Increased miR-194 expression inhibits breast cancer cell migration and invasion.

(A) miR-194 expression in the stable clones of BT474 cells. BT474 cells were stably transfected with an empty pEGFP-C1 vector or pEGFP-miR-194 vector under the selection of G418. Two control clones #17 and #19 that contain empty vector and two miR-194-expressing clones #22 and #23 were established and subjected for QRT-PCR analysis. Hsa-miR-194 was purchased from ABI (Assay ID 000493). (B) Cell viability assay of BT474 stable cells that express miR-194 or its control vector. BT474 cells were stably transfected with empty pEGFP-C1 vector or pEGFP-miR194 construct under the selection of G418. Two control clones #17 and #19 that contain empty vector and two miR-194-expressing clones #22 and #23 were chosen to measure viability of crystal violet-stained cells on day 1, day 3 and day 5. (C) Effect of miR-194 precursor on cell migration in SKBr3 cells. SKBr3 cells were transiently transfected with a miR-194 precursor or a control miRNA (miR CTRL) for 48 hrs and motility was measured overnight in a Transwell assay. (D) Quantitation of the SKBr3 cell migration as shown in (C). * p<0.05 compared to miR control. (E) Effect of miR-194 precursor on cell invasion in SKBr3 cells. SKBr3 cells were transiently transfected with a miR-194 precursor or a control miRNA (miR CTRL) for 48 hrs and invasion measured overnight. * p<0.05 compared to miR control. (F) miR-194 expression in transiently transfected SKBr3 cells. SKBr3 cells were transiently transfected with a miR-194 precursor or a control miRNA (miR CTRL) for 48 hrs. Total RNA was extracted and subjected to QRT-PCR analysis for miR-194 expression. Hsa-miR-194 was purchased from ABI (Assay ID 000493). (G) Assay of cell migration in BT474 stable cells that express miR-194 or a control vector. The control clone #17 and the miR-194-expressing clone #22 were chosen to study migration. * p<0.05 compared to #17 control. (H) Cell invasion assay in BT474 stable cells that express miR-194 or its control vector. The control clone #17 and the miR-194-expressing clone #22 were chosen to study invasion. * p<0.05 compared to #17 control. (I) BT474 xenograft tumor growth in vivo. BT474 xenografts in nude mice were established with the control clone #17 and the miR-194-expressing clone #22 as described in Methods. Tumors were collected and weighed after 4 weeks. * p<0.05 compared to #17 control.