Effect of platelet-activating factor receptor expression on CHO cell motility

Tumor cell migration may favor local mass expansion and metastasis dissemin ation. Several tumors were found to express the receptor for platelet-activ ating factor (PAF), a potent mediator of leukocyte chemotaxis and endotheli al cell migration. However, its functional role on tumor cells is largely u nexplored. In the present study, we evaluated the motogenic effect of PAF o n Chinese hamster ovarian (CHO) cancer cells transfected with the human PAF -receptor cDNA (CHO PAF-R). By using time-lapse recording, we detected a ra pid motogenic response to PAF stimulation on CHO PAF-R, whereas no effect w as evident on vector-only transfected cells. Such an effect was observed on scattered cell motility, on cells seeded on a fibronectin- or collagen-coa ted surface, and on migration of confluent monolayer cells. Cell speed incr eased at 1 h and was maximal 6-8 h after PAF stimulation on CHO PAF-R. Conc omitantly, PAT induced marked changes in cytoskeleton actin distribution wi th cell contraction. assembling of stress fibers, and polar foci of adhesio n. In conclusion, the present study demonstrates that PAF is a potent induc er of tumor cell motility, thus suggesting a role for this mediator in tumo r growth and dissemination. (C) 2000 Wiley-Liss, Inc.