EFFECT OF 60-F PRODUCT FROM CELL-FREE EXTRACT OF GROUP A STREPTOCOCCI AND OTHER MICROÖRGANISMS ON THE INVASION OF EHRLICH CARCINOMA CELLS IN MICE

Abstract

Since it was demonstrated that 60-F product, which was precipitated by 0.6-saturation of ammonium sulfate from streptomycin-pretreated cell-free extract of hemolytic streptococci Su strain (Su cocci), possessed a potent anticancer activity, isolation of 60-F product was carried out by the same method using other streptococci and microörganisms. Results obtained were as follows: (1) The 60-F product, which was effective in depriving the invasiveness of Ehrlich carcinoma cells, was obtained from Blackmore and C203S of group A streptococci, same as Su cocci, all of which possessed the streptolysin-S forming ability and an anticancer ability. (2) The 60-F product obtained from six other streptococci and microörganisms, all of which did not possess the streptolysin S-forming ability and the anticancer ability, was entirely ineffective. (3) All of the 60-F products with cytotoxic activity possessed a hemolytic activity, and hemolysis by these products was inhibited by Trypan Blue, indicating that the hemolysis is due to streptolysin-S contained in the 60-F product. From these results, it was deduced that the cytotoxic 60-F product against tumor cells is obtained from group A streptococci possessing the streptolysin-S forming ability and anticancer activity.