DNA polymerases I and II in regenerating rat liver and Morris hepatomas.

Transcriptionally active RNA polymerases from Morris hepatomas and rat liver. Elucidation of the mechanism for the preferential increase in the tumour RNA polymerase I.

The amount and/or activity of DNA-dependent RNA polymerase I, Ii and III from resting liver, regenerating liver and a series of Morris hepatomas (5123D, 7800, 7777, 3924A) were determined after extraction of the enzymes from whole tissue homogenates and subsequent fractionation by DEAE-Sephadex column chromatography. When compared with resting liver, the tumours exhibited a characteristic enzym...

The heterogeneity of DNA polymerases in rat liver and hepatomas.

Molecular Species of Phospholipid in Rat Hepatomas and in Fetal, Regenerating, and Adult Rat Livers1

The molecular species of phospholipid in rat hepatomas were found to be different from those in normal adult liver. Phosphatidylcholine in Yoshida hepatoma contained phosphatidylcholine with 34:1 as the sums of the chain length and of the unsaturation of fatty acids esterified at C-1 and C-2 of glycerol, as an example (PC34:i), PC36:2,PC36:i, PCa4:2,and PCae*, and its phosphatidylethanolamine c...

Separation of DNA polymerase from rat liver and hepatomas.

Sephadex G-200 column chromatography of hepatoma DNA polymerase yields two peaks of enzyme activity. Peak I contains enzyme having a marked preference for denatured DNA, and the levels of this enzyme increase in proportion to tumor growth rate. Peak II contains the enzyme fraction having a moderate preference for native DNA. Normal and regenerating rat liver have a predominance of Peak II, in c...

Increased DNA polymerase activity in a series of rat hepatomas.

It has previously been reported that there may be a correlation between DNA synthesis and the growth of a series of rat hepatomas. This study describes a similar correlation that exists with DNA polymerase activity partially purified from normal liver and from 12 types of hepatomas. Not only are the hepatomas characterized by increased DNA polymerase levels, but the hepatoma enzymes prefer dena...