB-436) or 1000mm3 or day 45 (OVCAR3). The groups evaluated include multiple dose levels of DAN-222 as monotherapy and those also combined with niraparib. Results: Results were consistent in both the HRD+ and HRD- tumor models with profound dose-response of DAN-222 monotherapy inhibiting tumor growth. Additionally, synergy was demonstrated when DAN-222 was combined with niraparib, clearly evident with low doses of both products when used in combination. The table below highlights the synergy of the combination of DAN-222 at 0.3 mg/kg and niraparib at 25 mg/kg above each agent alone on the tumor growth inhibition in the MDA-MB-436 xenograft. Conclusions: Combining a PARP inhibitor with a topoisomerase I inhibitor delivered via this polymeric nanoparticle delivery system (DAN-222) has synergistic efficacy in both HRD+ and HRD- xenograft tumor models. These data support continued development of DAN-222 to treat solid tumors and its combination use with PARP inhibitors.[Table: see text]

scholarly journals Practice-Changing Interventions in the Systemic Management of Breast Cancer

2020 ◽  
Vol 18 (7.5) ◽  
pp. 941-944
Author(s):  
William J. Gradishar
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Breast Cancer Subtype ◽  
Metastatic Breast ◽  
Parp Inhibitors ◽  
Targeted Agents ◽  
Her2 Positive ◽  
Nccn Guidelines ◽  
Estrogen Receptor Positive ◽  
Treatment Paradigm

Systemic treatment for metastatic breast cancer now incorporates many targeted agents and a plethora of combinations specific to the breast cancer subtype. New to the treatment paradigm are fam-trastuzumab deruxtecan-nxki, and tucatinib for HER2-positive disease; the PI3K inhibitor alpelisib in combination with fulvestrant for estrogen receptor–positive and PIK3CA-mutated tumors; PARP inhibitors for patients with germline BRCA1/2 mutations; and the anti–PD-L1 agent atezolizumab in combination with albumin-bound paclitaxel for triple-negative disease with PD-L1 mutations in tumors. In addition, for estrogen receptor–positive disease, the role of CDK4/6 inhibitors increased substantially during the past year, as overall survival results have emerged. These targeted agents are greatly improving patient outcomes, and thus have all been incorporated into the NCCN Guidelines for Breast Cancer.

scholarly journals Poly(ADP-Ribose) Polymerase Inhibitors (PARPi) for Patients With Advanced Breast Cancer: a Meta-analysis of Randomized Controlled Trials

2020 ◽  
Author(s):  
YongCheng Su ◽  
XiaoGang Zheng
Keyword(s):  
Breast Cancer ◽  
Randomized Controlled Trials ◽  
Fixed Effects ◽  
Meta Analysis ◽  
Parp Inhibitors ◽  
Cochrane Library ◽  
Controlled Trials ◽  
Randomized Controlled ◽  
Increased Risk ◽  
Grade 3

Abstract BACKGROUND: Poly(ADP–ribose) polymerase (PARP) inhibitors are new class of drugs that are currently being studied in several malignancies. However, datas about the efficacy and safety of the PARP inhibitors are limited. Therefore, we conducted a meta-analysis of randomized controlled trials (RCT) in patients with breast cancer.METHODS: Pubmed/Medline, Embase, Cochrane Library, and abstracts presented at the annual meeting of the American Society of Clinical Oncology (ASCO) were searched for articles published from 2000 to June 2018.Summary incidences and the RR, HR with 95% confidence intervals, were calculated by using a random-effects or fixed-effects model.RESULTS: The summary HR indicated PARPi was not associated with OS (HR=0.83, 95%CI 0.66–1.06, Z=1.49, P=0.14), while it could significantly improve PFS ande time to deterioration (TTD) of global health status/quality of life(GHS/QoL) as compared with traditional standard therapy, the HR was 0.60(95%CI 0.50-0.72; Z=5.52, P＜0.00001) and 0.4 (95%CI 0.29–0.54,z=5.80 ,p=0.000),respectively.The RR of grade 3 or more anemia ,fatigue and headache was 3.02 (95% CI, 0.69–13.17;p = 0.14,,I2=90%),0.77 (95%CI, 0.34–1.73;p=0.52,I2=7%) and 1.13 (95% CI,0.30–4.18;p=0.86,I2=0%),respectively.CONCLUSION: The findings of this meta-analysis showed that PARPi has no significant effect on OS, while it could significantly improve in PFS and TTD of GHS/QoL for patients with advanced or metastatic breast cancer.Furthermore,our findings also demonstrated that the PARPi treatment is connected with an increased risk of grade 3 or more anemia adverse events.

scholarly journals Rucaparib in patients presenting a metastatic breast cancer with Homologous Recombination Deficiency, without germline BRCA1/2 mutation

2020 ◽  
Author(s):  
Anne Patsouris ◽  
M'boyba Khadija DIOP ◽  
Olivier Tredan ◽  
Daniel Nenciu ◽  
Anthony Goncalves ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Homologous Recombination ◽  
Statistical Significance ◽  
Objective Response ◽  
Metastatic Breast ◽  
Parp Inhibitors ◽  
Small Subset ◽  
Durable Response ◽  
Homologous Recombination Deficiency

Abstract Breast cancer may present genomic alterations leading to homologous recombination deficiency. PARP inhibitors have proved their efficacy in patients with HER2-negative metastatic breast cancer (mBC) harboring germline (g) BRCA1/2 mutations. We conducted the phase 2 RUBY trial to assess the efficacy of rucaparib in HER2-negative mBC with high genomic loss of heterozygosity (LOH) score or somatic, without gBRCA1/2 mutation. 220 of 711 patients with mBC screened for LOH presented high LOH score which was associated with a higher likelihood of death (HR = 1.39, 95% CI: 1.11-1.75, p = 0.005). The primary objective was not reached with a clinical benefit rate (objective response or SD>16 weeks) of 13.5%. Two LOH-high patients, without somatic BRCA1/2 mutation, presented a complete and durable response (14 and 32 months). HRDetect tended to be associated with response to rucaparib, whithout reaching statistical significance (median HRDetect responders versus non responders: 0.465 versus, 0.040, p = 0.2135). Our data suggests that a small subset of patients with high LOH score could derive benefit from PARP inhibitors.

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