A human endometrial tumor (Ishikawa) cell line in culture responded to estradiol stimulation, as measured by growth and alkaline phosphatase activity. These effects were similar whether the medium was enriched with serum or was serum-free. Estradiol increased placental alkaline phosphatase activity 2-3-fold over control in these Ishikawa cells. The mechanism for this increase appeared to be at ...

Human liver alkaline phosphatase [ortho-phosphoric monoester phosphohydrolase (alkaline optimum), EC 3.1.3.1] was purified, and some of its physical and chemical properties were examined and compared to those of human placental alkaline phosphatase. The results indicated a different peptide structure for each, based upon HB2-terminal residue sequence, two-dimensional tryptic peptide maps, and d...

The effect of 5-bromo-2'-deoxyuridine (BrdUrd) and dibutyryl cyclic AMP (Bt2cAMP) on the expression of the placental isoenzyme of human alkaline phosphatase was examined in BeWo choriocarcinoma cells. By using a combination of specific immunoprecipitation and polyacrylamide-gel electrophoresis of cells labelled either metabolically with [35S]methionine or cell-surface-labelled with 125I, both B...

This case report describes for the first time a case of pure testicular carcinoid pre-aortic lymph node metastases in a 25 year old patient with carcinoid syndrome. The simultaneous occurrence of intratubular germ cell neoplasia in the surrounding testicular tissue was identified by OCT4 and placental-like alkaline phosphatase positivity. This confirmed that the tumour had a germ cell origin in...

Gene cloning and site-directed mutagenesis have had a profound effect on alkaline phosphatase research. Four distinct structural genes encoding placental, intestinal, and tissue-nonspecific isoenzymes have been cloned, sequenced, and mapped to human chromosomes. Differences in properties between the respective gene products are due to variations in primary structure involving only one, or a few...

A431 human epidermoid carcinoma cells monophenotypically express the placental alkaline phosphatase (PLAP)-like enzyme shown by its catalytic and antigenic characteristics, properties which are shared by the Nagao isozyme. More specifically, it is L-leucine sensitive just as is the rare placental D-variant of PLAP and the testicular heat-stable enzyme. Collectively, these are all referred to as...

In 11 adult testes studied, about 0.3 to 4.6% of the total alkaline phosphatase activity was heat stable and L-phenylalanine sensitive but L-homoarginine insensitive. The testicular heat-stable enzyme was more susceptible to inhibition by L-leucine and ethylenediaminetetraacetate than were the normal placental and intestinal enzymes. By antibody-directed enzyme inhibition test, the testicular h...