title: LAT1 expression in non-small-cell lung carcinomas: analyses by semiquantitative reverse transcription-PCR (237 cases) and immunohistochemistry (295 cases).
abstract: OBJECTIVE
  System l-amino acid transport mediates the uptake of aromatic neutral amino acids and nutritionally essential amino acids from extracellular fluids. Little is known about the role of l-amino acid transporter 1 (LAT1), a member of the system l-amino acid transporter family, in non-small-cell lung carcinomas (NSCLCs).
  
  
  METHODS
  We examined (i) LAT1 mRNA levels in 40 normal lung tissues (NLTs) and 237 NSCLCs using semiquantitative RT-PCR, (ii) LAT1 protein expression in 295 NSCLCs using immunohistochemistry, and (iii) whether LAT1 mRNA and protein expressions were related to clinicopathologic findings and outcome.
  
  
  RESULTS
  The LAT1 mRNA level was significantly higher in all NSCLCs (6.81+/-1.13) than in NLT (1.00+/-0.18). The LAT1 mRNA level showed no association with clinicopathologic findings or outcome. LAT1 protein was detected with a diffuse or granular appearance within the cytoplasm and/or on the plasma membrane of tumor cells. When tumors were graded as positive if staining indicating a plasma membrane expression of LAT1 protein made up more than 10% of the tumor, the frequency of this membrane expression was found to be associated with tumor histology, differentiation grade, pathologic stage, T classification, pleural invasion, lymph-vessel invasion, and overall survival rate.
  
  
  CONCLUSIONS
  Detection of a plasma membrane expression of LAT1 protein would appear to be of value in informing the prognosis in NSCLC cases.
authors: Division of Molecular Pharmacology, Department of Biosystems Science, Graduate School of Science and Technology, Kobe University, Nada 657-8601, Japan.
authors: Katsuyuki
authors: K
authors: Takeuchi
authors: Sho
authors: S
authors: Ogata
authors: Kuniaki
authors: K
authors: Nakanishi
authors: Yuichi
authors: Y
authors: Ozeki
authors: Sadayuki
authors: S
authors: Hiroi
authors: Susumu
authors: S
authors: Tominaga
authors: Shinsuke
authors: S
authors: Aida
authors: Hirotaka
authors: H
authors: Matsuo
authors: Tsuneaki
authors: T
authors: Sakata
authors: Toshiaki
authors: T
authors: Kawai
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D027283:Large Neutral Amino Acid-Transporter 1 / Q000235:genetics / Q000378:metabolism*; D008168:Lung / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D027283:Large Neutral Amino Acid-Transporter 1