Expression of L-type amino acid transporter 1 (LAT1) and 4F2 heavy chain (4F2hc) in oral squamous cell carcinoma and its precusor lesions

Background: Amino acid transporters play an important role in supplying organic nutrients to cells. The expression of L-type amino acid transporter 1 (LAT1) and its subunit 4F2 heavy chain (4F2hc) was evaluated to determine the alterations of these transporters in oral normal mucosa (ONM), oral precancerous lesion (OPL) and oral squamous cell carcinoma (OSCC). Materials and Methods: Sections from formalin-fixed, paraffin-embedded samples of ONM, OPL or OSCC were examined using immunohistochemical staining to detect LAT1 and 4F2hc proteins. Results: The LAT1 and 4F2hc expression increased progressively from ONM to hyperplastic and to dysplastic lesions and OSCC. In particular, LAT1 may be a more specific indicator of tumor progression than 4F2hc. Conclusion: LAT1 and 4F2hc may have an important role in the early stages of multistep oral carcinogenesis. In addition, the specific inhibition of LAT1 and 4F2hc might be a new rationale to suppress oral cancer progression.