[The expression, secretion and regulation of membrane-soluble syndecan-1 in human multiple myeloma cells]

To analyze the expression, secretion and regulation of membrane-soluble syndecan-1 in human multiple myeloma cells, and to explore the relationship between syndecan-1 and the development of human multiple myeloma.

Syndecan-1 expression on the surface of malignant plasma cells was analyzed by immuno-staining, the levels of soluble syndecan-1 in the supernatant of cultured tumor cells by ELISA.

1. Human multiple myeloma cells expressed high levels of syndecan-1. The density of syndecan-1 varied from 170,000 to 800,000 molecules per cell. The expression of syndecan-1 lost rapidly as the cells underwent apoptosis. 2. Most myeloma cells produced soluble syndecan-1, the rate of production did not correlate with the density of membrane syndecan-1. Moreover, the production of soluble syndecan-1 did not require serum. 3. The protein synthesis inhibitor cycloheximide inhibited the production of syndecan-1. The serine protease inhibitor antipain did not affect the secretion of syndecan-1.

As a receptor of many growth factors, cytokines and heparin-like growth factors, syndecan-1 might play an important role in tumor cell growth and homing in multiple myeloma development.