Tissue distribution and biochemical properties of an interspecific tumour-associated gamma foetal antigen

A late-gestation neonatal antigen (gamma foetal antigen; gamma-FA) immunologically and biochemically unrelated to murine alpha-foetoprotein, was identified in several spontaneous and carcinogen-induced sarcomas and hepatic carcinomas of the mouse and rat. An approximate mol. wt of 35,000 for gamma-FA from both foetus and tumour was obtained by molecular-sieve chromatography and sucrose-gradient centrifugation. Radial immunodiffusion analyses of organ extracts indicated that gamma-FA could be found in several neonatal tissues, the highest concentration occurring in the spleen. In the 2-month-old mouse, only splenic tissue contained gamma-FA and at much lower levels than in the organ of the newborn mouse.

Enhancement of mutagenesis during cell replication of cultured liver epithelial cells

The susceptibility to mutagenesis of proliferating and non-proliferating mammalian cells was studied in cultured rat liver epithelial cells. Cells brought to growth quiescence by a non-toxic means were stimulated to proliferate and both types of cultures were exposed to methyl methanesulfonate (MMS). Cultures enriched in proliferating cells were more susceptible to both the toxic and mutagenic action of the mutagen than were quiescent cultures with a low level of proliferation.

Inhibition of growth of mouse ehrlich ascites by normal tissue extracts

A dialyzable component from the aqueous extracts of mouse skeletal muscle and liver inhibited in vitro growth of a mouse Ehrlich ascites. A similar component was not detected in extracts of spleen, kidney, lung, skin, serum or small intestine. The muscle component appeared to be different from that of the liver in its resistance to heat and its stability in the culture medium. Both components however were stable on storage at 4, 23 and 37 degrees C for 72 h. Intraperitoneal injection of the muscle and liver component into mice previously innoculated with Ehrlich ascites significantly decreased tumor incidence in these animals as compared with the control.