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Fedets OM, Dmytruk KV, Adaszek L, Kurlyak IM, Dmytruk OV, Lisiecka U, Winiarczyk S. Polymorphism of glutathione S-transferase P1 of dogs with mammary tumours. Vet Comp Oncol 2023; 21:270-278. [PMID: 36808425 DOI: 10.1111/vco.12885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Revised: 01/21/2023] [Accepted: 01/23/2023] [Indexed: 02/23/2023]
Abstract
Mammary tumours constitute more than half of neoplasms in female dogs from different countries. Genome sequences are associated with cancer susceptibility but there is little information available about genetic polymorphisms of glutathione S-transferase P1 (GSTP1) in canine cancers. The aim of this study was to find single nucleotide polymorphisms (SNPs) in GSTP1 of dogs (Canis lupus familiaris) with mammary tumours compared to healthy dogs and to determine the association between GSTP1 polymorphisms and the occurrence of these tumours. The study population included 36 client-owned female dogs with mammary tumours and 12 healthy female dogs, with no previous diagnosis of cancer. DNA was extracted from blood and amplified by PCR assay. PCR-products were sequenced by Sanger method and analysed manually. The 33 polymorphisms were found in GSTP1: 1 coding SNP (exon 4), 24 non-coding SNPs (9 in exon 1), 7 deletions and 1 insertion. The 17 polymorphisms have been found in introns 1, 4, 5 and 6. The dogs with mammary tumours have significant difference from healthy in SNPs I4 c.1018 + 123 T > C (OR 13.412, 95%CI 1.574-114.267, P = .001), I5 c.1487 + 27 T > C (OR 10.737, 95%CI 1.260-91.477, P = .004), I5 c.1487 + 842 G > C (OR 4.714, 95% CI 1.086-20.472, P = .046) and I6 c.2481 + 50 A > G (OR 12.000, 95% CI 1.409-102.207, P = .002). SNP E5 c.1487 T > C and I5 c.1487 + 829 delG also differed significantly (P = .03) but not to the confidence interval. The study, for the first time, showed a positive association of SNPs in GSTP1 with mammary tumours of dogs, that can possibly be used to predict the occurrence of this pathology.
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Affiliation(s)
- Oleh M Fedets
- Department of Biological and General Chemistry, Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnologies Lviv, Lviv, Ukraine
| | - Kostyantyn V Dmytruk
- Department of Molecular Genetics and Biotechnology, Institute of Cell Biology National Academy of Sciences of Ukraine, Lviv, Ukraine
| | - Lukasz Adaszek
- Department of Epizootiology and Clinic of Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Lublin, Poland
| | - Iryna M Kurlyak
- Department of Biological and General Chemistry, Stepan Gzhytskyi National University of Veterinary Medicine and Biotechnologies Lviv, Lviv, Ukraine
| | - Olena V Dmytruk
- Department of Molecular Genetics and Biotechnology, Institute of Cell Biology National Academy of Sciences of Ukraine, Lviv, Ukraine
- Department of Biotechnology and Microbiology, University of Rzeszow, Rzeszów, Poland
| | - Urszula Lisiecka
- Department of Epizootiology and Clinic of Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Lublin, Poland
| | - Stanislaw Winiarczyk
- Department of Epizootiology and Clinic of Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, Lublin, Poland
- National Veterinary Research Institute, Pulawy, Poland
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Nance RL, Sajib AM, Smith BF. Canine models of human cancer: Bridging the gap to improve precision medicine. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2022; 189:67-99. [PMID: 35595353 DOI: 10.1016/bs.pmbts.2021.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Dogs are remarkable, adaptable, and dependable creatures that have evolved alongside humans while contributing tremendously to our survival. Our canine companions share many similarities to human disease, particularly cancer. With the advancement of next-generation sequencing technology, we are beginning to unravel the complexity of cancer and the vast intra- and intertumoral heterogeneity that makes treatment difficult. Consequently, precision medicine has emerged as a therapeutic approach to improve patient survival by evaluating and classifying an individual tumor's molecular profile. Many canine and human cancers share striking similarities in terms of genotypic, phenotypic, clinical, and histological presentations. Dogs are superior to rodent models of cancer because they are a naturally heterogeneous population in which tumors occur spontaneously, are exposed to similar environmental conditions, and show more similarities in key modulators of tumorigenesis and clinical response, including the immune system, drug metabolism, and gut microbiome. In this chapter, we will explore various canine models of human cancers and emphasize the dog's critical role in advancing precision medicine and improving the survival of both man and man's best friend.
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Affiliation(s)
- Rebecca L Nance
- Scott-Ritchey Research Center, Auburn University College of Veterinary Medicine, Auburn, AL, United States; Department of Pathobiology, Auburn University College of Veterinary Medicine, Auburn, AL, United States
| | - Abdul Mohin Sajib
- Division of Cellular and Gene Therapies, Center for Biologics Evaluation and Research, US Food and Drug Administration, Silver Spring, MD, United States
| | - Bruce F Smith
- Scott-Ritchey Research Center, Auburn University College of Veterinary Medicine, Auburn, AL, United States; Department of Pathobiology, Auburn University College of Veterinary Medicine, Auburn, AL, United States.
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Batool A, Hazafa A, Ahmad S, Khan HA, Abideen HMZ, Zafar A, Bilal M, Iqbal HMN. Treatment of lymphomas via regulating the Signal transduction pathways by natural therapeutic approaches: A review. Leuk Res 2021; 104:106554. [PMID: 33684680 DOI: 10.1016/j.leukres.2021.106554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 02/25/2021] [Accepted: 02/26/2021] [Indexed: 02/07/2023]
Abstract
Lymphoma is a heterogeneous group of malignancies, which comprises 4.2 % of all new cancer cases and 3.3 % of all cancer deaths in 2019, globally. The dysregulation of immune system, certain bacterial or viral infections, autoimmune diseases, and immune suppression are associated with a high risk of lymphoma. Although several conventional strategies have improved during the past few decades, but their detrimental impacts remain an obstacle to be resolved. However, natural compounds are considered a good option in the treatment of lymphomas because of their easy accessibility, specific mode of action, high biodegradability, and cost-effectiveness. Vegetables, fruits, and beverages are the primary sources of natural active compounds. The present review investigated the activities of different natural medicinal compounds including curcumin, MK615, resveratrol, bromelain, EGCG, and Annonaceous acetogenins to treat lymphomas. Moreover, in vitro and in vivo studies, classification, risk factors, and diagnosis of lymphoma are also discussed in the present review. The accumulated data proposed that natural compounds regulate the signaling pathways at the level of cell proliferation, apoptosis, and cell cycle to exhibit anti-lymphoma activities both in-vivo and in-vitro studies and suggested that these active compounds could be a good therapeutic option in the treatment of different types of lymphomas.
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Affiliation(s)
- Ammara Batool
- Department of Biochemistry, Faculty of Sciences, University of Agriculture, Faisalabad, 38000, Pakistan
| | - Abu Hazafa
- Department of Biochemistry, Faculty of Sciences, University of Agriculture, Faisalabad, 38000, Pakistan; International Society of Engineering Science and Technology, Coventry, CV1 5EH, United Kingdom.
| | - Saeed Ahmad
- Centre of Biotechnology and Microbiology, University of Peshawar, Peshawar, 25120, Pakistan
| | - Hamid Ali Khan
- Institute of Biological Sciences, Sarhad University of Science and Information Technology, Peshawar, 25000, Pakistan
| | - Hafiz M Z Abideen
- Institute of Public Health, The University of Lahore, Lahore, 54590, Pakistan
| | - Ayesha Zafar
- Institute of Biochemistry and Biotechnology, Faculty of Biosciences, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Muhammad Bilal
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, 223003, China
| | - Hafiz M N Iqbal
- School of Engineering and Sciences, Tecnologico de Monterrey, Av. Eugenio Garza Sada 2501 Sur, Tecnológico, 64849, Monterrey, NL, Mexico
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Hull MB, Schermerhorn T, Vieson MD, Reinhart JM. Feasibility of hepatic fine needle aspiration as a minimally invasive sampling method for gene expression quantification of pharmacogenetic targets in dogs. Vet Med Sci 2020; 7:41-45. [PMID: 32951355 PMCID: PMC7840213 DOI: 10.1002/vms3.351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/14/2020] [Accepted: 08/29/2020] [Indexed: 12/29/2022] Open
Abstract
Background Quantifying hepatic gene expression is important for many pharmacogenetic studies. However, this usually requires biopsy (BX), which is invasive. Objectives The objectives of this study were to determine the feasibility of using minimally invasive fine needle aspirate (FNA) to quantify hepatic gene expression and to assess expression variability between different sampling sites. Methods Biopsy and FNA samples were acquired from central and peripheral locations of the right and left lateral liver lobes of a dog. Relative expression of ABCB1, GSTT1 and CYP3A12 were measured via reverse transcriptase, quantitative PCR. The effect of sampling method, lobe and location within the lobe on gene expression was assessed using a three‐way ANOVA. Results Relative expression of ABCB1 and GSTT1 were not statistically different between sampling methods but CYP3A12 expression was higher in samples collected by BX (p = .013). Lobe sampled affected ABCB1 expression (p = .001) and site within lobe affected ABCB1 (p = .018) and GSTT1 (p = .025) expression. Conclusions FNA appears to be a feasible technique for minimally invasive evaluation of hepatic gene expression but results should not be directly compared to biopsy samples. Sampling location impacts expression of some targets; combination of FNAs from multiple sites may reduce variation.
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Affiliation(s)
- Matthew B Hull
- The Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL, USA
| | - Thomas Schermerhorn
- The Department of Small Animal Clinical Science, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Miranda D Vieson
- The Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL, USA
| | - Jennifer M Reinhart
- The Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana, IL, USA
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Craun K, Ekena J, Sacco J, Jiang T, Motsinger‐Reif A, Trepanier LA. Genetic and environmental risk for lymphoma in boxer dogs. J Vet Intern Med 2020; 34:2068-2077. [PMID: 32667715 PMCID: PMC7517848 DOI: 10.1111/jvim.15849] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 06/23/2020] [Accepted: 06/26/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Non-Hodgkin lymphoma in humans is associated with environmental chemical exposures, and risk is enhanced by genetic variants in glutathione S-transferases (GST) enzymes. OBJECTIVE We hypothesized that boxer dogs, a breed at risk for lymphoma, would have a higher prevalence of GST variants with predicted low activity, and greater accumulated DNA damage, compared to other breeds. We also hypothesized that lymphoma in boxers would be associated with specific environmental exposures and a higher prevalence of canine GST variants. ANIMALS Fifty-four healthy boxers and 56 age-matched nonboxer controls; 63 boxers with lymphoma and 89 unaffected boxers ≥10 years old. METHODS We resequenced variant loci in canine GSTT1, GSTT5, GSTM1, and GSTP1 and compared endogenous DNA damage in peripheral leukocytes of boxers and nonboxers using the comet assay. We also compared GST variants and questionnaire-based environmental exposures in boxers with and without lymphoma. RESULTS Endogenous DNA damage did not differ between boxers and nonboxers. Boxers with lymphoma were more likely to live within 10 miles of a nuclear power plant and within 2 miles of a chemical supplier or crematorium. Lymphoma risk was not modulated by known canine GST variants. CONCLUSIONS AND CLINICAL IMPORTANCE Proximity to nuclear power plants, chemical suppliers, and crematoria were significant risk factors for lymphoma in this population of boxers. These results support the hypothesis that aggregate exposures to environmental chemicals and industrial waste may contribute to lymphoma risk in dogs.
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Affiliation(s)
- Kaitlyn Craun
- Department of Medical Sciences, School of Veterinary MedicineUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - Joanne Ekena
- Department of Medical Sciences, School of Veterinary MedicineUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
| | - James Sacco
- Drake University College of Pharmacy and Health SciencesDes MoinesIowaUSA
| | - Tao Jiang
- Department of StatisticsNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Alison Motsinger‐Reif
- Biostatistics & Computational Biology Branch, NIEHSDurhamNorth CarolinaUSA
- Department of StatisticsNorth Carolina State UniversityRaleighNorth CarolinaUSA
| | - Lauren A. Trepanier
- Department of Medical Sciences, School of Veterinary MedicineUniversity of Wisconsin‐MadisonMadisonWisconsinUSA
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Luethcke KR, Ekena J, Chun R, Trepanier LA. Glutathione S-transferase theta genotypes and environmental exposures in the risk of canine transitional cell carcinoma. J Vet Intern Med 2019; 33:1414-1422. [PMID: 31008543 PMCID: PMC6524089 DOI: 10.1111/jvim.15504] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 04/08/2019] [Indexed: 12/20/2022] Open
Abstract
Introduction Transitional cell carcinoma (TCC) in humans is associated with environmental exposures and variants in glutathione S‐transferase (GST) genes. Scottish Terriers have a high breed risk for TCC, but the relationship between genetic and environmental risk in dogs is not fully understood. Hypotheses Scottish Terriers have a higher frequency of GST‐theta variants compared to lower risk breeds. Dogs with TCC of any breed have a higher frequency of GST‐theta variants along with higher environmental exposures, compared to controls. Animals One hundred and five Scottish Terriers and 68 controls from lower risk breeds; 69 dogs of various breeds with TCC, and 72 breed‐ and sex‐matched unaffected geriatric dogs. Methods In this prospective case‐control study, dogs were genotyped for 3 canine GST‐theta variants: GSTT1 I2+28 G>A, a GSTT1 3′UTR haplotype, and GSTT5 Asp129_Gln130del. Owners of dogs with TCC and unaffected geriatric controls completed a household environmental questionnaire. Results The GSTT1 3′UTR haplotype and GSTT5 Asp129_Gln130del variants were significantly underrepresented in Scottish Terriers (minor allele frequency [MAF] = 0.000 for both), compared to dogs from lower risk breeds (MAF = 0.108 and 0.100; P ≤ .0002). Dogs with TCC did not differ from unaffected geriatric controls across the 3 investigated loci. Transitional cell carcinoma was associated with household insecticide use (odds ratio [OR] = 4.28, 95% confidence interval [CI] = 1.44‐12.33, P = .02), and was negatively associated with proximity to a farm (OR = 0.49, 95% CI = 0.25‐0.99, P = .04). Conclusions and Clinical Importance Low‐activity GST‐theta loci are unlikely contributors to TCC risk in dogs. Increased risk is associated with household insecticide use, and possibly with less rural households.
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Affiliation(s)
- Katherine R Luethcke
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Joanne Ekena
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Ruthanne Chun
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Lauren A Trepanier
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
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Ekena J, Wood E, Manchester A, Chun R, Trepanier LA. Glutathione-S-transferase-theta genotypes and the risk of cyclophosphamide toxicity in dogs. Vet Comp Oncol 2018; 16:529-534. [PMID: 29984447 DOI: 10.1111/vco.12411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/15/2018] [Accepted: 05/17/2018] [Indexed: 01/15/2023]
Abstract
The antineoplastic agent cyclophosphamide (CP) has dose-limiting side effects including sterile haemorrhagic cystitis (SHC), bone marrow (BM) suppression and gastrointestinal (GI) toxicity in dogs. The metabolites acrolein and phosphoramide that mediate these toxicities are glutathione-S-transferase (GST) substrates, and low functioning GST alleles are associated with CP toxicity in humans. The aim of this study was to determine whether variants in 2 canine GST genes, GSTT1 and GSTT5, were over-represented in dogs that developed CP toxicity. Dogs undergoing pulse or metronomic CP chemotherapy were recruited (n = 101) and genotyped for 6 GSTT1 polymorphisms and 1 GSTT5 6-bp deletion that leads to non-functional enzyme. Median cumulative CP dosages for dogs with SHC (1350 mg/m2 ) were significantly higher than for dogs with GI/BM toxicity (871 mg/m2 ) or no toxicity (991 mg/m2 ; P = .0012). Dogs with SHC were more likely to have had metronomic (84.2%, 16 of 19 SHC cases) vs pulse (15.8%, 3 of 19 SHC cases) CP dosing (P < .0001). All dogs with BM or GI toxicity (n = 30) had pulse chemotherapy. GSTT1 and GSTT5 variant allele frequencies were not significantly different in CP-treated dogs with SHC or GI/BM toxicity compared to dogs without documented adverse effects. Work is underway to identify which canine GSTs detoxify acrolein and phosphoramide, so that better tools are available to predict the risk of CP toxicity in dogs.
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Affiliation(s)
- J Ekena
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - E Wood
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - A Manchester
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - R Chun
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - L A Trepanier
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
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Craft S, Ekena J, Sacco J, Luethcke K, Trepanier L. A 6-bp Deletion Variant in a Novel Canine Glutathione-S-Transferase Gene (GSTT5) Leads to Loss of Enzyme Function. J Vet Intern Med 2017; 31:1833-1840. [PMID: 29105159 PMCID: PMC5697189 DOI: 10.1111/jvim.14861] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/23/2017] [Accepted: 09/20/2017] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVES Glutathione-S-transferases (GSTs) detoxify reactive xenobiotics, and defective GST gene polymorphisms increase cancer risk in humans. A low activity GST-theta variant was previously found in research beagles. The purpose of our study was to determine the molecular basis for this phenotype and its allele frequency in pet dogs. METHODS Banked livers from 45 dogs of various breeds were screened for low GST-theta activity by the substrate 1,2-dichloro-4-nitrobenzene (DCNB), and were genotyped for variants in a novel canine GST gene, GSTT5. Whole-genome sequences from 266 dogs were genotyped at one discovered variant GSTT5 locus. RESULTS Canine livers ranged 190-fold in GST-theta activities, and a GSTT5 exon coding variant 385_390delGACCAG (Asp129_Gln130del) was significantly associated with low activity (P < 0.0001) and a marked decrease in hepatic protein expression (P = 0.0026). Recombinant expression of variant GSTT5 led to a 92% decrease in Vmax for DCNB (P = 0.0095). The minor allele frequency (MAF) for 385_390delGACCAG was 0.144 in 45 dog livers, but was significantly higher in beagles (0.444) versus nonbeagles (0.007; P = 0.0004). The homozygous genotype was significantly over-represented in Pembroke Welsh corgis (P < 0.0001) based on available whole-genome sequence data. CONCLUSIONS An Asp129_Gln130del variant in canine GSTT5 is responsible for marked loss of GST-theta enzyme activity. This variant is significantly over-represented in purpose-bred laboratory beagles and in Pembroke Welsh corgis. Additional work will determine the prevalence of this variant among other purebred dogs, and will establish the substrate range of this polymorphic canine enzyme with respect to common environmental carcinogens.
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Affiliation(s)
- S. Craft
- Department of Medical SciencesSchool of Veterinary MedicineUniversity of Wisconsin‐MadisonMadisonWI
| | - J. Ekena
- Department of Medical SciencesSchool of Veterinary MedicineUniversity of Wisconsin‐MadisonMadisonWI
| | - J. Sacco
- Department of Pharmaceutical, Biomedical & Administrative SciencesCollege of Pharmacy and Health SciencesDrake UniversityDes MoinesIA
| | - K. Luethcke
- Department of Medical SciencesSchool of Veterinary MedicineUniversity of Wisconsin‐MadisonMadisonWI
| | - L. Trepanier
- Department of Medical SciencesSchool of Veterinary MedicineUniversity of Wisconsin‐MadisonMadisonWI
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Sacco J, Mann S, Toral K. Single nucleotide polymorphisms and microsatellites in the canine glutathione S-transferase pi 1 ( GSTP1) gene promoter. Canine Genet Epidemiol 2017; 4:9. [PMID: 29046813 PMCID: PMC5635497 DOI: 10.1186/s40575-017-0050-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/19/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Genetic polymorphisms within the glutathione S-transferase P1 (GSTP1) gene affect the elimination of toxic xenobiotics by the GSTP1 enzyme. In dogs, exposure to environmental chemicals that may be GSTP1 substrates is associated with cancer. The objectives of this study were to investigate the genetic variability in the GSTP1 promoter in a diverse population of 278 purebred dogs, compare the incidence of any variants found between breeds, and predict their effects on gene expression. To provide information on ancestral alleles, a number of wolves, coyotes, and foxes were also sequenced. RESULTS Fifteen single nucleotide polymorphisms (SNPs) and two microsatellites were discovered. Three of these loci were only polymorphic in dogs while three other SNPs were unique to wolves and coyotes. The major allele at c.-46 is T in dogs but is C in the wild canids. The c.-185 delT variant was unique to dogs. The microsatellite located in the 5' untranslated region (5'UTR) was a highly polymorphic GCC tandem repeat, consisting of simple and compound alleles that varied in size from 10 to 22-repeat units. The most common alleles consisted of 11, 16, and 17-repeats. The 11-repeat allele was found in 10% of dogs but not in the other canids. Unequal recombination and replication slippage between similar and distinct alleles may be the mechanism for the multiple microsatellites observed. Twenty-eight haplotypes were constructed in the dog, and an additional 8 were observed in wolves and coyotes. While the most common haplotype acrossbreeds was the wild-type *1A(17), other prevalent haplotypes included *3A(11) in Greyhounds, *6A(16) in Labrador Retrievers, *9A(16) in Golden Retrievers, and *8A(19) in Standard Poodles. Boxers and Siberian Huskies exhibited minimal haplotypic diversity. Compared to the simple 16*1 allele, the compound 16*2 allele (found in 12% of dogs) may interfere with transcription factor binding and/or the stability of the GSTP1 transcript. CONCLUSIONS Dogs and other canids exhibit extensive variation in the GSTP1 promoter. Genetic polymorphisms within distinct haplotypes prevalent in certain breeds can affect GSTP1 expression and carcinogen detoxification, and thus may be useful as genetic markers for cancer in dogs.
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Affiliation(s)
- James Sacco
- Ellis Pharmacogenomics Laboratory, College of Pharmacy and Health Sciences, Drake University, Des Moines, IA 50311 USA
| | - Sarah Mann
- Ellis Pharmacogenomics Laboratory, College of Pharmacy and Health Sciences, Drake University, Des Moines, IA 50311 USA
| | - Keller Toral
- Ellis Pharmacogenomics Laboratory, College of Pharmacy and Health Sciences, Drake University, Des Moines, IA 50311 USA
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Craft S, Ekena J, Mayer B, Thamm DH, Saba C, Chun R, Trepanier LA. Characterization of a low expression haplotype in canine glutathione S-transferase (GSTT1) and its prevalence in golden retrievers. Vet Comp Oncol 2017; 16:E61-E67. [PMID: 28840668 DOI: 10.1111/vco.12333] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 06/05/2017] [Accepted: 06/11/2017] [Indexed: 12/12/2022]
Abstract
Glutathione S-transferase-theta (GSTT1) is a carcinogen detoxification enzyme, and low activity variants are associated with lymphoma in humans. We recently found a variant in the 3' untranslated region (UTR) of canine GSTT1, *101_102insT, which was predicted to change miRNA binding and was found in 5 of 17 golden retriever (GR) dogs with lymphoma but none of 14 healthy GRs. The aim of this study was to determine whether this variant led to decreased GSTT1 expression and was a discernible risk factor for lymphoma within the GR breed. On resequencing, *101_102insT appeared to be in complete linkage disequilibrium with 3 additional 3'UTR variants, leading to the inferred haplotype *3T>C; *101_102insT; *190C>A; *203T>C. In canine livers that were heterozygous for this variant haplotype, GSTT1 protein expression was significantly lower compared to the reference haplotype (densitometry .40 vs .64, P = .022), and GSTT1 transcript levels by qPCR were also significantly lower (fold difference .52, P = .012), without evidence of substantial allelic expression imbalance. The variant haplotype led to >50% decrease in expression in vitro (.31 ± .07 vs .64 ± .19; P = .019). We found no significant difference in minor allele frequencies between 71 GR dogs with lymphoma (MAF .162) and 33 healthy age-matched controls (MAF .136, P = .69). Our results indicate that the variant GSTT1 3'UTR haplotype containing *101_102insT reduces gene expression, which could lead to impaired carcinogen detoxification, but was not a detectable risk factor for lymphoma in GR dogs.
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Affiliation(s)
- S Craft
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - J Ekena
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - B Mayer
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - D H Thamm
- Flint Animal Cancer Center, Colorado State University, Fort Collins, Colorado
| | - C Saba
- Department of Small Animal Medicine and Surgery, University of Georgia, Athens, Georgia
| | - R Chun
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - L A Trepanier
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin
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12
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Klopfleisch R, Kohn B, Gruber AD. Mechanisms of tumour resistance against chemotherapeutic agents in veterinary oncology. Vet J 2015; 207:63-72. [PMID: 26526523 DOI: 10.1016/j.tvjl.2015.06.015] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2015] [Revised: 06/23/2015] [Accepted: 06/30/2015] [Indexed: 12/17/2022]
Abstract
Several classes of chemotherapy drugs are used as first line or adjuvant treatment of the majority of tumour types in veterinary oncology. However, some types of tumour are intrinsically resistant to several anti-cancer drugs, and others, while initially sensitive, acquire resistance during treatment. Chemotherapy often significantly prolongs survival or disease free interval, but is not curative. The exact mechanisms behind intrinsic and acquired chemotherapy resistance are unknown for most animal tumours, but there is increasing knowledge on the mechanisms of drug resistance in humans and a few reports on molecular changes in resistant canine tumours have emerged. In addition, approaches to overcome or prevent chemotherapy resistance are becoming available in humans and, given the overlaps in molecular alterations between human and animal tumours, these may also be relevant in veterinary oncology. This review provides an overview of the current state of research on general chemotherapy resistance mechanisms, including drug efflux, DNA repair, apoptosis evasion and tumour stem cells. The known resistance mechanisms in animal tumours and the potential of these findings for improving treatment efficacy in veterinary oncology are also explored.
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Affiliation(s)
- R Klopfleisch
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertag-Straße 15, 14163 Berlin, Germany.
| | - B Kohn
- Small Animal Clinic, Freie Universität Berlin, Oertzenweg 19 b, 14163 Berlin, Germany
| | - A D Gruber
- Institute of Veterinary Pathology, Freie Universität Berlin, Robert-von-Ostertag-Straße 15, 14163 Berlin, Germany
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