Clinicopathologic significance of the expression of Snail in hepatocellular carcinoma

Abstract

Background/aims: E-cadherin is involved in intercellular binding and cellular polarity formation. Snail is a key regulator of the epithelial-mesenchymal transition and is closely associated with tumor invasiveness due to its ability to suppress E-cadherin expression. We investigated the expressions of E-cadherin and Snail in hepatocellular carcinoma (HCC) tissue to determine the clinical significance of these proteins in HCC.

Methods: Immunohistochemistry was used to examine the expressions of E-cadherin and Snail in resected tissues from 59 patients diagnosed with HCC. We also evaluated the relationship between the expressions of these two molecules in HCC tissue and clinicopathologic factors in the patients.

Results: Immunohistochemistry showed that Snail was stained in 20.3% of the HCC tissues and 3.4% of noncancerous tissues. Snail was not stained in the area of E-cadherin expression. The expression of Snail in the HCC tissue was associated with poorly differentiated HCC (P=0.028). The expression of Snail without E-cadherin staining in HCC tissue was significantly associated with postoperative HCC recurrence (P=0.013).

Conclusions: The expression of Snail in HCC tissue was associated with decreased expression of E-cadherin and poorly differentiated HCC. The expression of Snail without E-cadherin staining in HCC was associated with postoperative recurrence.

Figure 1

Immunohistochemical staining patterns of Snail and E-cadherin in hepatocellular carcinomas (HCCs). (A) Positive staining of Snail is seen in the tumor portion. (B) E-cadherin is not stained in the tumor portion where they show positive staining for Snail. (C) Positive staining of E-cadherin is noted in the cytomembrane of the tumor portion. (D) Snail is not stained in the tumor portion where they show positive staining for E-cadherin (A: Snail, ×400, B: E-cadherin, ×400, C: E-cadherin, ×400, D: Snail, ×400).

Figure 2

Cumulative recurrence-free survival rate of HCC according to immunohistochemical staining patterns of Snail and E-cadherin (Kaplan-Meier survival curve, P-value by log-rank test). (A) The cumulative recurrence-free survival rate of HCC is significantly higher in negative E-cadherin staining than in positive E-cadherin staining in the case of positive Snail staining. (B) The cumulative recurrence-free survival rate of HCC does not differ significantly according to the E-cadherin staining pattern in the case of negative Snail staining.