DNMT1 and central nervous system cancer: Moreover, we found that miR-21 inhibitor-Dex complex treatment increased DNMT1 expression in CD45−Ter-119− PDGFR-α+Sca-1+ mouse MSCs [54–56] infiltrating in glioma (Fig. S7A, B), indicating that the miR-21 inhibitor disrupted the miR-21/DNMT1 positive feedback loop in MSCs.