Expression of Amino Acid Transporters (LAT1 and ASCT2) in Patients with Stage III/IV Laryngeal Squamous Cell Carcinoma

The aim of this study is to evaluate the clinicopathological significance of L-type amino acid transporter 1 (LAT1) expression in patients with advanced laryngeal squamous cell carcinoma (LSCC). A total of 73 patients with advanced LSCC were retrospectively reviewed. Tumor sections were stained by immunohistochemistry for LAT1, 4F2hc, system ASC amino acid transporter-2 (ASCT2), cell proliferation by Ki-67, microvessel density (MVD) determined by CD34 and p53. A positive LAT1, 4F2hc and ASCT2 expression (staining more than a quarter) in the primary sites were recognized in 85, 80 and 45 %, respectively, and a high LAT1, 4F2hc and ASCT2 expression (staining more than a half) yielded 48, 31 and 18 %, respectively. High expression of LAT1 was significantly associated with lymph node metastasis, 4F2hc, ASCT2, Ki-67 and p53. The expression of LAT1 was significantly correlated with ASCT2, 4F2hc, cell proliferation, and MVD. By univariate analysis, there was no statistically significant relationship between LAT1 expression and prognosis in advanced LSCC. LAT1, 4F2hc and ASCT2 were highly expressed in patients with advanced laryngeal cancer. Our study suggests that the expression of LAT1 plays a crucial role in the metastasis and tumor progression in advanced LSCC.