Li Jin-tian, Liu Wei, Kuang Zhi-he, Zhang Ru-hua, Chen Han-kui, Feng Qi-sheng
Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, PR China.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi. 2004 Feb;21(1):43-6.
To explore the mutation and amplification of RIT1 gene and their correlation with carcinogenesis of hepatocellular carcinoma (HCC).
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.
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%.
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.
探讨RIT1基因的突变和扩增及其与肝细胞癌（HCC）发生的相关性。
采用聚合酶链反应-直接测序法检测50例HCC组织及癌旁组织RIT1基因全部6个外显子序列中的突变情况。采用荧光定量聚合酶链反应法检测RIT1基因的扩增情况。
在1例患者的HCC组织中检测到RIT1基因第5外显子241位核苷酸G→C替换，癌旁组织未检测到；该241 G→C替换导致保守结构域结合GTP的第81位氨基酸由Glu变为Gln。在全部50例HCC组织及癌旁组织中均检测到5'-UTR（距起始密码子-21 bp）处核苷酸G→C替换，43例合格病例中有11例检测到RIT1基因2至297倍扩增，扩增频率为25.6%。
基因扩增是HCC中RIT1基因的主要激活方式之一，其扩增可能与HCC发生相关，而点突变可能无关。
