Proteomic Approach Revealed Galectin-4 as a Lymph Node Metastasis Predictor in Lung Adenocarcinoma
Takuo Hayashi, Tsuyoshi Saito, Kazuya Takamochi, Keiko Mitani, Shiaki Oh, Kenji Suzuki, Takashi Yao. Juntendo University, School of Medicine, Tokyo, Japan
Background: Lung cancer remains the most common cause of cancer related death. Despite advances in treatment modalities, powerful prognostic and metastasis predictive markers remains unclear. The purpose of this study was to develop lymph node (LN) metastasis predictive markers in lung adenocarcinomas using a protemic approach.
Design: We examined the proteomic profile of 10 lung adenocarcinomas (5 cases with LN metastasis and 5 cases without LN metastasis) using two-dimensional difference gel electrophoresis. The predictive performance of candidates was further validated by immunohistochemistry on surgically resected specimens of 709 lung adenocarcinomas (stage I to IV). Positive staining was defined as >10% positive carcinoma cells.
Results: We identified 6 spots whose intensity was different between lung adenocarcinoma with and without LN metastasis. Subsequent mass spectrometric protein identification showed that two of six spots derived from galectin-4, a carbohydrate-binding protein belonging to the galectin family. Immunohistochemically, LN metastasis occurred 28.1 % and 15.8 % for patients with galectin-4-positvie and galectin-4-negative adenocarcinomas, respectively (P=0.0003). Notably, when we classified all adenocarcinomas by IASLC/ATS/ERS classification of lung adenocarcinoma, this trend became more obvious in acinar type predominant (LN metastasis rate: 46.9% in galectin-4-positive cases and 15.6% in galectin-4-negative cases. P<0.0001).
Conclusions: We proposed galectin-4 as a biomarker for LN metastasis predictor in lung adenocarcinomas, especially for acinar type predominant, which is the most common subtype of lung adenocarcinoma. Furthermore, this result may provide an optimum therapeutic implication after surgical treatment for lung cancer patients.
Monday, March 4, 2013 1:00 PM
Poster Session II # 293, Monday Afternoon