Expression of Wnt11 and Rock2 protein with clinical characteristics of esophageal squamous cell carcinoma in Kazakh and Han patients

Abstract

Background: Esophageal squamous cell carcinoma (ESCC) is one of the most malignancies with a very poor outcome in China. Wnt11 and Rock2, new identified proteins highly associated with metastasis of many cancers, which were never reported in esophageal squamous cell carcinoma (ESCC). Here we measured the expression levels of Wnt11 and Rock2 in tissues from 265 patients with ESCC. Immunohistochemical staining was employed to detect the correlation of Wnt11 and Rock2 expression with clinicopathological features.

Methods: The expression of Wnt11 and Rock2 was detected by immunohistochemistry in esophageal squamous cell carcinomas and normal esophageal tissues. A chi-square test was used to assess the statistical significance of the correlations between Wnt11, Rock2 expression and different clinicopathological parameters, respectively.

Results: The high-expression of Wnt11 and Rock2 was observed in ESCCs. Seventy-five cases of ESCC (51.7%) showed a positive expression of Wnt11, which indicated a significant association with the AJCC stage (P=0.007). Ninety-eight cases of ESCC (65.5%) showed a positive expression of Rock2, which indicated a significant association with ethnic background. There were no close correlations between Rock2 expression and gender, tumor location, AJCC stage, lymph node metastasis. Specifically, the expression of Rock2 was significantly different between Hans and Kazaks ethnicities (P=0.000). In Kaplan-Meier curve analysis, no significant correlation was observed between the expression of Wnt11, Rock-2 and the poor prognosis of ESCCs.

Conclusion: Our finding suggests that the over-expression of Rock2 may play an important role in the carcinogenesis and progression, and may become a new underlying molecular marker in the diagnosis and treatment in ESCC.

Keywords: Esophageal squamous cell carcinoma; Rock2; Wnt11; clinicopathologic factors; immunohistochemistry.

Figure 1

Representative photomicrographs of tissue sections immunostained for Wnt11 and Rock2. A. Rock-2 expression was detected in normal esophageal squamous epithelium (×200). B. Primary esophageal cancer negative for Rock-2 expression in cancer cell nests (×200). C. Primary esophageal cancer with Rock-2 Low-expression detected in the cytoplasm of cancer cell nests (×200). D. Primary esophageal cancer with Rock-2 High- expression detected in the cytoplasm of cancer cell nests (×200). E. Wnt11 expression was detected in normal esophageal squamous epithelium intercellular (×200). F. Primary esophageal cancer negative for Wnt11 expression in cancer cell intercellular (×200). G. Primary esophageal cancer with Wnt11 expression detected in intercellular of cancer cell (×200).

Figure 2

Postoperative survival according to Wnt11 and Rock2 expression. Overall survival rates of ESCC patients with Wnt11 and Rock2-positive expression.