Detection of a progression-linked DNA restriction fragment in rat hepatoma cells probed with a hexokinase cDNA.

We have compared genomic DNA isolated from a series of rat hepatomas and from normal rat liver tissue by restriction fragment analysis. Our objective was to identify a tumor-specific restriction fragment that would be present in rapidly growing tumors and missing in normal tissues. Using a cDNA probe specific for the C-terminal half of rat brain hexokinase, we have identified several changes in DNA restriction fragment lengths in rat hepatomas vs. normal rat liver. Most of these involved restriction fragments that were present in normal rat DNA and missing in tumor DNA. However, one HinfI fragment of M(r) = 13.4 kilobase pairs (kb) was found to be present in rapidly growing rat hepatomas, but missing in normal rat tissue and in hepatomas of slow or intermediate growth rate.