BILE-ACID SYNTHESIS BY THE HUH-7 CELL-LINE DERIVED FROM A HUMAN HEPATOCELLULAR-CARCINOMA

Bile acids in conditioned media used for culture of the HuH-7 cell lin e, derived from a human hepatocellular carcinoma, were analyzed by gas chromatography and gas chromatography/mass spectrometry to ascertain the presence or absence of any abnormalities in bile acid metabolism. Cholic and chenodeoxycholic acids, the primary bile acids of humans, w ere found in the conditioned media, and more than half of the bile aci ds were conjugated with glycine but not with taurine or sulfuric acid. In addition, 3beta-hydroxy-5-cholenoic, alpha,7alpha,12alpha-trihydro xy-5beta-cholestanoic and 3alpha,7alpha-dihydroxy-5beta-cholestanoic a cids were found in the media, and most of the 3beta- hydroxy-5-choleno ic acid was in a sulfated form, while all of the cholestanoic acids we re unconjugated. Since the cells had been cultured in serum-free media , all these bile acids had to have been newly synthesized and conjugat ed. In this study, 3beta-hydroxy-5-cholenoic acid, a presumed intermed iate for the alternative pathway of chenodeoxycholic acid synthesis, w as the major bile acid synthesized by the HuH-7 cells. These results s uggest that HuH-7 cells may employ some unusual and unique metabolic p athways for the production of bile acid.