0%) 16 (64.0%) 0.724   ≧ 60 15 6 (40.0%) 9 (60.0%)   Gendera Male 35 15 (42.9%) 20 (57.1%) 0.081   Female 5 0 (0.0%) 5 (100.0%)   T classificationb 1 2 1 (50.0%) 1 (50.0%) 0.036*   2 10 7 (70.0%) 3 (30.0%)     3 22 4 (18.2%) 18 (81.8%)     4 6 3 (50.0%) 3 (50.0%)   Histological gradeb I 21 7 (33.3%) 14 (66.7%) 0.551   II 12 6 (50.0%) 6 check details (50.0%)     III 7 2 (28.6%) 5 (71.4%)   Vascular invasiona Negative 32 13 (40.6%) 19 (59.4%) 0.350   Positive 8 2 (25.0%) 6 (75.0%)   Lymphatic invasiona Negative 22 11 (50.0%) 11 (50.0%) 0.069   Positive 18 4 (22.2%)

14 (77.8%)   Perineural invasiona Negative 30 13 (43.3%) 17 (56.7%) 0.174   Positive 10 2 (20.0%) 8 (80.0%)   aFisher’s exact test, bChi-square test. *Statistically significant. LN = lymph node. We used a multiple logistic regression model to further analyze the variables that were significantly correlated with lymph node metastasis in the aforementioned univariate analyses. As shown in Table 4, lower CDH-1 mRNA expression alone, and not Cox-2 mRNA S63845 mouse expression or T-classification, was found to be the independent risk factor affecting lymph node metastasis in this series (odds ratio = 0.905, p = 0.041). Table 4 Multivariate analysis of factors predictive of lymph node

metastasis Variable Odds ratio 95% confidence interval p valuea T-classification 1.119 0.418 – 2.993 0.823 Cox-2 1.011 0.965 – 1.060 0.648 CDH-1 0.905 0.822 – 0.996 0.041* aMultiple logistic regression model. *Statistically significant. Discussion Our in vitro results revealed that, in HNSCC cells, the selective Cox-2 inhibitors Montelukast Sodium led to the suppression of the EMT by restoring the expression of E-cadherin through the downregulation of its transcriptional repressors. Moreover, the extent of the effect of Cox-2 inhibition was shown to depend on the baseline expression levels of both E-cadherin and Cox-2 in each cell; i.e., tumor cells expressing lower E-cadherin and higher Cox-2 are expected to be more sensitive to Cox-2 inhibition

in terms of the restoration of E-cadherin expression. Such a finding is consistent with a previous study of bladder cancer cells using another Cox-2 inhibitor, etodolac. In that study, etodolac upregulated E-cadherin expression only in T24 cells, which express the highest level of Cox-2 and the lowest level of E-cadherin; it did not do so in 5637 cells or K47 cells, which express a lower level of Cox-2 and a higher level of E-cadherin [42]. Interestingly, using the same three bladder cancer cell lines and three different Cox-2 inhibitors (etodolac, Selleck I-BET151 celecoxib, and NS-398), Adhim et al. found that E-cadherin mRNA was enhanced in all three cell lines by at least two Cox-2 inhibitors in each cell line, although the fold of increase remained the highest in T24 cells [43].