EXPRESSION OF 65-KDA ONCOFETAL PROTEIN IN EXPERIMENTAL HEPATOMA AFTERANTICANCER THERAPY

We have tested the expression of a 65-kDa oncofetal protein (p65) afte r combined treatment with menadione and methotrexate in hamsters trans planted with Kirkman-Robbins hepatoma. The treatment of tumor-bearing animals with these compounds significantly inhibited both the tumor de velopment and the expression of p65. This inhibition in tumor tissue w as calculated from densitograms of Western blots. The inhibition of p6 5 expression was also confirmed in the serum of hepatoma bearing anima ls by using solid-phase radioimmunoassay (RIA) to quantify the specifi city of polyclonal antibodies to fetal p65 molecules. Additionally, p6 5 was shown to localize both in cytoplasm and in the nuclear extracts prepared from hepatoma tissue.