In vitro anti-tumour activity of tumour necrosis serum

Abstract

A method measuring 3H-thymidine incorporation in Meth A sarcoma cells was used to quantify in vitro anti-tumour activity of tumour necrosis serum and compared with a method using cell viability as a parameter. Tumour necrosis serum obtained from mice pretreated with Corynebacterium parvum and elicited with endotoxin two weeks later greatly inhibited 3H-thymidine incorporation, whereas sera of normal mice and of mice treated with C. parvum or endotoxin alone were much less inhibitory. All sera reduced viable cell numbers, tumour necrosis serum being most active.

The 3H-thymidine incorporation assay is suited for screening mouse sera on anti-tumour activity. It was shown that the anti-tumour activity of normal mouse serum can be potentiated by in vivo pretreatment of mice with bacterial agents. The mechanism of the anti-tumour action(s) and the factor(s) involved remain to be elucidated.