TSLC1 in ATL cell line plays an important role in adhesion to the vascular endothelial cells and self-aggregation. (A) Northern hybridization of TSLC1 in ED transformants. ED cells (ED/TSLC1 and ED/TSLC2) were transduced with a retrovirus vector containing the TSLC1 gene. A 4.4-kb band of TSLC1 transcript was detected in ED/TSLC1 and ED/TSLC2 cells (lanes 3 and 4). ED/neo (mock transformants) and Jurkat cells (lanes 1 and 6) were used as negative controls. OMT and KK-1 (lanes 4 and 5) were ATL cell lines as positive controls. (B) Cell aggregation experiments with TSLC1 transformants. To examine the aggregation activity of TSLC1 in parental ED cells, ED/TSLC1 and ED/TSLC2 transformants were well suspended just before the experiment and kept for 30 minutes in a 3.5-cm² dish. Photographs were taken with an inverted microscope (model CKX41; Olympus, Tokyo, Japan) at a magnification of 100 × (objective × 10/0.25 NA). (C) Cell adhesion experiments with TSLC1 transformants. To examine the adhesion activity of TSLC1, parental ED, ED/neo, ED/TSLC1, and ED/TSLC2 were incubated with monolayer HUVECs for 30 minutes. Each value represents the average obtained from 3 independent experiments. Bars indicate standard deviation errors.