Fig. 1. CXCR4 mRNA is highly expressed in primary multiple myeloma (MM) cells, CLA expression increases with myeloma progression; CXCR4 protein expression is widely present in MM cells, while E-selectin protein is highly expressed in endothelial cells and stromal cells.

Gene expression of E-selectin (ID 206211_at), CLA (ID 209879_at), and CXCR4 (ID 217028_at) mRNA analyzed in CD138+ bone marrow plasma cells isolated from newly diagnosed MM patients (n = 559) using the Gene Expression Omnibus database [log scale] (a). The expression of CLA mRNA in CD138+ plasma cells harvested from healthy donors (n = 22), MGUS patients (n = 44), and newly diagnosed MM patients (n = 559) using the Gene Expression Omnibus database [log scale] analyzed using one-way analysis of variance test (b). Percentage of CLA+- and CXCR4+-positive cells in MM cell lines demonstrated as mean ± s.e.m (c). CLA and C-X-C chemokine receptor type 4 (CXCR4) protein expression levels in MM cell lines demonstrated as RMFI (mean ± s.e.m.). Results are obtained from three independent biological replicates and repeated minimum in three separate experiments (d). Expression of cell surface proteins including E-selectin, CLA, and CXCR4 in endothelial cells (human umbilical vein endothelial cells), malignant stromal cells (MSP-1), and normal stromal cells (HS-5) demonstrated as the percentage of positive cells (e) and RMFI (f). Results are representative of at least three independent experiments and demonstrated as mean ± s.e.m. CLA cutaneous lymphocyte-associated antigen, MGUS monoclonal gammopathy of undetermined significance, RMFI relative mean fluorescent intensity