title: Clinical significance of expression of cancer/testis antigen and down-regulation of HLA class-I in patients with stage I non-small cell lung cancer.
abstract: OBJECTIVE
  The purpose of this study was to investigate the clinical significance of expression of cancer/testis (CT) antigen and down-regulation of HLA class-I in patients with stage I non-small cell lung cancer (NSCLC), which underwent complete surgical resection.
  
  
  METHODS
  The expression of HLA class-I molecules was evaluated in 136 resected NSCLC specimens by immunohistochemistry. The results were scored as the percentage of stained tumor cells and categorized into two groups: 0-79%, reduced expression; and >80%, normal expression. The expression of CT antigen was performed by reverse transcription-polymerase chain reaction (RT-PCR).
  
  
  RESULTS
  The expression of HLA class-I was normal in 49 tumors (36%), and there was reduced expression in 87 tumors (64%). The expression of Melanoma antigen (MAGE)-A3, MAGE-A4, and Kita-Kyushu lung cancer antigen-1 (KK-LC-1) was positive in 34 (25.0%), 22 (16.2%), and 42 (30.9%) patients, respectively. There was no significant difference in the proportion of HLA class-I expression associated with the expression of any of the CT antigens. Among the patients with positive expression of at least one of the CT antigens, the 5-year survival rate of the patients with the normal expression of HLA class-I was 87.5%; however, it was 63.4% in patients with the reduced expression of HLA class-I (p=0.0477).
  
  
  CONCLUSIONS
  Reduced expression of HLA class-I was an unfavorable prognostic factor in patients with positive expression of CT antigen, and represents an important hurdle to antigen-based cancer immunotherapy.
authors: Second Department of Surgery, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu 807-8555, Japan. hanagiri@med.uoeh-u.ac.jp
authors: Takeshi
authors: T
authors: Hanagiri
authors: Yoshiki
authors: Y
authors: Shigematsu
authors: Shinji
authors: S
authors: Shinohara
authors: Masaru
authors: M
authors: Takenaka
authors: Sohich
authors: S
authors: Oka
authors: Yasuhiro
authors: Y
authors: Chikaishi
authors: Yoshika
authors: Y
authors: Nagata
authors: Tetsuro
authors: T
authors: Baba
authors: Hidetaka
authors: H
authors: Uramoto
authors: Tomoko
authors: T
authors: So
authors: Sohsuke
authors: S
authors: Yamada
mesh_terms: D000230:Adenocarcinoma / Q000276:immunology / Q000401:mortality* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000951:Antigens, Neoplasm / Q000235:genetics / Q000378:metabolism*; D002289:Carcinoma, Non-Small-Cell Lung / Q000276:immunology / Q000401:mortality* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000276:immunology / Q000401:mortality* / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D015395:Histocompatibility Antigens Class I / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007124:Immunoenzyme Techniques; D008175:Lung Neoplasms / Q000276:immunology / Q000401:mortality* / Q000473:pathology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate; D013737:Testis / Q000378:metabolism
chemical_list: D000951:Antigens, Neoplasm; C104948:CTAG1B protein, human; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D012333:RNA, Messenger
keywords: HLA class-I expression; Non-small cell lung cancer; cancer/testis antigen; immune escape; prognosis; surgery