Skeletal Alkaline Phosphatase Activity Is Primarily Released from Human Osteoblasts in an Insoluble Form, and the Net Release Is Inhibited by Calcium and Skeletal Growth Factors

1998 ◽  
Vol 62 (4) ◽  
pp. 332-340 ◽  
Author(s):  
D. J. Anh ◽  
H. P. Dimai ◽  
S. L. Hall ◽  
J. R. Farley
Keyword(s):  
Alkaline Phosphatase ◽  
Growth Factors ◽  
Phosphatase Activity ◽  
Alkaline Phosphatase Activity ◽  
Skeletal Growth ◽  
Human Osteoblasts ◽  
Insoluble Form ◽  
Skeletal Alkaline Phosphatase ◽  
Net Release

Alkaline phosphatase activity from human osteosarcoma cell line SaOS-2: an isoenzyme standard for quantifying skeletal alkaline phosphatase activity in serum.

1989 ◽  
Vol 35 (2) ◽  
pp. 223-229 ◽  
Author(s):  
J R Farley ◽  
E Kyeyune-Nyombi ◽  
N M Tarbaux ◽  
S L Hall ◽  
D D Strong
Keyword(s):  
Alkaline Phosphatase ◽  
Phosphatase Activity ◽  
Cell Lines ◽  
Alkaline Phosphatase Activity ◽  
Osteosarcoma Cell ◽  
Kinetic Assay ◽  
Human Osteosarcoma ◽  
Alp Activity ◽  
Human Osteosarcoma Cell ◽  
Skeletal Alkaline Phosphatase

Abstract Earlier we described a kinetic assay for quantifying skeletal alkaline phosphatase (ALP) isoenzyme activity in serum. The precision of the assay depends on including ALP standards for the skeletal, hepatic, intestinal, and placental isoenzymes. We wondered whether human osteosarcoma cells could provide an efficient alternative to human bone or Pagetic serum as a source of the skeletal ALP standard. ALP activities prepared from five human osteosarcoma cell lines were compared with a bone-derived ALP standard with respect to heat stability and sensitivity to chemical effectors. Two of the cell lines (SaOS-2 and TE-85) contained ALP activities that resembled the bone-derived standard. We selected SaOS-2 cells for additional evaluation (as a potential source of isoenzyme standard), because they contained 40-50 times more ALP activity than did the TE-85 cells. To include the SaOS-2 cell-derived ALP activity in the quantitative isoenzyme assay, we diluted the enzyme in a solution containing heat-inactivated (i.e., ALP-negative) human serum. Surprisingly, this dilution caused a 60-125% increase in maximum enzyme activity. In the quantitative assay of ALP isoenzyme in serum, the SaOS-2 derived ALP was indistinguishable from the serum skeletal ALP standard, with respect to the above criteria and assay variations. Evidently ALP from SaOS-2 cells is suited as a standard for measuring skeletal ALP activity in this assay.

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