All tests for significance were two-tailed, and P <0.05 was considered statistically significant. The cumulative incidence of intra- and extra-hepatic recurrence was calculated using the Kaplan-Meier method, and differences among groups were assessed using the log-rank test. A paired t-test was used to analyze differences in the mRNAs levels of enzymes related with S1P metabolism, and the levels of S1P, ceramide, and sphingosine in tumors and corresponding non-tumorous tissues. Data processing and analysis were performed using SPSS software version 17.0 or 19.0 (SPSS, Inc, Chicago, IL).
The results of the in vitro experiments are expressed as the means and standard error of the mean (SEM). The results were considered significant when P-values were < 0.05.
The results of the in vitro experiments are expressed as the means and standard error of the mean (SEM). The results were considered significant when P-values were < 0.05.