Aberrant expression of laminin γ2 correlates with poor prognosis and promotes invasion in extrahepatic cholangiocarcinoma

Background: To investigate the potential role of laminin gamma 2 and its correlation with prognosis in patients with extrahepatic cholangiocarcinoma (CCA). Materials and methods: Laminin gamma 2 expression was evaluated by immunohistochemistry in 72 extrahepatic CCA patients after surgical resection. Knockdown of laminin gamma 2 was achieved via small interfering RNA transfection in the extrahepatic CCA cell line QBC939. Results: Thirty-six of 72 extrahepatic CCAs (50%) stained positive for laminin gamma 2 in two types of patterns: stromal staining (28/72, 39%) and cytoplasmic staining (24/72, 33%). All 16 paracancerous tissue samples showed negative staining. Both stromal and cytoplasmic laminin gamma 2 expressions correlated with lymph node metastasis. Kaplan-Meier analysis showed that aberrant expression of laminin gamma 2 correlated with poor overall survival and early recurrence. Cox regression analysis further demonstrated that laminin gamma 2 expression was a significant independent predictor of poor overall survival and early recurrence. Immunofluorescence staining revealed cytoplasmic expression of laminin gamma 2 in QBC939 cells. Knockdown of laminin gamma 2 significantly reduced QBC939 cell invasion and migration. Conclusions: Aberrant expression of laminin gamma 2 correlates with poor prognosis and promotes invasion in extrahepatic CCA. Crown Copyright (C) 2014 Published by Elsevier Inc. All rights reserved.