Overexpression of β3 Chains of Laminin-332 is Associated With Clinicopathologic Features and Decreased Survival in Patients With Pancreatic Adenocarcinoma

BACKGROUND: Laminin-332 (LM-332, formerly termed laminin-5) is a heterotrimeric glycoprotein that promotes cellular adhesion and migration. The heterotrimer consists of an α3, a β3, and a γ2 chain. The aim of this investigation was to clarify the clinicopathologic significance of laminin-332β3 (LNβ3) chain expression and determine its influence on survival in pancreatic ductal adenocarcinoma. MATERIALS AND METHODS: Quantitative real-time polymerase chain reaction was used to validate and detect the expression of LNβ3 mRNA in 37 pancreatic carcinoma tissue specimens and non-neoplastic pancreatic tissue samples. In addition, the protein expression of LNβ3 was detected by immunohistochemistry methods in 96 pancreatic carcinoma specimens and 90 non-neoplastic pancreatic tissues. We analyzed the association between immunohistochemically detected LNβ3 expression in pancreatic ductal adenocarcinoma and clinicopathologic characteristics. Survival curves were completed using the Kaplan-Meier method and compared using log-rank analysis. RESULTS: Quantitative real-time polymerase chain reaction indicated that the relative value of LNβ3 mRNA was 1.427±1.554 and 1.423±1.439 by 2(−Δ(ΔCt)) in pancreatic carcinoma and non-neoplastic pancreatic tissues, respectively, values that were not statistically associated (P=0.991). Immunostaining for LNβ3 was expressed in all patients with pancreatic ductal adenocarcinoma. LNβ3 expression was related to differentiation (P=0.000) and advanced stage (P=0.034). Tumors with low expression of LNβ3 had a survival advantage compared with tumors that had high expression of LNβ3 (P=0.016). Multivariate analysis indicated that location is an independent predictor of overall survival, whereas other clinicopathologic characteristics such as tumor size, duodenal invasion, differentiation, extent of invasion, hepatic metastasis, and expression of LNβ3 were not. CONCLUSION: Our results suggest that LNβ3 expression may play a key role in the progression and prognosis of pancreatic ductal adenocarcinoma.