22 results on '"Lewis Gallagher"'
Search Results
2. Figure 3 from Novel Oncogenic Transcription Factor Cooperation in RB-Deficient Cancer
- Author
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Karen E. Knudsen, Johann S. de Bono, Chris M. McNair, Matthew J. Schiewer, Irina A. Vasilevskaya, Galina Semenova, Emanuela Dylgjeri, Lewis Gallagher, Denisa Bogdan, Talya S. Laufer, Wei Yuan, Jennifer J. McCann, Ayesha A. Shafi, and Amy C. Mandigo
- Abstract
Supplemental Figure 3
- Published
- 2023
3. Supplementary Figure Legends from Novel Oncogenic Transcription Factor Cooperation in RB-Deficient Cancer
- Author
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Karen E. Knudsen, Johann S. de Bono, Chris M. McNair, Matthew J. Schiewer, Irina A. Vasilevskaya, Galina Semenova, Emanuela Dylgjeri, Lewis Gallagher, Denisa Bogdan, Talya S. Laufer, Wei Yuan, Jennifer J. McCann, Ayesha A. Shafi, and Amy C. Mandigo
- Abstract
Supplemental Figure Legends
- Published
- 2023
4. Figure 4 from Novel Oncogenic Transcription Factor Cooperation in RB-Deficient Cancer
- Author
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Karen E. Knudsen, Johann S. de Bono, Chris M. McNair, Matthew J. Schiewer, Irina A. Vasilevskaya, Galina Semenova, Emanuela Dylgjeri, Lewis Gallagher, Denisa Bogdan, Talya S. Laufer, Wei Yuan, Jennifer J. McCann, Ayesha A. Shafi, and Amy C. Mandigo
- Abstract
Supplemental Figure 4
- Published
- 2023
5. Data from Novel Oncogenic Transcription Factor Cooperation in RB-Deficient Cancer
- Author
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Karen E. Knudsen, Johann S. de Bono, Chris M. McNair, Matthew J. Schiewer, Irina A. Vasilevskaya, Galina Semenova, Emanuela Dylgjeri, Lewis Gallagher, Denisa Bogdan, Talya S. Laufer, Wei Yuan, Jennifer J. McCann, Ayesha A. Shafi, and Amy C. Mandigo
- Abstract
The retinoblastoma tumor suppressor (RB) is a critical regulator of E2F-dependent transcription, controlling a multitude of protumorigenic networks including but not limited to cell-cycle control. Here, genome-wide assessment of E2F1 function after RB loss in isogenic models of prostate cancer revealed unexpected repositioning and cooperation with oncogenic transcription factors, including the major driver of disease progression, the androgen receptor (AR). Further investigation revealed that observed AR/E2F1 cooperation elicited novel transcriptional networks that promote cancer phenotypes, especially as related to evasion of cell death. These observations were reflected in assessment of human disease, indicating the clinical relevance of the AR/E2F1 cooperome in prostate cancer. Together, these studies reveal new mechanisms by which RB loss induces cancer progression and highlight the importance of understanding the targets of E2F1 function.Significance:This study identifies that RB loss in prostate cancer drives cooperation between AR and E2F1 as coregulators of transcription, which is linked to the progression of advanced disease.
- Published
- 2023
6. Data from Functional Genomic Identification of Predictors of Sensitivity and Mechanisms of Resistance to Multivalent Second-Generation TRAIL-R2 Agonists
- Author
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Simon S. McDade, Ultan McDermott, Daniel B. Longley, Mathew Garnett, Lodewyk Wessels, David A. Tice, Amy Wesa, Ido Sloma, Daniel Ciznadija, Syd Barthorpe, Aikaterini Chatzipli, Vivek Iyer, Magali Michaut, Lewis Gallagher, Jess Bateson, Jamie Young, Jochen Prehn, Katherine McAllister, Christopher McCann, Andrea Lees, Stacey Price, Nyree Crawford, Mark Wappett, and Vera Grinkevitch
- Abstract
Multivalent second-generation TRAIL-R2 agonists are currently in late preclinical development and early clinical trials. Herein, we use a representative second-generation agent, MEDI3039, to address two major clinical challenges facing these agents: lack of predictive biomarkers to enable patient selection and emergence of resistance. Genome-wide CRISPR knockout screens were notable for the lack of resistance mechanisms beyond the canonical TRAIL-R2 pathway (caspase-8, FADD, BID) as well as p53 and BAX in TP53 wild-type models, whereas a CRISPR activatory screen identified cell death inhibitors MCL-1 and BCL-XL as mechanisms to suppress MEDI3039-induced cell death. High-throughput drug screening failed to identify genomic alterations associated with response to MEDI3039; however, transcriptomics analysis revealed striking association between MEDI3039 sensitivity and expression of core components of the extrinsic apoptotic pathway, most notably its main apoptotic effector caspase-8 in solid tumor cell lines. Further analyses of colorectal cell lines and patient-derived xenografts identified caspase-8 expression ratio to its endogenous regulator FLIP(L) as predictive of sensitivity to MEDI3039 in several major solid tumor types and a further subset indicated by caspase-8:MCL-1 ratio. Subsequent MEDI3039 combination screening of TRAIL-R2, caspase-8, FADD, and BID knockout models with 60 compounds with varying mechanisms of action identified two inhibitor of apoptosis proteins (IAP) that exhibited strong synergy with MEDI3039 that could reverse resistance only in BID-deleted models. In summary, we identify the ratios of caspase-8:FLIP(L) and caspase-8:MCL-1 as potential predictive biomarkers for second-generation TRAIL-R2 agonists and loss of key effectors such as FADD and caspase-8 as likely drivers of clinical resistance in solid tumors.
- Published
- 2023
7. Supplementary Figure from Functional Genomic Identification of Predictors of Sensitivity and Mechanisms of Resistance to Multivalent Second-Generation TRAIL-R2 Agonists
- Author
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Simon S. McDade, Ultan McDermott, Daniel B. Longley, Mathew Garnett, Lodewyk Wessels, David A. Tice, Amy Wesa, Ido Sloma, Daniel Ciznadija, Syd Barthorpe, Aikaterini Chatzipli, Vivek Iyer, Magali Michaut, Lewis Gallagher, Jess Bateson, Jamie Young, Jochen Prehn, Katherine McAllister, Christopher McCann, Andrea Lees, Stacey Price, Nyree Crawford, Mark Wappett, and Vera Grinkevitch
- Abstract
Supplementary Figure from Functional Genomic Identification of Predictors of Sensitivity and Mechanisms of Resistance to Multivalent Second-Generation TRAIL-R2 Agonists
- Published
- 2023
8. Supplementary Data from Functional Genomic Identification of Predictors of Sensitivity and Mechanisms of Resistance to Multivalent Second-Generation TRAIL-R2 Agonists
- Author
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Simon S. McDade, Ultan McDermott, Daniel B. Longley, Mathew Garnett, Lodewyk Wessels, David A. Tice, Amy Wesa, Ido Sloma, Daniel Ciznadija, Syd Barthorpe, Aikaterini Chatzipli, Vivek Iyer, Magali Michaut, Lewis Gallagher, Jess Bateson, Jamie Young, Jochen Prehn, Katherine McAllister, Christopher McCann, Andrea Lees, Stacey Price, Nyree Crawford, Mark Wappett, and Vera Grinkevitch
- Abstract
Supplementary Data from Functional Genomic Identification of Predictors of Sensitivity and Mechanisms of Resistance to Multivalent Second-Generation TRAIL-R2 Agonists
- Published
- 2023
9. Erratum to 'B7-H3 as a Therapeutic Target in Advanced Prostate Cancer' [Eur Urol 2023;83(3):224–38]
- Author
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Christina Guo, Ines Figueiredo, Bora Gurel, Antje Neeb, George Seed, Mateus Crespo, Suzanne Carreira, Jan Rekowski, Lorenzo Buroni, Jon Welti, Denisa Bogdan, Lewis Gallagher, Adam Sharp, Maria D. Fenor de la Maza, Pasquale Rescigno, Daniel Westaby, Khobe Chandran, Ruth Riisnaes, Ana Ferreira, Susana Miranda, Bianca Calì, Andrea Alimonti, Silvia Bressan, Alana H.T. Nguyen, Michael M. Shen, Jessica E. Hawley, Aleksandar Obradovic, Charles G. Drake, Claudia Bertan, Chloe Baker, Nina Tunariu, Wei Yuan, and Johann S. de Bono
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Urology - Published
- 2023
10. Circulating tumour DNA sequencing to determine therapeutic response and identify tumour heterogeneity in patients with paediatric solid tumours
- Author
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Reda Stankunaite, Sally L. George, Lewis Gallagher, Sabri Jamal, Ridwan Shaikh, Lina Yuan, Debbie Hughes, Paula Z. Proszek, Paul Carter, Grzegorz Pietka, Timon Heide, Chela James, Haider Tari, Claire Lynn, Neha Jain, Laura Rey Portela, Tony Rogers, Sucheta J. Vaidya, Julia C. Chisholm, Fernando Carceller, Elwira Szychot, Henry Mandeville, Paola Angelini, Angela B. Jesudason, Michael Jackson, Lynley V. Marshall, Susanne A. Gatz, John Anderson, Andrea Sottoriva, Louis Chesler, and Michael Hubank
- Subjects
Adult ,Cancer Research ,Whole Genome Sequencing ,Oncology ,Neoplasms ,Mutation ,Biomarkers, Tumor ,High-Throughput Nucleotide Sequencing ,Humans ,Child ,Cell-Free Nucleic Acids ,Circulating Tumor DNA - Abstract
Clinical diagnostic sequencing of circulating tumour DNA (ctDNA) is well advanced for adult patients, but application to paediatric cancer patients lags behind.To address this, we have developed a clinically relevant (67 gene) NGS capture panel and accompanying workflow that enables sensitive and reliable detection of low-frequency genetic variants in cell-free DNA (cfDNA) from children with solid tumours. We combined gene panel sequencing with low pass whole-genome sequencing of the same library to inform on genome-wide copy number changes in the blood.Analytical validity was evaluated using control materials, and the method was found to be highly sensitive (0.96 for SNVs and 0.97 for INDEL), specific (0.82 for SNVs and 0.978 for INDEL), repeatable (0.93 [95% CI: 0.89-0.95]) and reproducible (0.87 [95% CI: 0.87-0.95]). Potential for clinical application was demonstrated in 39 childhood cancer patients with a spectrum of solid tumours in which the single nucleotide variants expected from tumour sequencing were detected in cfDNA in 94.4% (17/18) of cases with active extracranial disease. In 13 patients, where serial samples were available, we show a close correlation between events detected in cfDNA and treatment response, demonstrate that cfDNA analysis could be a useful tool to monitor disease progression, and show cfDNA sequencing has the potential to identify targetable variants that were not detected in tumour samples.This is the first pan-cancer DNA sequencing panel that we know to be optimised for cfDNA in children for blood-based molecular diagnostics in paediatric solid tumours.
- Published
- 2022
11. Novel Oncogenic Transcription Factor Cooperation in RB-Deficient Cancer
- Author
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Galina Semenova, Irina A. Vasilevskaya, Jennifer J. McCann, Matthew J. Schiewer, Christopher McNair, Wei Yuan, Karen E. Knudsen, Emanuela Dylgjeri, Ayesha A. Shafi, Lewis Gallagher, Denisa Bogdan, Amy C. Mandigo, Johann S. de Bono, and Talya S. Laufer
- Subjects
Male ,Cancer Research ,Carcinogenesis ,Cell Survival ,Ubiquitin-Protein Ligases ,Regulator ,Apoptosis ,Biology ,Transfection ,law.invention ,Cohort Studies ,Prostate cancer ,law ,Cell Line, Tumor ,medicine ,Humans ,E2F1 ,Transcription factor ,Oncogene Proteins ,Binding Sites ,Retinoblastoma ,Prostatic Neoplasms ,Cancer ,Oncogenes ,medicine.disease ,Gene Expression Regulation, Neoplastic ,Androgen receptor ,Retinoblastoma Binding Proteins ,Oncology ,Receptors, Androgen ,Gene Knockdown Techniques ,Cancer research ,Suppressor ,biological phenomena, cell phenomena, and immunity ,E2F1 Transcription Factor ,Protein Binding ,Signal Transduction - Abstract
The retinoblastoma tumor suppressor (RB) is a critical regulator of E2F-dependent transcription, controlling a multitude of protumorigenic networks including but not limited to cell-cycle control. Here, genome-wide assessment of E2F1 function after RB loss in isogenic models of prostate cancer revealed unexpected repositioning and cooperation with oncogenic transcription factors, including the major driver of disease progression, the androgen receptor (AR). Further investigation revealed that observed AR/E2F1 cooperation elicited novel transcriptional networks that promote cancer phenotypes, especially as related to evasion of cell death. These observations were reflected in assessment of human disease, indicating the clinical relevance of the AR/E2F1 cooperome in prostate cancer. Together, these studies reveal new mechanisms by which RB loss induces cancer progression and highlight the importance of understanding the targets of E2F1 function. Significance: This study identifies that RB loss in prostate cancer drives cooperation between AR and E2F1 as coregulators of transcription, which is linked to the progression of advanced disease.
- Published
- 2021
12. B7-H3 as a Therapeutic Target in Advanced Prostate Cancer
- Author
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Christina Guo, Ines Figueiredo, Bora Gurel, Antje Neeb, George Seed, Mateus Crespo, Suzanne Carreira, Jan Rekowski, Lorenzo Buroni, Jon Welti, Denisa Bogdan, Lewis Gallagher, Adam Sharp, Maria D. Fenor de la Maza, Pasquale Rescigno, Daniel Westaby, Khobe Chandran, Ruth Riisnaes, Ana Ferreira, Susana Miranda, Bianca Calì, Andrea Alimonti, Silvia Bressan, Alana H.T. Nguyen, Michael M. Shen, Jessica E. Hawley, Aleksandar Obradovic, Charles G. Drake, Claudia Bertan, Chloe Baker, Nina Tunariu, Wei Yuan, and Johann S. de Bono
- Subjects
Urology - Abstract
B7-H3 is a cell surface immunomodulatory glycoprotein overexpressed in prostate cancers (PCs). Understanding its longitudinal expression at emergence of castration resistance and association with tumour genomics are critical to the development of and patient selection for B7-H3 targeted therapies.To characterise B7-H3 expression in same-patient hormone-sensitive (HSPC) and castration-resistant (CRPC) PC biopsies, associating this with PC genomics, and to evaluate the antitumour activity of an anti-B7-H3 antibody-drug conjugate (ADC) in human CRPC in vitro and in vivo.We performed immunohistochemistry and next-generation sequencing on a cohort of 98 clinically annotated CRPC biopsies, including 72 patients who also had HSPC biopsies for analyses. We analysed two CRPC transcriptome and exome datasets, and PC scRNASeq datasets. PC organoids (patient-derived xenograft [PDX]-derived organoids [PDX-Os]) were derived from PDXs generated from human CRPC biopsies.We evaluated B7-H3 mRNA expression in relation to a panel of 770 immune-related genes, compared B7-H3 protein expression between same-patient HSPC and CRPC biopsies, determined associations with PC genomic alterations, and evaluated the antitumour activity of DS-7300a, a topoisomerase-1 inhibitor payload anti-B7-H3 ADC, in human PC cell lines, organoids (PDX-Os), and xenografts (PDXs) of different histologies, B7-H3 expressions, and genomics.B7-H3 was among the most highly expressed immunomodulatory genes in CRPCs. Most CRPCs (93%) expressed B7-H3, and in patients who developed CRPC, B7-H3 expression was frequently expressed at the time of HSPC diagnosis (97%). Conversion from B7-H3 positive to negative, or vice versa, during progression from HSPC to CRPC was uncommon. CRPC with neuroendocrine features were more likely to be B7-H3 negative (28%) than adenocarcinomas. B7-H3 is overexpressed in tumours with defective DNA repair gene (ATM and BRCA2) alterations and is associated with ERG expression, androgen receptor (AR) expression, and AR activity signature. DS7300a had antitumour activity against B7-H3 expressing human PC models including cell lines, PDX-Os, and PDXs of adenocarcinoma and neuroendocrine histology.The frequent overexpression of B7-H3 in CRPC compared with normal tissue and other B7 family members implicates it as a highly relevant therapeutic target in these diseases. Mechanisms driving differences in B7-H3 expression across genomic subsets warrant investigation for understanding the role of B7-H3 in cancer growth and for the clinical development of B7-H3 targeted therapies.B7-H3, a protein expressed on the surface of the most lethal prostate cancers, in particular those with specific mutations, can be targeted using drugs that bind B7-H3. These findings are relevant for the development of such drugs and for deciding which patients to treat with these new drugs.
- Published
- 2022
13. Tumour evolvability metrics predict recurrence beyond 10 years in locally-advanced prostate cancer
- Author
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Andrea Sottoriva, Javier Fernandez-Mateos, George Cresswell, Nicholas Trahearn, Katharine Webb, Christine Stuttle, Catherine Corbishley, Vasilis Starvrinides, Luis Zapata, Inma Spiteri, Timon Heide, Lewis Gallagher, Chela James, Annie Gao, Zsofia Kote-Jarai, Ahmet Acar, Lesley Truelove, Paula Proszek, Julia Murray, Alison Reid, Anna Wilkins, Michael Hubank, Rosalind Eeles, and David Dearnaley
- Abstract
Cancers evolve obeying Darwinian laws and therefore the evolutionary paradigm lays the ground for predictive oncology. However, the predictive power of evolutionary metrics in cancer has been seldom tested. There is a need for quantitative measurements in controlled clinical trials with long term follow-up information. This is particularly true in locally-advanced prostate cancer, which can recur more than a decade after diagnosis. Here we mapped genomic intra-tumour heterogeneity in 642 samples from 114 patients who took part in the prostate radiotherapy trials at The Royal Marsden Hospital, for which full clinical information and 12y median follow-up was available. We concomitantly assessed phenotypic (morphological) heterogeneity using deep learning in 1,923 histological sections from 250 IMRT patients (fully overlapping with the genetic set). We found that evolvability, measured as genetic divergence as well as morphological diversity, was a strong independent predictor of recurrence (respectively HR=72.06, 95% CI 2.97-1748.5, p=0.009 and HR=6.2, 95% CI 1.86-20.72, p=0.003). Combined, these two measurements together also identified a group of patients with half the median time to recurrence compared to the rest of the cohort (5.6 vs 11.5 years). We also found a small subset of MYC/FGFR1 amplified cases (4.4%) with particularly poor prognosis. The overall burden of chromosomal alterations correlated with higher Gleason score. We identified associations between 24 chromosomal arm copy number changes and Gleason score (e.g. -22q, +5p, +8q, +16p, +7p), and show that loss of chromosome 6p (encompassing the HLA locus) was correlated with markedly reduced immune cell infiltration. This study shows that combining genomics with AI-aided histopathology in clinical trials leads to the identification of novel clinical biomarkers.
- Published
- 2022
14. Functional Genomic Identification of Predictors of Sensitivity and Mechanisms of Resistance to Multivalent Second-Generation TRAIL-R2 Agonists
- Author
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Vera Grinkevitch, Mark Wappett, Nyree Crawford, Stacey Price, Andrea Lees, Christopher McCann, Katherine McAllister, Jochen Prehn, Jamie Young, Jess Bateson, Lewis Gallagher, Magali Michaut, Vivek Iyer, Aikaterini Chatzipli, Syd Barthorpe, Daniel Ciznadija, Ido Sloma, Amy Wesa, David A. Tice, Lodewyk Wessels, Mathew Garnett, Daniel B. Longley, Ultan McDermott, and Simon S. McDade
- Subjects
Cancer Research ,Oncology - Abstract
Multivalent second-generation TRAIL-R2 agonists are currently in late preclinical development and early clinical trials. Herein, we use a representative second-generation agent, MEDI3039, to address two major clinical challenges facing these agents: lack of predictive biomarkers to enable patient selection and emergence of resistance. Genome-wide CRISPR knockout screens were notable for the lack of resistance mechanisms beyond the canonical TRAIL-R2 pathway (caspase-8, FADD, BID) as well as p53 and BAX in TP53 wild-type models, whereas a CRISPR activatory screen identified cell death inhibitors MCL-1 and BCL-XL as mechanisms to suppress MEDI3039-induced cell death. High-throughput drug screening failed to identify genomic alterations associated with response to MEDI3039; however, transcriptomics analysis revealed striking association between MEDI3039 sensitivity and expression of core components of the extrinsic apoptotic pathway, most notably its main apoptotic effector caspase-8 in solid tumor cell lines. Further analyses of colorectal cell lines and patient-derived xenografts identified caspase-8 expression ratio to its endogenous regulator FLIP(L) as predictive of sensitivity to MEDI3039 in several major solid tumor types and a further subset indicated by caspase-8:MCL-1 ratio. Subsequent MEDI3039 combination screening of TRAIL-R2, caspase-8, FADD, and BID knockout models with 60 compounds with varying mechanisms of action identified two inhibitor of apoptosis proteins (IAP) that exhibited strong synergy with MEDI3039 that could reverse resistance only in BID-deleted models. In summary, we identify the ratios of caspase-8:FLIP(L) and caspase-8:MCL-1 as potential predictive biomarkers for second-generation TRAIL-R2 agonists and loss of key effectors such as FADD and caspase-8 as likely drivers of clinical resistance in solid tumors.
- Published
- 2022
15. The KDR (VEGFR-2) Genetic Polymorphism Q472H and c-KIT Polymorphism M541L Are Associated With More Aggressive Behaviour in Astrocytic Gliomas
- Author
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Persephone Du Parcq, Lewis Gallagher, Suzanne MacMahon, Lisa Thompson, Jamshid S. Khorashad, Clara LimbÄck-Stanic, Serena Santhana Dass, and Niyaz Zaman
- Subjects
Male ,Cancer Research ,Bioinformatics analysis ,Angiogenesis ,VEGF receptors ,CD34 ,Astrocytoma ,Biochemistry ,Polymorphism, Single Nucleotide ,Glioma ,Genetics ,medicine ,Biomarkers, Tumor ,Humans ,Clinical significance ,Molecular Biology ,Gene ,neoplasms ,Retrospective Studies ,biology ,business.industry ,Brain Neoplasms ,High-Throughput Nucleotide Sequencing ,Middle Aged ,medicine.disease ,Prognosis ,Vascular Endothelial Growth Factor Receptor-2 ,Survival Rate ,Proto-Oncogene Proteins c-kit ,biology.protein ,Cancer research ,cardiovascular system ,Immunohistochemistry ,Female ,business ,Follow-Up Studies ,Research Article - Abstract
Background/aim Better diagnostic and prognostic markers are required for a more accurate diagnosis and an earlier detection of glioma progression and for suggesting better treatment strategies. This retrospective study aimed to identify actionable gene variants to define potential markers of clinical significance. Materials and methods 56 glioblastomas (GBM) and 44 grade 2-3 astrocytomas were profiled with next generation sequencing (NGS) as part of routine diagnostic workup and bioinformatics analysis was used for the identification of variants. CD34 immunohistochemistry (IHC) was used to measure microvessel density (MVD) and Log-rank test to compare survival and progression in the presence or absence of these variants. Results Bioinformatic analysis highlighted frequently occurring variants in genes involved in angiogenesis regulation (KDR, KIT, TP53 and PIK3CA), with the most common ones being KDR (rs1870377) and KIT (rs3822214). The KDR variant was associated with increased MVD and shorter survival in GBM. We did not observe any correlation between the KIT variant and MVD; however, there was an association with tumour grade. Conclusion This study highlights the role of single-nucleotide variants (SNVs) that may be considered non-pathogenic and suggests the prognostic significance for survival of KIT rs3822214 and KDR rs1870377 and potential importance in planning new treatment strategies for gliomas.
- Published
- 2020
16. First Report of Macrophomina phaseolina Causing a Crown Rot of Strawberry in Florida.
- Author
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Mertely J, Seijo T, and Peres N
- Abstract
Strawberry (Fragaria × ananassa Duchesne) is produced as an annual winter crop in raised, plastic-mulched beds on 2,800 ha in west central Florida. In December 2001, a grower submitted collapsed and dying strawberry plants from a commercial field to the University of Florida in Dover. The cut crowns of affected plants revealed dark brown necrotic areas on the margins and along the woody vascular ring. Macrophomina phaseolina was isolated from pieces of infected tissue cut aseptically from the crowns and placed on a medium containing 12 g of Difco potato dextrose broth, 17 g of Bacto agar, 250 mg of ampicillin, and 100 mg of streptomycin sulfate per liter of water. The fungus produced numerous, dark, oblong sclerotia in the isolation medium after 4 to 5 days incubation at 24°C under constant fluorescent lighting. In 10-day-old cultures, sclerotia ranged in size from 55 to 190 μm long by 50 to 135 μm wide (average 105 × 74 μm). Ostiolate pycnidia bearing relatively large, broadly ellipsoidal, hyaline conidia occasionally developed on the host tissue after 8 to 10 days of incubation (2). During the 2003-2004 season, M. phaseolina was isolated from dying strawberry plants taken from the original field and two additional farms. Affected plants were often found along field margins or other areas inadequately fumigated with methyl bromide. Two single-spore isolates from different fields were tested for pathogenicity on nursery runner plants (cv. Strawberry Festival) grown for 4 weeks in the greenhouse on artificial potting soil. The fungal isolates were grown on corn meal agar at 24°C for 4 days and allowed to colonize sterile wooden toothpicks placed on the medium for an additional 5 days. Prior to use, the toothpicks were sterilized by autoclaving twice in deionized water and a third time in V8 juice. Six plants were inoculated with each isolate by inserting a colonized toothpick into each crown. Sterile, V8-infused toothpicks were inserted into the crowns of corresponding control plants. The plants were incubated in a greenhouse in a randomized complete block design with two replicates of three plants each. After 3 days, 33 to 100% of the inoculated plants developed wilting in one or more leaves. All inoculated plants collapsed or died within 2 weeks of inoculation, while the control plants remained healthy during the observation period. The pathogen was readily reisolated from inoculated plants. Charcoal rot disease caused by M. phaseolina has been reported on strawberry in France, India, and Illinois (2,3). To our knowledge, this is the first report from Florida. M. phaseolina may be an emerging threat as the Florida strawberry industry transitions from methyl bromide to other fumigants in 2005. References: (1) J. Maas. Macrophomina leaf blight and dry crown rot. Page 26 in: Compendium of Strawberry Diseases. 2nd ed. J. L. Maas, ed. The American Phytopathological Society, St. Paul, MN, 1998. (2) G. S. Smith and T. D. Wyllie. Charcoal rot. Pages 29-31 in: Compendium of Soybean Diseases. G. L. Hartman et al., eds. 4th ed. The American Phytopathological Society, St. Paul, MN. 1999. (3) B. Tweedy et al. Plant Dis. Rep. 42:107, 1958.
- Published
- 2005
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17. Timing of Fungicide Applications for Botrytis cinerea Based on Development Stage of Strawberry Flowers and Fruit.
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Mertely JC, MacKenzie SJ, and Legard DE
- Abstract
During the 1999-2000 and 2000-2001 growing seasons, field experiments were conducted to identify the developmental stage(s) of strawberry flowers and fruit that requires fungicide applications to control Botrytis fruit rot. Fenhexamid, a protectant fungicide, was applied to individual newly opened flowers or fruit of cultivar Sweet Charlie at defined intervals after anthesis. In 1999-2000, a single application of fenhexamid at anthesis controlled Botrytis fruit rot as well as multiple weekly applications beginning at anthesis. During both seasons, disease control deteriorated as applications were delayed 7 and 14 days after anthesis. This trend was described by linear regression equations relating the time of application to Botrytis fruit rot incidence. Additional treatments tested the effects of emasculation and petal removal 3 to 7 days after anthesis. Emasculation significantly reduced disease incidence in 2000-2001. Petal removal produced modest but significant reductions in 1999-2000, but not in 2000-2001. These results demonstrate that strawberry flowers are more susceptible to Botrytis cinerea than green fruit, and suggest that stamens are the principal infection court. Fungicide applications should focus on peak bloom periods to minimize fungicide use and optimize control of preharvest Botrytis fruit rot. During these periods, applications should be made at close intervals (≤7 days) to minimize losses to Botrytis.
- Published
- 2002
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18. Oversummer Survival of Inoculum for Colletotrichum Crown Rot in Buried Strawberry Crown Tissue.
- Author
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Ureña-Padilla AR, Mitchell DJ, and Legard DE
- Abstract
The oversummer survival of Colletotrichum gloeosporioides in strawberry crown tissue under field conditions was investigated in 1998 and 1999. Strawberry crowns infected naturally with C. gloeosporioides were placed inside cloth bags containing field soil, buried in the field at 5 or 13 cm, then recovered over 6 months of each year. The recovered crowns were plated onto a Colletotrichum spp. semiselective medium and speciated by colony, spore morphology, and molecular markers with species-specific DNA primers. Pathogenicity of selected isolates was confirmed by greenhouse bioassays on strawberry. Of the 428 isolates of Colletotrichum spp. recovered from buried crowns, 96% were C. gloeosporioides and 4% Colletotrichum acutatum. Following an initial increase in the detection of the fungus, survival of C. gloeosporioides was stable for 2 to 3 weeks, then declined. No Colletotrichum spp. were detected after burial for 56 days in 1998 and 98 days in 1999. Because the time between crop seasons is typically more than 170 days, these data support the hypothesis that inoculum of C. gloeosporioides does not survive in buried plant debris between seasons in Florida and, therefore, oversummering crop debris does not contribute inoculum for epidemics of Colletotrichum crown rot in Florida.
- Published
- 2001
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19. Control of Postharvest Botrytis Fruit Rot with Preharvest Fungicide Applications in Annual Strawberry.
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Blacharski RW, Bartz JA, Xiao CL, and Legard DE
- Abstract
The control of postharvest Botrytis fruit rot was evaluated during 1997-98 and 1998-99. Weekly applications of captan and thiram were examined at two or three different rates, respectively. Iprodione applications were combined with the captan and thiram treatments and also applied alone for two peak bloom periods. Strawberry fruit were harvested and graded twice weekly for marketable yield and preharvest incidence of Botrytis fruit rot. For postharvest evaluations, fruit from four harvests were selected and stored at 4°C, and Botrytis fruit rot incidence was recorded over 14 days of storage. Fungicide treatments reduced the incidence of preharvest Botrytis fruit rot and increased marketable yield. The incidence of postharvest Botrytis fruit rot was significantly affected by harvest date, length of time in storage, and fungicide treatment. The highest rate captan and thiram treatments had the least Botrytis fruit rot and the longest storage life. Reduced-rate captan and thiram treatments generally did not provide the same control as their respective high-rate treatments. Iprodione added to either the captan or thiram treatments did not consistently reduce the preharvest or postharvest incidence of Botrytis fruit rot or increase yield. Regular, full-rate fungicide treatments appear to be necessary to control Botrytis fruit rot in Florida and to provide the storage life necessary to reach distant markets.
- Published
- 2001
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20. Management of Botrytis Fruit Rot in Annual Winter Strawberry Using Captan, Thiram, and Iprodione.
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Legard DE, Xiao CL, Mertely JC, and Chandler CK
- Abstract
The management of Botrytis fruit rot on annual strawberry by fungicides was evaluated in Florida during the 1995-96, 1996-97, and 1997-98 seasons. Weekly applications of captan or thiram, bloom applications of iprodione applied twice during each of two peak flowering periods, and weekly applications of captan combined with iprodione bloom applications were evaluated. Significant treatment effects (P ≤ 0.05) on the incidence of Botrytis fruit rot were detected for the early, late, and whole-season periods each season. Weekly applications of captan or thiram controlled Botrytis fruit rot, reducing disease incidence by more than 41% compared to the untreated control. These treatments also affected marketable yield during two seasons, with a 42 to 127% increase in yield compared to the control. Weekly fungicide applications did not reduce the incidence of Botrytis fruit rot until at least the fourth week of harvest, 9 to 10 weeks after applications began. Bloom applications of iprodione alone reduced the incidence of Botrytis fruit rot during the second peak bloom period, and the reductions in incidence occurred 1 to 3 weeks after the start of bloom applications. This suggests that iprodione applications control infections at flowering or early stages of fruit development. However, early-season bloom applications did not reduce the incidence of Botrytis fruit rot. The control of Botrytis fruit rot by weekly captan applications was not improved by the addition of iprodione bloom applications. These data suggest that early-season fungicide applications for the control of Botrytis fruit rot in annual winter strawberry are of limited efficacy, and that bloom applications of Botryticides such as iprodione should be focused on the second peak bloom period.
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- 2001
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21. Comparison of Sanitation and Fungicides for Management of Botrytis Fruit Rot of Strawberry.
- Author
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Mertely JC, Chandler CK, Xiao CL, and Legard DE
- Abstract
To determine the effects of sanitation on yield and incidence of Botrytis fruit rot (Botrytis cinerea) in annual strawberry, replicated experiments were conducted during the 1995-96, 1996-97, and 1998-99 seasons. Leaf sanitation (removal of senescent and necrotic leaves) and fruit sanitation (removal of unmarketable fruit from alleys between beds) were compared to a standard fungicide control program (weekly applications of captan plus four bloom applications of iprodione) and combined sanitation and fungicide treatments. Leaf sanitation reduced Botrytis fruit rot incidence from 12.6 to 8.2% over the entire 1996-97 season, and from 17.6 to 11.8% during the latter half of the 1998-99 season, compared to untreated controls. However, sanitation did not increase marketable yield. Supplementing fungicides with leaf sanitation or leaf and fruit sanitation did not improve disease control and frequently reduced yield. Fruit sanitation had no significant effect on Botrytis incidence or yield. Losses to Botrytis fruit rot in the sanitation treatments were significantly higher (P ≤ 0.05) than in the fungicide treatments each season; marketable yields were significantly lower in 1996-97 and 1998-99. Under Florida conditions, fungicides control Botrytis fruit more effectively and economically than does sanitation.
- Published
- 2000
- Full Text
- View/download PDF
22. Effects of Plant Spacing and Cultivar on Incidence of Botrytis Fruit Rot in Annual Strawberry.
- Author
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Legard DE, Xiao CL, Mertely JC, and Chandler CK
- Abstract
The effects of within-row plant spacing and cultivar on the incidence of Botrytis fruit rot (Botrytis cinerea) and marketable yield of annual strawberry were evaluated during the 1997-98 and 1998-99 seasons. Three cultivars (Camarosa, Rosa Linda, and Sweet Charlie) and four plant spacings (23, 30, 38, and 46 cm) were evaluated. Marketable yield and the incidence of Botrytis fruit rot were determined twice weekly. Cultivar and spacing effects were analyzed for three periods each season (early, late, and whole season). In 1997-98, spacing effects were observed on weekly incidence of Botrytis rot for the late period (P = 0.0925) and on cumulative incidence for the whole season period (P = 0.0795). Further analysis of the late and whole season periods revealed a spacing effect for Camarosa (P = 0.0102). Spacing also had a dramatic effect on cumulative and weekly Botrytis incidence for the late and whole season periods during the 1998-99 season (P ≤ 0.0014), when narrower spacings had higher incidence of Botrytis than wider spacings. Marketable yields were higher at narrower spacings during the early period for both seasons. Whole season marketable yields were also higher at the narrower spacings despite higher incidence of Botrytis. There were significant differences in susceptibility among cultivars.
- Published
- 2000
- Full Text
- View/download PDF
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