Detection of a novel lactate dehydrogenase isozyme and an apparent differentiation-associated shift in isozyme profile in hepatoma cell lines.

Abstract A hitherto unreported lactate dehydrogenase (LD) isoenzyme, which migrates electrophoretically to the relative position between LD 2 and LD 3 has been identified in the electropheratogram in 7 of 7 (100%) cultured hepatoma cell lines with various degrees of differentiation and is thus given the name LD 2–3 . LD 2–3 seems to be specific for hepatoma cells because this atypical isoenzyme can not be detected in other tumor cell lines. In addition, the hepatoma cell lines also show a distinct pattern of LD isoenzyme and the isoenzyme pattern varies with the degree of differentiation. Hence, the expression pattern of LD isoenzyme phenotypes may provide a good marker for the investigation of human hepatoma cell differentiation.