Effects of the chemokine stromal cell-derived factor-1 on the migration and localization of precursor-B acute lymphoblastic leukemia cells within bone marrow stromal layers

Abstract

Acute lymphoblastic leukemia (ALL) blasts undergo migration into layers of bone marrow fibroblasts (BMF) in vitro, utilizing the ␤1 integrins VLA-4 and VL-5 as adhesion molecules. However, it has been unclear as to whether this is a selective process mediated by specific chemoattractant molecules, or simply a reflection of the highly motile nature of early B cell precursors. We further characterized this process using a transwell culture system, in which the two chambers were separated by an 8 m diameter microporous membrane, through which leukemic cells could move. When a BMF layer was grown on the upper surface of the membrane there was an 84.1% reduction in transmigration of the human pre-B ALL cell line NALM-6 into the lower chamber, compared to control membrane with no BMF layer. Localization of leukemic cells under the BMF layer was confirmed ultrastructurally, suggesting the possibility that the migration of leukemic cells was directed by a chemotactic agent secreted by BMF. The involvement of the chemokine stromal cell-derived factor-1 (SDF-1) in this process was next investigated. BMF were shown to express m-RNA for SDF-1. Addition of SDF-1 at 100 ng/ml into the lower chamber increased transmigration of NALM-6 across the membrane by 2.2-fold, and also induced a 1.4-to 6.1-fold increase in movement of NALM-6 through a BMF layer into the lower chamber. The receptor for SDF-1, CXCR4, was demonstrated by flow cytometry on all 10 cases of precursor-B ALL analyzed, as well as on NALM-6, KM-3 and REH lines. An inhibitory antibody to CXCR4 was able to block the migration of NALM-6 cells into BMF monolayers grown on plastic by 51%, and in nine cases of ALL by 8-40%, as well as partially inhibit transmigration of leukemic cells through BMF layers along an SDF-1 concentration gradient. These results confirm that precursor-B ALL cells selectively localize within bone marrow stroma in vitro, and that this process is partially due to the stromal chemokine SDF-1 binding to its receptor CXCR4 on leukemic cells. SDF-1 may be important in influencing the localization of precursor-B ALL cells in marrow microenvironmental inches which regulate their survival and proliferation. Leukemia (2000) 14, 882-888.

CXCR4 chemokine receptors (CD184) and α4β1 integrins mediate spontaneous migration of human CD34+ progenitors and acute myeloid leukaemia cells beneath marrow stromal cells (pseudoemperipolesis)

“…When co-cultured with marrow stromal cells, CD34 + haematopoietic progenitors and, to a lesser degree, AML cells spontaneously migrated beneath the stromal cells, a migration phenomenon termed pseudoemperipolesis. Pseudoemperipolesis has been described earlier for B-and T-lineage cell migration beneath marrow stroma or synovial fibroblasts (Hiai et al, 1981;Hewson et al, 1996;Takeuchi et al, 1999;Bradstock et al, 2000), and has been demonstrated to involve a4b1 and a5b1 (VLA-4, VLA-5 or CD49d, CD49e) integrin binding to corresponding stromal ligands (fibronectin and VCAM-1) (Miyake et al, 1992). The importance of a4b1 and a5b1 integrins in heterotypic adherence between precursor cell lines (pre-B Nalm-6 and multipotential UT-7) and marrow stromal cells has been demonstrated by several investigators (Ryan et al, 1991;Patrick et al, 1995;Robledo et al, 1998;Turner et al, 1998), but the molecular mechanism of haematopoietic stem cell migration beneath stromal cells has not yet been defined.…”

“…It has been noted, however, that integrins alone mediate only the initial attachment of precursor or AML cells to stroma, but are not sufficient for the retention or subsequent migration beneath the stromal cells (Miyake et al, 1992;Bendall et al, 1993;Patrick et al, 1995). It has recently been demonstrated that activation of CXCR4 chemokine receptors (CD184) on normal and malignant B cells by the stromal-cell-derived factor (SDF-1/CXCL12) plays a key role in B-cell pseudoemperipolesis (Burger et al, 1999(Burger et al, , 2001Bradstock et al, 2000).…”

Expression of immune-related molecules in primary EBV positive chinese nasopharyngeal carcinoma: Associated with latent membrane protein 1 (LMP1) expression

“…This function of SDF-1/CXCR4 axis has been confirmed in several tumors such as lung cancer, prostate carcinoma and breast cancer. 14,15,17,[43][44][45][46][47][48][49][50][51] Our previous report found that the CXCR4 expression in NPC lesions was positively correlated with tumor distant metastasis and poor survive. 52 In this study, in 56 NPC lesions 30% (17/56) had a high expression level of CXCR4, and the CXCR4 was expressed in the cellular nucleus or cytoplasm and membrane of NPC tumor cells (Fig.…”

CXCR4 antagonists: targeting the microenvironment in leukemia and other cancers

“…25 We reported that B-ALL cells express functional CXCR4 receptors that induce leukemia cell chemotaxis to CXCL12 and spontaneous migration beneath CXCL12-secreting stromal cells in a CXCR4-and VLA4 integrin-dependent manner, using the B-cell precursor lines NALM-6 and REH, 47,120 findings that were subsequently confirmed with primary ALL cells. 121,122 CXCR4 receptors on ALL cells participate in homing of leukemia cells to the marrow in NOD/SCID mice. 123,124 A recent study by Sipkins et al 18 provided in vivo evidence that CXCR4 is necessary for homing of ALL cells to the marrow.…”