LAMP1 Expression is Associated with Malignant Behaviours and Predicts Unfavourable Prognosis in Laryngeal Squamous Cell Carcinoma

Lysosome-associated membrane protein-1 (LAMP1) has been suggested to play complicated roles in cancer development and metastasis. The aim of this study was to explore the expression of LAMP1 in laryngeal squamous cell carcinoma (LSCC) and investigate the relationship between LAMP1 expression and clinicopathological characteristics in LSCC patients. One-step quantitative reverse transcription PCR (qPCR) tests (20 fresh LSCC and non-cancerous tissue samples) and immunohistochemistry (IHC) analyses (137 paraffin-embedded LSCC and non-cancerous tissue samples) were performed to evaluate the LAMP1 expression in both mRNA and protein levels. Results showed that the expression of LAMP1 in LSCC tissues was significantly higher than that in non-cancerous tissues. Furthermore, the expression level of LAMP1 protein was statistically associated with lymph node metastasis and TNM stage. Results of Kaplan-Meier survival and Cox regression analyses revealed that LSCC patients with high LAMP1 cytoplasmic expression (p=0.044), high cytoplasmic+low mesenchymal expression of LAMP1 (H+L) (p=0.015) and histopathological grade (p=0.014) encountered poor overall survival. The data implied that high LAMP1 expression is associated with unfavourable prognosis in LSCC patients, and LAMP1 may be identified as a novel prognostic biomarker.