NOTE Surgery Serum Amyloid A Promotes Invasion of Feline Mammary Carcinoma Cells

ABSTRACT. The serum amyloid A (SAA) concentration is higher in mammary tumors with metastases in both humans and animals. In the pres-ent study, the direct effects of recombinant feline SAA (rfSAA) protein on invasiveness of feline mammary carcinoma cells were evaluated. As an indicator of invasiveness, matrix metalloproteinase-9 (MMP-9) expression was investigated in 4 feline mammary carcinoma cell lines of different origins. In 3 of 4 cell lines, MMP-9 expression was significantly increased by rfSAA stimulation. The invasive capacities of fe-line mammary carcinoma cells were also stimulated by rfSAA. The findings of this study have identified a novel role for SAA in mammary tumorigenesis and suggest that therapeutic strategies targeting SAA may provide new alternatives in treating tumor invasion and metastasis. KEY WORDS: feline, invasiveness, mammary carcinoma, matrix metalloproteinase, serum amyloid A doi: 10.1292/jvms.14-0108; J. Vet. Med. Sci. 76(8): 1183–1188, 2014 Serum amyloid A (SAA) is one of the major acute phase proteins (APPs) in mammals, including humans and cats [6, 27]. Acute phase reaction is a systemic response to inflam-matory stimulations, such as infection or trauma, and APPs including SAA are synthesized mainly in the liver as part of the reaction [7]. Gene expression and protein synthesis of SAA are stimulated by several inflammatory cytokines