HHV-8 induced in vitro endothelial cells motility and invasion correlated with the expression of PAX2. (A) The motility of uninfected HMECs (o), HHV-8–infected HMECs (■) and HHV-8-infected HMEC-AS (▲) was monitored by time-lapse analysis and measured in μm/h as described in “Cell motility.” Results are mean plus or minus SD of 3 individual experiments. ANOVA with Dunnett multiple comparison test was performed (*P < .05, infected HMECs, infected HMEC-AS, and uninfected HMECs). (B) The invasion of Matrigel-coated filters by uninfected HMECs or HMECs and HMEC-AS infected with HHV-8 was evaluated. Cells were seeded onto Matrigel precoated upper well (100 μg/well) and incubated for 48 hours at 37°C, 5% CO₂, in a humidified atmosphere. The lower wells were loaded with medium plus 10% FCS. Cells that migrated to the underside of the filters were fixed with methanol, stained with Giemsa solution, and counted in 5 microscopic fields in each well. Data are mean plus or minus SD of 3 independent experiments performed in triplicate. ANOVA with Newman-Keuls multiple comparison test was performed (*P < .05, infected HMECs vs uninfected HMEC; #P < .05, infected HMEC-AS vs infected HMECs). (C) Representative zymographic analysis of uninfected HMECs (lane 2), HMECs (lane 3), and HMEC-AS (lane 4) 3 days after infection with HHV-8; HMECs (lane 5) and HMEC-AS (lane 6) 7 days after infection with HHV-8; HMECs (lane 7) and HMEC-AS (lane 8) 14 days after infection with HHV-8. Lane 1 shows the control RPMI supplemented with 10% FCS (lane 1). Three experiments were performed with similar results.