The Study On Inhibitory Effects Of Curcumin On Human Tongue Squamous Cell Carcinoma Tca8113 Cells

Background and ObjectiveTongue squamous cell carcinoma is a common malignant tumor of oromaxillo-facial region, and its constituent is the highest in oral squamous cell carcinoma, it is reported the ratio is about 32.3% in our nation and between 21%and 52% in Europe and America. In recent years, the incidence of tongue squamous cell carcinoma shows rapid upward trend, which has attracted national attention. Fast-growing and high invasion is the character of this kind of tumor .Moreover, the tongue with frequent movement, has rich lymphatic and blood circulation. Early cervical lymph node metastasis often happens and prognosis is poor. Patients often need chemotherapy after tumor resected to enhance the therapeutic effect, but traditional chemotherapy often leads to treatment failure due to drug-resistance of tumor cells or drugs side effects. To study and develop new anti-cancer drugs for squamous cell carcinoma of the tongue is a clinical research focus. Chinese traditional medicine is being paid much attention because of its unique therapeutic effect on tumors in recent years. Curcumin is a Chinese turmeric active ingredient with antioxidant, anti-tumor, anti-inflammatory, scavenging free radicals, anti-microbial effect and with pharmacological effect on the cardiovascular system, digestive system, etc. In particular, the anti-tumor effect of curcumin has attracted much attention by many scholars at home and abroad, a lot of research has been done on the anti-tumor effect and mechanism of curcumin. It is confirmed that curcumin can inhibit tumor cells proliferation and induce tumor cells apoptosis.However,the study on its anti-tumor of head and neck is rarely reported in terms. In this study, tongue squamous cell carcinorma Tca8113 cells were treated by different concentrations of curcumin to observe the inhibitory effects of curcumin on Tca8113 cell lines in vitro, and to explore the possible related mechanism of curcumin on human tongue squamous carcinorma Tca8113 cells preliminarily, in order to provide new ideas and reference for clinical studies.Materials and MethodsTca8113 cell lines was offered by Stomatology School of Shanghai Jiao tong University. Curcumin was produced by Shanghai You Si Biological Technology Company.Tca8113 cells were cultured in commn RPMI-1640.The experimental groups culture medium contained different concentrations of curcumin (5μmol/l, 10μmol/l, 20μmol/l, 40μmol/l), the control group had no curcumin in Culture medium. Various indexes were detected after the cultured time terminated. Observing the change of cells morphology under inverted microscope, proliferation inhibitory effects were detected by MTT assay; Cell cycle,apoptosis and quantitative analysis of the expression of caspase-3 were analyzed by flow cytometry(FCM); The expression changes of Survivin,Ki-67 and Bax were detected by immnocytochemistry. The statistical analysis was executed by SPSS13.0 software, using chi-square test, analysis of variance for statistical, statistically significant level was "α=0.05".Results(1) With the higher concentrations of curcumin and treated time increasing,the effect of inhibitory on cells significantly enhanced. Under inverted microscope, the cells growth and proliferation became slow,the cells became small and round , more and and cells floated in culture medium;The results of MTT assay showed that the inhibitory effects of curcumin on cells growth and proliferation were depended on concentrations and time .(2) With higher concentrations of curcumin and treated time increasing, the cells in G₁ phase gradually increased from 46.20% to 64.8%, the cells in S phase decreased from 53.10% to 31.40%. Statistics showed that the cells arrested in G₁ phase, which was positively correlated with concentration and time. It was statistially significant in comparison with the control group (P<0.05).(3)With concentrations of curcumin and treated time increasing, the apoptotic cells ratio gradually increased from 1.80% to 22.27%. Statistics showed that the ratio of apoptosis was positively correlated with the concentration and time. It was statistially significant in comparison with the control group (P<0.05).(4) After treated in curcumin, the expression of anti-apoptosis gene Survivin and nuclear proliferation-associated antigen Ki-67 protein were significantly downward in Tca8113 cells compared with the control group, the staining of Survivin in the cytoplasm and the staining of Ki-67 in the nuclei of cells were reduced;The expression of pro-apoptotic gene Bax and pro-apoptotic protein kinase Caspase-3 markedly enhanced, the staining of Bax in the cytoplasm enhanced, and quantitative analysis of protein showed that the expression of caspase-3 increased significantly.Conclusions(1) Curcumin can significantly inhibit Tca8113 cells growth and proliferation, it is relied on concentrations and time.(2) Curcumin can change Tca8113 cells cycle distribution, and can arrest cells in G₁ phase, it is correlated with the concentrations and time.(3) Curcumin can change the apoptotic ratio of Tca8113 cells, which is correlated with the concentrations and time.(4) Curcumin can induce Tca8113 cell apoptosis through reducing the expression of Survivin and Ki-67, and elevating the expression of Bax and Caspase-3.(5) It is perhaps one of the mechanisms of inhibitory effects of curcumin on Tca8113 cells that curcumin can arrest cell cycle, regulate apoptosis-related genes,reduce the expression of Survivin and Ki-67, and increase the expression of Bax andCaspase-3.