title: A Comparative Study on the In Vitro Effects of the DNA Methyltransferase Inhibitor 5-Azacytidine (5-AzaC) in Breast/Mammary Cancer of Different Mammalian Species.
abstract: Murine models are indispensible for the study of human breast cancer, but they have limitations: tumors arising spontaneously in humans must be induced in mice, and long-term follow up is limited by the short life span of rodents. In contrast, dogs and cats develop mammary tumors spontaneously and are relatively long-lived. This study examines the effects of the DNA methyltransferase (DNMT) inhibitor 5-Azacytidine (5-AzaC) on normal and tumoral mammary cell lines derived from dogs, cats and humans, as proof of concept that small companion animals are useful models of human breast cancer. Our findings show that treatment with 5-AzaC reduces in vitro tumorigenicity in all three species based on growth and invasion assays, mitochondrial activity and susceptibility to apoptosis. Interestingly, we found that the effects of 5-AzaC on gene expression varied not only between the different species but also between different tumoral cell lines within the same species, and confirmed the correlation between loss of methylation in a specific gene promotor region and increased expression of the associated gene using bisulfite sequencing. In addition, treatment with a high dose of 5-AzaC was toxic to tumoral, but not healthy, mammary cell lines from all species, indicating this drug has therapeutic potential. Importantly, we confirmed these results in primary malignant cells isolated from canine and feline adenocarcinomas. The similarities observed between the three species suggest dogs and cats can be useful models for the study of human breast cancer and the pre-clinical evaluation of novel therapeutics.
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14850, USA.
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Harman
authors.affiliation: Department of Biological Sciences, State University of New York at Cortland, Cortland, NY, USA.
authors.forename: Theresa M
authors.initials: TM
authors.lastname: Curtis
authors.affiliation: Royal (Dick) School of Veterinary Studies and Roslin Institute, The University of Edinburgh, Edinburgh, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Argyle
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14850, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Coonrod
authors.affiliation: Baker Institute for Animal Health, College of Veterinary Medicine, Cornell University, Ithaca, NY, 14850, USA. grv23@cornell.edu.
authors.forename: Gerlinde R
authors.initials: GR
authors.lastname: Van de Walle
mesh_terms: D000818:Animals; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D001374:Azacitidine / Q000009:adverse effects / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D002415:Cats; D002460:Cell Line; D045744:Cell Line, Tumor; D019175:DNA Methylation / Q000187:drug effects; D015254:DNA Modification Methylases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D004791:Enzyme Inhibitors / Q000009:adverse effects / Q000494:pharmacology*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D015674:Mammary Neoplasms, Animal / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D009363:Neoplasm Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000187:drug effects; D000075082:Proof of Concept Study; D013045:Species Specificity; D014407:Tumor Cells, Cultured
chemical_list: D000964:Antimetabolites, Antineoplastic; D004791:Enzyme Inhibitors; D009363:Neoplasm Proteins; D015254:DNA Modification Methylases; D001374:Azacitidine
keywords: 5-Azacytidine (5-AzaC); Cat; Dog; Human; Mammary cancer cell line; Primary mammary tumor