Experimental study on human leukemia cell line K562 senescence induced by ginsenoside Rg1

Objective: To observe the effect and mechanism of ginsenoside Rg1 in inducing senescence human leukemia K562 cell line.Method: Proliferation of K562 cell line induced by Rg1 was detected by MTT colorimetric test for the purpose to screen optimal active concentration and time(20 μmol·L-1,48 h).Impact of Rg1 on cell cycle was analyzed using flow cytometry.The percentage of staining positive cells was detected by SA-β-Gal staining.The expressions of senescence-related genes such as p16,p53,p21,Rb,were detected by RT-PCR and the changes in ultramicro-morphology were observed by transmission electron microscopy.Result: Rg1 can significantly inhibit the proliferation of K562 cells in vitro and arrest the cells in G2/M phase.The percentage of positive cells stained by SA-β-Gal was dramatically increased(P0.05) and the expression of cell senescence-related genes were up-regulated.The observation of ultrastructure showed that cell volume increase,heterochromatin condensation and fragmentation,mitochondrial volume increase,lysosomes increase in size and number.Conclusion: Rg1 can induce the senescence of leukemia cell line K562 and play an important role in regulating p53-p21-Rb,p16-Rb cell signaling pathway.