Figure 4. Bioengineered miR-34a prodrug induced a G2 cell cycle arrest in osteosarcoma 143B cells.

(A) Comparison of flow cytometry histograms of propidium iodide-stained cells treated with vehicle, tRNA/MSA and tRNA/mir-34a. (B) Comparison of each cell cycle (G1, S and G2) phase percentage. (C) Images of biomarker Ki-67 fluorescence in 143B cells with different treatments. (D) Nuclear Ki-67 fluorescence intensities were compared for different treatments, which were quantitated with ImageJ software and normalized to the numbers of cells in corresponding groups. Cells were treated with 4 nM tRNA/mir-34a or tRNA/MSA, or the vehicle for 72 h, stained with propidium iodide, and flow cytometric analyses were conducted to define cell cycle phases. A different batch of treated cells were fixed with 10% formalin, stained with Alexa Fluor dye-labeled Ki-67 antibody, and counterstained with DAPI. Ki-67 fluorescence and DAPI-stained nuclei images were acquired with a confocal microscope. Values are mean ± SD of triplicate treatments. *P < 0.05, **P < 0.01, and ***P < 0.001 (two- or one-way ANOVA), as compared with either tRNA/MSA or vehicle treatment.