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Constitutively lower expressions of CD54 on primary myeloma cells and their different localizations in bone marrow
Author(s) -
Iqbal Mohd S.,
Otsuyama KenIchiro,
Shamsasenjan Karim,
Asaoku Hideki,
Mahmoud Maged S.,
Gondo Toshikazu,
Kawano Michio M.
Publication year - 2009
Publication title -
european journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 84
eISSN - 1600-0609
pISSN - 0902-4441
DOI - 10.1111/j.1600-0609.2009.01284.x
Subject(s) - stromal cell , bone marrow , cd38 , multiple myeloma , plasma cell , cxcr4 , immunohistochemistry , biology , cell culture , pathology , in vitro , cancer research , microbiology and biotechnology , receptor , medicine , immunology , chemokine , stem cell , cd34 , biochemistry , genetics
To evaluate nuclear factor‐κB (NF‐κB) activity in primary myeloma cells from myeloma patients, we confirmed that the expression levels of CD54 showed a good correlation with the levels of DNA binding activity for NF‐κB in human myeloma cell lines, and thus analyzed the expression levels of CD54 on CD38(++) plasma cell fractions as one of NF‐κB activity. Primary myeloma cells unexpectedly showed constitutively lower expressions of CD54 than normal bone marrow (BM) plasma cells. Furthermore, the expression levels of CD54 on these plasma cells showed a significant correlation with the plasma levels of CXCL12 stromal cell‐derived factor‐1α (SDF‐1α) in their BM aspirates, and the expressions of CXCR4, the receptor for CXCL12, decreased on primary myeloma cells compared with normal BM plasma cells. It was also confirmed that the addition of CXCL12 to the in vitro culture significantly induced the up‐regulation of CD54 expression in primary myeloma cells. In addition, myeloma cells with lower expressions of CD54 were more unstable in the in vitro culture, resulting in a marked reduction of the viable cell number. In the immunohistochemical analysis of BM aspirates, myeloma cells with lower CD54 expression resided in the perivascular regions. Therefore, these data suggest that primary myeloma cells exhibit constitutively lower CD54 that might be partially regulated by CXCL12, and their localizations in the BM may be associated with the expression levels of CD54.