摘要
Objective： To observe the change of DNA methyltransferase （Dnmt） in osteosarcoma cell lines differentiation induction in vitro, so as to explore the function and relativity of Dnmt in malignant osteosarcoma cell during differentiation induction in vitro. Methods： After in vitro differentiation induction by all trans-retinoic acid （ATRA）, morphological and functional changes of the cells were observed. The expression levels of Dnmt and PCNA mRNA were detected by semi-quantitative RT-PCR. Changes of cell cycle were determined by flow cytometry （FCM）. Results： After treatment with ATRA, the growth of MG-63 cell was inhibited. The cells underwent morphological and functional differentiation. Alkaline phosphatase activity of the cells was increased. The relative expression levels of Dnmt and PCNA mRNA were decreased remarkably in osteosarcoma cells with the time delayed. Osteosarcoma cells were arrested in G1 phase. Conclusion： ATRA could inhibit cell growth and induce differentiation of MG-63 ceils in morphologic and function. The Dnmt regulation directly links to cell cycle and PCNA mRNA levels. Inhibition of the Dnmt mRNA expression in MG-63 ceils may be one of the important mechanisms of ATRA inducing differentiation of osteosarcoma cells.
