Ruo-Chia Tseng1, Jia-Ming Chang, Jeng-Hung Chen, Way-Ren Huang, Yen-An Tang, I-Ying Kuo, Jing-Jou Yan, Wu-Wei Lai, Yi-Ching Wang. 1. *Department of Molecular Biology and Human Genetics, College of Life Science, Tzu Chi University, Hualien, Taiwan; †Department of Surgery, Chia-Yi Christian Hospital, Chiayi, Taiwan; ‡Institute of Clinical Medicine, College of Medicine, National Cheng Kung University, Tainan, Taiwan; §Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan; ‖Department of Biomedical Engineering, School of Biomedical Science and Engineering, National Yang-Ming University, Taipei, Taiwan; ¶Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan; #Department of Pathology, College of Medicine, National Cheng Kung University, Tainan, Taiwan; and **Department of Surgery, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Abstract
INTRODUCTION: SLIT2, a secreted protein, has been found to inactivate Cdc42 GTPase to modulate neural cell migration. However, alteration of SLIT2-mediated Cdc42 in terms of migration regulation remains undefined in esophageal squamous cell carcinoma (ESCC). METHODS: We report here in ESCC cell, animal, and clinical models that SLIT2 acts as a migration suppressor and serves as a prognostic biomarker. RESULTS: The immunohistochemistry data indicated that 31.8% (49 of 154) of tumors from ESCC patients showed low expression of SLIT2 protein which correlated with poor overall survival and disease-free survival. DNA methylation analysis suggested that promoter hypermethylation is responsible for low expression of SLIT2 in ESCC. Knockdown of SLIT2 increased ESCC cell migration, while SLIT2 stable overexpression reduced cell migration. ESCC cells treated with conditioned media from cells overexpressing SLIT2 also suppressed cell migration. Importantly, silencing of SLIT2 decreased the complex formation, and thus induced Cdc42 activity and promoted membrane localization of focal adhesion kinase and Paxillin. Anti-metastatic effect of SLIT2 was confirmed in an experimental metastasis model of SLIT2 knockdown ESCC cells. CONCLUSION: Our results provide novel evidence that low expression of SLIT2 correlates with poor prognosis and promotes metastasis in ESCC, which may be regulated by the Cdc42-mediated pathways.
INTRODUCTION:SLIT2, a secreted protein, has been found to inactivate Cdc42 GTPase to modulate neural cell migration. However, alteration of SLIT2-mediated Cdc42 in terms of migration regulation remains undefined in esophageal squamous cell carcinoma (ESCC). METHODS: We report here in ESCC cell, animal, and clinical models that SLIT2 acts as a migration suppressor and serves as a prognostic biomarker. RESULTS: The immunohistochemistry data indicated that 31.8% (49 of 154) of tumors from ESCC patients showed low expression of SLIT2 protein which correlated with poor overall survival and disease-free survival. DNA methylation analysis suggested that promoter hypermethylation is responsible for low expression of SLIT2 in ESCC. Knockdown of SLIT2 increased ESCC cell migration, while SLIT2 stable overexpression reduced cell migration. ESCC cells treated with conditioned media from cells overexpressing SLIT2 also suppressed cell migration. Importantly, silencing of SLIT2 decreased the complex formation, and thus induced Cdc42 activity and promoted membrane localization of focal adhesion kinase and Paxillin. Anti-metastatic effect of SLIT2 was confirmed in an experimental metastasis model of SLIT2 knockdown ESCC cells. CONCLUSION: Our results provide novel evidence that low expression of SLIT2 correlates with poor prognosis and promotes metastasis in ESCC, which may be regulated by the Cdc42-mediated pathways.