Antioxidant enzymes in canine mammary tumors

Abstract

Spontaneous mammary tumors are very common in bitches. The involvement of oxidative stress and the function of antioxidant enzymes in cancerogenesis have been studied in depth in human medicine, while data in veterinary medicine are still fragmentary. The main aim of this study was to evaluate the activity and the expression of superoxide dismutases (Cu-ZnSOD and MnSOD) and the activity of catalase (CAT) in canine mammary tumors in comparison with the adjacent healthy tissue. Six female dogs (mean age 10.4 years) were included in this study. After surgery, fresh tumor and healthy tissue samples were immediately frozen in dry ice and stored at -80°C for biochemical analyses, while the remaining parts were used for histopathological analysis. Enzyme activity was measured by spectrophotometric assays and protein expression by western blotting. In canine mammary tumors, Cu-ZnSOD activity and expression increased signifi cantly compared with healthy control tissues (p=0.03). MnSOD showed a signifi cantly lower activity in tumoral tissues at stage 2 (p<0.05), while a signifi cant increase of expression was measured in tumors. CAT activity was signifi cantly higher in healthy tissues respect to tumors (p=0.015). These variations of antioxidant enzymes activities and expression could be related to an increase of oxidative stress in breast cancer tissues and could be considered as biomarker candidates for neoplastic transformation.

Marcadores De Estresse Oxidativo Em Cães Com Neoplasias: Revisão Sistemática E Metanálise

“…Não obstante a tal divergência e alta heterogeneidade (I 2 = 98), a hipótese de aumento da atividade de SOD nos tecidos tumorais mamários se confirmou na presente metanálise (Figura 2). Acredita-se que o aumento da atividade de SOD em cães com neoplasia esteja associado a maior produção de espécies reativas de oxigênio (EROs) e maiores concentrações intracelulares de íons superóxido (HO) que estimulam a proliferação celular e, potencialmente, o desenvolvimento de metástases (Andreani et al, 2017).…”

Triple-Negative Breast Cancer Comparison With Canine Mammary Tumors From Light Microscopy to Molecular Pathology

“…These compounds can be used in nontumoral conditions and in conjunction with chemotherapy and radiotherapy to increase the effectiveness of therapy in cancer cells (170). Andreani et al (171) found that Cu-ZnSOD activity and expression in canine mammary tumors increased substantially compared with healthy control tissues. In a study in domestic cats, the enrichment of the ovary transport medium with SOD decreased cellular apoptosis and improved cumulus-oocyte complexes (COC) survival and in vitro embryo production (IVEP) (172).…”