ABSTRACT
<p><b>OBJECTIVE</b>To investigate the expression of B lymphocyte stimulator (BlyS) and its receptors in multiple myeloma (MM) cells, and to explore the relationship between BLyS and the development of human multiple myeloma.</p><p><b>METHODS</b>Flow cytometry, RT-PCR and Western blot were used to examine the expression of BLyS and its receptors in MM (KM3 and CZ1) cells. Fluorescence immunocytochemical method and confocal laser scanning technique were applied to the localization of BLyS in KM3 cell. WST proliferation assay was used to examine the effect of BLyS on MM cells growth and survival. Linear correlation analysis was used to detect LDH and beta 2-microglobulin (beta2M) levels with BLyS protein and mRNA expressions in MM patients.</p><p><b>RESULTS</b>(1) BLyS and its receptors were expressed in MM cells. (2) BLyS protein was localized on the KM3 plasma membrane. (3) BLyS promoted survival and proliferation of MM cells. (4) MM patients had significantly higher expression levels of BLyS [77.42% (24/31)] BLyS mRNA [93.55% (29/31)], which were significantly correlated with the levels of LDH and beta 2-microglobulin (beta2M).</p><p><b>CONCLUSION</b>BLyS and its receptors in MM cell lines and MM patient bone marrow might have a potential role in the growth and survival of malignant plasma cells.</p>