Search Results (561)

The human Poly ADP-ribose Polymerase (PARP) family comprises 17 enzymes responsible for the transfer of ADP-ribose to proteins, forming poly- or mono-ADP-ribosylation. This post-translational modification regulates DNA repair and programmed cell death, processes affecting cancer biology. PARP inhibitors, including the FDA-approved olaparib, are used to treat BRCA-dependent breast and ovarian cancers. Although therapies with use of PARP inhibitors are showing clinical success, their effects on the immune system remain understudied. Prior work has shown that PARP inhibition can modulate inflammatory responses and alter innate immunity. In this study, we evaluated the immunomodulatory effects of olaparib on myeloid cells in vivo, focusing on bone marrow and spleen. Olaparib treatment altered the composition and activation state of dendritic cells, neutrophils, and macrophages. In the bone marrow, olaparib increased the proportion of cDC2 population, mature neutrophils and inflammatory macrophages expressing CD80. In contrast, splenic myeloid cells exhibited enhanced expression of markers associated with tolerogenic phenotypes, including CD206 and CD124 in neutrophils and macrophages. The spleen also showed an increase in immature monocyte-derived dendritic cells (CD206+) and a bias toward the cDC2 subset. These findings indicate that PARP inhibition can induce short-term phenotypic remodeling of myeloid cell populations, promoting a more immunoregulatory profile, especially in the spleen. These changes may contribute to an altered immune landscape with implications for anti-tumor immunity. Full article

The concept of “platinum sensitivity” has long guided prognostic assessment and treatment selection in recurrent ovarian cancer. However, the emergence of targeted agents, such as bevacizumab and poly (ADP-ribose) polymerase inhibitors, has complicated its clinical utility. In contrast, emerging evidence suggests that platinum sensitivity may also be applicable to recurrent endometrial cancer. As in ovarian cancer, a prolonged platinum-free interval (PFI) in recurrent endometrial cancer is associated with an improved efficacy of subsequent platinum-based chemotherapy. The PFI is linearly correlated with the response rate to platinum re-administration, progression-free survival, and overall survival. Patients are typically classified as having platinum-resistant or platinum-sensitive disease based on a PFI cutoff of 6 or 12 months. However, unlike in ovarian cancer—where the duration of response to second-line platinum-based chemotherapy rarely exceeds the prior PFI (~3%)—approximately 30% of patients with recurrent endometrial cancer exhibit a sustained response to platinum rechallenge that extends beyond their preceding PFI. Despite the incorporation of immune checkpoint inhibitors into the treatment landscape of endometrial cancer, the role of platinum sensitivity in clinical decision-making—particularly regarding treatment sequencing and drug selection—remains a critical and unresolved issue. Further research is warranted to elucidate the mechanisms underlying platinum resistance and to guide optimal therapeutic strategies. Full article

Head and neck squamous cell carcinomas (HNSCCs) represent a heterogeneous group of tumors with a complex molecular profile. Despite therapeutic advances, patient prognosis remains poor, emphasizing the need for more effective treatment strategies. Traditional chemotherapy, with cisplatin and 5-fluorouracil (5-FU), remains the gold standard but is limited by toxicity and tumor resistance. Immunotherapy, particularly immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1) and its ligand (PD-L1), has improved overall survival, especially in patients with high PD-L1 expression. In parallel, targeted therapies such as poly (ADP-ribose) polymerase 1 (PARP1) inhibitors—which impair DNA repair and increase replication stress—have shown promising activity in HNSCC. Cyclin-dependent kinase (CDK) inhibitors are also under investigation due to their potential to correct dysregulated cell cycle control, a hallmark of HNSCC. This review aims to summarize current and emerging pharmacotherapies for HNSCC, focusing on chemotherapy, immunotherapy, and PARP and CDK inhibitors. It also discusses the evolving role of targeted therapies in improving clinical outcomes. Future research directions include combination therapies, nanotechnology-based delivery systems to enhance treatment specificity, and the development of diagnostic tools such as PARP1-targeted imaging to better guide personalized treatment approaches. Full article

Background: The identification of pathogenic variants in the Breast Cancer Genes 1 and 2 (BRCA1/2) is a critical predictive biomarker for poly (ADP-ribose) polymerase inhibitor (PARPi) therapy in epithelial ovarian cancer (EOC). The aim of this study is to define real-world rates and determinants of germline and somatic BRCA1/2 testing and subsequent PARPi utilisation in Australia using a national clinical quality registry. Methods: This multi-centre cohort study analysed data from 1503 women with non-mucinous EOC diagnosed between May 2017 and July 2022, captured by the Australian National Gynae-Oncology Registry (NGOR). We evaluated rates of germline and somatic testing and PARPi use, using multivariate logistic regression to identify associated clinical and demographic factors. Results: Overall germline and somatic testing rates were 68% and 32%, respectively. For the high-grade serous ovarian cancer (HGSOC) cohort, rates were higher, at 78% and 39%, respectively. Germline testing was significantly less likely for women aged >80 years (OR 0.49), those in regional areas (OR 0.61), and those receiving single-modality treatment. Somatic testing uptake increased significantly following public reimbursement for PARPi (p = 0.004). Among eligible women with a newly diagnosed BRCA pathogenic variant and advanced disease (n = 110), 52% commenced first-line maintenance PARPi. Conclusions: This national study offers valuable insights into Australian ovarian cancer care, highlighting opportunities to enhance testing equity for older women (aged >80) and regional patients. Furthermore, it identifies the translation of a positive test into PARPi therapy as a complex area that warrants further collaborative investigation to optimise patient outcomes. Full article

DNA damage repair is a hallmark of any cancer growth, eventually leading to drug resistance and death. The poly ADP-ribose polymerase (PARP) enzyme is vital in repairing damaged DNA in normal and cancer cells with mutated DNA damage response (DDR) genes. Inhibitors of the PARP enzyme aid in chemotherapy, as shown by drug combinations such as Olaparib and Irinotecan in breast cancer treatment. However, the effect of Olaparib in colon cancer has not been studied extensively. Synthetic drugs have a significant limitation in cancer treatment due to drug resistance, leading to colon cancer relapse. Bioavailability of Olaparib and other PARP inhibitors is limited due to their hydrophobicity, which poses a significant challenge. These limitations and challenges can be addressed by encapsulating Olaparib in nanoparticles that could possibly increase the bioavailability of the drug at the site of action. New age nanoparticles, such as hybrid nanoparticles, provide superior quality in terms of design and circulatory time of the drug in the plasma. The side effects of Olaparib as a chemotherapeutic pave the way for exploring phytochemicals that may have similar effects. The combined impact of Olaparib and phytochemicals such as genistein, resveratrol and others in nano-encapsulated form can be explored in the treatment of colon cancer. Full article

Treatment for HIV infection has become more manageable due to advances in combination antiretroviral therapy (cART). However, HIV still significantly affects the central nervous system (CNS) in infected individuals, even with effective plasma viral suppression, due to persistent viral reservoirs and chronic neuroinflammation. This ongoing inflammation contributes to the development of HIV-associated neurocognitive disorders (HANDs), including dementia and Alzheimer’s disease-like pathology. These complications are particularly prevalent among the aging population with HIV. This review aims to provide a comprehensive overview of HAND, with a focus on the contribution of oxidative stress induced by HIV-mediated reactive oxygen species (ROS) production through viral proteins such as gp120, Tat, Nef, Vpr, and reverse transcriptase. In addition, we discuss current and emerging therapeutic interventions targeting HAND, including antioxidant strategies and poly (ADP-ribose) polymerase (PARP) inhibitors. These are potential adjunctive approaches to mitigate neuroinflammation and oxidative damage in the CNS. Full article

BGP-15, a poly(ADP-ribose) polymerase-1 (PARP-1) inhibitor exerts cardioprotective effects; however, the underlying mechanisms remain unclear. Therefore, our study aimed to investigate the effects of BGP-15 on the imatinib (Imtb)-induced cardiac inflammation at the biochemical level. Male rats were divided to control, Imtb-treated (60 mg/kg/day for 14 days), and Imtb + BGP-15-treated animals. In this group Imtb was co-administered with BGP-15 at the dose of 10 mg/kg/day. At the end of the experiment, nuclear factor-kappa B/p65 (NF-κB/p65), nuclear transcription factor erythroid-2 related factor (Nrf2), heme oxygenase-1 (HO-1), high mobility group box 1 (HMGB1), and myeloperoxidase (MPO) were measured by Western blot. Chemokine and interleukins (ILs) were determined by Legendplex. Additionally, cardiac specific changes were visualized by immunohistochemistry. We demonstrated that Imtb increased NF-κB/p65, IL-6, IL-1β, IL-18, MCP-1, HMGB1, as well as the expression and activity of MPO. Conversely, the expressions of antioxidant Nrf2 and HO-1 were decreased. Administration of BGP-15 effectively mitigated these inflammatory alterations by significantly reducing pro-inflammatory cytokines and MPO activity, while simultaneously restoring and enhancing the levels of Nrf2 and HO-1, thereby promoting antioxidant defenses. The immunohistochemical staining further supported these biochemical changes. Our study provides new and comprehensive biochemical insight for managing Imtb-induced inflammatory responses via BGP-15-induced PARP1 inhibition. Full article

Current guidelines recommend either radical prostatectomy (RP) or radiation with androgen deprivation therapy (ADT) for unfavorable intermediate- or high-risk prostate cancer. There has been emerging interest in the potential benefits of neoadjuvant ADT prior to RP for this population. Past trials indicate neoadjuvant ADT may be associated with reduced surgical complexity, pathologic downstaging, decreased positive margins, and decreased rates of nodal positivity, although they have not shown benefits for cancer progression and survival. Accordingly, neoadjuvant ADT is currently not recommended for surgical patients. Conversely, ADT is a mainstay of treatment in metastatic disease, and interest remains in expanding its use towards patients with clinically localized disease. There are several ongoing trials of second-generation androgen blockers such as enzalutamide, darolutamide, radiopharmaceuticals, and poly (ADP-ribose) polymerase (PARP) inhibitors to explore long-term cancer-specific survival benefits with neoadjuvant use. In this narrative review, we provide a comprehensive overview of the recent literature and ongoing efforts to incorporate neoadjuvant therapy for clinically localized prostate cancer patients who are at high-risk of recurrence after prostatectomy. Full article

Janus kinase 2 (JAK2) inhibitors have gained regulatory approval for treating various human diseases. While the JAK2/signal tranducer and activator of transcription 3 (STAT3) pathway plays a role in tumorigenesis, JAK2/STAT3 inhibitors have shown limited therapeutic efficacy in triple-negative breast cancer (TNBC). In this study, we assessed the antiproliferative effects of clinically approved JAK2 inhibitors in TNBC cell lines (MDA-MB-231 and HS578T) using the MTT assay. Among the four JAK2 inhibitors evaluated (fedratinib, cerdulatinib, peficitinib, and filgotinib), fedratinib significantly inhibited the proliferation of TNBC cells with IC₅₀ values below 2 μM. Fedratinib also demonstrated superior efficacy in inhibiting long-term colony formation compared to other JAK2 inhibitors. Western blot analyses showed that fedratinib uniquely inhibits the phosphoinositide 3-kinase (PI3K)/AKT pathway and moderately affects the MAP kinase/ERK kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway, in addition to targeting JAK2/STAT3 signaling. Moreover, fedratinib distinctly decreased MYC and cyclin D1 protein levels while inducing poly (ADP-ribose) polymerase (PARP) cleavage and apoptotic cell death more effectively than other JAK2 inhibitors. We next investigated the effects of simultaneously inhibiting JAK2/STAT3 together with the MEK/ERK or PI3K/AKT pathways, as well as the impact of triple pathway inhibition. Notably, combining ceduratinib with either cobimetinib (MEK inhibitor) and ipatasertib (AKT inhibitor) or trametinib (MEK inhibitor) and alpelisib (PI3K inhibitor) mimicked the effects of fedratinib on the cell proliferation, MYC and cyclin D1 suppression, and pro-apoptotic protein induction. These finding suggest that JAK2 inhibition enhances the anticancer effects of concurrent MEK/ERK and PI3K/AKT pathway inhibition, while JAK2 inhibition alone shows minimal efficacy in TNBC cells. Full article

Poly(ADP-ribose) polymerases (PARP) are a family of enzymes that were proven to play an essential role in the initiation and activation of DNA repair processes in the case of DNA single-strand breaks. The inhibition of PARP enzymes might be a promising option for the treatment of several challenging types of cancers, including triple-negative breast cancer (TNBC) and non-small cell lung carcinoma (NSCLC). This study utilizes several techniques to screen the compound collection of the Leibniz Institute of Plant Biochemistry (IPB) to identify novel hPARP-1 inhibitors. First, an in silico pharmacophore-based docking study was conducted to virtually screen compounds with potential inhibitory effects. To evaluate these compounds in vitro, a cell-free enzyme assay was developed, optimized, and employed to identify hPARP-1 inhibitors, resulting in the discovery of two novel scaffolds represented by compounds 54 and 57, with the latter being the most active one from the compound library. Furthermore, fluorescence microscopy and synergism assays were performed to investigate the cellular and nuclear pathways of hPARP-1 inhibitor 57 and its potential synergistic effect with the DNA-damaging agent temozolomide. The findings suggest that the compound requires further lead optimization to enhance its ability to target the nuclear PARP enzyme effectively. Nonetheless, this new scaffold demonstrated a five-fold higher PARP inhibitory activity at the enzyme level compared to the core structure of olaparib (OLP), phthalazin-1(2H)-one. Full article

Background: Breast cancer (BC) is the most common cancer in women worldwide. Much progress has been made to improve treatment options for patients suffering from the disease, including a novel therapy—Poly (ADP-ribose) polymerase inhibitor (PARPi) that specifically targets tumors with deficiencies in the Homologous Recombination (HR) DNA repair pathway. To benefit better from conventional therapy, many patients seek alternative supplementation, with 20–30% of cancer patients using herbal medication on top of their regular treatment. An example of such easily available over-the-counter supplements is curcumin, a natural compound derived from turmeric (Curcuma longa). Various studies reported the potential HR deficiency (HRD) inducing effect of curcumin in cancer cells. Methods: Eight BrC and three normal cell lines and a BrC PDX model were used to evaluate the effect of curcumin on RAD51 ionizing radiation-induced focus (IRIF) formation. Three breast BrC cell lines underwent further analysis using the BRCA2 Western blot technique. To assess cell survival after treatment with curcumin and/or PARPi, a clonogenic survival assay was performed on both normal and cancerous cell lines. Results: Curcumin treatment led to a reduction in RAD51 IRIF formation capacity across all tested models. A decrease in BRCA2 levels was observed in the tested cell lines. Our findings demonstrate that HRD can be induced in both cancerous and normal cells, suggesting that curcumin treatment may increase the risk of toxicity when combined with PARPi therapy. Conclusions: The use of curcumin in combination with certain anti-cancer treatments should not be implemented without extensive monitoring for deleterious side effects. Full article

Ovarian cancer is the most lethal gynecologic malignancy, which causes 313,959 new cases and 207,252 deaths worldwide annually. The lack of specific symptoms, together with no effective screening tools, results in 75% of patients receiving their diagnosis at an advanced stage. The combination of cytoreductive surgery with platinum-based chemotherapy plays a pivotal role in the treatment of advanced epithelial ovarian cancer, but patients still experience poor long-term survival because of frequent relapses and chemotherapy resistance. The treatment landscape has evolved because bevacizumab and Poly-ADP Ribose Polymerase inhibitors now serve as frontline and maintenance therapies for homologous recombination-deficient tumors. Treatment decisions for recurrent disease depend on platinum sensitivity assessment, which determines the appropriate therapeutic approach, while targeted agents deliver significant benefits to specific patient groups. The development of antibody-drug conjugates such as mirvetuximab soravtansine and immunotherapy, including checkpoint inhibitors and cancer vaccines, demonstrates promising investigative potential. The precision of therapy improves through the use of emerging biomarkers and molecular profiling techniques. The future management of this disease may change because of innovative approaches that include adoptive cell therapy, cytokine therapy, and oncolytic viruses. The progress made in ovarian cancer treatment still faces challenges when it comes to drug resistance, survival improvement, and life quality preservation. The development of translational research alongside clinical trials remains essential to bridge treatment gaps while creating personalized therapies based on molecular and clinical tumor characteristics. Full article

Objectives: The objective of this single-site retrospective study was to assess the association between Computed Tomography (CT)-based whole-body composition values with dose reduction in patients with a diagnosis of epithelial ovarian cancer (EOC) treated with poly ADP-ribose polymerase (PARP) inhibitors (PARPi). Methods: Forty-eight patients (median age 61 years; interquartile range 53–68.5) with EOC who had a thorax and abdomen CT scan (performed before starting PARPi) were enrolled. Recorded clinical data included age, weight, height, stage, start and end date of PARPi, dose reduction, premature discontinuation of therapy, date of last contact, progression, and death. Body composition values were automatically extracted by dedicated software. Given the exploratory nature of the study, the statistical analysis combined univariate assessments (univariate logistic regression) used to evaluate the individual effect of each variable on the probability of dose reduction, with a classification tree approach—a data-driven machine learning method considering all variables simultaneously as covariates. This integrated strategy was designed to identify empirical cut-offs defining body composition profiles associated with increased risk of toxicity. Results: Univariate logistic regression showed no statistically significant effect of body composition variables on the probability of dose reduction. Due to the complexity of variable relations, a machine-learning approach with a classification tree showed that SKM (skeletal muscle) was the sole body composition variable significantly associated with dose reduction. Specifically, there was a higher risk of dose reduction with SKM values ≥ 7506 cm³ and < 8650 cm³ (p = 0.0118). Conclusions: In this exploratory study, a significant association of whole-body composition parameters (SKM) with dose reduction was observed in patients with a 7506 cm³ ≤ SKM < 8650 cm³. If confirmed in larger cohorts, these findings could help clinicians identify patients who might benefit from an upfront reduced PARPi dose. Full article

Homologous recombination deficiency (HRD) is a key biomarker associated with increased sensitivity to PARP inhibitors (PARPi) in advanced epithelial ovarian cancer. Accurate identification of HRD status is essential for selecting patients most likely to benefit from these therapies. Current diagnostic approaches combine sequencing to detect mutations in homologous recombination repair genes—particularly BRCA1 and BRCA2—with genome-wide analysis of structural genomic alterations indicative of HRD. This review briefly outlines the biological basis of HRD and its clinical significance and then focuses on currently available assays for HRD assessment. We compare their molecular strategies, including the use of targeted gene panels and genomic instability metrics such as loss of heterozygosity, telomeric allelic imbalance, and large-scale state transitions. The review also highlights the strengths and limitations of each platform and discusses their role in guiding clinical decision-making. Challenges related to dynamic tumor evolution and the interpretation of HRD status in recurrent disease settings are also addressed. Full article

Background: Approximately 25.0% of metastatic prostate cancer patients harbour DNA damage repair mutations, including BRCA1 and BRCA2, which are actionable targets for poly(ADP-ribose) polymerase (PARP) inhibitors. Accurate detection of BRCA1/2 mutations is critical for guiding targeted therapies, but crucial pre-analytical factors, such as tissue storage duration and DNA fragmentation, drastically affect the reliability of next-generation sequencing (NGS) using real-world diagnostic specimens. Methods: This multicentre study analysed 954 formalin-fixed paraffin-embedded tissue samples from 11 centres, including 559 biopsies and 395 surgical specimens. This study examined the impact of storage duration (<1 year, 1–2 years, and >2 years) and DNA parameters (concentration and fragmentation index) on NGS success rates. Logistic regression and Cox regression analyses were used to assess correlations between these factors and sequencing outcomes. Results: NGS success rates decreased significantly with longer storage, from 87.8% (<1 year) to 69.1% (>2 years). Samples with higher DNA concentrations and fragmentation indexes had higher success rates (p < 0.001). Surgical specimens had superior success rates (83.3%) compared with biopsies (72.8%) due to better DNA quality. The DNA degradation rate was more pronounced in older samples, underscoring the negative impact of extended storage. Conclusions: Timely testing of BRCA1/2 mutations is critical for optimizing the identification of prostate cancer patients eligible for PARP inhibitors. Surgical specimens provide more reliable results than biopsies and minimizing the storage duration significantly enhances testing outcomes. Standardizing pre-analytical and laboratory procedures across centres is essential to ensure personalized treatments and improve patient outcomes. Full article