PARP inhibitors for targeted treatment in ovarian cancer

Parthanatos: Mechanisms, modulation, and therapeutic prospects in neurodegenerative disease and stroke

Parthanatos is a cell death signaling pathway that has emerged as a compelling target for pharmaceutical intervention. It plays a pivotal role in the neuron loss and neuroinflammation that occurs in Parkinson's Disease (PD), Alzheimer's Disease (AD), Huntington's Disease (HD), Amyotrophic Lateral Sclerosis (ALS), and stroke. There are currently no treatments available to humans to prevent cell death in any of these diseases. This review provides an in-depth examination of the current understanding of the Parthanatos mechanism, with a particular focus on its implications in neuroinflammation and various diseases discussed herein. Furthermore, we thoroughly review potential intervention targets within the Parthanatos pathway. We dissect recent progress in inhibitory strategies, complimented by a detailed structural analysis of key Parthanatos executioners, PARP-1, AIF, and MIF, along with an assessment of their established inhibitors. We hope to introduce a new perspective on the feasibility of targeting components within the Parthanatos pathway, emphasizing its potential to bring about transformative outcomes in therapeutic interventions. By delineating therapeutic opportunities and known targets, we seek to emphasize the imperative of blocking Parthanatos as a precursor to developing disease-modifying treatments. This comprehensive exploration aims to catalyze a paradigm shift in our understanding of potential neurodegenerative disease therapeutics, advocating for the pursuit of effective interventions centered around Parthanatos inhibition.

Efficacy and safety of PARP inhibitors for maintenance treatment of ovarian cancer, regardless of BRCA or HRD status: a comprehensive updated meta-analysis

Without taking into account existing biomarkers like genetic mutations (BRCA mutation, Homologous recombination deficiency) with advanced ovarian cancer (OC), the overall survival (OS), progress-free survival (PFS) of the aggregate all groups that have been classified were hazard ratio (HR): 0.72, 95% confidence intervals (CI): 0.66-0.79 and HR: 0.48, 95%CI: 0.44-0.52, respectively. Meanwhile, the OS and PFS of the whole population (regardless of existing genetic mutation markers) were HR: 0.74, 95%CI: 0.64-0.87 and HR: 0.52, 95%CI: 0.42-0.65, separately. Furthermore, the OS and PFS of positive gene mutation markers were HR: 0.71, 95%CI: 0.61-0.83 (HRD and BRACm) and HR: 0.47, 95%CI: 0.42-0.52 (HRD and BRACm), individually. The poly ADP-ribose polymers (PARP) inhibitors have desired efficiency and security in the maintenance treatment of advanced OC patients with BRCAm or BRCAwt, HRD or HRP and unknown gene status.

Targeting receptor tyrosine kinases in ovarian cancer: Genomic dysregulation, clinical evaluation of inhibitors, and potential for combinatorial therapies

Epithelial ovarian cancer (EOC) remains one of the leading causes of cancer-related deaths among women worldwide. Receptor tyrosine kinases (RTKs) have long been sought as therapeutic targets for EOC, as they are frequently hyperactivated in primary tumors and drive disease relapse, progression, and metastasis. More recently, these oncogenic drivers have been implicated in EOC response to poly(ADP-ribose) polymerase (PARP) inhibitors and epigenome-interfering agents. This evidence revives RTKs as promising targets for therapeutic intervention of EOC. This review summarizes recent studies on the role of RTKs in EOC malignancy and the use of their inhibitors for clinical treatment. Our focus is on the ERBB family, c-Met, and VEGFR, as they are linked to drug resistance and targetable using commercially available drugs. The importance of these RTKs and their inhibitors is highlighted by their impact on signal transduction and intratumoral heterogeneity in EOC and successful use as maintenance therapy in the clinic through suppression of the VEGF/VEGFR axis. Finally, the therapeutic potential of RTK inhibitors is discussed in the context of combinatorial targeting via co-inhibiting proliferative and anti-apoptotic pathways, epigenomic/transcriptional programs, and harnessing the efficacy of PARP inhibitors and programmed cell death 1/ligand 1 immune checkpoint therapies.

Systematic analysis of cancer-specific synthetic lethal interactions provides insight into personalized anticancer therapy

The concept of synthetic lethality has great potential for anticancer therapy as a new strategy to specifically kill cancer cells while sparing normal cells. To further understand the potential molecular interactions and gene characteristics involved in synthetic lethality, we performed a comprehensive analysis of predicted cancer-specific genetic interactions. Many genes were identified as cancer-associated genes that contributed to multiple biological processes and pathways, and the gene features were not random, indicating their potential roles in human carcinogenesis. Some relevant genes detected in multiple cancers were prone to be enriched in specific biological progresses and pathways, especially processes associated with DNA damage, chromosome-related functions and cancer pathways. These findings strongly implicated potential roles for these genes in cancer pathophysiology and functional relationships, as well as applications for future anticancer drug discovery. Further experimental validation indicated that the synthetic lethal interaction of APC and GFER may provide a potential anticancer strategy for patients with APC-mutant colon cancer. These results will contribute to further exploration of synthetic lethal interactions and broader application of the concept of synthetic lethality in anticancer therapeutics.

Mitochondria-associated endoplasmic reticulum membranes dysfunction contributes to PARP-1-dependent cell death under oxidative stress in retinal precursor cells

Persistent poly (ADP-ribose) polymerase 1 (PARP-1) activation has proven detrimental and can lead to PARP-1-dependent cell death. Mitochondria-associated endoplasmic reticulum (ER) membranes (MAMs) serve as essential hubs for many biological pathways, such as autophagy and mitochondria fission and fusion. This study aimed to alleviate the effects of hydrogen peroxide (H₂ O₂ )-induced persistent PARP-1 activation and MAM dysregulation by the usage of a PARP-1 inhibitor. Results showed that receptor-interacting protein kinase (RIPK) 1 inhibitor (necrostatin-1) and PARP-1 inhibitor (olaparib) protected retinal precursor cells from H₂ O₂ -induced death, while a pan-caspase inhibitor (Z-VAD-FMK) failed to protect R28 cells. Olaparib also alleviated H₂ O₂ -induced MAM dysregulation, as evidenced by decreased VDAC1/ITPR3 interactions and reduced mitochondrial membrane potential collapse. Additionally, olaparib also inhibited H₂ O₂ -induced autophagy. Inhibiting autophagic flux increased MAM signaling under both normal and oxidative conditions. Furthermore, H₂ O₂ treatment caused a reduction in the protein level of mitofusin-2 (MFN2) in a dose- and time-dependent manner. Mfn2 knockdown was found to further magnify MAM dysregulation and mitochondrial dysfunction under normal and oxidative conditions. Mfn2 overexpression surprisingly enhanced H₂ O₂ -induced MAM signaling and failed to rescue H₂ O₂ -induced mitochondrial dysfunction. These results indicate that MAMs probably serve as a membrane source for oxidative stress-associated autophagy. MAM dysregulation also contributed to H₂ O₂ -induced PARP-1-dependent cell death. However, more studies are required to decipher the link between the modulation of Mfn2 expression, changes in MAM integrity, and alterations in mitochondrial performances.

Anlotinib Suppressed Ovarian Cancer Progression via Inducing G2/M Phase Arrest and Apoptosis

Ovarian cancer remains the most common gynecologic malignancy, because of its chemotherapy resistance and relapse. Anlotinib, a new oral multi-targeted tyrosine kinase inhibitor, has shown encouraging antitumor activity in several preclinical and clinical trials, while its effect on ovarian cancer has not been reported. In this study, we investigated the antitumor activity and underlying mechanism of anlotinib in ovarian cancer. Cell viability was analyzed by Cell Counting Kit-8 assay. Migration was measured by wound-healing assay. The cell cycle distribution and cell apoptosis rate were detected by flow cytometry. In vivo antitumor effect was analyzed in mouse ovarian carcinoma peritoneal metastasis model. We found that anlotinib inhibited the proliferation of ovarian cancer cells in a dose- and time- dependent manner by inducing G2/M phase arrest and apoptosis. Moreover, anlotinib upregulated the the phosphorylation of Histone H3, and expression of p21 protein in vitro. In addition, anlotinib inhibited the migration of ovarian cancer cells in vitro. Furthermore, anlotinib inhibited tumor growth by inhibiting cell proliferation and suppressing ovarian cancer angiogenesis in vivo. This study demonstrated the extraordinary anti-ovarian cancer effect of anlotinib, which may provide a promising therapeutic strategy for ovarian cancer.

Olaparib, a PARP-1 inhibitor, protects retinal cells from ocular hypertension-associated oxidative damage

Glaucoma is the most common cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) and relative hypoxia in the retina stimulate the production of reactive oxygen species (ROS), which, in turn, puts the retina and optic nerve under chronic oxidative stress. Emerging evidence has shown that oxidative stress can trigger PARP-1 overactivation, mitochondrial-associated endoplasmic reticulum membrane (MAM) dysregulation, and NLRP3 activation. Oxidative damage can trigger inflammasome activation, and NLRP3 is the only inflammasome associated with MAM dysregulation. In addition, multiple transcription factors are located on the MAM. This study aimed to investigate the protective effects and underlying mechanisms of a PARP-1 inhibitor (olaparib) against chronic ocular hypertension-associated retinal cell damage. We also mimicked hypoxic stimulation of a retinal precursor cell line by exposing the cells to 0.2% O₂in vitro. We discovered that chronic ocular hypertension (COH) induces oxidative damage and MAM dysregulation in the retinal ganglion cells (RGCs). The protein levels of cleaved-PARP and NLRP3 were upregulated in the retinas of the COH rats. Olaparib, a PARP-1 inhibitor, alleviated COH-induced RGC loss, retinal morphological alterations, and photopic negative response amplitude reduction. Olaparib also relieved hypoxic stimulation-induced loss of cell viability and MAM dysregulation. Additionally, some indicators of mitochondrial performance, such as reactive oxygen species accumulation, mitochondrial Ca²⁺ influx, and mitochondrial membrane potential collapse, decreased after olaparib treatment. Olaparib attenuated the hypoxia-induced upregulation of NLRP3 protein levels as well as the phosphorylation of ERK1/2 and histone H2A.X. These results suggest that olaparib protects RGCs from chronic intraocular pressure elevation in vivo and alleviates the abnormal MAM dysregulation and mitochondrial dysfunction caused by hypoxia in vitro. This protection may be achieved by inhibiting PARP-1 overactivation, NLRP3 upregulation, and phosphorylation of ERK1/2.

The disruption of the CCDC6 – PP4 axis induces a BRCAness like phenotype and sensitivity to PARP inhibitors in high-grade serous ovarian carcinoma

Background

Treatment with PARP inhibitors (PARPi) is primarily effective against high-grade serous ovarian cancers (HGSOC) with BRCA1/2 mutations or other deficiencies in homologous recombination (HR) repair mechanisms. However, resistance to PARPi frequently develops, mostly as a result of BRCA1/2 reversion mutations. The tumour suppressor CCDC6 is involved in HR repair by regulating the PP4c phosphatase activity on γH2AX. In this work, we reported that in ovarian cancer cells, a physical or functional loss of CCDC6 results synthetic lethal with the PARP-inhibitors drugs, by affecting the HR repair. We also unravelled a role for CCDC6 as predictive marker of PARPi sensitivity in ovarian cancer, and the impact of CCDC6 downregulation in overcoming PARPi resistance in these tumours.

Methods

A panel of HGSOC cell lines (either BRCA-wild type or mutant) were treated with PARPi after CCDC6 was attenuated by silencing or by inhibiting USP7, a CCDC6-deubiquitinating enzyme, and the effects on cell survival were assessed. At the cellular and molecular levels, the processes underlying the CCDC6-dependent modification of drugs’ sensitivity were examined. Patient-derived xenografts (PDXs) were immunostained for CCDC6, and the expression of the protein was analysed statistically after digital or visual means.

Results

HGSOC cells acquired PARPi sensitivity after CCDC6 depletion. Notably, CCDC6 downregulation restored the PARPi sensitivity in newly generated or spontaneously resistant cells containing either wild type- or mutant-BRCA2. When in an un-phosphorylated state, the CCDC6 residue threonine 427 is crucial for effective CCDC6-PP4 complex formation and PP4 sequestration, which maintains high γH2AX levels and effective HR. Remarkably, the PP4-dependent control of HR repair is influenced by the CCDC6 constitutively phosphorylated mutant T427D or by the CCDC6 loss, favouring PARPi sensitivity. As a result, the PP4 regulatory component PP4R3α showed to be essential for both the activity of the PP4 complex and the CCDC6 dependent PARPi sensitivity. It's interesting to note that immunohistochemistry revealed an intense CCDC6 protein staining in olaparib-resistant HGSOC cells and PDXs.

Conclusions

Our findings suggest that the physical loss or the functional impairment of CCDC6 enhances the PP4c complex activity, which causes BRCAness and PARPi sensitivity in HGSOC cells. Moreover, CCDC6 downregulation might overcome PARPi resistance in HGSOCs, thus supporting the potential of targeting CCDC6 by USP7 inhibitors to tackle PARPi resistance.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-022-02459-2.

PARP inhibitors rising as an epoch-making strategy in first-line maintenance therapy of ovarian cancer: A systematic review and meta-analysis

Background To illustrate the accurate location of PARP inhibitor (PARPi) as the first-line maintenance therapy in advanced ovarian cancer (AOC).Methods Search for eligible studies and calculate clinical outcomes.Results PARPi as a first-line maintenance treatment significantly prolonged the BRCAmut population and the HRD positive population.Conclusion PARPi as first-line maintenance therapy significantly improves the PFS in AOC, especially in the BRCAmut and HRD positive populations. PARPi has been becoming the standard first-line maintenance therapy for AOC.

Ovarian cancer: epigenetics, drug resistance, and progression

Ovarian cancer (OC) is one of the most common malignant tumors in women. OC is associated with the activation of oncogenes, the inactivation of tumor suppressor genes, and the activation of abnormal cell signaling pathways. Moreover, epigenetic processes have been found to play an important role in OC tumorigenesis. Epigenetic processes do not change DNA sequences but regulate gene expression through DNA methylation, histone modification, and non-coding RNA. This review comprehensively considers the importance of epigenetics in OC, with a focus on microRNA and long non-coding RNA. These types of RNA are promising molecular markers and therapeutic targets that may support precision medicine in OC. DNA methylation inhibitors and histone deacetylase inhibitors may be useful for such targeting, with a possible novel approach combining these two therapies. Currently, the clinical application of such epigenetic approaches is limited by multiple obstacles, including the heterogeneity of OC, insufficient sample sizes in reported studies, and non-optimized methods for detecting potential tumor markers. Nonetheless, the application of epigenetic approaches to OC patient diagnosis, treatment, and prognosis is a promising area for future clinical investigation.

Exosome component 1 cleaves single-stranded DNA and sensitizes human kidney renal clear cell carcinoma cells to poly(ADP-ribose) polymerase inhibitor

Targeting DNA repair pathway offers an important therapeutic strategy for Homo sapiens (human) cancers. However, the failure of DNA repair inhibitors to markedly benefit patients necessitates the development of new strategies. Here, we show that exosome component 1 (EXOSC1) promotes DNA damages and sensitizes human kidney renal clear cell carcinoma (KIRC) cells to DNA repair inhibitor. Considering that endogenous source of mutation (ESM) constantly assaults genomic DNA and likely sensitizes human cancer cells to the inhibitor, we first analyzed the statistical relationship between the expression of individual genes and the mutations for KIRC. Among the candidates, EXOSC1 most notably promoted DNA damages and subsequent mutations via preferentially cleaving C site(s) in single-stranded DNA. Consistently, EXOSC1 was more significantly correlated with C>A transversions in coding strands than these in template strands in human KIRC. Notably, KIRC patients with high EXOSC1 showed a poor prognosis, and EXOSC1 sensitized human cancer cells to poly(ADP-ribose) polymerase inhibitors. These results show that EXOSC1 acts as an ESM in KIRC, and targeting EXOSC1 might be a potential therapeutic strategy.

ELFN1-AS1 accelerates cell proliferation, invasion and migration via regulating miR-497-3p/CLDN4 axis in ovarian cancer

Previous studies indicated that long non-coding RNAs (LncRNAs) were involved in the progression of multiple cancers including ovarian cancer (OV). LncRNA ELFN1-AS1 functioned as an oncogene in many cancers, but its potential roles in OV were largely unclear. In the current study, we were aimed at clarifying the biological roles and molecular mechanisms of ELFN1-AS1 in OV. We found that ELFN1-AS1 was significantly upregulated in OV tissues and cell lines. High expression of ELFN1-AS1 was associated with poor prognosis in OV patients. Knockdown of ELFN1-AS1 inhibited the proliferation, migration and invasion of SKOV3 cell lines and repressed tumor growth in xenografted ovarian models. Mechanistically, ELFN1-AS1 promoted the proliferation, migration and invasion of SKOV3 cells by sponging miR-497-3p. Additionally, CLDN4 was verified to be the target of miR-497-3p. Rescue experiments revealed that miR-497-3p inhibition could partly reverse the inhibitory effect of ELFN1-AS1 silencing on proliferation, migration and invasion of SKOV3 cell lines. Taken together, our findings indicated that ELFN1-AS1 acted as an oncogene in ovarian cancer through regulating the expression of CLDN4 by directly interacting with miR-497-3p. The results suggested that ELFN1-AS1 might act as a promising therapeutic target for OV.

FEN1 Blockade for Platinum Chemo-Sensitization and Synthetic Lethality in Epithelial Ovarian Cancers

Simple Summary

Overall survival outcomes, despite platinum-based chemotherapy, for patients with advanced ovarian cancer remains poor. Increased DNA repair capacity is a key route to platinum resistance in ovarian cancer. In the current study, we show that FEN1, a key player in DNA repair, is overexpressed in ovarian cancer and associated with poor survival. Pre-clinically FEN1 blockade not only increased platinum sensitivity but was also synthetically lethal in BRCA2 and POLβ deficient ovarian cancer cells. Together the data provides evidence that FEN1 is a promising anti-cancer target in ovarian cancer.

Abstract

FEN1 plays critical roles in long patch base excision repair (LP-BER), Okazaki fragment maturation, and rescue of stalled replication forks. In a clinical cohort, FEN1 overexpression is associated with aggressive phenotype and poor progression-free survival after platinum chemotherapy. Pre-clinically, FEN1 is induced upon cisplatin treatment, and nuclear translocation of FEN1 is dependent on physical interaction with importin β. FEN1 depletion, gene inactivation, or inhibition re-sensitizes platinum-resistant ovarian cancer cells to cisplatin. BRCA2 deficient cells exhibited synthetic lethality upon treatment with a FEN1 inhibitor. FEN1 inhibitor-resistant PEO1R cells were generated, and these reactivated BRCA2 and overexpressed the key repair proteins, POLβ and XRCC1. FEN1i treatment was selectively toxic to POLβ deficient but not XRCC1 deficient ovarian cancer cells. High throughput screening of 391,275 compounds identified several FEN1 inhibitor hits that are suitable for further drug development. We conclude that FEN1 is a valid target for ovarian cancer therapy.

Prognostic Evidence of the miRNA-Based Ovarian Cancer Signature MiROvaR in Independent Datasets

Simple Summary

Epithelial ovarian cancers (EOC) have an unpredictable frequent recurrence often associated with incurable chemo-resistant disease. Basing on the miRNA expression profile of 892 EOC patients, we previously developed a 35 miRNA-based classifier, MiROvaR, able to predict EOC risk of early relapse. Further independent analysis of prediction accuracy represents a crucial step in the test-validation phase. Here we exploited an external and independently collected, handled and profiled EOC cohort, to challenge MirovaR accuracy. Our analysis confirmed the MiROvaR prognostic power, thus opening the way to its prospective validation as a clinical grade assay entering into clinical practice to help in the refinement of therapeutic intervention for high risk EOC patients.

Abstract

Epithelial ovarian cancer (EOC) remains the second most common cause of gynecological cancer deaths. To improve patients’ outcomes, we still need reliable biomarkers of early relapse, of which external independent validation is a crucial process. Our previously established prognostic signature, MiROvaR, including 35 microRNAs (miRNA) able to stratify EOC patients for their risk of relapse, was challenged on a new independent cohort of 197 EOC patients included in the Pelvic Mass Study whose miRNA profile was made publically available, thus resulting in the only accessible database aside from the EOC TCGA collection. Following accurate data matrix adjustment to account for the use of different miRNA platforms, MiROvaR confirmed its ability to discriminate early relapsing patients. The model’s original cutoff separated 156 (79.2%) high- and 41 (20.8%) low-risk patients with median progression free survival (PFS) of 16.3 months and not yet reached (NYR), respectively (hazard ratio (HR): 2.42–95% Confidence Interval (CI) 1.49–3.93; Log-rank p = 0.00024). The MiROvaR predictive accuracy (area under the curve (AUC) = 0.68; 95% Cl 0.57–0.79) confirms its prognostic value. This external validation in a totally independently collected, handled and profiled EOC cohort suggests that MiROvaR is a strong and reliable biomarker of EOC early relapse, warranting prospective validation.

Deep exploration of PARP inhibitors in breast cancer: monotherapy and combination therapy

OBJECTIVE

Nearly 5% of patients with breast cancer carry germline BRCA mutations, which are more common in triple-negative breast cancer (TNBC). Previous clinical trials demonstrated the therapeutic efficacy of poly (ADP-ribose) polymerase inhibitors (PARPis) against BRCA-mutated metastatic breast cancer. The current study conducted a systemic review and meta-analysis of the clinical efficiency and safety of PARPis, either alone or combined with chemotherapy, in patients with TNBC.

METHODS

We searched PubMed, EMBASE, and ClinicalTrials.gov to identify randomized controlled trials comparing PARPi therapy with chemotherapy, and comparisons of chemotherapy plus PARPis with chemotherapy alone were included. The study endpoints included the clinical response, progression-free survival, and adverse event rates.

RESULTS

PARPi therapy was revealed to improve progression-free survival in patients with advanced breast cancer, either alone or in combination with chemotherapy. Subgroup analysis illustrated that patients with mutant BRCA1 and mutant BRCA2 and those who had not been treated with platinum-based agents could specifically benefit from PARPis.

CONCLUSION

PARPi monotherapy can significantly improve clinical outcomes in patients with advanced breast cancer, especially those with TNBC, those who had not previously received platinum therapy, and those with mutant BRCA1/2. PARPis combined with chemotherapy represent new treatment options for patients with advanced cancer.

A functional polymorphism in the poly(ADP-ribose) polymerase-1 gene is associated with platinum-based chemotherapeutic response and prognosis in epithelial ovarian cancer patients

OBJECTIVE

To explore the effects of two functional genetic variants of poly(ADP-ribose) polymerase-1 (PARP-1) on the susceptibility to epithelial ovarian cancer (EOC), the platinum-based chemotherapeutic response, and the prognosis of northern Chinese patients.

STUDY DESIGN

This case-control study included 710 EOC patients in the case group and 700 healthy women in the control group. Two polymorphisms (rs1136410 and rs8679) of PARP-1 were genotyped by polymerase chain reaction and ligase detection reaction.

RESULTS

The genotype frequencies of rs1136410 and rs8679 were not significantly different between the case and control groups. However, the CC genotype of rs1136410 was significantly associated with a favorable response to platinum drugs. Compared with the TT genotype, the CC genotype of rs1136410 was related to a reduced risk of platinum resistance (adjusted OR: 0.40; 95% CI = 0.24-0.67; P = 0.001). In addition, multivariable analysis containing clinical variables showed that patients who carried the rs1136410 CC genotype had a significantly improved progression-free survival compared with patients who carried the TT genotype (HR = 0.67, 95% CI = 0.47-0.97, P = 0.031).

CONCLUSION

The rs1136410 polymorphism may serve as a potential marker for predicting the response to platinum agents and prognosis of EOC patients treated with surgery and platinum-based chemotherapy.

Scoring systems for the evaluation of adnexal masses nature: current knowledge and clinical applications

Adnexal masses are a common finding in women, with 20% of them developing at least one pelvic mass during their lifetime. There are more than 30 different subtypes of adnexal tumours, with multiple different subcategories, and the correct characterisation of the pelvic masses is of paramount importance to guide the correct management. On that basis, different algorithms and scoring systems have been developed to guide the clinical assessment. The first scoring system implemented into the clinical practice was the Risk of Malignancy Index, which combines ultrasound evaluation, menopausal status, and serum CA-125 levels. Today, current guidelines regarding female patients with adnexal masses include the application of International Ovarian Tumours Analysis simple rules, logistic regression model 1 (LR1) and LR2, OVERA, cancer ovarii non-invasive assessment of treating strategy, and assessment of Different Neoplasias in the adnexa. In this scenario, the choice of the scoring system for the discrimination between benign and malignant ovarian tumours can be complex when approaching patients with adnexal masses. This review aims to summarise the available evidence regarding the different scoring systems to provide a complete overview of the topic.

MicroRNA-338-3p suppresses ovarian cancer cells growth and metastasis: implication of Wnt/catenin beta and MEK/ERK signaling pathways

BACKGROUND

Downregulation of microRNA-338-3p (miR-338-3p) was detected in many malignant tumors, which indicated miR-338-3p might serve as a role of antioncogene in those cancers. The present study aimed to explore the roles of miR-338-3p in the growth and metastasis of ovarian cancer cells and elaborate the underlying possible molecular mechanism.

METHODS

Multiply biomedical databases query and KEGG pathway enrichment assay were used to infilter possible target genes and downstream pathways regulated by miR-338-3p. Overexpression miR-338-3p lentiviral vectors were transfected into ovarian cancer OVCAR-3 and OVCAR-8 cells, cell proliferation, migration and invasion were analyzed by MTT, colony formation, transwell, Matrigel assay and xenograft mouse model. One 3'-untranslated regions (UTRs) binding target gene of miR-338-3p, MACC1 (MET transcriptional regulator MACC1), and its regulated gene MET and downstream signaling pathway activities were examined by western blot.

RESULTS

Biomedical databases query indicated that miR-338-3p could target MACC1 gene and regulate Met, downstream Wnt/Catenin beta and MEK/ERK pathways. Rescue of miR-338-3p could inhibit the proliferation, migration and invasion of ovarian cancer cells, and suppress the growth and metastasis of xenograft tumor. Restoration of miR-338-3p could attenuate MACC1 and Met overexpression induced growth, epithelial to mesenchymal transition (EMT) and activities of Wnt/Catenin beta and MEK/ERK signaling in vitro and in vivo.

CONCLUSIONS

The present data indicated that restoration of miR-338-3p could suppress the growth and metastasis of ovarian cancer cells, which might due to the inhibition of proliferation and EMT induced by MACC1, Met and its downstream Wnt/Catenin beta and MEK/ERK signaling pathways.

Comprehensive analysis of serum tumor markers and BRCA1/2 germline mutations in Chinese ovarian cancer patients

Background

The serum tumor markers has been widely used in ovarian cancer diagnosis. BRCA1/2 germline mutations are the most common predisposing factors for ovarian cancer development. This study aimed to comprehensively investigate serum tumor markers and BRCA1/2 germline mutations and analyze their associations with ovarian cancer.

Methods

Levels of 11 serum tumor markers were examined in ovarian cancer patients and controls with benign gynecologic diseases. By integrating multiplex PCR and next‐generation sequencing technologies, BRCA1/2 germline mutations were analyzed and confirmed by Sanger sequencing. The discriminative models with serum tumor markers and BRCA1/2 mutation status were constructed for ovarian cancer detection and patient stratification.

Results

Among 11 markers, six of them were significantly elevated and only beta‐human chorionic gonadotropin (β‐HCG) was significantly reduced in ovarian cancer patients. A total of 54 (23.3%) ovarian cancer patients were found to harbor BRCA1/2 deleterious mutations, and BRCA1/2 mutations were significantly associated with Hereditary Breast and Ovarian Cancer‐related tumors and family history of cancer. Carbohydrate antigen 125 showed a good performance in ovarian cancer detection as a single marker (AUC = 0.799), while a panel of eight markers showed a good performance in BRCA1 mutation detection with an AUC value of 0.974. In addition, a panel of five serum tumor markers combined with BRCA1/2 mutation status showed a good performance in lymph node metastasis prediction (AUC = 0.843).

Conclusions

We found the association between BRCA1/2 germline mutation status and serum tumor marker levels, and identified discriminative models that combined serum tumor markers with BRCA1/2 mutation status for ovarian cancer detection and patient stratification.

Platinum Resistance in Ovarian Cancer: Role of DNA Repair

Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer. It is initially responsive to cisplatin and carboplatin, two DNA damaging agents used in first line therapy. However, almost invariably, patients relapse with a tumor resistant to subsequent treatment with platinum containing drugs. Several mechanisms associated with the development of acquired drug resistance have been reported. Here we focused our attention on DNA repair mechanisms, which are fundamental for recognition and removal of platinum adducts and hence for the ability of these drugs to exert their activity. We analyzed the major DNA repair pathways potentially involved in drug resistance, detailing gene mutation, duplication or deletion as well as polymorphisms as potential biomarkers for drug resistance development. We dissected potential ways to overcome DNA repair-associated drug resistance thanks to the development of new combinations and/or drugs directly targeting DNA repair proteins or taking advantage of the vulnerability arising from DNA repair defects in EOCs.

Platinum Resistance in Ovarian Cancer: Role of DNA Repair

Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer. It is initially responsive to cisplatin and carboplatin, two DNA damaging agents used in first line therapy. However, almost invariably, patients relapse with a tumor resistant to subsequent treatment with platinum containing drugs. Several mechanisms associated with the development of acquired drug resistance have been reported. Here we focused our attention on DNA repair mechanisms, which are fundamental for recognition and removal of platinum adducts and hence for the ability of these drugs to exert their activity. We analyzed the major DNA repair pathways potentially involved in drug resistance, detailing gene mutation, duplication or deletion as well as polymorphisms as potential biomarkers for drug resistance development. We dissected potential ways to overcome DNA repair-associated drug resistance thanks to the development of new combinations and/or drugs directly targeting DNA repair proteins or taking advantage of the vulnerability arising from DNA repair defects in EOCs.

Platinum Resistance in Ovarian Cancer: Role of DNA Repair

Epithelial ovarian cancer (EOC) is the most lethal gynecological cancer. It is initially responsive to cisplatin and carboplatin, two DNA damaging agents used in first line therapy. However, almost invariably, patients relapse with a tumor resistant to subsequent treatment with platinum containing drugs. Several mechanisms associated with the development of acquired drug resistance have been reported. Here we focused our attention on DNA repair mechanisms, which are fundamental for recognition and removal of platinum adducts and hence for the ability of these drugs to exert their activity. We analyzed the major DNA repair pathways potentially involved in drug resistance, detailing gene mutation, duplication or deletion as well as polymorphisms as potential biomarkers for drug resistance development. We dissected potential ways to overcome DNA repair-associated drug resistance thanks to the development of new combinations and/or drugs directly targeting DNA repair proteins or taking advantage of the vulnerability arising from DNA repair defects in EOCs.

Involved-field radiation therapy for recurrent ovarian cancer: Results of a multi-institutional prospective phase II trial

OBJECTIVE

To evaluate the efficacy and safety of involved-field radiation therapy (IFRT) in patients with locoregionally confined recurrent or persistent epithelial ovarian cancer.

METHODS

This study included patients with recurrent epithelial ovarian cancer eligible for IFRT either during diagnosis of the recurrence or after salvage therapies. IFRT was performed at a dose of ≥45 Gy for all tumors with 10-15-mm margins as seen on standard imaging. The primary endpoint was progression-free survival (PFS); the secondary endpoints were safety, response rate, local control, and overall survival (OS).

RESULTS

Thirty patients with a mean number of 5.7 metastatic lesions each were enrolled between 2014 and 2016. Seventeen were treated with 3-D conformal radiation therapy (RT) and 13 with intensity-modulated RT. IFRT was well tolerated in all patients, and acute toxicity ≥ grade 2 was not observed. One case of grade 3 abdominal pain was reported 10 months post-RT. The overall and complete response rates were 85.7% and 50%, respectively. After a median follow-up of 28 (range, 17-42) months, the median PFS was 7 months. The 2-year PFS rate was 39.3%. Six of the 16 patients who developed outfield disease progression after IFRT were successfully treated with repeat IFRT as salvage treatment. The 3-year local control and OS rates were 84.4% and 55.8%, respectively.

CONCLUSIONS

Although the primary endpoint was not met, IFRT might be safe and effective for in-field tumor control in patients with persistent epithelial ovarian cancer with a limited number of metastatic foci. We plan to conduct a larger scale multi-center phase II prospective study.

Where Do We Stand on the Integration of PARP Inhibitors for the Treatment of Breast Cancer?

PURPOSE OF REVIEW

To provide an overview of the clinical development of poly(ADP-ribose) polymerase inhibitors (PARPi) in breast cancer to date and to review existing challenges and future research directions.

RECENT FINDINGS

We summarize the clinical development of PARPi in breast cancer from bench to bedside, and discuss the results of recent phase 3 trials in patients with metastatic breast cancer (MBC) and germline mutations in BRCA1/2 (gBRCAm). We will also provide an update regarding mechanisms of action and resistance to PARPi, and review clinical trials of PARPi as monotherapy or in combination regimens. PARPi are a novel treatment approach in persons with gBRCA1/2m-associated MBC. Going forward, the clinical applicability of these compounds outside the gBRCAm setting will be studied in greater detail. The identification of accurate predictive biomarkers of response is a research priority.