OBJECTIVE: To explore the effect of tea polyphenols (TP) on adhesion in human ovarian cancer SKOV3 and 3AO cells, and investigate the impact of TP on the expression of E-cadhern and N-cadherin. METHODS: SKOV3 and 3AO cells were treated with different doses of TP at 0, 5, 10, 20, 40, 80 and 160 μg/mL for 24 h in vitro, the inhibitory rate of cell proliferation was assessed by MTT assay. SKOV3 ... [Show full abstract] cells were treated with TP at doses of 5, 10 and 20 μg/mL and 3AO cells were treated with TP at doses of 10, 20 and 40 μg/mL for 24 hs respectively. The control cells were treated with culture medium for 24 hours only. The ability of cell-cell adhesion was detected by cell detachment experiment, and the cell-matrix adhesion was tested by cell adhesion assay. Cellular expression levels of E-cadherin and N-cadherin were examined with real-time fluorescence quantitative PCR and western blot. RESULTS: With the increasing concentration of TP, the inhibitory rate of SKOV3 (χ2=18.96, P=0.004) and 3AO (χ2=16.98, P=0.009) cells were increased. The results of cell detachment experiment showed that with the increasing concentration of TP, the detachment rates of SKOV3 and 3AO cells were decreased significantly at 10 and 20 minutes among groups, all P values <0.05. The cell adhesion assay was showed as follows: the adhesion rates of SKOV3 cells in control group, TP 5, 10 and 20 μg/mL group were 100.00%, 93.89%, 82.50% and 67.32%, respectively, the differences were statistically significant, χ2=9.583, P=0.022. The adhesion rates of 3AO cell in control group, TP 10, 20 and 40 μg/mL group were 100.00%, 92.65%, 86.90% and 76.71%, the differences were statistically significant, χ2=10.532, P=0.015. The results of real-time PCR showed that the expression of E-cadherin mRNA increased, χ2=10.532, P=0.015, and that of N-cadherin mRNA decreased in SKOV3 cells after treatment with TP, χ2=9.583, P=0.022. The expression of N-cadherin mRNA decreased, χ2=10.532, P=0.015, E-cadherin mRNA was not significant in 3AO cells, χ2=4.499, P=0.212. The results of western blot showed that the expression of protein levels of E-cadherin increased, χ2=10.116, P=0.018, and that of N-cadherin decreased in SKOV3 after treatment with TP, χ2=9.804, P=0.02. The expression of protein levels of N-cadherin decreased, χ2=8.868, P=0.031, and that of E-cadherin was not significant in 3AO cells, χ2=1.17, P=0.76. CONCLUSIONS: Tea polyphenols could significantly inhibit the adhesion ability of SKOV3 and 3AO ovarian cancer cells. The underlying mechanisms may be correlated with the upregulation of E-cadherin and downregulation of N-cadherin by treatment with TP. ©, 2015, The Editorial Board of Chinese Journal of Cancer Prevention and Treatment. All right reserved.