Inductive Effect Of GM3 Ganglioside On Apoptosis Of Multiple Myeloma U266 Cell And Its Mechanism

Objective:Multiple myeloma is a kind of B cell tumor characterized by abnormal clone of plasma cells,which is the second most common hematological malignancy.Recent years,due to the in-depth study of MM biological characteristics,cytogenetic abormalities and tumor pathogenesis was carried out,some new targeted drugs were applied to MM patients,such as proteasome inhibitors,immune modulators,CD38 monoclonal antibody,and so on.These drugs improved the remission rate in patients with MM,but it was still an incurable disease.GM3 ganglioside is a glycolipid containing sialic acid and has been found to be associated with tumor formation.In this study,we investigated the effects of GM3 ganglioside on human multiple myeloma U266 cell line and explored its possible mechanism of suppressing the multiple myeloma U266 cell line growth.Methods:1.To evaluate the inhibitory effect of GM3 ganglioside on the growth of U266cells:the logarithmic growth phase of U266 cells with different concentrations(0 μmol/L,20 μmol/L,40 μmol/L,80 μmol/L,160μmol/L)GM3 ganglioside 48 hours,the proliferation inhibition rate of U266 cells was detected by MTT.2.To examine the apoptosis inducting effect of GM3 ganglioside on U266 cells:Flow cytometry was used to detect the apoptosis of U266 cells and to observe cell cycle after treated with different concentrations GM3 ganglioside(0 μmol/L,20 μmol/L,40μmol/L,80 μmol/L,160 μmol/L).3.To detect the effects of GM3 ganglioside on the expression of Bcl-2 mRNA andBax mRNA in U266 cells:Real-Time PCR was used to detect the expression of Bcl-2 and Bax in U266 cells induced by GM3 ganglioside at different concentrations(20 μmol/L,40 μmol/L,80 μmol/L,160 μmol/L).Results:1.GM3 ganglioside can inhibit the proliferation of U266 cells.MTT method showed that GM3 ganglioside within a certain range of concertration(0 μmol/L,20 μmol/L,40μmol/L,80 μmol/L,160 μmol/L)could inhibit the growth of U266 cells,and its inhibiting effect to proliferation of U266 cells was in a dose-dependent manner.The inhibition rate had statistical difference between experience group(20 μmol/L,40 μmol/L,80 μmol/L,160 μmol/L)and control group(0 μmol/L)(P<0.05).2.Apoptosis of U266 cells induced by GM3 ganglioside after 48 h.After the action of GM3 ganglioside on U266 cells,the early apoptosis rates of experience groups(20 μmol/L,40 μmol/L,80 μmol/L,160 μmol/L)and control group(0 μmol/L)were(1.34 ± 0.18)%,(29.13 ± 1.15)%,(32.88 ± 0.78)%,(42.2 ± 7.19)% and(4.46 ± 1.22)%,respectively.In the range of 20~160 mol/L concentration,the early apoptosis rate of U266 cells increased with the increase of concentration.The experimental group compared with the control group,the difference of the experimental group and the control group was statistically significant(P<0.05).3.Effects of GM3 ganglioside on the expression of Bcl-2 and Bax mRNA in U266 cells.After U266 cells were treated with GM3 ganglioside,with the increase of drug concentration,the expression of Pro-apoptotic gene Bax mRNA was on the rise,while the anti-apoptotic gene Bcl-2 mRNA showed a downward trend.Statistically significant difference could be found between GM3 ganglioside treated group and control group(P<0.05).Conclusion:1.GM3 ganglioside could inhibit the proliferation of U266 cells.Within a certain range of concentration(0 μmol/L,20 μmol/L,40 μmol/L,80 μmol/L,160 μmol/L),the inhibition rate of GM3 ganglioside increased in a dose-dependent manner.2.GM3 ganglioside could induce apoptosis of U266 cells.Using flow cytometry to detect different concentrations of GM3 ganglioside on apoptosis of U266 cells,the experimental results showed that GM3 ganglioside could induce U266 cell apoptosis and block the U266 cell cycle in S phase in a dose-dependent manner.3.The mechanism of GM3 ganglioside inducing apoptosis of U266 cells may be related to the expression of Bcl-2 and Bax mRNA.GM3 ganglioside may induce the apoptosis of U266 cells by up regulating the expression of Bax m RNA and down regulating the expression of Bcl-2 mRNA.