Studies on the Anticancer and Streptolysin S-Forming Abilities of Hemolytic Streptococci

Abstract

The present review summarizes most of the data obtained in experimental anticancer studies with hemolytic streptococcus in our laboratories and in others during these past 12 years.
The principal results are as follows:
(1) Streptococci possessing streptolysin S-forming ability act against a wide range of transplantable animal tumors.
(2) Bernheimer's basal medium (BBM) differs from other simpler media, such as 0.85% NaCl and phosphate-buffered saline, in that the streptolysin Sforming and anti-cancer abilities of cocci suspended in BBM is resistant to heating at 45C for 30 minutes.
(3) A procedure consisting of preincubation of live cocci suspended in BBM containing penicillin (2-4×10⁴units/ml) at 37C for 20 minutes followed by heating at 45C for 30 minutes, yields a potent anticancer preparation of having neither streptolysin S-forming ability nor virulence for mice and rabbits. The preparation is about 20 times more effective than the nontreated live coccus suspended in 0.85% NaCl in inhibiting the growth and metastasis of Ehrlich ascites carcinoma in mice, but it is somewhat pyrogenic.