Functional analysis of miR-629-3p, miR-210-3p, and miR-874-3p for CDDP resistance. (A) Schematic representation of cell viability analysis with and without cisplatin. After 24 hours, medium was switched to CDDP (20 µM) condition or no CDDP condition, and after another 48 h, the Cell Counting Kit-8 (CCK-8) reagent was reacted for 2 h, and the absorbance was measured at 450 nm in a microtiter plate reader. (B) Cell viability of SAS cells transfected with each miRNA. Fold changes of CDDP(+)/CDDP(−) was calculated for each miRNA. Cell viability was normalized to negative control (NC). (C) The sensitivity of CDDP in miR-210-3p, miR-629-3p, miR-874-3p, or NC-expressing SAS cells. CDDP sensitivity was determined by MTT assay. (D) Caspase 3/7 activity assay of in miR-210-3p, miR-629-3p, miR-874-3p or NC-expressing SAS cells. (E) Representative images (left) and relevant quantification (right) of migration assays in in miR-210-3p, miR-629-3p, miR-874-3p, or NC-expressing SAS cells. Scale bar, 100 µm. (F) Kaplan–Meier plots of the probabilities of survival in head and neck cancer cases classified according to the expression levels of miR-210, miR-629, and miR-874.