Expression of liver-specific functions and secretion of a hepatocyte growth factor by a newly established rat hepatoma cell line growing in a chemically-defined serum-free medium.

A rat hepatoma cell line 3'-mRLh-2 was established from 3'-methyl-4-dimethylaminoazobenzene-induced hepatoma. Cells proliferated well in 5Fs-DM-160, a chemically-defined serum-free medium; population doubling time was 68.5 h, and modal chromosome number was 81 (21%). The cells were transplantable, and the transplanted tumors were histologically diagnosed as hepatocellular carcinoma. They were cytochemically positive for gamma-glutamyl transpeptidase. The cells possessed about 30% of tyrosine aminotransferase activity level in the rat liver, and showed 5.5 to 7.4-fold induction of this enzyme activity in response to dexamethasone. Also, the cells secreted alpha-fetoprotein, albumin, transferrin, alpha 1-acid glycoprotein, C-reactive protein, fibrinogen, complement component C3, and other five-serum proteins. Furthermore, the conditioned medium stimulated DNA synthesis in primary cultures of adult rat hepatocytes in a dose-dependent, saturable manner and in the absence of epidermal growth factor. These properties of the cell line 3'-mRLh-2 were compared with those of the popular rat hepatoma cell lines, such as H4-II-E-C3 from Reuber hepatoma H35 and HTC from Morris hepatoma 7288C.