NUCLEAR-DNA POLYMERASES OF HUMAN CARCINOMAS

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  • 1 January 1977
    • journal article
    • research article
    • Vol. 37  (3) , 702-704
Abstract
Comparisons were made of the DNA polymerases of normal human lung and cecum, primary carcinomas of human lung, breast and cecum, and resting and regenerating rat liver. The picture for the normal human tissues is similar to the one for unstimulated rat liver. That for carcinomas resembles regenerating rat liver. Human tissues contain 2 polymerases with sedimentation coefficients of about 3 and 7 S, the enzymes are restricted to the nucleus, and the specific activities of the 7 S polymerase, but not of the 3 S enzyme, are elevated in cancer. Just as with regenerating rat liver polymerases, the 3 S activity of a bronchogenic carcinoma was unaffected by cytosine arabinoside-5''-triphosphate and only little reduced by novobiocin; DNA synthesis by the 7 S enzyme was abolished by both compounds. A variety of other inhibitory agents had similar effects on the 7 S polymerases of human carcinomas and regenerating rat liver.