DNA's from human hepatoma and gastric cancer mitochondria

1. Mitochondria isolated from human liver, hepatoma and gastric cancer contain DNA. The DNA content per mitochondrial protein is about ten times as much in cancer as in normal liver. 2. Human liver, hepatoma and gastric cancer contain circular DNA molecules in their mitochondria. Circular DNAs from normal liver and cancer mitochondria are mostly about 5 μ long, and the frequency of circular DNAs of multiple or shorter length is higher in cancer mitochondrial DNA. The outline of the present paper was presented at the 26th Congress of Japanese Cancer Association (1967) (52, 53).