DNMT1 and lung cancer: Changed the methylome of lung cancer and pre-malignant oral cell linesReduced both nuclear and cytoplasmic DNMT1 and DNMT3B within 1 weekExhibited a strong cytotoxicity against the lung cancer cell line H1299Reactivated the growth arrest and DNA damage-inducible 45 (GADD45) signaling pathwayInduced an anti-tumor pathway epigenetically reactivated by DNA demethylation in lung cancer cell