Transfection of miR-1 into NPC-TW01 cells induces apoptosis. From left to right: untransfected NPC-TW01 cells (blank), transfection reagent only (mock), transfection reagent and miR-negative control (miR-negative), and transfection reagent and miR-1 (miR-1). Photos were taken by time-lapse microscopy 150 hours after transfection. (B) MTT assay after transfection with miR-1 for 150 hours. Most miR-1 transfected cells were dead (12% cell viability), whereas only a few control transfected died. (***Comparison between two groups as indicated, p < 0.001. Error bars correspond to mean ± SD) (C) The process of apoptotic body budding was visualized by time-lapse microscopy in miR-1 transfected cells. The time above each photograph represents the specific time that NPC-TW01 cells were transfected with miR-1.