miR-221/miR-222 and miR-31 are involved in KSHV-induced endothelial migration. (A) miR-31 induces cell migration. HMEC1 cells stably transduced with miR-31 or the vector control by lentivirus were used to detect the expression level of miR-31 by qRT-PCR (right panel) and were also subjected to the Transwell cell-migration assay (left panel; n = 3). (B) Knockdown of miR-31 reduces KSHV-induced cell migration. KSHV-infected HMEC1 cells (HK cells) transfected with the siGFP control or the anti–miR-31 antagomir by electroporation were used to detect the expression of miR-31 (right panel) and were also subjected to the Transwell cell-migration assay (left panel; n = 3). (C) LTCs with miR-31 knockdown were subjected to the Transwell cell-migration assay (n = 3). Migrated cells were stained (representative pictures are shown in bottom panel) and counted. (D-F) Both miR-221 and miR-222 inhibit cell migration. HMEC1 cells (D) or LTCs (E) stably transduced with the miR-221/miR-222 cluster or HMEC1 cells knocked down with specific antagomirs to a single miRNA or to both by electroporation (F) were used to detect the expression levels of miR-221 and miR-222 and were also subjected to the Transwell cell-migration assay (n = 3). Scale bar represents 100 μm.