The Effects And Mechanism Of Lithium Compounds On K562 CML Cell Line

The lithium ion which is a monovalent cation exerts its varied biological effects on human body. Lithium has been confirmed to possess a varieties of effects on immuno-regulation and tumor inhibition both in vitro and in vivo. Our aim is to investigate the effects of lithium compounds on K562 cells by using typical methods in experimental hematology, cell biology and molecular biology etc. The main results of the experiments are as follows:1. The effects of LiC1, T2 and T6 on proliferation of K562 cell lineThe data from liquid culture indicated that Lid (10-50mM), T2 (10-3-10-1mM), T6 (5*10-2-1mM) inhibited to some extent the proliferation of K562 cells after exposure for 5 days. The results from semi-solid agar culture also showed that LiCl (10-50mM), T2 (5* 10-3 - 10-1mM ) , T6 (5 * 10-2- 1 mM ) decreased to some extent the colony formation of K562 cells compared with the control group. The results of MTT assay also demonstrated that LiCl (10-50mM),T2 (10-3-10-1mM),T6 (5 × 10-2- 1mM) inhibited the proliferation of K562 cells in a dose-dependent manner.2. The effects of LiCl on differentiation of K562 cell lineThe effects of LiCl (10mM) on differentiation of K562 cells weredetermined by cell morphologys NBT reduction assay, NSE assay, benzidine stain assay and specific antigen expression with flow cytometry. These results revealed that LiC1 (10mM) induced K562 cells to express the characteristics of erythroid lineage.3. The effects of LiCl on apoptosis of K562 cell lineLiCl (30mM) induced K562 cells toward apoptosis verified by cellular morphology and agarose gel electrophoresis of DNA fragments.4. The effect of LiCl on gene expression of K562 cell lineAfter 72h exposure to LiCl (30mM), the bcr/abl mRNA expression was decreased by 74% in K562 cells.5. The effects of FSK or TTX on intracellular Li+ concentration in K562 cells.The intracellular Li+ concentration in K562 cells began to increase after treated with 30mM LiCl for 30min and the concentration reached apex after 2h treatment, then the concentration decreased gradually. After incubation of K562 cells with FSK(5 × 10-5M)or TTX(3.4× 10-7M) for 15min, then with LiCl (30mM) treatment for 30min, the intracellular Li+ concentration in K562 cells was higher than that in cells just treated with LiCl (30mM) alone. And the data from liquid culture showed that the inhibition of K562 cell growth with LiCl (30mM) could be enhanced by pre-antagonism of either K+ channel or Na+channel with FSK or TTX.Conclusion:1. LiCl (10-50mM), T2 (5*10-3-10-1mM),T6 (5×10-2-1mM)inhibited the proliferation of K562 cells in a dose-dependent manner.2. LiCl (10mM) induced K562 cells to express erythroid characteristics.3. LiCl (30mM) induced K562 cells toward apoptosis.4. LiCl (30mM) down-regulated the expression of bcr/abl mRNA inK562 cells.5. K+channel blocker (FSK) or Na+ channel blocker (TTX) enchancedthe inhibiton effect on K562 cell growth with LiCl (30mM) treatment.