CHARACTERIZATION OF ALKALINE-PHOSPHATASE GENES EXPRESSED IN SEMINOMA BY CDNA CLONING

Two members of a placental alkaline phosphatase (PLAP) family, FLAP an d FLAP-like or germ cell alkaline phosphatase, are aberrantly expresse d in tumors of ecotropic origin. To characterize alkaline phosphatase induced in seminoma, alkaline phosphatase cDNA clones were isolated fr om a cDNA library constructed from seminoma cells and characterized by nucleotide sequence determination. Thus, isolated cDNA clones were cl assified into two types, germ cell alkaline phosphatase (PLAP-like) an d liver/bone/kidney-type alkaline phosphatase (L/B/K AP). These result s suggest that other than the FLAP family members, the expression of L /B/K AP is enhanced in seminoma and can serve as a tumor marker in sem inoma.