D-δ-tocotrienols On The Proliferation And Apoptosis Of Nasopharyngeal Carcinoma Cells And Its Molecular Mechanisms

OBJECTIVE: In this study, nasopharyngeal carcinoma cell line 5-8F was clultured in vitro and used cell culture technology and molecular biology techniques to probe proliferation, cell cycle, apoptosis and nasopharyngeal carcinoma cellular biology malignant phenotype related molecular Bax and Bcl - 2 when intervened with d-δ-tocotrienols, to study the biological activity of d-δ-tocotrienols against nasopharyngeal carcinoma and provide preliminary experimental data and evidence for the application of d-δ-tocotrienols anti-NPC.Methods :Nasopharyngeal carcinoma cell line 5-8F was cultured in vitro and divided into control group and observed groups, the control group was not intervened, the observed group were treated with 40,50 and 60μmol/l of d-δ-tocotrienols respectively for 48h. (1),The morphologies of cells were observed under an inverted microscope when cell line 5-8F intervened with d-δ-tocotrienols for 48h; Apoptosis was observed under fluorescence microscope with appropriate amount of Hoechst33258 dye. (2),Proliferation was detected with MTT when cell line 5-8F intervened by d-δ-tocotrienols for 48h. (3),Apoptosis was detected by flow cytometry when cell line 5-8F intervened by d-δ-tocotrienols for 48h. (4),Cell cycle was detected by flow cytometry when cell line 5-8F intervened by d-δ-tocotrienols for 48h . (5),The expression of apoptosis-related protein Bax, Bcl-2 were detected with Western-blot when cell line 5-8F intervened by d-δ-tocotrienols for 48h.Results: (1),Cell line 5-8F handled with d-δ-tocotrienols for 48h, with the concentration increased, decrease in the number of living cells was observed, the number of floating dead cells and strong nuclear staining cells increased, cell growth was significant inhibited and apoptosis was observed. (2),Cell proliferation assay revealed that cell growth inhibition rates of observed groups were (46.03±4.16)%, (67.68±3.12)% and (95.05±0.10)%, cell growth inhibition rate of control group was 0,compared with control group, p <0.01, there were statistical differences among control group and observed groups. (3),Apoptosis analysis discovered that apoptotic rate of control group was(0.83±0. 12),apoptotic rate of observed groups were (2.60±0.30)%, (7.54±1.01)% and (21.17±0.81)%,compared with control group, p <0.01, there were statistical differences among control group and observed groups. (4),Percentage of S phase cells in control group is(16.33±0.15)%, percentage of S phase cells in observed groups were (27.67±1.67)%, (31.37±1.30)% and (33.00±0.70)%, compared with control group, p <0.01, there were statistical differences among control group and observed groups, the cells were arrested in S phase. (5),Compared with the control group, the expression of Bax protein increased and Bcl-2 protein decreased in the observed groups, Bax / Bcl-2 increased in accordance with concentration .Conclusions: D-δ-tocotrienols can inhibit the proliferation of 5-8F cells, induce apoptosis, arrest the cells in S phase, activate Bax and inhibit Bcl-2 of the apoptosis regulatory genes, has the biological activity of potential anti-NPC.