title: [Study on loss of heterozygosity and microsatellite instability in hepatocellular carcinoma].
abstract: OBJECTIVE
  To investigate the role of loss of heterozygosity (LOH) in tumor suppressor genes (TSG) and microsatellite instability (MSI) in hepatocarcinogenesis, as well as their correlation with clinicopathologic features.
  
  
  METHODS
  LOH in 6 TSG (APC, DCC, MCC, OGG1, p53 and RB1) was detected in 36 informative cases of hepatocellular carcinoma (HCC), among 92 surgically resected HCC. Thirteen polymorphic microsatellite markers were also studied in 15 of these cases by microdissection-based PCR amplification and direct DNA sequencing. The correlation between genetic alterations and clinicopathologic features was analyzed.
  
  
  RESULTS
  The overall incidence of LOH in HCC was 41.7% (15/36). There was no LOH in MCC gene. 46.2% (6/13) microsatellites showed LOH in 9 of the 15 cases of HCC (60%). Certain clinicopathologic differences were observed between cases (number = 7) with LOH in APC, OGG1 and DCC ("type I") and cases (number = 8) with LOH in p53 and RB1 ("type II"). The mean tumor size of these two types was 2.9 (+/- 1.7) cm and 7.2 (+/- 3.4) cm, respectively (P < 0.01); and the mean survival was 72.0 (+/- 38.6) months, and 51.0 (+/- 30.4) months, respectively (P < 0.05).
  
  
  CONCLUSIONS
  Compared with MSI pathway, LOH pathway plays a more important role in the development of HCC. A multistep hepatocarcinogenesis is likely, with LOH in APC, OGG1 and DCC ("type I") being an early event and LOH in p53 and RB1 ("type II") being a late event. On the other hand, MCC gene seems to play no role in the whole process.
authors.affiliation: Department of Pathology, Oriental Hepatobiliary Surgery Hospital, Second Military Medical University Shanghai 200438, China. wmcong@smmu.edu.cn
authors.forename: Wen-Ming
authors.initials: WM
authors.lastname: Cong
authors.forename: Shu-Hui
authors.initials: SH
authors.lastname: Zhang
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Xian
authors.forename: Wei-Qing
authors.initials: WQ
authors.lastname: Wu
authors.forename: Meng-Chao
authors.initials: MC
authors.lastname: Wu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000235:genetics* / Q000473:pathology; D005260:Female; D017491:Genes, APC; D016163:Genes, DCC; D017431:Genes, MCC; D016147:Genes, Tumor Suppressor; D016158:Genes, p53; D006801:Humans; D007223:Infant; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology; D019656:Loss of Heterozygosity; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged