Expression of iron-related proteins in feline and canine mammary gland reveals unexpected accumulation of iron

Abstract

Dysregulation of cellular iron homeostasis in human breast cancer is reflected by the altered expression of regulatory proteins. The expressions of iron-related proteins in the mammary glands of cats and dogs have not been assessed. We evaluated the expressions of ferritin, ferroportin, hepcidin and transferrin receptor 1 in benign and malignant mammary gland lesions in cats and dogs. Iron deposition was detected using Perls’ Prussian blue staining. We found no major differences in the expression of iron-related proteins between benign and malignant mammary gland lesions in either cats or dogs; however, these species exhibited accumulation of iron in benign lesions. Our findings provide an explanation for the absence of higher iron requirements by tumor cells in these animals. Further investigation of local iron homeostasis in cats and dogs and differences in their physiology compared to human breast cancer is required.

Key words:

• cat
• dog
• homeostasis
• iron
• mammary gland
• siderosome

Acknowledgments

O Marques acknowledges Fundação para a Ciência e Tecnologia (FCT) for a PhD grant (SFRH/BD/2011/78184). The authors also acknowledge financial support from ICBAS/AI&NS-UMIB and by national funds through FCT and Ministério da Educação e Ciência and, when applicable, co-funded by FEDER funds within the partnership agreement PT2020 related with the research unit number 4293. IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT. This work is funded by FEDER funds through the Operational Programme for Competitiveness Factors-COMPETE and National Funds through the FCT, under the projects “PEst-C/SAU/LA0003/2013.”

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of this paper.