The effects of BAL overexpression on cellular migration.

(A) Western blot analysis of BAL expression in aggressive B-cell lymphoma cell lines (DHL-6, OCI-Ly3, OCI-Ly10, DHL-4, DHL-7, DHL-8, and DHL-10) and stable pRcCMV-only or pRcCMV-BAL B-cell lymphoma transfectants. An antiserum generated against the BAL C-terminus recognizes the expected approximately 88 kd BAL protein, which is most abundant in the OCI-Ly3, OCI-Ly10, and DHL-7 cell lines. The BAL antiserum recognizes the expected approximately 88 kd BAL protein in pRcCMV-BAL but not pRcCMV-only transfectants. The blot was also probed with anti-tubulin to confirm equal loading. (B) Transwell migration assays of BAL-overexpressing or vector-only B-cell lymphoma transfectants. Two independent pRcCMV-only and pRcCMV-BAL transfectants were evaluated for migration through a separating 8-μm membrane into lower transwell chambers that contained medium alone or medium supplemented with SDF-1α. The results are represented as the mean number of cells that have migrated to the lower chamber in presence or absence of recombinant human SDF-1α (right and left panels respectively). BAL-overexpressing transfectants had approximately 4-fold higher rates of migration than vector-only transfectants in either the presence or absence of SDF-1α (P < .0001, Student 1-sided ttest).