title: Expression analysis of THOP1 in background liver, a prognostic predictive factor in hepatocellular carcinoma, extracted by multiarray analysis.
abstract: BACKGROUND
  Hepatocellular carcinoma (HCC) often recurs and multicentric occurrence is more common than intrahepatic metastases after surgery. Prognostic prediction is insufficient when considering only factors in resected primary tumor.
  
  
  METHODS
  Control samples, termed supernormal (SN) liver, were taken from 11 cases of metastatic secondary malignancies of the liver. We selected adjacent nonneoplastic liver tissue from a patient with HCC and liver cirrhosis by hepatitis C (CN) for comparison. Expression profiling and methylation arrays were performed. We identified genes showing differences in both arrays. Prognosis was predicted for 179 cases of HCC based on gene expression.
  
  
  RESULTS
  Expression profiling showed that expression of thimet oligopeptidase (THOP1) gene was decreased 4.119-fold in CN. Methylation array showed a higher value for CN (0.869) than SN (0.488). We studied THOP1 gene expression by real-time reverse transcriptase polymerase chain reaction. The average expression level of THOP1 (THOP1 value × 10(3)/GAPDH) decreased in matching normal tissue (14.53 ± 10.14) relative to SN (78.14 ± 44.50). The group with higher than average THOP1 expression (n = 74) showed significant correlations with prolonged survival (P = 0.0383). Strongly reduced THOP1 expression (<3.0, n = 50) was shown to be an independent prognostic factor by multivariate analysis (P = 0.0024).
  
  
  CONCLUSIONS
  Expression of the THOP1 gene in the background liver of HCC is likely to be a good biomarker for risk of HCC development. When assessing HCC, it is important to extract prognostic factors from background liver tissue as well as considering malignant factors of the primary cancer lesion.
authors.affiliation: Department of Surgery II, Nagoya University Graduate School of Medicine, Nagoya, Japan, snomoto@med.nagoya-u.ac.jp.
authors.forename: Shuji
authors.initials: S
authors.lastname: Nomoto
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Hishida
authors.forename: Yoshikuni
authors.initials: Y
authors.lastname: Inokawa
authors.forename: Nao
authors.initials: N
authors.lastname: Takano
authors.forename: Mitsuro
authors.initials: M
authors.lastname: Kanda
authors.forename: Yoko
authors.initials: Y
authors.lastname: Nishikawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Fujii
authors.forename: Masahiko
authors.initials: M
authors.lastname: Koike
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Sugimoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kodera
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D016022:Case-Control Studies; D019175:DNA Methylation; D005260:Female; D005500:Follow-Up Studies; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D016174:Hepacivirus / Q000302:isolation & purification; D006526:Hepatitis C / Q000235:genetics / Q000401:mortality / Q000821:virology; D006801:Humans; D008099:Liver / Q000378:metabolism / Q000473:pathology*; D008103:Liver Cirrhosis / Q000235:genetics / Q000401:mortality / Q000821:virology; D008113:Liver Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D008297:Male; D008666:Metalloendopeptidases / Q000235:genetics*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D009367:Neoplasm Staging; D020411:Oligonucleotide Array Sequence Analysis; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D012333:RNA, Messenger; D008666:Metalloendopeptidases; C022510:thimet oligopeptidase