The levels of
UDP-galactose: N-acetylglucosamine(beta 1-4)galactosyltransferase activity (GalT-4) were determined in the sera, in solid
tumors, and in corresponding cell cultures of rats bearing two lines of prostate
adenocarcinomas (PA-2 and PA-3), and in the sera of rats bearing other transplanted and autochthonous
adenocarcinomas. Sera and tissues from normal (
tumor-free) rats were used as controls. Prostate
adenocarcinoma cell cultures had five times greater levels of
enzyme activity than did
tumor cell infiltrated lymph nodes from animals bearing the prostate
adenocarcinomas. The levels of activity in the cells of both prostate
tumor lines were equivalent, even though they metastasize through different routes. Serum levels of
galactosyltransferase activity were detected in the blood, and in rats bearing a mammary
adenocarcinoma with extensive
necrosis of the
tumor mass (
tumor mass greater than 22.0 g/200 g
body weight). The increase was three times the control value. The sera of L-W rats bearing prostate
tumors (PA-2 and PA-3) were inactive with the GalNAc-containing acceptor, Gm2 (GalNAc beta 1-4(NeuAc alpha 2-3)Gal beta 1-4Glc-Cer) but active with either free GlcNAc (Km = 0.25 mM) or LcOse3Cer (GlcNAc beta 1-3 Gal beta 1-4Glc--Cer; GlcNAc--R).