Discovery of Ruthenium(II) Metallocompound and Olaparib Synergy for Cancer Combination Therapy.

Synergistic drug combinations can extend the use of poly(ADP-ribose) polymerase inhibitors (PARPi) such as Olaparib to BRCA-proficient tumors and overcome acquired or de novo drug resistance. To identify new synergistic combinations for PARPi, we screened a "micro-library" comprising a mix of commercially available drugs and DNA-binding ruthenium(II) polypyridyl complexes (RPCs) for Olaparib synergy in BRCA-proficient triple-negative breast cancer cells. This identified three hits: the natural product Curcumin and two ruthenium(II)-rhenium(I) polypyridyl metallomacrocycles. All combinations identified were effective in BRCA-proficient breast cancer cells, including an Olaparib-resistant cell line, and spheroid models. Mechanistic studies indicated that synergy was achieved via DNA-damage enhancement and resultant apoptosis. Combinations showed low cytotoxicity toward non-malignant breast epithelial cells and low acute and developmental toxicity in zebrafish embryos. This work identifies RPC metallomacrocycles as a novel class of agents for cancer combination therapy and provides a proof of concept for the inclusion of metallocompounds within drug synergy screens.

Hyperthermia synergistically enhances antitumor efficacy of PARP inhibitor through impacting homologous recombination repair and oxidative stress in vitro.

Tumors with homologous recombination (HR) deficiency are particularly responsive to PARP inhibitors, however strategies to improve the sensitivity of epithelial ovarian carcinoma (EOC) with sufficient HR abilities still need to be deeply explored. In the present study, we firstly validated that hyperthermia (HT) changed diverse genes and signal pathways related to HR and oxidative stress in HR proficient EOC cells. HT impaired HR efficiency through inhibiting Olaparib (Olap) induced RAD51 foci formation in EOC cells, which was independent of the expression level of RAD51. Combination therapy of HT and Olap synergistically induced oxidative stress and oxidative DNA damage of EOC cells. Furthermore, we revealed that HT and Olap synergistically aggravated double-strand breaks of DNA in EOC cells. Conclusively, our findings confirmed that HT could synergistically enhance HR proficient EOC cells' sensitivity to PARP inhibitor through impairing HR efficiency and increasing oxidative stress.

Olaparib: A Clinically Applied PARP Inhibitor Protects from Experimental Crohn's Disease and Maintains Barrier Integrity by Improving Bioenergetics through Rescuing Glycolysis in Colonic Epithelial Cells.

Crohn's disease (CD) is an inflammatory disorder of the intestines characterized by epithelial barrier dysfunction and mucosal damage. The activity of poly(ADP-ribose) polymerase-1 (PARP-1) is deeply involved in the pathomechanism of inflammation since it leads to energy depletion and mitochondrial failure in cells. Focusing on the epithelial barrier integrity and bioenergetics of epithelial cells, we investigated whether the clinically applied PARP inhibitor olaparib might improve experimental CD. We used the oral PARP inhibitor olaparib in the 2,4,6-trinitrobenzene sulfonic acid- (TNBS-) induced mouse colitis model. Inflammatory scoring, cytokine levels, colon histology, hematological analysis, and intestinal permeability were studied. Caco-2 monolayer culture was utilized as an epithelial barrier model, on which we used qPCR and light microscopy imaging, and measured impedance-based barrier integrity, FITC-dextran permeability, apoptosis, mitochondrial oxygen consumption rate, and extracellular acidification rate. Olaparib reduced the inflammation score, the concentration of IL-1ß and IL-6, enhanced the level of IL-10, and decreased the intestinal permeability in TNBS-colitis. Blood cell ratios, such as lymphocyte to monocyte ratio, platelet to lymphocyte ratio, and neutrophil to lymphocyte ratio were improved. In H2O2-treated Caco-2 monolayer, olaparib decreased morphological changes, barrier permeability, and preserved barrier integrity. In oxidative stress, olaparib enhanced glycolysis (extracellular acidification rate), and it improved mitochondrial function (mitochondrial coupling efficiency, maximal respiration, and spare respiratory capacity) in epithelial cells. Olaparib, a PARP inhibitor used in human cancer therapy, improved experimental CD and protected intestinal barrier integrity by preventing its energetic collapse; therefore, it could be repurposed for the therapy of Crohn's disease.

Discovery and biological evaluation of phthalazines as novel non-kinase TGFß pathway inhibitors.

TGFß is crucial for the homeostasis of epithelial and neural tissues, wound repair, and regulating immune responses. Its dysregulation is associated with a vast number of diseases, of which modifying the tumor microenvironment is one of vital clinical interest. Despite various attempts, there is still no FDA-approved therapy to inhibit the TGFß pathway. Major mainstream approaches involve impairment of the TGFß pathway via inhibition of the TGFßRI kinase. With the purpose to identify non-receptor kinase-based inhibitors to impair TGFß signaling, an in-house chemical library was enriched, through a computational study, to eliminate TGFßRI kinase activity. Selected compounds were screened against a cell line engineered with a firefly luciferase gene under TGFß-Smad-dependent transcriptional control. Results indicated moderate potency for a molecule with phthalazine core against TGFß-Smad signaling. A series of phthalazine compounds were synthesized and evaluated for potency. The most promising compound (10p) exhibited an IC50 of 0.11 ± 0.02 µM and was confirmed to be non-cytotoxic up to 12 µM, with a selectivity index of approximately 112-fold. Simultaneously, 10p was confirmed to reduce the Smad phosphorylation using Western blot without exhibiting inhibition on the TGFßRI enzyme. This study identified a novel small-molecule scaffold that targets the TGFß pathway via a non-receptor-kinase mechanism.

Olaparib-mediated enhancement of 5-fluorouracil cytotoxicity in mismatch repair deficient colorectal cancer cells.

BACKGROUND: The advances in colorectal cancer (CRC) treatment include the identification of deficiencies in Mismatch Repair (MMR) pathway to predict the benefit of adjuvant 5-fluorouracil (5-FU) and oxaliplatin for stage II CRC and immunotherapy. Defective MMR contributes to chemoresistance in CRC. A growing body of evidence supports the role of Poly-(ADP-ribose) polymerase (PARP) inhibitors, such as Olaparib, in the treatment of different subsets of cancer beyond the tumors with homologous recombination deficiencies. In this work we evaluated the effect of Olaparib on 5-FU cytotoxicity in MMR-deficient and proficient CRC cells and the mechanisms involved. METHODS: Human colon cancer cell lines, proficient (HT29) and deficient (HCT116) in MMR, were treated with 5-FU and Olaparib. Cytotoxicity was assessed by MTT and clonogenic assays, apoptosis induction and cell cycle progression by flow cytometry, DNA damage by comet assay. Adhesion and transwell migration assays were also performed. RESULTS: Our results showed enhancement of the 5-FU citotoxicity by Olaparib in MMR-deficient HCT116 colon cancer cells. Moreover, the combined treatment with Olaparib and 5-FU induced G2/M arrest, apoptosis and polyploidy in these cells. In MMR proficient HT29 cells, the Olaparib alone reduced clonogenic survival, induced DNA damage accumulation and decreased the adhesion and migration capacities. CONCLUSION: Our results suggest benefits of Olaparib inclusion in CRC treatment, as combination with 5-FU for MMR deficient CRC and as monotherapy for MMR proficient CRC. Thus, combined therapy with Olaparib could be a strategy to overcome 5-FU chemotherapeutic resistance in MMR-deficient CRC.

Identification of PARP-1 in cancer stem cells of gastrointestinal cancers: A preliminary study.

Advanced-stage gastrointestinal tumors have high mortality due to chemotherapy limitations. One of the causes of treatment failure is the presence of cancer stem cells (CSCs), which show resistance mechanisms against DNA damage, such as poly (adenosine diphosphate-ribose) polymerase 1 (PARP-1). However, little is known about the relevance of PARP-1 in these tumor cells. Our purpose is to analyze the expression of PARP-1 in cancer cells and CSCs from gastrointestinal tumors, its relationship with the DNA damage repair process and its modulation by cytotoxic and PARP-1 inhibitors. We used pancreatic, liver and colon cancer cell lines and isolated CSCs using Aldefluor technology to analyze PARP-1 expression. In addition, we examined the effect of classic cytotoxic drugs (Doxorubicin, Gemcitabine, Irinotecan and 5-Fluorouracil) and a PARP-1 inhibitor (Olaparib) in cultured cells and 3D tumorspheres. We demonstrated that PARP-1 is highly expressed in pancreatic, liver and colon tumor cells and that this expression was significantly higher in cell populations with CSC characteristics. In addition, Doxorubicin and Gemcitabine increased their cytotoxic effect when administered simultaneously with Olaparib, decreasing the formation of 3D tumorspheres. Our findings suggest that PARP-1 is a common and relevant resistance mechanism in CSCs from gastrointestinal tumors and that the use of PARP-1 inhibitors may be an adjuvant therapy to increase apoptosis in this type of cells which are responsible to cancer recurrence and metastasis.

Zebrafish as an in vivo screening tool to establish PARP inhibitor efficacy.

Double strand break (DSB) repair through Homologous Recombination (HR) is essential in maintaining genomic stability of the cell. Mutations in the HR pathway confer an increased risk for breast, ovarian, pancreatic and prostate cancer. PARP inhibitors (PARPi) are compounds that specifically target tumours deficient in HR. Novel PARPi are constantly being developed, but research is still heavily focussed on in vitro data, with mouse xenografts only being used in late stages of development. There is a need for assays that can: 1) provide in vivo data, 2) early in the development process of novel PARPi, 3) provide fast results and 4) at an affordable cost. Here we propose a combination of in vivo zebrafish assays to accurately quantify PARP inhibitor efficacy. We showed that PARPi display functional effects in zebrafish, generally correlating with their PARP trapping capacities. Furthermore, we displayed how olaparib mediated radiosensitization is conserved in our zebrafish model. These assays could aid the development of novel PARPi by providing early in vivo data. In addition, using zebrafish allows for high-throughput testing of combination therapies in search of novel treatment strategies.

Maraviroc, celastrol and azelastine alter Chlamydia trachomatis development in HeLa cells.

Introduction . Chlamydia trachomatis (Ct) is an obligate intracellular bacterium, causing a range of diseases in humans. Interactions between chlamydiae and antibiotics have been extensively studied in the past.Hypothesis/Gap statement: Chlamydial interactions with non-antibiotic drugs have received less attention and warrant further investigations. We hypothesized that selected cytokine inhibitors would alter Ct growth characteristics in HeLa cells.Aim. To investigate potential interactions between selected cytokine inhibitors and Ct development in vitro.Methodology. The CCR5 receptor antagonist maraviroc (Mara; clinically used as HIV treatment), the triterpenoid celastrol (Cel; used in traditional Chinese medicine) and the histamine H1 receptor antagonist azelastine (Az; clinically used to treat allergic rhinitis and conjunctivitis) were used in a genital in vitro model of Ct serovar E infecting human adenocarcinoma cells (HeLa).Results. Initial analyses revealed no cytotoxicity of Mara up to 20 µM, Cel up to 1 µM and Az up to 20 µM. Mara exposure (1, 5, 10 and 20 µM) elicited a reduction of chlamydial inclusion numbers, while 10 µM reduced chlamydial infectivity. Cel 1 µM, as well as 10 and 20 µM Az, reduced chlamydial inclusion size, number and infectivity. Morphological immunofluorescence and ultrastructural analysis indicated that exposure to 20 µM Az disrupted chlamydial inclusion structure. Immunofluorescence evaluation of Cel-incubated inclusions showed reduced inclusion sizes whilst Mara incubation had no effect on inclusion morphology. Recovery assays demonstrated incomplete recovery of chlamydial infectivity and formation of structures resembling typical chlamydial inclusions upon Az removal.Conclusion. These observations indicate that distinct mechanisms might be involved in potential interactions of the drugs evaluated herein and highlight the need for continued investigation of the interaction of commonly used drugs with Chlamydia and its host.

Olaparib for advanced breast cancer.

Olaparib, an oral PARP-inhibitor, has shown clinical benefit for HER2-negative advanced breast cancer patients carrying a germinal BRCA1/2 mutation. In a randomized Phase III trial, olaparib significantly prolonged progression-free survival as compared with chemotherapy of physician choice. Moreover, in the same trial, a prespecified subgroup analysis reported an overall survival benefit for patients not previously pretreated with chemotherapy for metastatic disease. This review focuses on available preclinical, pharmacokinetic and pharmacodynamic data regarding olaparib and clinical evidence of its antitumor efficacy (both as monotherapy and in combination) and tolerability in breast cancer patients. Open questions, such as use of appropriate biomarkers for patient selection and combination/sequencing with other anticancer drugs, are also addressed.

Pharmacological screening and transcriptomic functional analyses identify a synergistic interaction between dasatinib and olaparib in triple-negative breast cancer.

Identification of druggable vulnerabilities is a main objective in triple-negative breast cancer (TNBC), where no curative therapies exist. Gene set enrichment analyses (GSEA) and a pharmacological evaluation using a library of compounds were used to select potential druggable combinations. MTT and studies with semi-solid media were performed to explore the activity of the combinations. TNBC cell lines (MDAMB-231, BT549, HS-578T and HCC3153) and an additional panel of 16 cell lines were used to assess the activity of the two compounds. Flow cytometry experiments and biochemical studies were also performed to explore the mechanism of action. GSEA were performed using several data sets (GSE21422, GSE26910, GSE3744, GSE65194 and GSE42568), and more than 35 compounds against the identified functions were evaluated to discover druggable opportunities. Analyses done with the Chou and Talalay algorithm confirmed the synergy of dasatinib and olaparib. The combination of both agents significantly induced apoptosis in a caspase-dependent manner and revealed a pleotropic effect on cell cycle: Dasatinib arrested cells in G0/G1 and olaparib in G2/M. Dasatinib inhibited pChk1 and induced DNA damage measured by pH2AX, and olaparib increased pH3. Finally, the effect of the combination was also evaluated in a panel of 18 cell lines representative of the most frequent solid tumours, observing a particularly synergism in ovarian cancer. Breast cancer, triple negative, dasatinib, olaparib, screening.

Berberine attenuates XRCC1-mediated base excision repair and sensitizes breast cancer cells to the chemotherapeutic drugs.

Berberine (BBR) is a natural isoquinoline alkaloid, which is used in traditional medicine for its anti-microbial, anti-protozoal, anti-diarrhoeal activities. Berberine interacts with DNA and displays anti-cancer activities, yet its effects on cellular DNA repair and on synthetic treatments with chemotherapeutic drugs remain unclear. In this study, we investigated the effects of BBR on DNA repair and on sensitization of breast cancer cells to different types of DNA damage anti-tumoural drugs. We found BBR arrested cells in the cell cycle S phase and induced DNA breaks. Cell growth analysis showed BBR sensitized MDA-MB-231 cells to cisplatin, camptothecin and methyl methanesulfonate; however, BBR had no synergistic effects with hydroxurea and olaparib. These results suggest BBR only affects specific DNA repair pathways. Western blot showed BBR down-regulated XRCC1 expressions, and the rescued XRCC1 recovered the resistance of cancer cells to BBR. Therefore, we conclude that BBR interferes with XRCC1-mediated base excision repair to sensitize cancer cells to chemotherapeutic drugs. These finding can contribute to understanding the effects of BBR on cellular DNA repair and the clinical employment of BBR in treatment of breast cancer.

Fast dose fractionation using ultra-short laser accelerated proton pulses can increase cancer cell mortality, which relies on functional PARP1 protein.

Radiotherapy is a cornerstone of cancer management. The improvement of spatial dose distribution in the tumor volume by minimizing the dose deposited in the healthy tissues have been a major concern during the last decades. Temporal aspects of dose deposition are yet to be investigated. Laser-plasma-based particle accelerators are able to emit pulsed-proton beams at extremely high peak dose rates (~109 Gy/s) during several nanoseconds. The impact of such dose rates on resistant glioblastoma cell lines, SF763 and U87-MG, was compared to conventionally accelerated protons and X-rays. No difference was observed in DNA double-strand breaks generation and cells killing. The variation of the repetition rate of the proton bunches produced an oscillation of the radio-induced cell susceptibility in human colon carcinoma HCT116 cells, which appeared to be related to the presence of the PARP1 protein and an efficient parylation process. Interestingly, when laser-driven proton bunches were applied at 0.5 Hz, survival of the radioresistant HCT116 p53-/- cells equaled that of its radiosensitive counterpart, HCT116 WT, which was also similar to cells treated with the PARP1 inhibitor Olaparib. Altogether, these results suggest that the application modality of ultrashort bunches of particles could provide a great therapeutic potential in radiotherapy.

A new phthalazinone derivative and a new isoflavonoid glycoside from lichen-associated Amycolatopsis sp.

A new phthalazinone derivative, named amycophthalazinone A (1), and a new isoflavonoid glycoside, 7-O-methyl-5-O-α-L-rhamnopyranosylgenestein (2), along with an isoflavonoid glycoside, 7-O-α-D-arabinofuranosyl daidzein (3) firstly found from natural sources, and eight known compounds (4-11), were isolated from the culture broth of the lichen-associated Amycolatopsis sp. YIM 130642. The structures of new compounds were elucidated on the basis of spectroscopic analysis. Compound 1 was the first example of naturally occurring phthalazinone derivative. The antimicrobial activities of all compounds towards five pathogenic strains were evaluated by a broth microdilution assay. Compound 1 exhibited the most potent inhibitory activity against Staphylococcus aureus, Salmonella typhi, and Candida albicans with MIC values of 32, 32, and 64 µg/mL, respectively.

In vitro evaluation of the inhibition and induction potential of olaparib, a potent poly(ADP-ribose) polymerase inhibitor, on cytochrome P450.

1. In vitro studies were conducted to evaluate potential inhibitory and inductive effects of the poly(ADP-ribose) polymerase (PARP) inhibitor, olaparib, on cytochrome P450 (CYP) enzymes. Inhibitory effects were determined in human liver microsomes (HLM); inductive effects were evaluated in cultured human hepatocytes. 2. Olaparib did not inhibit CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2D6 or CYP2E1 and caused slight inhibition of CYP2C9, CYP2C19 and CYP3A4/5 in HLM up to a concentration of 100 µM. However, olaparib (17-500 µM) inhibited CYP3A4/5 with an IC50 of 119 µM. In time-dependent CYP inhibition assays, olaparib (10 µM) had no effect against CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6 and CYP2E1 and a minor effect against CYP3A4/5. In a further study, olaparib (2-200 µM) functioned as a time-dependent inhibitor of CYP3A4/5 (KI, 72.2 µM and Kinact, 0.0675 min-1). Assessment of the CYP induction potential of olaparib (0.061-44 µM) showed minor concentration-related increases in CYP1A2 and more marked increases in CYP2B6 and CYP3A4 mRNA, compared with positive control activity; however, no significant change in CYP3A4/5 enzyme activity was observed. 3. Clinically significant drug-drug interactions due to olaparib inhibition or induction of hepatic or intestinal CYP3A4/5 cannot be excluded. It is recommended that olaparib is given with caution with narrow therapeutic range or sensitive CYP3A substrates, and that prescribers are aware that olaparib may reduce exposure to substrates of CYP2B6.

A Novel Use of Olaparib for the Treatment of Metastatic Castration-Recurrent Prostate Cancer.

Although mortality from prostate cancer has declined over the past 20 years as a result of early detection and treatment, the 5-year survival rate for men with prostate cancer who develop metastatic disease is only 29%. Current treatment options for metastatic castration-recurrent prostate cancer (mCRPC) are associated with toxicity and a limited durable response; therefore, additional lines of efficacious and minimally toxic therapy are needed. Olaparib, a poly(adenosine 5'-diphosphate) ribose polymerase (PARP) inhibitor, received a U.S. Food and Drug Administration breakthrough therapy designation in January 2016 for the treatment of patients with BRCA1/2 or ATM gene-mutated mCRPC based on results of a compelling phase II trial of olaparib in patients with advanced castration-resistant prostate cancer (TOPARP-A). This study found that men with mCRPC and genetic mutations in DNA damage repair genes had an overall response rate of nearly 90% with olaparib treatment. In this review, we describe current therapies for mCRPC, the rationale for anti-PARP therapies, the pharmacology of olaparib for prostate cancer, clinical trials of olaparib for mCRPC, our clinical experience with olaparib for prostate cancer at a comprehensive cancer center, and future directions of olaparib for the treatment of mCRPC. Olaparib may constitute a promising treatment to prolong survival in patients with mCRPC, with an acceptable adverse effect profile. As the role of PARP inhibition in prostate cancer and other malignancies becomes further elucidated, olaparib may be shown to be beneficial for other patient populations.

Tyrosine Kinase Inhibitor, Vatalanib, Inhibits Proliferation and Migration of Human Pterygial Fibroblasts.

PURPOSE: Vatalanib is a small-molecule tyrosine kinase inhibitor. We investigated the effects of vatalanib on the proliferation and migration of cultured human pterygial fibroblasts (HPFs). METHODS: Pterygium tissues were obtained after pterygium excision surgery and subjected to primary culture. HPFs were treated with vatalanib at various concentrations. Mitomycin C (MMC) was used as a positive control. Cell proliferation and migration assays were used to investigate the effects of vatalanib. Cell death was measured using flow cytometry analysis. Western blot analysis was performed to identify signaling molecules associated with the response to vatalanib. RESULTS: Vatalanib inhibited both proliferation and migration of HPFs in a dose-dependent manner. Cell proliferation was significantly suppressed by vatalanib (10 and 100 µM) and MMC (0.004% and 0.04%) treatments. Migration assays revealed significant HPF delay when treated with vatalanib (1, 10, and 100 µM) and MMC (0.004% and 0.04%) compared with that in a negative control. Cell death analysis showed that high concentrations of vatalanib (100 µM) and MMC (0.004% and 0.04%) decreased cell numbers. Western blot analysis of vatalanib-treated cells showed vascular endothelial growth factor and transforming growth factor-ß significantly reduced, but there was no alteration in p53 protein levels in HPFs. CONCLUSIONS: These results indicate that vatalanib significantly suppressed the proliferation and migration of HPFs by decreasing vascular endothelial growth factor and transforming growth factor-ß. Vatalanib showed less toxicity than that of MMC. Based on these results, vatalanib may potentially serve as a new adjuvant treatment after pterygium excision surgery.

Inhibiting poly ADP-ribosylation increases fatty acid oxidation and protects against fatty liver disease.

BACKGROUND & AIMS: To date, no pharmacological therapy has been approved for non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to evaluate the therapeutic potential of poly ADP-ribose polymerase (PARP) inhibitors in mouse models of NAFLD. METHODS: As poly ADP-ribosylation (PARylation) of proteins by PARPs consumes nicotinamide adenine dinucleotide (NAD+), we hypothesized that overactivation of PARPs drives NAD+ depletion in NAFLD. Therefore, we assessed the effectiveness of PARP inhibition to replenish NAD+ and activate NAD+-dependent sirtuins, hence improving hepatic fatty acid oxidation. To do this, we examined the preventive and therapeutic benefits of the PARP inhibitor (PARPi), olaparib, in different models of NAFLD. RESULTS: The induction of NAFLD in C57BL/6J mice using a high-fat high-sucrose (HFHS)-diet increased PARylation of proteins by PARPs. As such, increased PARylation was associated with reduced NAD+ levels and mitochondrial function and content, which was concurrent with elevated hepatic lipid content. HFHS diet supplemented with PARPi reversed NAFLD through repletion of NAD+, increasing mitochondrial biogenesis and ß-oxidation in liver. Furthermore, PARPi reduced reactive oxygen species, endoplasmic reticulum stress and fibrosis. The benefits of PARPi treatment were confirmed in mice fed with a methionine- and choline-deficient diet and in mice with lipopolysaccharide-induced hepatitis; PARP activation was attenuated and the development of hepatic injury was delayed in both models. Using Sirt1hep-/- mice, the beneficial effects of a PARPi-supplemented HFHS diet were found to be Sirt1-dependent. CONCLUSIONS: Our study provides a novel and practical pharmacological approach for treating NAFLD, fueling optimism for potential clinical studies. LAY SUMMARY: Non-alcoholic fatty liver disease (NAFLD) is now considered to be the most common liver disease in the Western world and has no approved pharmacological therapy. PARP inhibitors given as a treatment in two different mouse models of NAFLD confer a protection against its development. PARP inhibitors may therefore represent a novel and practical pharmacological approach for treating NAFLD.

Antioxidant activities of curcumin in allergic rhinitis.

We investigated the antioxidant effects of curcumin in an experimental rat model of allergic rhinitis (AR). Female Wistar albino rats (n = 34) were divided randomly into four groups: healthy rats (control group, n = 8), AR with no treatment (AR + NoTr group, n = 10), AR with azelastine HCl treatment (AR + Aze group, n = 8), and AR with curcumin treatment (AR + Curc group, n = 8). On day 28, total blood IgE levels were measured. For measurement of antioxidant activity, the glutathione (GSH) level and catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activities were measured in both inferior turbinate tissue and serum. Malondialdehyde (MDA) levels were measured only in inferior turbinate tissue, and paraoxonase (PON) and arylesterase (ARE) activities were measured only in serum. Statistically significant differences were found for all antioxidant measurements (GSH levels and CAT, SOD, GSH-Px activities in the serum and tissue, MDA levels in the tissue, and PON and ARE activities in the serum) between the four groups. In the curcumin group, serum SOD, ARE, and PON and tissue GSH values were higher than the control group. Moreover, tissue GSH levels and serum GSH-Px activities in the curcumin group were higher than in the AR + NoTr group. In the azelastine group, except MDA, antioxidant measurement values were lower than in the other groups. Curcumin may help to increase antioxidant enzymes and decrease oxidative stress in allergic rhinitis. We recommend curcumin to decrease oxidative stress in allergic rhinitis.

Discovery of AZ0108, an orally bioavailable phthalazinone PARP inhibitor that blocks centrosome clustering.

The propensity for cancer cells to accumulate additional centrosomes relative to normal cells could be exploited for therapeutic benefit in oncology. Following literature reports that suggested TNKS1 (tankyrase 1) and PARP16 may be involved with spindle structure and function and may play a role in suppressing multi-polar spindle formation in cells with supernumerary centrosomes, we initiated a phenotypic screen to look for small molecule poly (ADP-ribose) polymerase (PARP) enzyme family inhibitors that could produce a multi-polar spindle phenotype via declustering of centrosomes. Screening of AstraZeneca's collection of phthalazinone PARP inhibitors in HeLa cells using high-content screening techniques identified several compounds that produced a multi-polar spindle phenotype at low nanomolar concentrations. Characterization of these compounds across a broad panel of PARP family enzyme assays indicated that they had activity against several PARP family enzymes, including PARP1, 2, 3, 5a, 5b, and 6. Further optimization of these initial hits for improved declustering potency, solubility, permeability, and oral bioavailability resulted in AZ0108, a PARP1, 2, 6 inhibitor that potently inhibits centrosome clustering and is suitable for in vivo efficacy and tolerability studies.

In vivo studies of the PARP inhibitor, AZD-2281, in combination with fractionated radiotherapy: An exploration of the therapeutic ratio.

BACKGROUND AND PURPOSE: Pre-clinical data have shown that PARP inhibitors (PARPi) may increase the efficacy of radiotherapy in prostate cancer. However, it is uncertain as to whether PARPi lead to clonogenic kill when combined with radiotherapy (RT). MATERIAL AND METHODS: We tested the PARP inhibitor AZD-2281 as a radiosensitizing agent under oxic and hypoxic conditions for clonogenic survival in vitro and in vivo using the human prostate cancer cell line, 22Rv1. In addition, the effects of PARPi+RT on normal tissue were investigated using a crypt clonogenic assay. RESULTS: AZD-2281 inhibited cellular PARP activity under both oxic and hypoxic conditions. The addition of AZD-2281 radiosensitized 22Rv1 cells under oxia, acute hypoxia and chronic hypoxia in vitro. The combination of AZD-2281 with fractionated radiotherapy resulted in a significant growth delay and clonogenic kill in vivo. No increased gut toxicity was observed using this combined PARPi+radiotherapy regimen. CONCLUSIONS: This is the first preclinical study to demonstrate direct clonogenic kill in vivo by the addition of AZD-2281 to radiotherapy. As we did not observe gut toxicity, the use of PARPi in the context of prostate cancer radiotherapy warrants further investigation in clinical trials.