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Updated: Oct 5, 2026

A Simple Pit Assay Protocol to Visualize and Quantify Osteoclastic Resorption In Vitro
Published on: June 16, 2022
[Indices of proteolysis in evaluation of resorption in bone tumors]
Abstract:
Activities of acid and alkaline phosphatases, collagenase, cathepsin D, trypsin-like proteinases, alpha(1)-proteinase inhibitor (alpha(1)-PI), alpha(2)-macroglobulin (alpha(2)-MG) were measured in blood plasma and tumor tissue of patients with giant-cell tumor of the bone (GCTB) and bone chondrosarcoma. These tumors differed by enzymatic activities. GCTB is characterized by increased activity of alkaline phosphatase, while in chondrosarcoma tissue the activities of collagenase and cathepsin D were the highest. Activities of acid phosphatase, collagenase, trypsin-like proteinases were increased in the plasma of patients with both tumors; alpha(1)-PI/alpha(2)-MG ratio was increased. Bone resorption parameters correlated with proteolysis inhibitors. Activities of collagenase and acid phosphatase were increased in tumor tissue and plasma in the presence of low activities of alpha(2)-MG and increased alpha(1)-PI/alpha(2)-MG index, which seems to require special attention during the postoperative period.
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