PCNA and neoplasm: Moreover, after treatment with the miR-199a-5p AMO, the levels of miR-199a-5p (Fig. 5G), KI-67 and PCNA (Fig. 5I) significantly declined, while the protein levels of p27 and PIAS3 (Fig. 5H) significantly increased, suggesting that an inhibitor targeting miR-199a-5p could remarkably suppress tumour growth in OS.