[Expression and role of toll-like receptors in U937 cells].

The aim of study was to explore the potential application of targeting at Toll-like receptors (TLRs) in the immunotherapy of acute myelocytic leukemia, and to investigate the expression of TLR and the effects of TLR 8 agonist ssRNA40/LyoVec on proliferation, apoptosis and cell cycle of U937 cells. The expression of TLR 1 - 9 in U937 cells was detected by using reverse transcription polymerase chain reaction (RT-PCR) and the expression of TLR 8 was assayed by flow cytometry (FCM). The effect of TLR 8 agonist, ssRNA40/LyoVec, at different concentrations on U937 cells proliferation was evaluated by CCK-8, apoptosis and cell cycle were detected by FCM. The results showed that U937 cells expressed TLR 1 - 9. TLR 8 agonist ssRNA40/LyoVec could inhibit the growth of U937 cells both in time-and dose-dependent manner and the inhibitory rate could reach 70%. It also increased the percentage of cells in G(0)/G(1) phase. There was no significant difference in percentage of apoptotic cells between control and treated groups. It is concluded that TLRs including TLR 1 - 9 express on U937 cells and TLR 8 agonist ssRNA40/LyoVec may be able to inhibit the growth of U937 cells, arrest the cells in G(0)/G(1) phase, but have no effect of promoting apoptosis.