title: [Mutation and amplification of RIT1 gene in hepatocellular carcinoma].
abstract: OBJECTIVE
  To explore the mutation and amplification of RIT1 gene and their correlation with carcinogenesis of hepatocellular carcinoma (HCC).
  
  
  METHODS
  The polymerase chain reactioindirect sequencing method was used for detecting the mutations in the sequence of all 6 exons in the RIT1 gene of 50 HCC tissues and paratumor tissues. And the amplification of RIT1 gene was examined by fluorescence quantitative polymerase chain reaction method.
  
  
  RESULTS
  A nucleotide 241 G --> C substitution in exon 5 of RIT1 gene was detected in one patient's HCC tissue, but not in paratumor tissue; this 241 G --> C substitution leads to Glu81Gln amino acid alteration in the conservative domain binding GTP. A nucleotide G --> C substitution in 5'-UTR (-21 bp from initial codon) was detected in all of the 50 HCC tissues and paratumor tissues, and 2- to 297-fold amplification of RIT1 gene was detected in 11 of 43 qualified cases, the amplification frequency being 25.6%.
  
  
  CONCLUSIONS
  Gene amplification is one of the main activating ways of RIT1 gene in HCC, and its amplification might be correlated with HCC carcinogenesis, while point mutation might be not.
authors.affiliation: Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, PR China. lijintian006@hotmail.com
authors.forename: Jin-tian
authors.initials: JT
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Zhi-he
authors.initials: ZH
authors.lastname: Kuang
authors.forename: Ru-hua
authors.initials: RH
authors.lastname: Zhang
authors.forename: Han-kui
authors.initials: HK
authors.lastname: Chen
authors.forename: Qi-sheng
authors.initials: QS
authors.lastname: Feng
mesh_terms: D000328:Adult; D000368:Aged; D001483:Base Sequence; D006528:Carcinoma, Hepatocellular / Q000235:genetics*; D004252:DNA Mutational Analysis; D004273:DNA, Neoplasm / Q000737:chemistry / Q000235:genetics; D005260:Female; D005784:Gene Amplification; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation; D017354:Point Mutation; D018631:ras Proteins / Q000235:genetics*
chemical_list: D004273:DNA, Neoplasm; C486776:RIT1 protein, human; D018631:ras Proteins