An Experimental Study On Cerulenin Induced Apoptosis Of Human Osteosarcoma Cells

Objective:To investigate whether cerulenin could induce apoptosis and suppress the proliferation of human osteosarcoma cells.Methods:The inhibitory effect of fatty acid synthesis(FAS) inhibitor Cerulenin on the growth of human osteosarcoma cells(U2-OS) was determined by cellmorphology and microculture tetrazolium assay(MTT) in vitro.Flow cytometry(FCM) analysis was used to study the cell apoptosis and changes of cell cycle.Results:Cerulenin was able to induce U2-OS cells death via apoptosis.Cerulenin also inhibited the proliferation of cells in vitro and was dosedependent.The inhibition rates of U2-OS cells after 24 hours exposure to Cerulenin at 2.5,5,10 and 20 mg/L were 18.58±2.49%,35.11±3.49%,56.60±3.53%and 79.69±2.83%,respectively (p＜0.05 vs controls).Optical microscope revealed the characteristic apoptosis alterations,shrinking,cellular morphology,integrity cell membrane,karyopycnosis, fragment of nucleus,chromatin condensation and margination,cytoplasmiec vacuoles. FCM analysis showed that aider treatment with different concentrations of Cerulenin,the apoptosis rate of human osteosarcoma cells significantly increased in a dose-and time-dependent manner,After 24 hours exposure to Cerulenin at 2.5,5,10 and 20 mg/L the apoptotic U2-OS cells were 7.62±1.03%,22.95±3.12%,38.29±2.35 %and 51.49±1.76%,respectively(p＜0.05 vs controls);And after 24,48 and 72 hours exposure to Cerulenin at 5 mg/L the apoptotic U2-OS cells were 27.92±2.69 %,45.27±3.25%and 60.39±1.86%,respectively(p＜0.05 vs controls).The inhibitory effect of Cerulenin on proliferation of U2-OS cells was associated with cell cycle arrest from S to G₂/M phase transition and with induction of apoptosis,after cells were exposed to Cerulenin with at various Cerulenin concentrations for 24h,the proportion of S phase cells increased but that in G₂/M phase decreased significantly, at the concentration of 10mg / L,the U2-OS cells rates in S phase were increased from (38.26±0.78)%in the control group to(47.95±0.64)%in the treatment group,whlie in G₂/M phase it were decreased from(16.58±0.63)%to(1.59±0.27)%,respectively (p＜0.05 vs controls). Conclusion:Cerulenin could induce apoptosis and inhibit proliferation of U2-OS cells by inducing S block and apoptosis.The effect of Cerulenin displyas a time-dependent and dose-dependent manner.