Effect Of SIRT1 Agonists SRT1720 In Cell Proliferation, Apoptosis And Cell Cycle Of THP-1 Cells

Objective To investigate the effect of SIRT1 agonist SRT1720 in cell proliferation, apoptosis and cell cycle of acute mononuclear leukemia THP-1 cells in vitro, explore the role of silent mating-type information regulation 2 homologue 1 (SIRT1) in acute monocytic leukemia and possible molecularmechanisms, so as to clarify the potential value of SIRT1 in the diagnosis and treatment of acute mononuclear leukemia.Methods1. THP-1 cells exposed to SRT1720We added SRT1720 to logarithmic growth THP-1 cells for concentration of 1μM,2μM, 3μM, 4μM, 5μM and 6μM on the first day, negative control cells were received an equal volume of DMSO as cells with drug treatment,blank control cells were with nothing treated.2. Cell morphology observation and growth curve drawingWe used microscope to observe cell morphology and growth of THP-1 cells with different concentrations of SRT1720 and counted cell number every 24 h, then drawed cell growth curve of each group.3. Detection of cell proliferationWe used 10 μM CSFE to label THP-1 cells before adding SRT1720,after 4 days harvested all cells, then using flow cytometry to detect fluorescence of CSFE.4. Detection of cell apoptosisWe collected THP-1 cells exposed to SRT1720 for 48 h, added annexin V-fluorescein isothiocyanate ( AnnexinV-FITC, FITC) and propidium iodide(PropidiumIodide, PI) , incubated in dark, then using flow cytometry to detect cell apoptosis.5. Detection of cell cycleWe collected THP-1 cells exposed to SRT1720 for 48 h, added RNase A followed by propidium iodide (PropidiumIodide, PI), incubated in dark, then using flow cytometry to detect cell cycle distribution.6. Statistical analysisWe used SPSS 21.0 software for statistical analysis, p<0.05 was statistically significant. Continuous variables were presented as mean±standard deviation (X± S) , the Student test or ANOVA ( One-Way ANOVA) was used to describe the difference between the groups.Results1. THP-1 cells in 2～6 pM SRT1720 groups became wrinkled, their size and number decreased, the nucleus was shriveled. Granular material, cavity and cell fragments increased (p<0.05) . The concentration of SRT1720 was higher,expose time was longer, morphological change of THP-1 cells was more obvious.2. Cell proliferation index of THP-1 cells in 2～6 μM SRT1720 groups significantly decreased for 4 days (p<0.05) . The concentration of SRT1720 was higher, the decline was more obvious.3. Apoptosis rate of THP-1 cells in 2～6μM SRT1720 groups significantly increased for 48 h (p<0.05) . The concentration of SRT1720 was higher, the increase was more obvious.4. Percentage of S phase cells and G2 / M phase cells of THP-1 cells in 3～6μM SRT1720 groups significantly increased for 48 h (p<0.05 ) . The concentration of SRT1720 was higher,the increase was more obvious.Conclusions1. SRT1720 can inhibit cell growth and induce cell death of THP-1 cells in a concentration and time- dependent manner.2. SIRT1 may play a tumor suppressor role in acute mononuclear leukemia,possibly by inhibiting cell proliferation, inducing cell apoptosis and blocking S phase,G2 / M phase of acute mononuclear leukemia cells.