scholarly journals Clinical Implications of DNA Repair Defects in High-Grade Serous Ovarian Carcinomas

Cancers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1315 ◽  
Author(s):  
Michela Camilla Milanesio ◽  
Silvia Giordano ◽  
Giorgio Valabrega

Despite significant improvements in surgical and medical management, high grade serous ovarian cancer (HGSOC) still represents the deadliest gynecologic malignancy and the fifth most frequent cause of cancer-related mortality in women in the USA. Since DNA repair alterations are regarded as the “the Achille’s heel” of HGSOC, both DNA homologous recombination and DNA mismatch repair deficiencies have been explored and targeted in epithelial ovarian cancers in the latest years. In this review, we aim at focusing on the therapeutic issues deriving from a faulty DNA repair machinery in epithelial ovarian cancers, starting from existing and well-established treatments and investigating new therapeutic approaches which could possibly improve ovarian cancer patients’ survival outcomes in the near future. In particular, we concentrate on the role of both Poly (ADP-ribose) Polymerase (PARP) inhibitors (PARPis) and immune checkpoint inhibitors in HGSOC, highlighting their activity in relation to BRCA1/2 mutational status and homologous recombination deficiency (HRD). We investigate the biological rationale supporting their use in the clinical setting, pointing at tracking their route from the laboratory bench to the patient’s bedside. Finally, we deal with the onset of mechanisms of primary and acquired resistance to PARPis, reporting the pioneering strategies aimed at converting homologous-recombination (HR) proficient tumors into homologous recombination (HR)-deficient HGSOC.

2021 ◽  
Vol 22 (16) ◽  
pp. 8506
Author(s):  
Kristie-Ann Dickson ◽  
Tao Xie ◽  
Christian Evenhuis ◽  
Yue Ma ◽  
Deborah J. Marsh

Several poly (adenosine diphosphate-ribose) polymerase (PARP) inhibitors are now in clinical use for tumours with defects in BReast CAncer genes BRCA1 or BRCA2 that result in deficient homologous recombination repair (HRR). Use of olaparib, niraparib or rucaparib for the treatment of high-grade serous ovarian cancer, including in the maintenance setting, has extended both progression free and overall survival for women with this malignancy. While different PARP inhibitors (PARPis) are mechanistically similar, differences are apparent in their chemical structures, toxicity profiles, PARP trapping abilities and polypharmacological landscapes. We have treated ovarian cancer cell line models of known BRCA status, including the paired cell lines PEO1 and PEO4, and UWB1.289 and UWB1.289+BRCA1, with five PARPis (olaparib, niraparib, rucaparib, talazoparib and veliparib) and observed differences between PARPis in both cell viability and cell survival. A cell line model of acquired resistance to veliparib showed increased resistance to the other four PARPis tested, suggesting that acquired resistance to one PARPi may not be able to be rescued by another. Lastly, as a proof of principle, HRR proficient ovarian cancer cells were sensitised to PARPis by depletion of BRCA1. In the future, guidelines will need to emerge to assist clinicians in matching specific PARPis to specific patients and tumours.


Diagnostics ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 55 ◽  
Author(s):  
Boussios ◽  
Karathanasi ◽  
Cooke ◽  
Neille ◽  
Sadauskaite ◽  
...  

Poly (ADP-ribose) polymerase (PARP) inhibitors are a novel class of therapeutic agents that target tumors with deficiencies in the homologous recombination DNA repair pathway. Genomic instability characterizes high-grade serous ovarian cancer (HGSOC), with one half of all tumors displaying defects in the important DNA repair pathway of homologous recombination. Early studies have shown significant efficacy for PARP inhibitors in patients with germline breast related cancer antigens 1 and 2 (BRCA1/2) mutations. It has also become evident that BRCA wild-type patients with other defects in the homologous recombination repair pathway benefit from this treatment. Companion homologous recombination deficiency (HRD) scores are being developed to guide the selection of patients that are most likely to benefit from PARP inhibition. The choice of which PARP inhibitor is mainly based upon the number of prior therapies and the presence of a BRCA mutation or HRD. The identification of patients most likely to benefit from PARP inhibitor therapy in view of HRD and other biomarker assessments is still challenging. The aim of this review is to describe the current evidence for PARP inhibitors in ovarian cancer, their mechanism of action, and the outstanding issues, including the rate of long-term toxicities and the evolution of resistance.


2020 ◽  
Vol 13 (4) ◽  
pp. 375-379 ◽  
Author(s):  
Thomas Bartl ◽  
Alex Farr

SummaryBRCA mutation-related DNA repair deficiencies increase the individual sensitivity to DNA-targeting agents. Therefore, the patient’s BRCA mutational status is evaluated in clinical practice as a predictive marker in response to platinum salts and poly-ADP-ribose polymerase (PARP) inhibitors for breast cancer treatment. A substantial subset of BRCA wild-type breast cancer lesions, however, share both prominent molecular characteristics and clinical behavior patterns with cancer that harbors BRCA mutations, including DNA repair deficiencies. Also referred to as “BRCAness”, this observation is related to aberrations of the homologous recombination (HR) repair pathway, which deprive cancer cells of the ability to adequately mend potentially lethal double-strand breaks and result in a BRCA-like genomic instability. Hence, HR deficiency is a promising target for related therapeutic options and the predictive potential of HR testing for treatment response has been increasingly studied. Several HR deficiency-testing assays have been proposed and prospectively validated for various cancer types; however, preliminary results in early breast cancer are inconsistent. As scientific evidence for a potential therapeutic benefit in breast cancer is scarce, HR testing remains highly experimental and should be limited to the boundaries of clinical studies until results of ongoing phase 3 trials are available.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e15582-e15582
Author(s):  
Dineo Khabele ◽  
Andrew J Wilson ◽  
Annie Y Liu ◽  
Joseph Roland ◽  
Sarah Fletcher ◽  
...  

e15582 Background: The nucleolar protein, nucleophosmin (NPM1) is implicated multiple cellular processes, including proliferation, duplication of centrosomes, ARF-HDM2-p53 signaling. NPM1 is associated with sites of double strand DNA breaks, with persistence of its expression indicative of impaired DNA repair. Data from the TCGA data have emphasized that genomic instability through impaired DNA repair processes is a characteristic feature of many ovarian cancers. Our aim was to determine the expression of NPM1 in ovarian cancers and to determine the relationship between NPM1 expression and clinical outcomes including overall survival (OS), progression-free survival (PFS) and chemotherapy response. Methods: Tissue microarrays were created from 209 patients treated for ovarian cancer at a single institution from 1994-2004. Expression levels of NPM1 were examined by immunohistochemical staining. Slides were scored using the an automated image capture and analysis system. Positive nuclear staining was used to stratify tumors into high (>50%) and low (<50%) groups, and the results were related to overall survival (OS) and progression-free survival (PFS) via Kaplan-Meier analysis. The relationship between ki67, a proliferation marker and pH2AX, a mark of double strand DNA breaks was measured with Spearman rank correlation coefficient analyses. Results: The majority of tumors, 140/209 (69%) were of serous histology, advanced stage 146/209 (70%) and high grade 158/209 (76%). There was >50% NPM1 expression in 83/209 (40%) and <50% in 126/209 (60%) of the cases. Expression of NPM1 was higher in high grade tumors, and its expression alone was a significant predictor of PFS (p=0.022) but not OS (p=0.053). When adjusting for other predictors, NPM1 expression was predictive of PFS (p=0.047), but not OS (p=0.054). No relationship between NPM1 expression and response to platinum chemotherapy was observed. However, NPM1 expression correlated with Ki67 (r=0.43, p<0.0001) and pH2AX (r=0.22, p=0.0014). Conclusions: NPM1 expression is a mark of poor prognosis in ovarian cancer. Whether these observations reflect increased proliferation and/or genomic instability in ovarian cancer cells will be the focus of future investigation.


2018 ◽  
Vol 19 (10) ◽  
pp. 3249 ◽  
Author(s):  
Margarita Romeo ◽  
Juan Pardo ◽  
Anna Martínez-Cardús ◽  
Eva Martínez-Balibrea ◽  
Vanesa Quiroga ◽  
...  

Homologous recombination (HR) is a DNA repair pathway that is deficient in 50% of high-grade serous ovarian carcinomas (HGSOC). Deficient HR (DHR) constitutes a therapeutic opportunity for these patients, thanks to poly (ADP-ribose) polymerases (PARP) inhibitors (PARPi; olaparib, niraparib, and rucaparib are already commercialized). Although initially, PARPi were developed for patients with BRCA1/2 mutations, robust clinical data have shown their benefit in a broader population without DHR. This breakthrough in daily practice has raised several questions that necessitate further research: How can populations that will most benefit from PARPi be selected? At which stage of ovarian cancer should PARPi be used? Which strategies are reasonable to overcome PARPi resistance? In this paper, we present a summary of the literature and discuss the present clinical research involving PARPi (after reviewing ClinicalTrials.gov) from a translational perspective. Research into the functional biomarkers of DHR and clinical trials testing PARPi benefits as first-line setting or rechallenge are currently ongoing. Additionally, in the clinical setting, only secondary restoring mutations of BRCA1/2 have been identified as events inducing resistance to PARPi. The clinical frequency of this and other mechanisms that have been described in preclinics is unknown. It is of great importance to study mechanisms of resistance to PARPi to guide the clinical development of drug combinations.


2019 ◽  
Vol 49 (8) ◽  
pp. 703-707 ◽  
Author(s):  
Koji Matsumoto ◽  
Meiko Nishimura ◽  
Takuma Onoe ◽  
Hideki Sakai ◽  
Yusaku Urakawa ◽  
...  

Abstract After a brief summary of the current status of poly-ADP ribose polymerase (PARP) inhibitors for ovarian cancer, we summarize the current status of PARP inhibitors for BRCA wild type ovarian cancer, especially regarding gene alterations other than BRCA, homologous recombination deficiency (HRD), and combinations. Discussion of gene alterations other than BRCA include the results of multiple gene panels studying homologous recombination repair deficiency genes and cancer susceptibility genes, and influences of these alterations on efficacy of PARP inhibitors and cancer susceptibility. Discussions of HRD include the results of phase three trials using HRD assay, the definition of HRD assays, and the latest assays. Discussions of combinations include early phase trial results and ongoing trials combining PARP inhibitors with immune checkpoint inhibitors, anti-angiogenic agents, and triplets.


2019 ◽  
Vol 05 (01) ◽  
pp. 01-18
Author(s):  
Vikas Goswami ◽  
Venkata Pradeep Babu Koyyala ◽  
Sumit Goyal ◽  
Manish Sharma ◽  
Varun Goel ◽  
...  

AbstractPoly (ADP-ribose) polymerase (PARP) inhibitors are a unique class of therapeutic agents that focus on tumors with deficiencies in the homologous recombination DNA repair mechanism. Genomic instability outlines high-grade serous ovarian cancer, with 50% of all tumors displaying defects in the important DNA repair mechanism of homologous recombination. Earlier research studies have demonstrated considerable efficiency for PARP inhibitors in patients with germ line breast-related cancer antigens 1 and 2 (BRCA-1/BRCA-2) mutations. It has also been observed that BRCA wild-type patients with other defects in the homologous recombination repair mechanism get benefited from this therapy. Companion homologous recombination deficiency (HRD) scores are being developed to guide the selection of patients that are most likely to benefit from PARP inhibition. The selection of PARP inhibitor is mainly dependent upon the number of prior therapies and the presence of a BRCA mutation or HRD. The identification of cases which are most likely to get benefited from PARP inhibitor therapy in view of HRD and other biomarker assessments is still challenging. The purpose of this review is to focus and describe the current evidences for PARP inhibitors in ovarian malignancy, their mechanism of action, and the outstanding issues, including the rate of long-term toxicities and the evolving resistance.


Oncogene ◽  
2021 ◽  
Author(s):  
Jiahong Tan ◽  
Xu Zheng ◽  
Mengchen Li ◽  
Fei Ye ◽  
Chunyan Song ◽  
...  

AbstractPARP inhibitors (PARPi) are efficacious in treating high-grade serous ovarian cancer (HG-SOC) with homologous recombination (HR) deficiency. However, they exhibit suboptimal efficiency in HR-proficient cancers. Here, we found that the expression of CCAAT/enhancer-binding protein β (C/EBPβ), a transcription factor, was inversely correlated with PARPi sensitivity in vitro and in vivo, both in HR-proficient condition. High C/EBPβ expression enhanced PARPi tolerance; PARPi treatment in turn induced C/EBPβ expression. C/EBPβ directly targeted and upregulated multiple HR genes (BRCA1, BRIP1, BRIT1, and RAD51), thereby inducing restoration of HR capacity and mediating acquired PARPi resistance. C/EBPβ is a key regulator of the HR pathway and an indicator of PARPi responsiveness. Targeting C/EBPβ could induce HR deficiency and rescue PARPi sensitivity accordingly. Our findings indicate that HR-proficient patients may benefit from PARPi via targeting C/EBPβ, and C/EBPβ expression levels enable predicting and tracking PARPi responsiveness during treatment.


Cancers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 304
Author(s):  
Eros Azzalini ◽  
Domenico Tierno ◽  
Michele Bartoletti ◽  
Renzo Barbazza ◽  
Giorgio Giorda ◽  
...  

High-grade serous ovarian cancer (HGSOC) is among the deadliest gynecological malignancies. The acquired resistance to platinum-based therapies and the intrinsic heterogeneity of the disease contribute to the low survival rate. To improve patients’ outcomes, new combinatorial approaches able to target different tumor vulnerabilities and enhance the efficacy of the current therapies are required. AKT inhibitors are promising antineoplastic agents able to act in synergy with PARP inhibitors, but the spectrum of patients who can benefit from this combination is unclear, since the role of the three different isoforms of AKT is still unknown. Here, we study the expression of AKT isoforms on a retrospective cohort of archive tissue by RT-droplet digital PCR (ddPCR) analyzing their association with the clinicopathological features of patients. Based on AKT1/AKT2 and AKT1/AKT3 ratios, we define four AKT classes which were related to patients’ survival, tumor morphology and BRCA1 expression. Moreover, our results show that high AKT3 expression levels were frequently associated with tumors having classic features, a low number of mitoses and the presence of psammoma bodies. Overall, our study obtains new insights on AKT isoforms and their associations with the clinicopathological features of HGSOC patients. These evidences could help to better define the subsets of patients who can benefit from AKT and PARP inhibitors therapy in future clinical trials.


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