Univariate analysis demonstrated that venous infiltration, higher Edmondson-Steiner classification, advanced TNM staging and higher CtBP2 expression in tumor tissues were the poor prognosis factors (Table 2). Moreover, multivariate Cox proportional-hazard regression analysis indicated that venous infiltration, advanced TNM staging and higher CtBP2 expression in tumor tissues were independent prognostic factors (Table 2). These data indicated that CtBP2 overexpression in HCC tissues was a predictor of poor survival outlook after liver resection. To investigate whether there was a correlation between CtBP2 and GLI1 protein expression in HCC tissues, we conducted immunohistochemical (IHC) analysis of GLI1 expression in the clinical samples. As shown in Figure 1D, GLI1 was upregulated in HCC tissues when compared to adjacent liver tissues, which was consistent with the results of previous investigations [21, 26]. Similarly, SNAI1 expression was significantly elevated in HCC tissues when compared to adjacent liver tissues (Figure 1E). Spearman rank analysis positively associated elevated GLI1 expression with CtBP2 and SNAI1 in HCC tissues (r = 0.701, p < 0.001, Figure 1F). This result raised the possibility that GLI1 expression could be related to the overexpression of both CtBP2 and SNAI1 in HCC.
