Fig. 2.

MiR-22 increases chemosensitivity to CDDP in tongue cancer cells. a The miR-22 expression in the selected clones indicated that miR-22 overexpressing cell lines were successfully established; b, dose survival curve was plotted from the MTS assay results collected from three independent experiments, showing that miR-22 enhanced the effect of cDDP on oral cancer cells, and miR-22 inhibition promoted the resistance of both cell lines to cDDP. c and d, indicated cells were incubated in the presence of 4 μg/ml CDDP for 24 h and cleaved caspase 3 or PARP was detected by immunoblotting. e, cells were treated with 4 μg/ml CDDP for 24 h; apoptotic cells were determined by FACS. Quantification of apoptotic cells using 3 independent FACS experiments. Data show mean with SD. *P < 0.05. f, g, Mice transplanted with CAL-27/miR-22 stable cells (n = 5) or CAL-27/vector control cells (n = 5) were mock treated or treated with CDDP as shown. Tumor growth curve-based tumor volume measure was shown as figure g. *P < 0.05. (h-i), Separate groups of animals bearing CAL27 xenograft tumors were treated with Vivo -jetPEI-formulated mir-22 inhibitor or controls accompanied with 2 mg/kg CDDP or equal volume saline as shown. Xenograft tumor growth was monitored and growth curve was mapped in figure i. *P < 0.05