Increased activity of a beta-galactosyltransferase in tissues of rats bearing prostate and mammary adenocarcinomas.

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).