Abstract
Previous studies have shown that the expressions of the γ2 chain of laminin-5 and secreted protein acidic and rich in cysteine (SPARC) play important roles in oncogenesis and the development of carcinoma. To assess the expressions of laminin-5 γ2 chain and SPARC in esophageal squamous cell carcinoma (SCC), and to clarify the prognostic significance of the expressions of laminin-5 γ2 chain and SPARC in esophageal SCC, we detected the expressions of laminin-5 γ2 chain and SPARC in cancer tissue and corresponding normal mucosa from 116 patients with advanced (stages II-IV) esophageal SCC using the tissue microarray-based immunohistochemistry and analyzed the correlation of the expressions with clinicopathologic characteristics and survival. We found that in normal esophageal tissues, laminin-5 γ2 chain was expressed in the basement membrane, whereas in esophageal SCC tissues, laminin-5 γ2 chain was expressed in the cytoplasm of carcinoma cells, with a positive rate of 72.4%. SPARC was not detected in normal esophageal mucosa, but was expressed in stromal fibroblasts in 84.6% of esophageal SCC cases and in cancer cells in 7.8% of esophageal SCC cases. There was a significant correlation between laminin-5 γ2 chain and stromal SPARC expression in esophageal SCC (Spearman's rho=0.423, P<0.001). The expressions of both laminin-5 γ2 chain and stromal SPARC were correlated with survival (P=0.032 and P=0.034, respectively). In stage-II esophageal SCC, the expression of laminin-5 γ2 chain was significantly correlated with survival (P=0.023), while the expression of SPARC was not significantly correlated with survival (P=0.154). Patients with elevated levels of laminin-5 γ2 chain and SPARC expressions had a poorer prognosis than did those lacking elevated levels of laminin-5 γ2 chain expression and/or elevated levels of SPARC expression (P=0.001). In stage-II esophageal SCC, patients with elevated levels of laminin-5 γ2 chain and SPARC expressions had a poorer prognosis (P<0.001). These results suggest that laminin-5 γ2 chain and SPARC may play roles in the progression of esophageal SCC and their simultaneous expression is correlated with poorer prognosis, especially in patients with stage-II SCC.