The impact of L-type amino acid transporter 1 (LAT1) in human hepatocellular carcinoma

Abstract

Upregulation of L-type amino acid transporter 1 (LAT1) has been reported to be associated with a poor prognosis in a variety of malignant tumors. However, the impact of LAT1 in hepatocellular carcinoma (HCC) remains unclear. The objective of this study was to investigate whether the expression of LAT1 in HCC was associated with established clinicopathological features. Quantitative reverse transcription polymerase chain reaction was used to detect LAT1 mRNA expression in 23 pairs of fresh-frozen HCC tissues and corresponding noncancerous tissues. Results showed that LAT1 mRNA expression level in HCC tissues was significantly higher than that in corresponding noncancerous tissues. To investigate the association between LAT1 protein expression and clinicopathological characteristics of HCC, immunohistochemistry was performed in 148 archived paraffin-embedded HCC samples. High LAT1 expression in HCC was associated significantly with tumor size (P = 0.032), histological differentiation (P = 0.003), and tumor stage (P = 0.01). Kaplan-Meier curves demonstrated that patients with a high expression of LAT1 have a significantly increased risk of shortened survival time. Moreover, stepwise Cox regression showed that LAT1 expression may be an independent prognostic factor. Collectively, our study demonstrated that LAT1was overexpressed in HCC and could be served as a potential prognostic marker.