Summary
Hepatomas occurred in the liver of 5 of 386 ACI rats at the site of injection, 10–16 weeks previously, of cells of regenerating liver pre-incubated with DNA derived from the Morris hepatoma 3924C, transplantable in this strain. A tumor of undetermined nature developed in 1 of 62 rats 6 months after in trahepatic injection of a mixture of preneoplastic liver DNA and RNA.
No tumors occurred in 1480 other ACI rats (No. in parentheses) treated as follows: I. intrahepatic injection of regenerating liver cells pre-incubated with (a) hepatoma RNA (340), (b) preneoplastic DNA (124), (c) normal liver DNA (40), and (d) normal liver RNA (40); II. intrahepatic injection of (a) hepatoma DNA (280), (b) hepatoma RNA (246), (c) preneoplastic liver DNA (166), (d) preneoplastic liver RNA (184), (e) normal liver DNA (30), and (f) normal liver RNA (30).
The circumstances under which the hepatomas occurred seem to warrant the conclusion that a process of cell transformation by the hepatoma DNA was involved in their pathogenesis.
Supported in part by USPHS Grant Ca-07212 from the National Cancer Institute.