Enzyme release from cultured human melanoma cells.
The lysosomal enzyme beta-hexosaminidase and the melanocyte specific enzyme tyrosinase were examined in human melanoma cell cultures. The beta-hexosaminidase activity of the medium was approximately 40% of the total cellular activity after 24 h, while after 48 h the activity in the medium was twice that of the cells. The tyrosinase activity in the medium was 5% and 19% of the total cellular activity after the 24 h and 48 h incubation, respectively. The low level of lactate dehydrogenase activity in the medium after 24 as well as 48 h of incubation indicated that the release of beta-hexosaminidase and tyrosinase was not due to membrane injury. The data suggest, that 1) beta-hexosaminidase may be a candidate for tumor markers in malignant melanoma, and 2) the tyrosinase activity found in sera of melanoma patients may be due, at least partly, to enzyme release by living cancer cells.
Karg
E
E
Department of Dermatology, University of Lund, Sweden.
Hultberg
B
B
Isaksson
A
A
Rosengren
E
E
Rorsman
H
H
D002460:Cell Line; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008546:Melanoma, Experimental / Q000473:pathology*; D014442:Monophenol Monooxygenase / Q000378:metabolism*; D014407:Tumor Cells, Cultured / Q000201:enzymology*; D001619:beta-N-Acetylhexosaminidases / Q000378:metabolism*
D007770:L-Lactate Dehydrogenase; D014442:Monophenol Monooxygenase; D001619:beta-N-Acetylhexosaminidases