The expressions of oncogenes and liver-specific genes in Morris hepatomas

The expression of three liver-specific genes and four oncogenes was studied in the Morris hepatomas 8994, 7288c, 7777, 5123tc, and 7800. Total RNA isolated from these tumors was probed with cDNA's for alpha-fetoprotein (AFP), albumin, tyrosine aminotransferase (TAT), and the oncogenes Ha-ras, Ki-ras, myc and src. When compared to mRNA's levels expressed in normal adult liver, we found AFP levels elevated in AFP-producing tumors, albumin and TAT mRNA levels depressed in all tumors, except TAT is elevated in 5123tc and the oncogenes with the exception of src elevated in all tumors. These results argue against a coordinated expression of these genes as a result of transformation, but suggest that oncogene expression is related to tumorigenesis or proliferation.