Results: 36 patients fit the inclusion criteria. Gross ascites wasthe clinical parameter found to... more Results: 36 patients fit the inclusion criteria. Gross ascites wasthe clinical parameter found to be associated with suboptimal debulking. CT scan had low sensitivity (35-53%) in diagnosing small bowel mesenteric and porta hepatis disease and high sensitivity in diagnosing diffuse peritoneal thickening, omental disease, diaphragmatic and nodal disease. On univariate analysis diffuse peritoneal thickening and small bowel serosa and mesenteric disease were significantly consistent with sub optimal debulking. Conclusion: Finding out disease at the sites which are associated with suboptimal debulking (diffuse peritoneal thickening, smallbowel mesenteric and serosal disease) pre operatively or at the beginning of surgery can predict optimal debulking and can help avoid un necessary surgery.
Purpose: Therapy resistance and associated liver disease make hepatocellular carcinomas (HCC) dif... more Purpose: Therapy resistance and associated liver disease make hepatocellular carcinomas (HCC) difficult to treat with traditional cytotoxic therapies, whereas newer targeted approaches offer only modest survival benefit. We focused on DNA-dependent protein kinase, DNA-PKcs, encoded by PRKDC and central to DNA damage repair by nonhomologous end joining. Our aim was to explore its roles in hepatocarcinogenesis and as a novel therapeutic candidate. Experimental Design: PRKDC was characterized in liver tissues from of 132 patients [normal liver (n ¼ 10), cirrhotic liver (n ¼ 13), dysplastic nodules (n ¼ 18), HCC (n ¼ 91)] using Affymetrix U133 Plus 2.0 and 500 K Human Mapping SNP arrays (cohort 1). In addition, we studied a case series of 45 patients with HCC undergoing diagnostic biopsy (cohort 2). Histological grading, response to treatment, and survival were correlated with DNA-PKcs quantified immunohistochemically. Parallel in vitro studies determined the impact of DNA-PK on DNA repair and response to cytotoxic therapy. Results: Increased PRKDC expression in HCC was associated with amplification of its genetic locus in cohort 1. In cohort 2, elevated DNA-PKcs identified patients with treatment-resistant HCC, progressing at a median of 4.5 months compared with 16.9 months, whereas elevation of activated pDNA-PK independently predicted poorer survival. DNA-PKcs was high in HCC cell lines, where its inhibition with NU7441 potentiated irradiation and doxorubicin-induced cytotoxicity, whereas the combination suppressed HCC growth in vitro and in vivo. Conclusions: These data identify PRKDC/DNA-PKcs as a candidate driver of hepatocarcinogenesis, whose biopsy characterization at diagnosis may impact stratification of current therapies, and whose specific future targeting may overcome resistance. Clin Cancer Res; 21(4); 925-33. Ó2014 AACR.
Background: Hypoxia is observed in many aggressive solid organ malignancies and has been associat... more Background: Hypoxia is observed in many aggressive solid organ malignancies and has been associated with poor survival and resistance to chemoradiotherapy. Hypoxia-inducible factor 1 alpha (HIF-1α), which is expressed in hypoxic tissues, is detected in most ovarian cancer but alone does not predict response. Expression of DNA repair proteins are also under investigation as potential predictive biomarkers. It is crucial to determine the extent to which intra-operative and postoperative sample collection methods impact on ischemia, and hence HIF-1α, and other biomarkers for successful stratification of targeted therapies. Method: Tumour samples from patients undergoing surgery for ovarian cancer were harvested and sections were fixed in formalin or snap frozen immediately and after 30, 60 and 120 minutes. Nude mice bearing human tumour xenografts were culled and the tumours excised and snap frozen at the same time intervals. Frozen samples were pulverised and homogenised with Phosphosafe (Millipore Sigma) and protease inhibitors. Protein expression was analysed by Western Blotting. Protein expression in a TMA of the FFPE samples was determined by IHC. Results: Xenograft samples demonstrate a time-dependent increase in HIF1-α at 60 minutes with no changes in DNA repair proteins levels (PARP1, RAD51, DNAPKcs, phosphorylated DNAPKcs) by Western blot. Despite standardisation of sample collection intra-operatively there was significant variability in baseline expression of HIF1-α in patient samples as well as changes in expression with ischaemic time. Expression of DNA repair proteins showed highly variable time-related changes. Conclusion: Variable pre-analytical sample handling may result in substantial effects upon tissue hypoxia and DNA repair biomarker expression. Pre-existing patient factors and overall differences within the tumour specimens collected intra-operatively, as well as sample collection and processing, may contribute to the highly variable results observed in this pilot study. Studies are ongoing to optimise sample collection and improve reproducibility and standardisation of future biomarker studies.
White Rose Research Online (University of Leeds), 2015
This is a repository copy of Does tumour: stroma ratio have prognostic significance in endometria... more This is a repository copy of Does tumour: stroma ratio have prognostic significance in endometrial adenocarcinoma?.
Antifolates have been used to treat cancer for the last 50 years and remain the mainstay of many ... more Antifolates have been used to treat cancer for the last 50 years and remain the mainstay of many therapeutic regimes. Nucleoside salvage, which depends on plasma membrane transport, can compromise the activity of antifolates. The cardiovascular drug dipyridamole inhibits nucleoside transport and enhances antifolate cytotoxicity in vitro, but its clinical activity is compromised by binding to the plasma protein α 1-acid glycoprotein (AGP). We report the development of a novel pyrimidopyrimidine analogue of dipyridamole, NU3153, which has equivalent potency to dipyridamole, remains active in the presence of physiologic levels of AGP, inhibits thymidine incorporation into DNA, and prevents thymidine and hypoxanthine rescue from the multitargeted antifolate, pemetrexed. Pharmacokinetic evaluation of NU3153 suggested that a soluble prodrug would improve the in vivo activity. The valine prodrug of NU3153, NU3166, rapidly broke down to NU3153 in vitro and in vivo. Plasma NU3153 concentrations commensurate with rescue inhibition in vitro were maintained for at least 16 hours following administration of NU3166 to mice at 120 mg/kg. However, maximum inhibition of thymidine incorporation into tumors was only 50%, which was insufficient to enhance pemetrexed antitumor activity in vivo. Comparison with the cell-based studies revealed that pemetrexed enhancement requires substantial (≥90%) and durable inhibition of nucleoside transport. In conclusion, we have developed non-AGP binding nucleoside transport inhibitors. Pharmacologically active concentrations of the inhibitors can be achieved in vivo using prodrug approaches, but greater potency is required to evaluate inhibition of nucleoside rescue as a therapeutic maneuver. [
International Journal of Gynecological Cancer, Jul 1, 2016
This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License New... more This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License Newcastle University ePrints-eprint.ncl.ac.uk
Purpose: Therapy resistance and associated liver disease make hepatocellular carcinomas (HCC) dif... more Purpose: Therapy resistance and associated liver disease make hepatocellular carcinomas (HCC) difficult to treat with traditional cytotoxic therapies, whereas newer targeted approaches offer only modest survival benefit. We focused on DNA-dependent protein kinase, DNA-PKcs, encoded by PRKDC and central to DNA damage repair by nonhomologous end joining. Our aim was to explore its roles in hepatocarcinogenesis and as a novel therapeutic candidate. Experimental Design: PRKDC was characterized in liver tissues from of 132 patients [normal liver (n ¼ 10), cirrhotic liver (n ¼ 13), dysplastic nodules (n ¼ 18), HCC (n ¼ 91)] using Affymetrix U133 Plus 2.0 and 500 K Human Mapping SNP arrays (cohort 1). In addition, we studied a case series of 45 patients with HCC undergoing diagnostic biopsy (cohort 2). Histological grading, response to treatment, and survival were correlated with DNA-PKcs quantified immunohistochemically. Parallel in vitro studies determined the impact of DNA-PK on DNA repair and response to cytotoxic therapy. Results: Increased PRKDC expression in HCC was associated with amplification of its genetic locus in cohort 1. In cohort 2, elevated DNA-PKcs identified patients with treatment-resistant HCC, progressing at a median of 4.5 months compared with 16.9 months, whereas elevation of activated pDNA-PK independently predicted poorer survival. DNA-PKcs was high in HCC cell lines, where its inhibition with NU7441 potentiated irradiation and doxorubicin-induced cytotoxicity, whereas the combination suppressed HCC growth in vitro and in vivo. Conclusions: These data identify PRKDC/DNA-PKcs as a candidate driver of hepatocarcinogenesis, whose biopsy characterization at diagnosis may impact stratification of current therapies, and whose specific future targeting may overcome resistance. Clin Cancer Res; 21(4); 925-33. Ó2014 AACR.
SUPPLEMENTARY DATA Supplementary Figure S1: Talazoparib inhibition of PBMC PARP activity. The cha... more SUPPLEMENTARY DATA Supplementary Figure S1: Talazoparib inhibition of PBMC PARP activity. The change in percentage baseline PBMC PARP activity during cycle 1 of Part 1 is presented in the Figure below. During the single-dose assessment period, onset of inhibition was rapid (by the 2hour postdose assessment) and persisted through at least cycle 1 day 2, or approximately 24 hours postdose (data not shown). During the multiple-dose assessment period, consistent PARP inhibition was observed in all but one patient at dose levels 0.6 mg/day and above. During the washout period following dosing on day 35, PARP inhibition persisted in all patients at 0.6 mg/day and above through 24 hours postdose and in many patients through 96 hours postdose. Abbreviations: PARP, poly(ADP-ribose) polymerase; PBMC, peripheral blood mononuclear cell.
Neoadjuvant chemotherapy (NACT) has been known to induce genomic and transcriptomic alterations w... more Neoadjuvant chemotherapy (NACT) has been known to induce genomic and transcriptomic alterations within tumours. Here, using transcriptome profiling along with histological analysis of pre and post NACT, we show temporal and disease site-specific differences (omentum, ovary and other sites) in high grade serous ovarian cancer (HGSOC) and their association with progression free and overall survival. We observed a significant reduction in genome instability signature score following NACT irrespective of disease site, which correlated with homologous recombination repair (HRR) function measured by RAD51 foci formation. However, increase in immuno-oncology and inflammation signatures was only observed in the omentum and not in the ovary post-NACT. DNA damage immune response (DDIR) along with HRR function were strongly associated with CD8+ T-cell infiltration within tumours. Our study provides transcriptomic and phenotypic data highlighting the heterogeneity in HGSOCs during the course of...
PDF file - 103K, HR status and correlation with ex vivo cytotoxicity to PARP inhibitors. A, schem... more PDF file - 103K, HR status and correlation with ex vivo cytotoxicity to PARP inhibitors. A, schema outlining study demontrating tight correlation between HR deficiency and sensitivity to PARP inhibitor for both epithelial EOCs and other HRD cancers b, bar graph showing increase in RAD51 foci formation compared to untreated control and cell survival following PARP treatment for each individual primary culture. Cultures demonstrating high levels of RAD51 foci (HR competent) showed highest levels of cell survival following treatment.
PDF file - 62K, RAD51 foci and ex vivo cytotocicity in HR competent and HR deficient primary cult... more PDF file - 62K, RAD51 foci and ex vivo cytotocicity in HR competent and HR deficient primary cultures A. Box plot showing cytotoxicity to 10 muM rucaparib B. Box plot showing RAD51 foci formation after 24 hr exposure to rucaparib or hydroxyurea C. Scatter plot showing the level of RAD51 foci and cytotoxicity to 10 muM rucaparib in individual primary cultures- HR competent cultures showed >_ 200% RAD51 foci formation and >70% cell survival in ex vivo cytotocity assays.
Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 virus, is a major global health challen... more Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 virus, is a major global health challenge, as there is no efficient treatment for the moderate to severe disease. ADP-ribosylation events are involved in regulating the life cycle of coronaviruses and the inflammatory reactions of the host, hence we assessed the repurposing of registered PARP inhibitors for the treatment of COVID-19. We detected high levels of oxidative stress and strong PARylation in all cell types in the lungs of COVID-19 patients. Interestingly, rucaparib, unlike other PARP inhibitors, reduced SARS-CoV-2 infection rate through binding to the conserved 493-498 amino acid region located in the spike-ACE2 interface in the spike protein and prevented viruses from binding to ACE2. In addition, the spike protein-induced overexpression of IL-6, a key cytokine in COVID-19, was inhibited by rucaparib at pharmacologically relevant concentrations. These findings build a case for repurposing rucaparib for treating COV...
4999 Enzyme-mediated repair of DNA double-strand breaks (DSBs) is a major mechanism of resistance... more 4999 Enzyme-mediated repair of DNA double-strand breaks (DSBs) is a major mechanism of resistance to both ionizing radiation (IR) and drugs that cause DSBs as intermediates in repair processes. The major DNA DSB repair pathway in eukaryotes is nonhomologous end joining. An important component in this repair pathway is the DNA-dependent protein kinase (DNA-PK), whose catalytic subunit is a member of the phosphatidylinositol 3-kinase (PI 3-K)-related protein kinase (PIKK) family of enzymes. DNA-PK deficient cells are hypersensitive to IR and some DNA-damaging anticancer drugs, and inhibition of DNA-PK therefore represents a potential strategy for radio- and chemo-sensitization. NU7441 is a competitive and highly selective inhibitor of DNA-PK (IC 50 = 14 nM). The cellular specificity of NU7441 for DNA-PK was studied in V3 and V3-YAC cells, deficient and proficient in DNA-PK respectively. V3 cells were inherently more sensitive to IR and etoposide than V3-YAC cells and NU7441 increased ...
The clinical beliefs (expectations and demands) of veterinarians regarding herd-level strategies ... more The clinical beliefs (expectations and demands) of veterinarians regarding herd-level strategies to control mastitis, lameness, and Johne's disease were quantified in a numerical format; 94 veterinarians working in England (UK) were randomly selected and, during interviews, a statistical technique called probabilistic elicitation was used to capture their clinical expectations as probability distributions. The results revealed that markedly different clinical expectations existed for all 3 diseases, and many pairs of veterinarians had expectations with nonoverlapping 95% Bayesian credible intervals. For example, for a 3-yr lameness intervention, the most pessimistic veterinarian was centered at an 11% population mean reduction in lameness prevalence (95% credible interval: 0-21%); the most enthusiastic veterinarian was centered at a 58% reduction (95% credible interval: 38-78%). This suggests that a major change in beliefs would be required to achieve clinical agreement. Veterinarians' clinical expectations were used as priors in Bayesian models where they were combined with synthetic data (from randomized clinical trials of different sizes) to explore the effect of new evidence on current clinical opinion. The mathematical models make predictions based on the assumption that veterinarians will update their beliefs logically. For example, for the lameness intervention, a 200-farm clinical trial that estimated a 30% mean reduction in lameness prevalence was predicted to be reasonably convincing to the most pessimist veterinarian; that is, in light of this data, they were predicted to believe there would be a 0.92 probability of exceeding the median clinical demand of this sample of veterinarians, which was a 20% mean reduction in lameness. Currently, controversy exists over the extent to which veterinarians update their beliefs logically, and further research on this is needed. This study has demonstrated that probabilistic elicitation and a Bayesian framework are useful for evaluating the diversity and strength of veterinarians' clinical beliefs. The wide variations observed have implications for designing future projects. Although many factors influence disease control, nonetheless the heterogeneity in beliefs also raises concern over the extent to which a broadly consistent approach is currently being achieved; it supports the argument for more randomized clinical trials and for national programs to control nonstatutory endemic diseases.
Results: 36 patients fit the inclusion criteria. Gross ascites wasthe clinical parameter found to... more Results: 36 patients fit the inclusion criteria. Gross ascites wasthe clinical parameter found to be associated with suboptimal debulking. CT scan had low sensitivity (35-53%) in diagnosing small bowel mesenteric and porta hepatis disease and high sensitivity in diagnosing diffuse peritoneal thickening, omental disease, diaphragmatic and nodal disease. On univariate analysis diffuse peritoneal thickening and small bowel serosa and mesenteric disease were significantly consistent with sub optimal debulking. Conclusion: Finding out disease at the sites which are associated with suboptimal debulking (diffuse peritoneal thickening, smallbowel mesenteric and serosal disease) pre operatively or at the beginning of surgery can predict optimal debulking and can help avoid un necessary surgery.
Purpose: Therapy resistance and associated liver disease make hepatocellular carcinomas (HCC) dif... more Purpose: Therapy resistance and associated liver disease make hepatocellular carcinomas (HCC) difficult to treat with traditional cytotoxic therapies, whereas newer targeted approaches offer only modest survival benefit. We focused on DNA-dependent protein kinase, DNA-PKcs, encoded by PRKDC and central to DNA damage repair by nonhomologous end joining. Our aim was to explore its roles in hepatocarcinogenesis and as a novel therapeutic candidate. Experimental Design: PRKDC was characterized in liver tissues from of 132 patients [normal liver (n ¼ 10), cirrhotic liver (n ¼ 13), dysplastic nodules (n ¼ 18), HCC (n ¼ 91)] using Affymetrix U133 Plus 2.0 and 500 K Human Mapping SNP arrays (cohort 1). In addition, we studied a case series of 45 patients with HCC undergoing diagnostic biopsy (cohort 2). Histological grading, response to treatment, and survival were correlated with DNA-PKcs quantified immunohistochemically. Parallel in vitro studies determined the impact of DNA-PK on DNA repair and response to cytotoxic therapy. Results: Increased PRKDC expression in HCC was associated with amplification of its genetic locus in cohort 1. In cohort 2, elevated DNA-PKcs identified patients with treatment-resistant HCC, progressing at a median of 4.5 months compared with 16.9 months, whereas elevation of activated pDNA-PK independently predicted poorer survival. DNA-PKcs was high in HCC cell lines, where its inhibition with NU7441 potentiated irradiation and doxorubicin-induced cytotoxicity, whereas the combination suppressed HCC growth in vitro and in vivo. Conclusions: These data identify PRKDC/DNA-PKcs as a candidate driver of hepatocarcinogenesis, whose biopsy characterization at diagnosis may impact stratification of current therapies, and whose specific future targeting may overcome resistance. Clin Cancer Res; 21(4); 925-33. Ó2014 AACR.
Background: Hypoxia is observed in many aggressive solid organ malignancies and has been associat... more Background: Hypoxia is observed in many aggressive solid organ malignancies and has been associated with poor survival and resistance to chemoradiotherapy. Hypoxia-inducible factor 1 alpha (HIF-1α), which is expressed in hypoxic tissues, is detected in most ovarian cancer but alone does not predict response. Expression of DNA repair proteins are also under investigation as potential predictive biomarkers. It is crucial to determine the extent to which intra-operative and postoperative sample collection methods impact on ischemia, and hence HIF-1α, and other biomarkers for successful stratification of targeted therapies. Method: Tumour samples from patients undergoing surgery for ovarian cancer were harvested and sections were fixed in formalin or snap frozen immediately and after 30, 60 and 120 minutes. Nude mice bearing human tumour xenografts were culled and the tumours excised and snap frozen at the same time intervals. Frozen samples were pulverised and homogenised with Phosphosafe (Millipore Sigma) and protease inhibitors. Protein expression was analysed by Western Blotting. Protein expression in a TMA of the FFPE samples was determined by IHC. Results: Xenograft samples demonstrate a time-dependent increase in HIF1-α at 60 minutes with no changes in DNA repair proteins levels (PARP1, RAD51, DNAPKcs, phosphorylated DNAPKcs) by Western blot. Despite standardisation of sample collection intra-operatively there was significant variability in baseline expression of HIF1-α in patient samples as well as changes in expression with ischaemic time. Expression of DNA repair proteins showed highly variable time-related changes. Conclusion: Variable pre-analytical sample handling may result in substantial effects upon tissue hypoxia and DNA repair biomarker expression. Pre-existing patient factors and overall differences within the tumour specimens collected intra-operatively, as well as sample collection and processing, may contribute to the highly variable results observed in this pilot study. Studies are ongoing to optimise sample collection and improve reproducibility and standardisation of future biomarker studies.
White Rose Research Online (University of Leeds), 2015
This is a repository copy of Does tumour: stroma ratio have prognostic significance in endometria... more This is a repository copy of Does tumour: stroma ratio have prognostic significance in endometrial adenocarcinoma?.
Antifolates have been used to treat cancer for the last 50 years and remain the mainstay of many ... more Antifolates have been used to treat cancer for the last 50 years and remain the mainstay of many therapeutic regimes. Nucleoside salvage, which depends on plasma membrane transport, can compromise the activity of antifolates. The cardiovascular drug dipyridamole inhibits nucleoside transport and enhances antifolate cytotoxicity in vitro, but its clinical activity is compromised by binding to the plasma protein α 1-acid glycoprotein (AGP). We report the development of a novel pyrimidopyrimidine analogue of dipyridamole, NU3153, which has equivalent potency to dipyridamole, remains active in the presence of physiologic levels of AGP, inhibits thymidine incorporation into DNA, and prevents thymidine and hypoxanthine rescue from the multitargeted antifolate, pemetrexed. Pharmacokinetic evaluation of NU3153 suggested that a soluble prodrug would improve the in vivo activity. The valine prodrug of NU3153, NU3166, rapidly broke down to NU3153 in vitro and in vivo. Plasma NU3153 concentrations commensurate with rescue inhibition in vitro were maintained for at least 16 hours following administration of NU3166 to mice at 120 mg/kg. However, maximum inhibition of thymidine incorporation into tumors was only 50%, which was insufficient to enhance pemetrexed antitumor activity in vivo. Comparison with the cell-based studies revealed that pemetrexed enhancement requires substantial (≥90%) and durable inhibition of nucleoside transport. In conclusion, we have developed non-AGP binding nucleoside transport inhibitors. Pharmacologically active concentrations of the inhibitors can be achieved in vivo using prodrug approaches, but greater potency is required to evaluate inhibition of nucleoside rescue as a therapeutic maneuver. [
International Journal of Gynecological Cancer, Jul 1, 2016
This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License New... more This work is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License Newcastle University ePrints-eprint.ncl.ac.uk
Purpose: Therapy resistance and associated liver disease make hepatocellular carcinomas (HCC) dif... more Purpose: Therapy resistance and associated liver disease make hepatocellular carcinomas (HCC) difficult to treat with traditional cytotoxic therapies, whereas newer targeted approaches offer only modest survival benefit. We focused on DNA-dependent protein kinase, DNA-PKcs, encoded by PRKDC and central to DNA damage repair by nonhomologous end joining. Our aim was to explore its roles in hepatocarcinogenesis and as a novel therapeutic candidate. Experimental Design: PRKDC was characterized in liver tissues from of 132 patients [normal liver (n ¼ 10), cirrhotic liver (n ¼ 13), dysplastic nodules (n ¼ 18), HCC (n ¼ 91)] using Affymetrix U133 Plus 2.0 and 500 K Human Mapping SNP arrays (cohort 1). In addition, we studied a case series of 45 patients with HCC undergoing diagnostic biopsy (cohort 2). Histological grading, response to treatment, and survival were correlated with DNA-PKcs quantified immunohistochemically. Parallel in vitro studies determined the impact of DNA-PK on DNA repair and response to cytotoxic therapy. Results: Increased PRKDC expression in HCC was associated with amplification of its genetic locus in cohort 1. In cohort 2, elevated DNA-PKcs identified patients with treatment-resistant HCC, progressing at a median of 4.5 months compared with 16.9 months, whereas elevation of activated pDNA-PK independently predicted poorer survival. DNA-PKcs was high in HCC cell lines, where its inhibition with NU7441 potentiated irradiation and doxorubicin-induced cytotoxicity, whereas the combination suppressed HCC growth in vitro and in vivo. Conclusions: These data identify PRKDC/DNA-PKcs as a candidate driver of hepatocarcinogenesis, whose biopsy characterization at diagnosis may impact stratification of current therapies, and whose specific future targeting may overcome resistance. Clin Cancer Res; 21(4); 925-33. Ó2014 AACR.
SUPPLEMENTARY DATA Supplementary Figure S1: Talazoparib inhibition of PBMC PARP activity. The cha... more SUPPLEMENTARY DATA Supplementary Figure S1: Talazoparib inhibition of PBMC PARP activity. The change in percentage baseline PBMC PARP activity during cycle 1 of Part 1 is presented in the Figure below. During the single-dose assessment period, onset of inhibition was rapid (by the 2hour postdose assessment) and persisted through at least cycle 1 day 2, or approximately 24 hours postdose (data not shown). During the multiple-dose assessment period, consistent PARP inhibition was observed in all but one patient at dose levels 0.6 mg/day and above. During the washout period following dosing on day 35, PARP inhibition persisted in all patients at 0.6 mg/day and above through 24 hours postdose and in many patients through 96 hours postdose. Abbreviations: PARP, poly(ADP-ribose) polymerase; PBMC, peripheral blood mononuclear cell.
Neoadjuvant chemotherapy (NACT) has been known to induce genomic and transcriptomic alterations w... more Neoadjuvant chemotherapy (NACT) has been known to induce genomic and transcriptomic alterations within tumours. Here, using transcriptome profiling along with histological analysis of pre and post NACT, we show temporal and disease site-specific differences (omentum, ovary and other sites) in high grade serous ovarian cancer (HGSOC) and their association with progression free and overall survival. We observed a significant reduction in genome instability signature score following NACT irrespective of disease site, which correlated with homologous recombination repair (HRR) function measured by RAD51 foci formation. However, increase in immuno-oncology and inflammation signatures was only observed in the omentum and not in the ovary post-NACT. DNA damage immune response (DDIR) along with HRR function were strongly associated with CD8+ T-cell infiltration within tumours. Our study provides transcriptomic and phenotypic data highlighting the heterogeneity in HGSOCs during the course of...
PDF file - 103K, HR status and correlation with ex vivo cytotoxicity to PARP inhibitors. A, schem... more PDF file - 103K, HR status and correlation with ex vivo cytotoxicity to PARP inhibitors. A, schema outlining study demontrating tight correlation between HR deficiency and sensitivity to PARP inhibitor for both epithelial EOCs and other HRD cancers b, bar graph showing increase in RAD51 foci formation compared to untreated control and cell survival following PARP treatment for each individual primary culture. Cultures demonstrating high levels of RAD51 foci (HR competent) showed highest levels of cell survival following treatment.
PDF file - 62K, RAD51 foci and ex vivo cytotocicity in HR competent and HR deficient primary cult... more PDF file - 62K, RAD51 foci and ex vivo cytotocicity in HR competent and HR deficient primary cultures A. Box plot showing cytotoxicity to 10 muM rucaparib B. Box plot showing RAD51 foci formation after 24 hr exposure to rucaparib or hydroxyurea C. Scatter plot showing the level of RAD51 foci and cytotoxicity to 10 muM rucaparib in individual primary cultures- HR competent cultures showed >_ 200% RAD51 foci formation and >70% cell survival in ex vivo cytotocity assays.
Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 virus, is a major global health challen... more Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 virus, is a major global health challenge, as there is no efficient treatment for the moderate to severe disease. ADP-ribosylation events are involved in regulating the life cycle of coronaviruses and the inflammatory reactions of the host, hence we assessed the repurposing of registered PARP inhibitors for the treatment of COVID-19. We detected high levels of oxidative stress and strong PARylation in all cell types in the lungs of COVID-19 patients. Interestingly, rucaparib, unlike other PARP inhibitors, reduced SARS-CoV-2 infection rate through binding to the conserved 493-498 amino acid region located in the spike-ACE2 interface in the spike protein and prevented viruses from binding to ACE2. In addition, the spike protein-induced overexpression of IL-6, a key cytokine in COVID-19, was inhibited by rucaparib at pharmacologically relevant concentrations. These findings build a case for repurposing rucaparib for treating COV...
4999 Enzyme-mediated repair of DNA double-strand breaks (DSBs) is a major mechanism of resistance... more 4999 Enzyme-mediated repair of DNA double-strand breaks (DSBs) is a major mechanism of resistance to both ionizing radiation (IR) and drugs that cause DSBs as intermediates in repair processes. The major DNA DSB repair pathway in eukaryotes is nonhomologous end joining. An important component in this repair pathway is the DNA-dependent protein kinase (DNA-PK), whose catalytic subunit is a member of the phosphatidylinositol 3-kinase (PI 3-K)-related protein kinase (PIKK) family of enzymes. DNA-PK deficient cells are hypersensitive to IR and some DNA-damaging anticancer drugs, and inhibition of DNA-PK therefore represents a potential strategy for radio- and chemo-sensitization. NU7441 is a competitive and highly selective inhibitor of DNA-PK (IC 50 = 14 nM). The cellular specificity of NU7441 for DNA-PK was studied in V3 and V3-YAC cells, deficient and proficient in DNA-PK respectively. V3 cells were inherently more sensitive to IR and etoposide than V3-YAC cells and NU7441 increased ...
The clinical beliefs (expectations and demands) of veterinarians regarding herd-level strategies ... more The clinical beliefs (expectations and demands) of veterinarians regarding herd-level strategies to control mastitis, lameness, and Johne's disease were quantified in a numerical format; 94 veterinarians working in England (UK) were randomly selected and, during interviews, a statistical technique called probabilistic elicitation was used to capture their clinical expectations as probability distributions. The results revealed that markedly different clinical expectations existed for all 3 diseases, and many pairs of veterinarians had expectations with nonoverlapping 95% Bayesian credible intervals. For example, for a 3-yr lameness intervention, the most pessimistic veterinarian was centered at an 11% population mean reduction in lameness prevalence (95% credible interval: 0-21%); the most enthusiastic veterinarian was centered at a 58% reduction (95% credible interval: 38-78%). This suggests that a major change in beliefs would be required to achieve clinical agreement. Veterinarians' clinical expectations were used as priors in Bayesian models where they were combined with synthetic data (from randomized clinical trials of different sizes) to explore the effect of new evidence on current clinical opinion. The mathematical models make predictions based on the assumption that veterinarians will update their beliefs logically. For example, for the lameness intervention, a 200-farm clinical trial that estimated a 30% mean reduction in lameness prevalence was predicted to be reasonably convincing to the most pessimist veterinarian; that is, in light of this data, they were predicted to believe there would be a 0.92 probability of exceeding the median clinical demand of this sample of veterinarians, which was a 20% mean reduction in lameness. Currently, controversy exists over the extent to which veterinarians update their beliefs logically, and further research on this is needed. This study has demonstrated that probabilistic elicitation and a Bayesian framework are useful for evaluating the diversity and strength of veterinarians' clinical beliefs. The wide variations observed have implications for designing future projects. Although many factors influence disease control, nonetheless the heterogeneity in beliefs also raises concern over the extent to which a broadly consistent approach is currently being achieved; it supports the argument for more randomized clinical trials and for national programs to control nonstatutory endemic diseases.
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