Antitumor Activity and Mechanism of Plant Cytokinin ortho-Topolin Riboside in Human Leukemia Cell Line THP-1

In this study,human acute myeloid leukemia cell line THP-1 was taken as the research object to preliminarily investigate its anticancer activity and mechanism. Morphological and cell numbers of THP-1 cells were detected by optical microscope after treated with ortho-Topolin Riboside(oTR). The cytotoxicity of THP-1 cells was measured by CCK-8 assay. Apoptotic rate and cell differentiation was analyzed by flow cytometer. Effect of nucleoside transporter and adenosine receptor antagonists on the cell proliferation were detected by CCK-8 when treated with oTR. Results showed that,the proliferation of THP-1 cells was significantly(P<0.05)inhibite in a concentration-dependent manner when treated with oTR. The treatment of dipyridamole significantly(P<0.05)reversed the inhibitory effect of oTR on proliferation of THP-1 cells. However,there had no significant effects on four adenosine receptor antagonists(DPCPX,SCH58261,MRS1754 and MRA1191). The percentage of aneuploidy peaks in the oTR-inducible treatment group was significantly higher than that in the control group(P<0.05),and the expression of myeloid differentiation marker protein CD11b was significantly increased. In conclusion,oTR had obvious antitumor activity on THP-1 cells and induce apoptosis and differentiation of THP-1 cells,which was caused by the uptake of oTR by nucleoside transporter rather than adenosine receptor.