title: [Screening for differential methylation status by CpG island microarray in the hepatocellular carcinoma cell lines].
abstract: OBJECTIVE
  To profile the methylation alterations of CpG islands in hetpatocellular carcinoma cell lines.
  
  
  METHODS
  A global analysis of DNA methylation using the Human CpG-island 12K Array (HCGI12K) from Canada University Health Network was performed on nine human hepatocellular carcinoma (HCC) cell lines (Hep3B, HepG2, PLC/RPF/5/RPF/5, SMMC-7721, BEL-7402, MHCC97-H, MHCC97-L, HCCLM3, HCCLM6) and a control cell line Chang's liver. Metastatic potential related alterations were also screened in MHCC97 series cell lines (MHCC97-H, MHCC97-L, HCCLM3, HCCLM6), using MHCC97-L, a cell line with low metastatic potential, as control. To screen the key genes which are hypermethylation or hypomethylation in the HCC cell lines compared with the normal liver cell line by normalization processing and cluster analysis of microarray data. Two randomly selected genes was analyzed by methylation specific PCR to verify the chip results.
  
  
  RESULTS
  By a standard of methylation alteration ratio > or = 2 or < or = 0.5, fifty-eight CpG island cloning sites and sixty-six upstream or downstream tumor-related genes were identified. The genes were oncogenes, tumour suppressor genes and their ligand genes, apoptosis-related genes, cell proliferation and differentiation genes, cell cycle-related gene and cell signaling pathway key genes such as Wnt, ras, and FGF pathway-related genes. The methylation specific PCR results were consistent with those obtained by chips.
  
  
  CONCLUSIONS
  The results of this study demonstrate that there are a series of CpG island methylation alterations in HCC cell lines. The expression of many oncogenes, tumor suppressor genes and other key genes may be up- or down-regulated, respectively, because of their CpG island hypomethylation or hypermethylation accordingly. It may provide a basis for screening HCC biological markers by CpG island methylation profilling.
authors.affiliation: Liver Cancer Institute, Zhongshan Hospital, Fudan University, Shanghai 200032, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Zheng
authors.forename: Bin-Bin
authors.initials: BB
authors.lastname: Liu
authors.forename: Yin-Kun
authors.initials: YK
authors.lastname: Liu
authors.forename: Xiao-Nan
authors.initials: XN
authors.lastname: Kang
authors.forename: Lu
authors.initials: L
authors.lastname: Sun
authors.forename: Kun
authors.initials: K
authors.lastname: Guo
authors.forename: Rui-Xia
authors.initials: RX
authors.lastname: Sun
authors.forename: Jie
authors.initials: J
authors.lastname: Chen
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D006528:Carcinoma, Hepatocellular / Q000235:genetics / Q000473:pathology; D002460:Cell Line; D045744:Cell Line, Tumor; D018899:CpG Islands / Q000235:genetics*; D019175:DNA Methylation; D020869:Gene Expression Profiling / Q000379:methods*; D052138:Genes, Neoplasm; D006801:Humans; D008099:Liver / Q000166:cytology; D008113:Liver Neoplasms / Q000235:genetics* / Q000473:pathology; D020411:Oligonucleotide Array Sequence Analysis