k-ras 基因突变与结直肠癌的关系

 目的　探讨k-ras 基因在结直肠癌患者中的突变状况，为k-ras基因突变检测提供理论依据。方法　提取基因组DNA，采用PCR扩增和双向直接测序法，检测56例结直肠癌k-ras基因的突变状况。结果　56例结直肠癌中k-ras基因的突变率为46.63 %（26／56），其中20例（20／26，76.92 %）为密码子12的突变，6例（6／26，23.08 %）为密码子13的突变，未发现同时存在两个位点突变的样本。突变类型以G>A为主，密码子12的突变以GGT>GAT（G12D）为主。密码子13的突变以GGC>GAC为主。统计学分析发现，k-ras基因突变与患者的性别密切相关而与其他临床病理特征如：肿瘤发生部位、有无淋巴结转移等无关。结论　在结直肠癌患者中，k-ras基因突变主要发生于密码子12；突变类型以G>A为主；k-ras基因的突变可能与患者的性别相关。

Relationship of k-ras mutation and colorectal cancer

Objective To explore the status of mutations of k-ras gene in colorectal cancer (CRC) patients and to make theory preparation for the k-ras mutation detection in diagnosis laboratory. Methods The Genomic DNA was extracted, mutation analysis of k-ras was detected by PCR and bi-direction sequencing in the 56 specimens. Results Rate of k-ras mutation was 46.63 % (26/56) including 76.92 % (20/26) located at codon 12, and 23.08 %(6/26) located at codon 13, and no mutation was found at both codons simultaneously. G>A transition is the most common type of k-ras mutation,GGT>GAT (G12D) is the predominant mutation at codon 12 and GGOGAC (G13D) at codonl3. Chi-square analysis revealed the k-ras mutation was significantly correlated to the gender of the patients. Conclusion The k-ras mutation is mainly located at the codon 12, G>A transition is the most type of k-ras mutation in CRC. k-ras mutation seems to correlate with the gender of CRC patients.