Partial purification of a growth factor synthesized by a rat hepatoma cell line established in serum-free medium.
A rat hepatoma cell line was established from primary culture using RPMI 1640 without supplements. Hepatomas were induced in rats by 0.06% 3'-methyl-4-dimethylaminoazobenzene. An established cell line, FF101, has been maintained as a monolayer for longer than 34 months and subcultured for 42 passages. The population-doubling time was 78 h. The modal chromosome number was 66. FF101 was transplantable, and morphological examination of the transplanted tumors revealed a mixed type of hepatocellular and cholangiocellular carcinoma. FF101 retained the ability to express tyrosine aminotransferase and glucose-6-phosphatase. Also, FF101 synthesized alpha-fetoprotein. FF101-conditioned medium stimulated DNA synthesis and proliferation of several cell lines such as AH66, K562, and BALB/c3T3. The growth-promoting activity of FF101-conditioned medium was abolished by protease, dithiothreitol, acidic treatment, and heating. Gel filtration of conditioned medium on Sephacryl S-200 disclosed the growth-promoting activity at the molecular size of approximately 60,000 Da, and the isoelectric point (pI) was between 5.5 and 6.5. These results suggest that FF101 synthesizes a novel growth factor which has little specificity in both species and organs.
Matsuda
H
H
Second Department of Medicine, Hamamatsu University School of Medicine, Shizuoka, Japan.
Matsumoto
M
M
Haraguchi
S
S
Kanai
K
K
D000818:Animals; D003470:Culture Media; D006133:Growth Substances / Q000302:isolation & purification*; D008114:Liver Neoplasms, Experimental / Q000032:analysis* / Q000235:genetics / Q000473:pathology; D008297:Male; D008970:Molecular Weight; D009368:Neoplasm Transplantation; D051381:Rats; D014407:Tumor Cells, Cultured
D003470:Culture Media; D006133:Growth Substances