Alpha1-Fetoprotein Biosynthesis During the Growth Cycle of Differentiated Fetal Rat Hepatocytes in Primary Monolayer Culture

INTRODUCTION pregnant and growing (neonatal) rats (18, 19) as well as in the serum of adult rats induced by partial Serum proteins associated with malignancies (onhepatectomy to regenerate their liver (20, 21) . coproteins) have attracted considerable attention, These observations imply that biosynthesis and especially because of their possible use in the early release of a 1 F are related to the cell cycle . In the clinical detection of cancer (1, 2) . Perhaps the most studies described here, in which a well-characterintensively studied of these oncoproteins are the ized monolayer culture system of fetal rat hepatoembryonal carcinogenic antigen (3), associated cytes is used (22-24), direct evidence is presented mainly with gastrointestinal malignancies (4-6), which supports this hypothesis . and alpha s -fetoprotein (a 1 F) (l, 2), associated with primary hepatocellular carcinoma (I, 7-10), and MATERIALS AND METHODS teratoblastomas of gonadal origin (I l, 12) . However, oncoproteins may also be found in Reagents nonmalignant states (5, 13-18) . This is especially Tissue culture media and supplies required to grow the case of the a 1 F, which appears in the serum of fetal rat hepatocytes have been described in detail