Human cell lines expressing intestinal alkaline phosphatase.

At least three loci determine human alkaline phosphatases [orthophosphoric-monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1]: one coding for the placental form of the enzyme, at least one coding for the intestinal forms, and at least one for the liver, bone, and kidney forms. The alkaline phosphatase in cell line D98/AH-2 has been characterized by inhibition, thermostability, and electrophoretic studies. It is intestinal in type and resembles the fetal intestinal form somewhat more closely than the adult intestinal form. Intestinal alkaline phosphatase was found in the related cell lines Detroit 98, D98/S, and D98/AH-R. No placental alkaline phosphatase could be detected in any of these cell lines. This series of cell lines are believed, on the basis of earlier investigations, to be HeLa in origin but other HeLa cell lines show placental alkaline phosphatase. Loss of expression of the placental alkaline phosphatase locus probably occurred prior to the separation of Detroit-98 from the lineage leading to other HeLa cell lines and this has persisted in the Detroit-98 derivatives D98/AH-2, D98/S, and D98/AH-R. Another possibility is that placental alkaline phosphatase expression only appeared in the HeLa lineage subsequent to the separation of Detroit-98.