Fig. 6

Expression of microRNA-330-3p (miR-330-3p) affected the NSCLC BM potential in zebrafish xenograft models. (A and B) Quantification of the miR-330-3p expression in vitro. The appropriate transfection concentration was determined between 1 nM and 50 nM, according to the instructions. (C and D) The expression of miR-330-3p in H1975 cell line was knocked down by anti-miR-330-3p inhibitor and the expression of miR-330-3p in A549 cell line was overexpressed by over-miR-330-3p mimics. Transwell culture system was used to evaluate the effectiveness of transfection in vitro. Invaded cells were stained with crystal violet (0.5 %) and imaged after 24 h incubation. (E and F) Quantification of invaded cells in vitro. Colonies were quantified using Image Pro Plus. (G and H) H1975, H1975 with under-expressed miR-330-3p, A549 and A549 with over-expressed miR-330-3p were involved. About 100 cells (red fluorescence) were injected into the PVs of Tg (fli-1: EGFP) zebrafish at 2 dpf to evaluate the effectiveness of transfection in vivo, and the brain of zebrafish was imaged at 4 dpi. The white arrows indicated cancer cells in blood vessels of zebrafish brain. (I-L) Quantification of BM cells at 1 dpi and 4 dpi. The two dots connected by a straight line represented the number of BM cells of the same zebrafish at 1 dpi and 4 dpi. (M and N) Quantification and comparison of the BM potentials of the transfected cell lines and the original cell lines. (ns) indicated statistical insignificance, (*) indicated statistical significance P < 0.05, (**) P < 0.01 and (***) P < 0.001