Involvement of immune response in anti-tumor effects of Staphylococcus aureus filtrate preparation.
OBJECTIVE
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.


METHODS
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.


RESULTS
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-alpha and IFN-gamma in mice.


CONCLUSIONS
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.
Zhang
Bo
B
Institute of Pharmacology and Toxicology, School of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
Fang
Yanfen
Y
Cao
Ji
J
Zhang
Chong
C
Ying
Meidan
M
He
Qiaojun
Q
Yang
Bo
B
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology*; D006528:Carcinoma, Hepatocellular / Q000276:immunology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000276:immunology; D008113:Liver Neoplasms / Q000276:immunology; D051379:Mice; D008813:Mice, Inbred ICR; D013154:Spleen / Q000166:cytology; D013211:Staphylococcus aureus / Q000737:chemistry*
D000970:Antineoplastic Agents; D007155:Immunologic Factors