Involvement of immune response in anti-tumor effects of Staphylococcus Aureus Filtrate Preparation.

Staphylococcus Aureus Filtrate Preparation (SAFP) is a preparation of low-virulence strain of Staphylococcus aureus. In our study, we aimed to determine the anti-tumor activity of SAFP in vivo and explore the potential mechanism. Our study evaluated the anti-tumor activity of SAFP in four cancer cell models in vivo and determined its up-regulatory effects on mice immune system in vivo. It showed that 7.2 ng/10 g SAFP could inhibit the progression of murine hepatoma H22 and sarcoma S180, and the tumor inhibition rates achieved 48.1 and 35.7%, respectively. In human non-small cell lung cancer A549 and hepatoma BEL7402 xenograft athymic mice models, T/C of 7.2 ng/10 g SAFP group reached 41.0% in A549 model and 21.0% in BEL7402 model. Meanwhile, SAFP also significantly increased the proliferation of cultured mice splenocytes to 162.1%, and 7.2 ng/kg SAFP significantly ( P < 0.001) raised the activity of NK cells, elevated the serum level of IL-2, TNF-α and IFN-γ in mice. SAFP exhibited high efficiency in inhibiting the growth of cancer cells in a dose-dependent manner, which possibly attributed to its regulatory effects of immune system. [ABSTRACT FROM AUTHOR]