Enzyme Activities of Some Cultured Human Cells. ∗

Summary

The data presented here allow a comparison of the activity of 3 enzymes in diploid and heteroploid human cell cultures derived from both normal and neoplastic tissues. In general, acid phosphatase activity is similar in all of these cultures, although there is evidence that diploid cultures approaching or in phase III (decreased capacity for proliferation) have higher activities of this enzyme. Alkaline phosphatase activity was high in the cultures derived from neoplastic tissue, and low in the diploid cultures derived from normal tissues. Cultures derived from normal tissues and transformed in vitro by an oncogenic virus show activities lower than any of the diploid cultures.

Cultures derived from neoplastic tissues show lactate dehydrogenase activities 1.5- to 2-fold higher than the normal diploid or transformed cultures.